Toxic effects of mycotoxins in humans
September 1, 1999 Bulletin of the World Health Organization

By Peraica, M.; Radic, B.; Lucic, A.; Pavlovic, M.

In experimental animals, trichothecenes are 40 times more toxic when inhaled than when given orally.

Mycotoxicoses are diseases caused by mycotoxins, i.e. secondary metabolites of moulds. Although they occur more frequently in areas with a hot and humid climate, favourable for the growth of moulds, they can also be found in temperate zones. Exposure to mycotoxins is mostly by ingestion, but also occurs by the dermal and inhalation routes. Mycotoxicoses often remain unrecognized by medical professionals, except when large numbers of people are involved. The present article reviews outbreaks of mycotoxicoses where the mycotoxic etiology of the disease is supported by mycotoxin analysis or identification of mycotoxin-producing fungi. Epidemiological, clinical and histological findings (when available) in outbreaks of mycotoxicoses resulting from exposure to aflatoxins, ergot, trichothecenes, ochratoxins, 3-nitropropionic acid, zearalenone and fumonisins are discussed.

Mycotoxins are secondary metabolites of moulds that exert toxic effects on animals and humans. The toxic effect of mycotoxins on animal and human health is referred to as mycotoxicosis, the severity of which depends on the toxicity of the mycotoxin, the extent of exposure, age and nutritional status of the individual and possible synergistic effects of other chemicals to which the individual is exposed. The chemical structures of mycotoxins vary considerably, but they are all relatively low molecular mass organic compounds. The untoward effect of moulds and fungi was known already in ancient times. In the seventh and eighth centuries BC the festival "Robigalia" was established to honour the god Robigus, who had to be propitiated in order to protect grain and trees. It was celebrated on 25 April because that was the most likely time for crops to be attacked by rust or mildew.

In the Middle Ages, outbreaks of ergotism caused by ergot alkaloids from Claviceps purpurea reached epidemic proportions, mutilating and killing thousands of people in Europe. Ergotism was also known as ignis sacer (sacred fire) or St Anthony's fire, because at the time it was thought that a pilgrimage to the shrine of St Anthony would bring relief from the intense burning sensation experienced. The victims of ergotism were exposed to lysergic acid diethylamide (LSD), a hallucinogen, produced during the baking of bread made with ergot-contaminated wheat, as well as to other ergot toxins and hallucinogens, as well as belladonna alkaloids from mandragora apple, which was used to treat ergotism. While ergotism no longer has such important implications for public health, recent reports indicate that outbreaks of human mycotoxicoses are still possible. Some mycotoxicoses have disappeared owing to more rigorous hygiene measures. For example, citreoviridin-related malignant acute cardiac beriberi ("yellow rice disease" or shoshin-kakke disease in Japanese) has not been reported for several decades, following the exclusion of mouldy rice from the markets. Citreoviridin is a metabolic product of Penicillium citreonigrum, which grows readily on rice during storage after harvest, especially in the colder regions of Japan. Another mycotoxicosis not seen for decades is alimentary toxic aleukia, common in the 1930s and 1940s in the USSR. This disease was caused by trichothecenes produced by Fusarium strains on unharvested grain.

General interest in mycotoxins rose in 1960 when a feed-related mycotoxicosis called turkey X disease, which was later proved to be caused by aflatoxins, appeared in farm animals in England. Subsequently it was found that aflatoxins are hepatocarcinogens in animals and humans, and this stimulated research on mycotoxins. There is a long history of the use of certain moulds in the production of cheese and salami and in the fermentation of beer and wine. Moulds are also used in the production of drugs (antibiotics). The classification of mould metabolites as antibiotics or mycotoxins is based on their toxicity or beneficial effect in treating diseases. Some mould metabolites that were initially considered to be antibiotics (e.g. citrinin) were subsequently found to be highly toxic, and are currently classified as toxins. Ergot alkaloids are still used, inter alia, in the treatment of parkinsonism, as prolactin inhibitors, in cerebrovascular insufficiency, migraine treatment, venous insufficiency, thrombosis and embolisms, for the stimulation of cerebral and peripheral metabolism, in uterine stimulation, as a dopaminergic agonist.

The toxic effects of mycotoxins (e.g. ochratoxins, fumonisins, zearalenone, etc.) are mostly known from veterinary practice. Mycotoxicoses, which can occur in both industrialized and developing countries, arise when environmental, social and economic conditions combine with meteorological conditions (humidity., temperature) which favour the growth of moulds.

Involvement of mycotoxins in disease causation should be considered in instances when a disease appears in several persons, with no obvious connection to a known etiological agent, such as microorganisms. Given current trade patterns, mycotoxicoses resulting from contaminated food, locally grown or imported, could occur in developing and developed countries alike. Strict control of food and feed and appropriate public health measures are therefore of considerable importance in reducing the risks to human and animal health.

This review covers only the human aspects of the untoward effects of mycotoxins. However, owing to the frequent nonspecific effects of mycotoxin involvement, the results of animal experiments are useful for understanding possible effects on humans. Since review articles and books are available dealing with specific topics such as the chemistry, analytical procedures, metabolism, and economic aspects of mycotoxins (9-18), these aspects of mycotoxin toxicology are not presented here. Mycotoxicoses are usually insufficiently treated in medical textbooks and are not covered in curricula of many medical schools. The aim of this article is to summarize current understanding of the clinical aspects mainly of mycotoxicoses in humans, and to stress the importance of this class of naturally occurring toxins.

Ergot Ergot is the common name of the sclerotia of fungal species within the genus Claviceps, which produce ergot alkaloids. The sclerotium is the dark-coloured, hard fungal mass that replaces the seed or kernel of a plant following infestation. Ergot alkaloids are also secondary metabolites of some strains of Penicillium, Aspergillus and Rhizopus spp.

