Acute aflatoxicosis outbreak in rheas (Rhea americana) in Brazil: Case report.

Aflatoxins are mycotoxins capable of contaminating food, and can cause toxic effects, teratogenicity, mutagenicity, carcinogenicity, and immune system depression. The presence of fungi which produce this metabolite in ingredients that compose the animal feed increased the risk of the emergence of aflatoxicosis. The objective of this study was to report an aflatoxicosis outbreak in rheas (Rhea americana) from a farm in Teresina, PI, Brazil, fed with commercial feed. After the deaths of four animals, epidemiological data were collected and complementary examinations were performed, including necropsy, histopathology, parasitology, blood culture, in addition to the analysis of the presence of toxins in the birds' feed. The diagnosis was based on the acute clinical signs, necropsy findings, which included carcass jaundice, an oedematous, yellowish, friable liver of increased size, and histopathological findings of moderate to severe congestion in all organs. The parasitological and microbiological tests performed were negative, not indicating systemic infectious causes. The analysis of the presence of mycotoxins revealed the existence of Aflatoxins B1, B2 and G1 in the commercial feed supplied, constituting a total of 66.89 µg/kg. This amount of aflatoxin exceeds the maximum level allowed by the Brazilian legislation. To our knowledge this is the first report of aflatoxicosis in rheas, and emphasizes the importance of the diagnosis, control, and prevention of mycotoxins in the quality of food provided to animals kept ex situ.

Mycotoxin toxicity and residue in animal products: Prevalence, consumer exposure and reduction strategies - A review.

Mycotoxin residues are transferred from feed to animal products, yet, less attention has been paid to it in developing countries. There is a need to find alternative alleviation material for reducing the impact of mycotoxin. This review is meant to elucidate different additives that can reduce mycotoxin residue in animal products in the world, especially in developing countries. There is evidence of relationship between mycotoxin residue in breast milk of nursing mothers and mycotoxin exposure through crop and animal product (egg and milk) intake, especially in Asia, Africa, Middle East, Latin America, and some parts of Europe. Younger livestock tends to have more toxin residues in their tissue compared to older ones. Grazing animal are also exposed to mycotoxin intake which corresponds to high level of mycotoxins in their products including meat and milk. This review shows that phytogenic, probiotic, and prebiotic additives can decrease mycotoxin residues in milk, eggs, meat liver and other tissues of livestock. Specifically, bentonites, difructose anhydride III, yeast (Trichosporon mycotoxinivorans), Bacillus spp., or their biodegradable products can reduce mycotoxin residue in animal products. In addition, Ally isothiocyanates from mustard seed were able to mitigate mycotoxins in silo-simulated system. Evidence shows that there are now low-cost, accessible, and eco-friendly additives, which could alleviate the effect of mycotoxin in feed and food. In addition, there is need for aggressive public awareness and farmers' education on the prevalence, and danger caused by mycotoxins, as well as detoxification strategies that can reduce toxin absorption into animal products.

Epidemiologia de micoses, pitiose e micotoxicoses em equinos no sudeste do Rio Grande do Sul / Epidemiology of mycoses, pitiosis and micotoxicosis in horses in southeastern Rio Grande do Sul, Brazil

Descrevem-se os aspectos epidemiológicos das doenças causadas por fungos e oomicetos na população de equinos na região sudeste do Rio Grande do Sul, estabelecendo as taxas epidemiológicas, suas causas e sua importância sanitária na região. Foi realizada a epidemiologia descritiva por meio do cálculo da incidência das doenças encontradas ao longo dos anos e verificada a existência de associação entre a ocorrência dessas enfermidades e o sexo, a raça e a estação do ano. Entre os anos de 1978 e 2014 a pitiose teve prevalência de 49,71% (86/173), as micotoxicoses 30,05% (52/173), sendo 45 casos de leucoencefalomalácia e sete de ergotismo. As micoses tiveram prevalência de 19,65% (34/173), sendo as dermatofitoses as mais prevalentes com 58,82% (20/34) dos casos. As espécies de dermatófitos mais frequentemente isoladas foram Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) e Microsporum gypseum, Microsporum canis e Trichophyton verrucosum ambos responsáveis por 5% (1/20) das infecções. Rinosporidiose foi diagnosticada em 35,29% (12/34) dos casos. Micoses uterinas causadas por Candida albicans e Cryptococcus laurentii foram observadas em 5