The ca. 40 ergot alkaloids isolated from Claviceps sclerotia can be divided into three groups:

derivatives of lysergic acid (e.g. ergotamine and ergocristine);

derivatives of isolysergic acid (e.g. ergotaminine);

derivatives of dimethylergoline (clavines, e.g. agroclavine).

The source of the ergot strongly influences the type of alkaloids present, as well as the clinical picture of ergotism. Claviceps purpurea produces ergotamine-ergocristine alkaloids, which cause the gangrenous form of ergotism because of their vasoconstrictive activity. The initial symptoms are oedema of the legs, with severe pains. Paraesthesias are followed by gangrene at the tendons, with painless demarcation. The last-recorded outbreak of gangrenous ergotism occurred in Ethiopia in 1977-78; 140 persons were affected and the mortality was high (34%).

The other type of ergotism, a convulsive form related to intoxication with clavine alkaloids from Claviceps fusiformis was last seen during 1975 in India when 78 persons were affected. It was characterized by gastrointestinal symptoms (nausea, vomiting and giddiness) followed by effects on the central nervous system (drowsiness, prolonged sleepiness, twitching, convulsions, blindness and paralysis). The onset of symptoms occurred 1-48 hours following exposure; there were no fatalities.

Ergotism is extremely rare today, primarily because the normal grain cleaning and milling processes remove most of the ergot so that only very low levels of alkaloids remain in the resultant flours. In addition, the alkaloids that are the causative agents of ergotism are relatively labile and are usually destroyed during baking and cooking.

Aflatoxins occur in nuts, cereals and rice under conditions of high humidity and temperature and present a risk to human health that is insufficiently recognized. The two major Aspergillus species that produce aflatoxins are A. flavus, which produces only B aflatoxins, and A. parasiticus, which produces both B and G aflatoxins. Aflatoxins [M.sub.1] and [M.sub.2] are oxidative metabolic products of aflatoxins [B.sub.1] and [B.sub.2] produced by animals following ingestion, and so appear in milk (both animal and human), urine and faeces. Aflatoxicol is a reductive metabolite of aflatoxin [B.sub.1].

Aflatoxins are acutely toxic, immunosuppressive, mutagenic, teratogenic and carcinogenic compounds. The main target organ for toxicity and carcinogenicity is the liver. The evaluation of epidemiological and laboratory results carried out in 1987 by the International Agency for Research on Cancer (IARC) found that there is sufficient evidence in humans for the carcinogenicity of naturally occurring mixtures of aflatoxins, which are therefore classified as Group 1 carcinogens, except for aflatoxin [M.sub.1], which is possibly carcinogenic to humans (Group 2B). Several outbreaks of aflatoxicosis have occurred in tropical countries, mostly among adults in rural populations with a poor level of nutrition for whom maize is the staple food. The clinical picture presented by cases indicated acute toxic liver injury, which was confirmed by morphological changes in liver autopsy specimens that were indicative of toxic hepatitis. Mortality rates in the acute phase were 10-60 %. At the end of one year, surviving patients had no jaundice, and most of them had recovered clinically.

A case of attempted suicide with purified aflatoxin [B.sub.1] is reported to have occurred in 1966 in the USA. A young woman ingested a total of 5.5 mg of aflatoxin [B.sub.1] over 2 days and, 6 months later, a total of 35 mg over 2 weeks. Following the first exposure, she was admitted to hospital with a transient, nonpruritic, macular rash, nausea and headache; the second time she reported nausea only. On both occasions, physical, radiological and laboratory examinations were normal and liver biopsies appeared normal by light microscopy. A follow-up examination 14 years later did not reveal any signs or symptoms of disease or lesions. These findings suggest that the hepatotoxicity of aflatoxin [B.sub.1] may be lower in well nourished persons than in experimental animals or that the latent period for turnout formation may exceed 14 years.

Aflatoxins have been detected in the blood of pregnant women, in neonatal umbilical cord blood, and in breast milk in African countries, with significant seasonal variations. Levels of aflatoxins detected in some umbilical cord bloods at birth are among the highest levels ever recorded in human tissue and fluids.

Aflatoxins have been suggested as an etiological factor in encephalopathy and fatty degeneration of viscera, similar to Reye syndrome, which is common in countries with a hot and humid climate. The clinical picture includes enlarged, pale, fatty liver and kidneys and severe cerebral oedema. Aflatoxins have been found in blood during the acute phase of the disease, and in the liver of affected children. However, use of aspirin or phenothiazines is also suspected to be involved in the etiology.

In tropical countries, clinically recognizable jaundice is frequent during the neonatal period. In a large investigation undertaken on 327 Babies with jaundice and 80 matching controls in Nigeria, it was found that the occurrence of glucose-6-phosphate dehydrogenase (G6PD) deficiency together with the presence of aflatoxins in the serum are significant risk factors for the development of neonatal jaundice.

The geographical and seasonal prevalences of aflatoxins in food and of kwashiorkor show a remarkable similarity. In several tropical countries, aflatoxins have been found more frequently and in higher concentration in liver specimens from children with kwashiorkor than in controls. Clinical investigation of aflatoxin elimination in children with kwashiorkor and marasmic kwashiorkor, who were fed an aflatoxin-free diet, proved that aflatoxins in these children are slowly eliminated. In several studies, aflatoxicol was found in the serum, liver, urine and stools of children with kwashiorkor and marasmic kwashiorkor, in contrast to marasmic and control children where this metabolite was not found. It is not clear whether this difference is causally related to kwashiorkor or is a consequence of the disease.

In recent studies, aflatoxins were found in the brain and lungs of children who had died from kwashiorkor and in control children who had died from various other diseases. It was suggested that the presence of aflatoxins in the brains of control children might be due to metabolic imbalance or to a failure in the excretory mechanisms of children with conditions such as measles (which in 25% of cases precedes kwashiorkor), renal failure, pyloric stenosis, gastroenteritis. Aflatoxins in the lungs were found in all children diagnosed to have pneumonia, irrespective of the presence of kwashiorkor. This could be due to a reduced clearing ability of the lungs in pulmonary diseases or to exposure via the respiratory route. In the Philippines, a study of the relationship between the presence of aflatoxin in the serum and urine of children and the outcome of acute lower respiratory infection failed to prove a correlation. However, aflatoxin [B.sub.1] was found in the lungs of one textile and two agricultural workers who died from pulmonary interstitial fibrosis. These individuals were probably occupationally exposed to aflatoxin [B.sub.1] via the respiratory route. Aflatoxin [B.sub.1] was also detected in the lung tissue of a chemical engineer who had worked for 3 months on a method for sterilizing Brazilian peanut meal contaminated with Aspergillus flavus, and who died of alveolar cell carcinoma.

In the United Kingdom, it was found that intravenous heroin users can be exposed to aflatoxin [B.sub.1] from samples of heroin on sale. Through intravenous administration, aflatoxin [B.sub.1] bypasses the detoxifying mechanisms of the liver, which results in direct systemic exposure. In the United Kingdom and the Netherlands, analysis of 121 urine samples obtained from heroin addicts revealed a higher proportion of samples contaminated with aflatoxins [B.sub.1], [B.sub.2], [M.sub.1] and [M.sub.2] and aflatoxicol (20%) than those from normal adult volunteers (2%). In addition, aflatoxin [B.sub.1] was found at much lower concentrations in the latter group.

3-Nitropropionic acid 3-Nitropropionic acid (3-NPA) is a secondary metabolite of Arthrinium sp., considered to cause a form of acute food-poisoning called "mouldy sugarcane poisoning". The problem occurred during winter (February and March) in 13 provinces of northern China as a consequence of ingesting sugarcane that had been stored for at least two months and which was infested with Arthrinium sp. In the period 1972-88, a total of 884 persons were involved in outbreaks, with 88 (10%) fatalities. The main epidemiological feature is the small number of persons in one outbreak (one to five persons), with the victims being mostly children and young people. The incubation period is generally 2-3 hours following the ingestion of mouldy sugar-cane, and the main clinical symptoms are vomiting, dystonia, staring to one side, convulsions, carpopedal spasm and coma. Delayed dystonia develops in 10-50 % of patients as a consequence of bilateral symmetric necrosis of the basal ganglia. The development of delayed symptoms can be predicted by abnormality in the basal ganglia on cranial computed tomography (CT) scans. In adults, 3-NPA causes gastrointestinal symptoms; signs of severe encephalopathy are not common.

Ochratoxins are secondary metabolites of Aspergillus and Penicillium strains, found on cereals, coffee and bread, as well as on all kinds of food commodities of animal origin in many countries. The most frequent is ochratoxin A, which is also the most toxic. It has been shownn to be nephrotoxic, immunosuppressive, carcinogenic and teratogenic in all experimental animals tested so far.

Acute renal failure in one person, possibly caused by inhalation of ochratoxin A in a granary which had been closed for 2 years, was reported in Italy. The symptoms developed after 24 hours of transitory epigastric tension, respiratory distress, and retrosternal burning. Acute tubular necrosis was found on biopsy, but the blood was not analysed for ochratoxin A. The presence of the mycotoxin in wheat from the granary was proved qualitatively by thin-layer chromatography.

Owing to the similarity of morphological and functional kidney lesions in ochratoxin A-induced porcine nephropathy and endemic nephropathy, this mycotoxin has been proposed as the causative agent of endemic nephropathy, although the evidence for this is not substantial. This fatal renal disease occurs among rural populations in Croatia, Bosnia and Herzegovina, Yugoslavia, Bulgaria, and Romania, where it has been estimated that about 20,000 people are either suffering from or are suspected to have the disease. There is no acute phase of the illness; the first signs and symptoms of the disease are not specific and include fatigue, headache, loss of body weight and pale skin. A mild low-molecular-mass proteinuria without hypertension but with either aplastic or normochromic anaemia gradually develops over several years. The main features of endemic nephropathy are bilateral, primarily chronic lesions of the renal cortex (tubular degeneration, interstitial fibrosis and hyalinization of the glomeruli). In the advanced stage of the disease, the size and weight of kidneys are remarkably reduced, with diffuse cortical fibrosis, usually without signs of inflammation.

Ochratoxin A is found more frequently and in higher concentrations in the blood of inhabitants from endemic regions than control regions. Many samples of locally produced food and feed collected in the endemic area contained ochratoxin A. It should be emphasized that the grain analysed had been kept for many months in the inadequate food stores of individual families.

In Tunisia, ochratoxin A has been detected in high concentrations in the blood and food of patients with kidney impairment of unknown etiology. It has also been found in several countries, both in food and feed and in humans.

In endemic regions of Croatia, Bulgaria and Yugoslavia, the incidence of otherwise rare urothelial tumours of the pelvis and ureter is 50, 90 and 100 times greater, respectively, than in nonendemic regions. It has been suggested that ochratoxin A may be the causal agent for both endemic nephropathy and urothelial tumours. IARC classified ochratoxin A as a compound possibly carcinogenic to humans (Group 2B).

Trichothecenes are mycotoxins produced mostly by members of the Fusarium genus, although other genera (e.g. Trichoderma, Trichothecium, Myrothecium and Stachybotrys) are also known to produce these compounds. To date, 148 trichothecenes have been isolated, but only a few have been found to contaminate food and feed. The most frequent contaminants are deoxynivalenol (DON), also known as vomitoxin, nivalenol (NIV), diacetoxyscirpenol (DAS), while T-2 toxin is rarer.

Common manifestations of trichothecene toxicity are depression of immune responses and nausea, sometimes vomiting. The first recognized trichothecene mycotoxicosis was alimentary toxic aleukia in the USSR in 1932; the mortality rate was 60%. In regions where the disease occurred, 540% of grain samples cultured showed the presence of Fusarium sporotrichoides, while in those regions where the disease was absent this fungus was found in only 2-8% of samples. The severity of mycotoxicosis was related to the duration of consumption of toxic grain. Such severe trichothecene mycotoxicoses, the consequence of continuous ingestion of toxins, have not been recorded since this outbreak.

In several cases, trichothecene mycotoxicosis was caused by a single ingestion of bread containing toxic flour or rice. In experimental animals, trichothecenes are 40 times more toxic when inhaled than when given orally. Trichothecenes were found in air samples collected during the drying and milling process on farms, in the ventilation systems of private houses and office buildings, and on the walls of houses with high humidity. There are some reports showing trichothecene involvement in the development of "sick building syndrome". The symptoms of airborne toxicosis disappeared when the buildings and ventilation systems were thoroughly cleaned.

Zearalenone Zearalenone (previously known as F-2) is produced mainly by Fusarium graminearum and related species, principally in wheat and maize but also in sorghum, barley and compounded feeds. Zearalenone and its derivatives produce estrogenic effects in various animal species (infertility, vulval oedema, vaginal prolapse and mammary hypertrophy in females and feminization of males -- atrophy of testes and enlargement of mammary glands).

In Puerto Rico, zearalenone was found in the blood of children with precocious sexual development exposed to contaminated food. Zearalenone was also found together with other Fusarium mycotoxins in "scabby grain toxicosis" in China, but the significance of this finding is not clear.

Fumonisins are mycotoxins produced throughout the world by Fusarium moniliforme and related species when they grow in maize. Fumonisins [B.sub.1] and [B.sub.2] are of toxicological significance, while the others (B.sub.3], [B.sub.4], [A.sub.1] and [A.sub.2]) occur in very low concentrations and are less toxic.

In India a single outbreak of acute foodborne disease possibly caused by fumonisin [B.sub.1] has been reported. In the 27 villages involved, the individuals affected were from the poorest social strata, who had consumed maize and sorghum harvested and left in the fields during unseasonable rains. The main features of the disease were transient abdominal pain, borborygmus and diarrhoea, which began half an hour to one hour following consumption of unleavened bread prepared from mouldy sorghum or mouldy maize. Patients recovered fully when the exposure ceased and there were no fatalities. Fumonisin [B.sub.1] was found in much higher concentrations in the maize and sorghum from the affected households than from controls.

Fumonisin [B.sub.1] was found more frequently and in much higher concentrations in maize in regions of Transkei, China and north-east Italy with a higher incidence of oesophageal cancer than other regions. It was postulated that the high incidence of oesophageal cancer was related to the presence of this mycotoxin in maize, which is a staple food in these regions. The incidence and concentration of aflatoxin [B.sub.1], deoxynivalenol and fumonisins [B.sub.1], [B.sub.2] and [B.sub.3] were recently determined in maize samples from an area of China (Haimen) with a high incidence of primary liver cancer and from an area with a low incidence (Penlai). Aflatoxin [B.sub.1] was found in low concentrations in almost all maize samples from both these areas, but the incidence and concentration of deoxynivalenol and fumonisins were much higher in the samples from the area where the incidence of primary liver cancer was high. The authors put forward the hypothesis that fumonisins, which have known cancer-promoting activity in rat liver, and deoxynivalenol promote the initial lesion caused by aflatoxin [B.sub.1]. An IARC working group classified the toxins from F. moniliforme as possibly carcinogenic to humans (Group 2B).

Other unidentified mycotoxins
The impact of other mycotoxins on human health was reported in persons occupationally exposed to large amounts of different mycotoxin-producing fungi (farmers, workers in silos, etc.). In such cases, exposure to spores via the respirator), tract seems to be of considerable importance.

In Norway an extensive epidemiological study was undertaken between 1967 and 1991 on 192 417 births to test the hypotheses that perinatal death was associated with parental exposure to pesticides, Toxoplasma gondii infection from sheep or pigs, or mycotoxins found in grain. The proportion of late-term abortions (gestational age 16-27 weeks) was higher among farmers. The risk associated with grain farming was higher after the harvest, in seasons with a poor quality harvest and in pregnancies with multiple fetuses, which suggests that mycotoxins in grain induce labour at an early stage of pregnancy.

Pulmonary mycotoxicosis has been reported in ten persons exposed to large quantities of fungal hyphae and spores during the cleaning of silos. The clinical picture developed several hours afterwards, with burning eyes, throat and chest, irritating cough and fever. There was no wheezing, cyanosis or other sign of bronchospasm. In five patients, chest X-rays revealed reticular and fine nodular features compatible with interstitial pneumonitis. Histological study of a lung biopsy from one patient showed a multifocal acute process, with primary involvement of terminal bronchioles containing numbers of various spores. Cultures from lung biopsy material revealed at least five fungal species, including one Fusarium and one Penicillium. However, blood samples were not checked for the presence of mycotoxins. In contrast with the findings in patients with farmer's lung disease, these patients did not develop positive serological reactions to thermophilic actinomycetes or to extracts of fungi obtained from hay or silage. The patients were followed for periods of 1-10 years; they continued their work, avoiding massive re-exposure to fungal dust, and during the observation period there were no further incidents.

Acute mycotoxicoses can cause serious and sometimes fatal diseases. The possibility of mycotoxin intoxication should be considered when an acute disease occurs in several persons when there is no evidence of infection with a known etiological agent, and no improvement in the clinical picture following treatment. Most of the outbreaks of mycotoxicoses described are a consequence of the ingestion of food that is contaminated with mycotoxins. The strict control of food quality, in both industrialized and developing countries, is therefore necessary to avoid such outbreaks.

Acknowledgements We thank Dr R. Plestina for supervision and advice in all phases of the preparation of this paper.

Trichothecene Mycotoxins (T2) Signs and Symptoms

Exposure causes skin pain, pruritus, redness, vesicles, necrosis and sloughing of epidermis. Effects on the airway include nose and throat pain, nasal discharge, itching and sneezing, cough, dyspnea, wheezing, chest pain and hemoptysis. Toxin also produces effects after ingestion or eye contact. Severe poisoning results in prostration, weakness, ataxia, collapse, shock, and death. Diagnosis: Should be suspected if an aerosol attack occurs in the form of "yellow rain" with droplets of yellow fluid contaminating clothes and the environment. Confirmation requires testing of blood, tissue and environmental samples. Treatment: There is no specific antidote. Superactivated charcoal should be given orally if swallowed. Prophylaxis: The only defense is to wear a protective mask and clothing during an attack. No specific immunotherapy or chemotherapy is available for use in the field. Decontamination: The outer uniform should be removed and exposed skin should be decontaminated with soap and water. Eye exposure should be treated with copious saline irrigation. Once decontamination is complete, isolation is not required.

Overview The trichothecene mycotoxins are low molecular weight (250-500 daltons) nonvolatile compounds produced by filamentous fungi (molds) of the genera Fusarium, Myrotecium, Trichoderma, Stachybotrys and others. The structures of approximately 150 trichothecene derivatives have been described in the literature. These substances are relatively insoluble in water but are highly soluble in ethanol, methanol and propylene glycol. The trichothecenes are extremely stable to heat and ultraviolet light inactivation. Heating to 500o F for 30 minutes is required for inactivation, while brief exposure to NaOH destroys toxic activity. The potential for use as a BW toxin was demonstrated to the Russian military shortly after World War II when flour contaminated with species of Fusarium was baked into bread that was ingested by civilians. Some developed a protracted lethal illness called alimentary toxic aleukia (ATA) characterized by initial symptoms of abdominal pain, diarrhea, vomiting, prostration, and within days fever, chills, myalgias and bone marrow depression with granulocytopenia and secondary sepsis. Survival beyond this point allowed the development of painful pharyngeal/laryngeal ulceration and diffuse bleeding into the skin (petechiae and ecchymoses), melena, bloody diarrhea, hematuria, hematemesis, epistaxis and vaginal bleeding. Pancytopenia, and gastrointestinal ulceration and erosion were secondary to the ability of these toxins to profoundly arrest bone marrow and mucosal protein synthesis and cell cycle progression through DNA replication.

History and Significance Mycotoxins allegedly have been used in aerosol form ("yellow rain") to produce lethal and nonlethal casualties in Laos (1975-81), Kampuchea (1979-81), and Afghanistan (1979-81). It has been estimated that there were more than 6,300 deaths in Laos, 1,000 in Kampuchea, and 3,042 in Afghanistan. The alleged victims were usually unarmed civilians or guerrilla forces. These groups were not protected with masks and chemical protective clothing and had little or no capability of destroying the attacking enemy aircraft. These attacks were alleged to have occurred in remote jungle areas which made confirmation of attacks and recovery of agent extremely difficult. Much controversy has centered about the veracity of eyewitness and victim accounts, but there is enough evidence to make agent use in these areas highly probable.

Clinical Features T2 and other mycotoxins may enter the body through the skin and aerodigestive epithelium. They are fast acting potent inhibitors of protein and nucleic acid synthesis. Their main effects are on rapidly proliferating tissues such as the bone marrow, skin, mucosal epithelia, and germ cells. In a successful BW attack with trichothecene toxin (T2), the toxin(s) will adhere to and penetrate skin, be inhaled, and swallowed. Clothing will be contaminated and serve as a reservoir for further toxin exposure. Early symptoms beginning within minutes of exposure include burning skin pain, redness, tenderness, blistering, and progression to skin necrosis with leathery blackening and sloughing of large areas of skin in lethal cases. Nasal contact is manifested by nasal itching and pain, sneezing, epistaxis and rhinorrhea; pulmonary/tracheobronchial toxicity by dyspnea, wheezing, and cough; and mouth and throat exposure by pain and blood tinged saliva and sputum. Anorexia, nausea, vomiting and watery or bloody diarrhea with abdominal crampy pain occurs with gastrointestinal toxicity. Eye pain, tearing, redness, foreign body sensation and blurred vision may follow entry of toxin into the eyes. Skin symptoms occur in minutes to hours and eye symptoms in minutes. Systemic toxicity is manifested by weakness, prostration, dizziness, ataxia, and loss of coordination. Tachycardia, hypothermia, and hypotension follow in fatal cases. Death may occur in minutes, hours or days. The commonest symptoms were vomiting, diarrhea, skin involvement with burning pain, redness and pruritus, rash or blisters, bleeding, and dyspnea.

Diagnosis Rapid onset of symptoms in minutes to hours supports a diagnosis of a chemical or toxin attack. Mustard agents must be considered but they have an odor, are visible, and can be rapidly detected by a field available chemical test. Symptoms from mustard toxicity are also delayed for several hours after which mustard can cause skin, eye and respiratory symptoms. Staphylococcal enterotoxin B delivered by an aerosol attack can cause fever, cough, dyspnea and wheezing but does not involve the skin and eyes. Nausea, vomiting, and diarrhea may follow swallowing of inhaled toxin. Ricin inhalation can cause severe respiratory distress, cough, nausea and arthralgias. Swallowed agent can cause vomiting, diarrhea, and gastrointestinal bleeding, but it spares the skin, nose and eyes. Specific diagnosis of T-2 mycotoxins in the form of a rapid diagnostic test is not presently available in the field. Removal of blood, tissue from fatal cases, and environmental samples for testing using a gas liquid chromatography-mass spectrometry technique will confirm the toxic exposure. This system can detect as little as 0.1-1.0 ppb of T-2. This degree of sensitivity is capable of measuring T-2 levels in the plasma of toxin victims.

Medical Management Use of a chemical protective mask and clothing prior to and during a mycotoxin aerosol attack will prevent illness. If a soldier is unprotected during an attack the outer uniform should be discarded within 4 hours and decontaminated by exposure to 5% hypochlorite for 6-10 hours. The skin should be thoroughly washed with soap and uncontaminated water if available. The M291 skin decontamination kit should also be used to remove skin adherent T-2. Superactive charcoal can absorb swallowed T-2 and should be administered to victims of an unprotected aerosol attack. The eyes should be irrigated with normal saline or water to remove toxin. No specific antidote or therapeutic regimen is currently field available. All therapy is symptomatic and supportive.

Physical protection of the skin and airway are the only proven effective methods of protection during an attack. Immunological (vaccines) and chemoprotective pretreatments are being studied in animal models, but are not available for field use by the warfighter.

Staphylococcal Enterotoxin B Summary Signs and Symptoms

From 3-12 hours after aerosol exposure, sudden onset of fever, chills, headache, myalgia, and nonproductive cough. Some patients may develop shortness of breath and retrosternal chest pain. Fever may last 2 to 5 days, and cough may persist for up to 4 weeks. Patients may also present with nausea, vomiting, and diarrhea if they swallow toxin. Higher exposure can lead to septic shock and death. Diagnosis: Diagnosis is clinical. Patients present with a febrile respiratory syndrome without CXR abnormalities. Large numbers of soldiers presenting with typical symptoms and signs of SEB pulmonary exposure would suggest an intentional attack with this toxin.

Treatment is limited to supportive care. Artificial ventilation might be needed for very severe cases, and attention to fluid management is important. Prophylaxis: Use of protective mask. There is currently no human vaccine available to prevent SEB intoxication. Decontamination: Hypochlorite (0.5% for 10-15 minutes) and/or soap and water. Destroy any food that may have been contaminated. Overview Staphylococcus aureus produces a number of exotoxins, one of which is Staphylococcal enterotoxin B, or SEB. Such toxins are referred to as exotoxins since they are excreted from the organism; however, they normally exert their effects on the intestines and thereby are called enterotoxins. SEB is one of the pyrogenic toxins that commonly causes food poisoning in humans after the toxin is produced in improperly handled foodstuffs and subsequently ingested. SEB has a very broad spectrum of biological activity. This toxin causes a markedly different clinical syndrome when inhaled than it characteristically produces when ingested. Significant morbidity is produced in individuals who are exposed to SEB by either portal of entry to the body.

History and Significance SEB has caused countless endemic cases of food poisoning. Often these cases have been clustered, due to common source exposure in a setting such as a church picnic or passengers eating the same toxin-contaminated food on an airliner. Although this toxin would not be likely to produce significant mortality on the battlefield, it could render up to 80 percent or more of exposed personnel clinically ill and unable to perform their mission for a fairly prolonged period of time. Therefore, even though SEB is not generally thought of as a lethal agent, it may incapacitate soldiers for up to two weeks, making it an extremely important toxin to consider.

Toxin Characteristics Staphylococcal enterotoxins are extracellular products produced by coagulase-positive staphylococci. They are produced in culture media and also in foods when there is overgrowth of the staph organisms. At least five antigenically distinct enterotoxins have been identified, SEB being one of them. These toxins are heat stable. SEB causes symptoms when inhaled at very low doses in humans: a dose of several logs lower than the lethal dose by the inhaled route would be sufficient to incapacitate 50 percent of those soldiers so exposed. This toxin could also be used (theoretically) in a special forces or terrorist mode to sabotage food or low volume water supplies.

Mechanism of Toxicity Staphylococcal enterotoxins produce a variety of toxic effects. Inhalation of SEB can induce extensive pathophysiological changes to include widespread systemic damage and even septic shock. Many of the effects of staphylococcal enterotoxins are mediated by interactions with the host's own immune system. The mechanisms of toxicity are complex, but are related to toxin binding directly to the major histocompatibility complex that subsequently stimulates the proliferation of large numbers of T cell lymphocytes. Because these exotoxins are extremely potent activators of T cells, they are commonly referred to as bacterial superantigens. These superantigens stimulate the production and secretion of various cytokines, such as tumor necrosis factor, interferon-(, interleukin-1 and interleukin-2, from immune system cells. Released cytokines are thought to mediate many of the toxic effects of SEB.

Clinical Features Relevant battlefield exposures to SEB are projected to cause primarily clinical illness and incapacitation. However, higher exposure levels can lead to septic shock and death. Intoxication with SEB begins 3 to 12 hours after inhalation of the toxin. Victims may experience the sudden onset of fever, headache, chills, myalgias, and a nonproductive cough. More severe cases may develop dyspnea and retrosternal chest pain. Nausea, vomiting, and diarrhea will also occur in many patients due to inadvertently swallowed toxin, and fluid losses can be marked. The fever may last up to five days and range from 103 to 106o F, with variable degrees of chills and prostration. The cough may persist up to four weeks, and patients may not be able to return to duty for two weeks. Physical examination in patients with SEB intoxication is often unremarkable. Conjunctival injection may be present, and postural hypotension may develop due to fluid losses. Chest examination is unremarkable except in the unusual case where pulmonary edema develops. The chest X-ray is also generally normal, but in severe cases increased interstitial markings, atelectasis, and possibly overt pulmonary edema or an ARDS picture may develop.

Diagnosis As is the case with botulinum toxins, intoxication due to SEB inhalation is a clinical and epidemiologic diagnosis. Because the symptoms of SEB intoxication may be similar to several respiratory pathogens such as influenza, adenovirus, and mycoplasma, the diagnosis may initially be unclear. All of these might present with fever, nonproductive cough, myalgia, and headache. SEB attack would cause cases to present in large numbers over a very short period of time, probably within a single 24 hour period. Naturally occurring pneumonias or influenza would involve patients presenting over a more prolonged interval of time. Naturally occurring staphylococcal food poisoning cases would not present with pulmonary symptoms. SEB intoxication tends to progress rapidly to a fairly stable clinical state, whereas pulmonary anthrax, tularemia pneumonia, or pneumonic plague would all progress if left untreated. Tularemia and plague, as well as Q fever, would be associated with infiltrates on chest radiographs. Nerve agent intoxication would cause fasciculations and copious secretions, and mustard would cause skin lesions in addition to pulmonary findings; SEB inhalation would not be characterized by these findings. The dyspnea associated with botulinum intoxication is associated with obvious signs of muscular paralysis, bulbar palsies, lack of fever, and a dry pulmonary tree due to cholinergic blockade; respiratory difficulties occur late rather than early as with SEB inhalation. Laboratory findings are not very helpful in the diagnosis of SEB intoxication. A nonspecific neutrophilic leukocytosis and an elevated erythrocyte sedimentation rate may be seen, but these abnormalities are present in many illnesses. Toxin is very difficult to detect in the serum by the time symptoms occur; however, a serum specimen should be drawn as early as possible after exposure. Data from rabbit studies clearly show that SEB in the serum is transient; however, it accumulates in the urine and can be detected for several hours post exposure. Therefore, urine samples should be obtained and tested for SEB. High SEB concentrations inhibit kidney function. Because most patients will develop a significant antibody response to the toxin, acute and convalescent serum should be drawn which may be helpful retrospectively in the diagnosis.

Medical Management Currently, therapy is limited to supportive care. Close attention to oxygenation and hydration are important, and in severe cases with pulmonary edema, ventilation with positive end expiratory pressure and diuretics might be necessary. Acetaminophen for fever, and cough suppressants may make the patient more comfortable. The value of steroids is unknown. Most patients would be expected to do quite well after the initial acute phase of their illness, but most would generally be unfit for duty for one to two weeks.

Although there is currently no human vaccine for immunization against SEB intoxication, several vaccine candidates are in development. Preliminary animal studies have been encouraging and a vaccine candidate is nearing transition to advanced development and safety and immunogenicity testing in man. Experimentally, passive immunotherapy can reduce mortality, but only when given within 4-8 hours after inhaling SEB.

Source: U.S. Army Handbook on infectious Diseases August 1996

Outdoor Environment Molds Are Ubiquitous

Moist conditions involving drywall, wood, carpeting, or paper material are the focal proliferation medium in the indoor environment. Since Americans spend 75 to 90% of their time indoors, they are exposed to molds that may grow indoors. Molds enter the indoor environment through doorways, windows, heating and ventilation systems, and air conditioning systems, given the appropriate circumstances. Spores in the air deposit on people, animals, clothing, shoes, and bags, turning them into common and potential carriers of molds into the indoor environments. Indoor environments that contain excessive moisture such as leakage from roofs, walls, plant pots, or pet urine cause proliferation and development of molds. The most common molds which are found indoor are Cladosporium, Penicillium, and Aspergillus. In order to proliferate molds need nutrients which are commonly present in building environments such as cellular substrates in paper, paper products, cardboard, ceiling tiles, wood, wood products, drywall, carpet, fabric, insulation materials, wallpaper, paints, and dusts. Some of the indoor molds have the potential to produce extremely toxic materials called mycotoxins. Those molds which have the potential of producing toxic materials include Fusarium and Stachybotrys, among others.

Depending on the quantities produced and consumed, mycotoxins can cause acute or chronic toxicity in animals and humans. Home dampness with resulting mold growth may be associated with several medical conditions (one or sometimes all) including immediate hypersensitivity reaction, hypersensitivity pneumonia, or what has been described as "humidifier fever". Onset of asthma, recent onset sinusitis, and/or recent onset skin rashes. Several studies have shown a clear correlation and association between the occurrence of molds in the inside air environment, dampness in the indoor environment, and the symptomatology of the skin, and respiratory tract, especially in children. This has been summarized in an interesting study published in the American Journal of Epidemiology by Robert E. Dales. Since the symptoms in this study were comparable to the symptoms described with humidifier fever and mycotoxicosis, the authors suggested a common pathogenic and etiological mechanism.

The role of indoor molds, especially the most toxic one - Stachybotrys, has been shown recently in a scientific paper published in the journal Pediatrics. The authors described a child with pulmonary hemorrhaging where Stachybotrys was isolated from the lung. Indeed, epidemiological data to support the connection between mold exposure and lung hemorrhage was published in the scientific literature from Cleveland, Ohio, which was later examined by the Center for Disease Control. The scientific data clearly demonstrates a high spore count of Stachybotrys in 9 out of 10 of the houses where these infants lived, and 5 infants had recurrence of the bleeding of the lungs on reentry to their homes, implicating that the fungus is a potential agent in the pathogenesis of infantile pulmonary hemorrhage. The study by Okan Alidemir, et al, shows the isolation of Stachybotrys atra from the BAL fluid of a child with pulmonary hemorrhage, thus connecting the epidemiological data and the historical data in this case report with objective findings of Stachybotrys from the lung fluids. In the scientific paper entitled "Stachybotrys: Mycotoxin Producing Fungus of Increasing Toxicological Importance", the investigators concluded "Current data on the toxicology of mycotoxins produced by Stachybotrys demonstrates that this group of mycotoxins is capable of producing immunosuppression and inflammatory insults to the gastrointestinal and pulmonary system".

While it is an ideal situation to have "statistical firmness", in medicine the clinician established a diagnosis and causation based on known and accepted factors where statistical firmness is not a pre-requisite. The causal clinical association between allergic reaction to the sinuses in the form of rhinitis, sinusitis, or asthma and indoor air mold exposure has been very well documented in the scientific literature in an early review by Susan Gravesen.

That indoor moisture and molds represents a public health issue is described in the scientific paper by Hodgson. These authors report an outbreak of disease associated with exposure to these molds in 2 buildings in Florida. The specific buildings were a new court house and office building which were constructed between 1986 and 1989. Within weeks after moving in patients described mucous membrane irritation, fatigue, headaches, and chest tightness. Moisture problems such as window and roof leaks have been described as starting in 1987 and persisting through 1992. Utilizing epidemiological methodology the investigators concluded that this outbreak represents a likely human response to inhaled fungal toxins in indoor air environments. What to do when you suspect molds as a cause for symptomatology. First and most importantly is to see a doctor who specializes in the fields of internal medicine, occupational medicine and toxicology with the understanding of building-related illnesses and toxic molds. The doctor will have to rule out other diseases, perform laboratory studies, and provide an opinion as to whether these symptoms can be and have been described with molds. Upon determination that these symptoms may be related to mold exposure, you should have an industrial hygienists go and inspect your residence or alternatively office/work place (depending on where the suspected mold resides) to do a careful investigation of any water damages, and air counts both inside and outside at several locations for molds and spores. A well-trained industrial hygienist will not only take air counts but also will go under and behind the walls and/or carpeting where the water damage is anticipated to be in order to further evaluate for mold spores and mold growth. Once molds are discovered, depending on the damage that occurred, either expert remediation (with appropriate protective devices and removal of the inhabitants from the area) or at times destruction and rebuilding of the damaged house or building area is necessary.

During the last 5 years I have treated patients with various mold related illnesses contracted at either industrial buildings such as old buildings, schools, and governmental offices, as well as residences, all of which have suffered either faulty ventilation, water damages, or both. The most common presenting symptoms are those of cough, asthma, atypical asthma, nasal congestion, sinusitis/rhinitis, skin rashes, and generalized fatigue. On many occasions the patients presented with neurological symptoms such as headaches, reduced concentration ability, and memory loss. The patients may present with only one symptom (such as sinusitis) or a combination of symptoms.

Nachman Brautbar, M.D. is board certified in internal medicine, forensic medicine, and nephrology with a specialization in toxicology. Dr. Brautbar is a medical professor at USC, school of medicine, has published over 230 journal articles, manuscripts, abstracts and book chapters. references on file

Chronic Fatigue Syndrome
This year I enter my 11th year of practice. Some call me an HIV specialist while others call me a Chronic Fatigue Syndrome specialist. Although these two groups of patients make up a large majority of my practice, I also have a very active Internal Medicine practice including over 100 nursing home patients. I consider myself a specialist in Internal Medicine. Perhaps no other training would have prepared me more for my future as a practitioner in Chronic Fatigue Syndrome than my Internal Medicine training.

The practice of medicine is an art which is far more than the application of scientific principles to a particular biological model. Its focus is on the patient whose welfare is the continuing purpose. That purpose of medicine is self-evident in theory, but more difficult to sustain under the pressures of medical practice. This is no more true than in the field of CFS which for years has been both ignored and ridiculed by a large part of the medical community.

I was asked to write about the frustration in treating patients with CFS. Many superficial hassles immediately comes to mind--lists of endless symptoms; pages of questions without answers; disability letters and repeat disability letters and repeat disability letters; medical necessity letters to insurance companies; applications for disabled parking permits; letters to families, schools, employer, court, attorneys, and other doctors explaining the physical limitations of patients with CFS. As I think on a deeper level.

Health Effects

Heath Effects of Toxic Mold

Exposure to fungi and mycotoxins can, depending on dose and duration of exposure cause ill health or aggravate conditions including :::

Children's Health
Asthma and allergy in children is increasing in many countries. This condition can be related to exposure of a variety of environmental agents (allergens, cat dander, air pollution, infections) including microbial products (fungal spores and hyphae. Several studies from around the world have shown a clear relationship between respiratory symptoms and disease with moisture problems / dampness and mold exposure.

Toxic Mycotoxins
Dr. Straus, the Texas Tech professor, is the author of a 1998 study that showed a strong correlation between Stachybotrys and public buildings that appeared to make people sick. "If you're working with this stuff, you've got to wear a moon suit and a respirator," he said. "If you get this stuff on your skin, it's going to cause sores and rashes. If you inhale it, it's going to cause serious health problems."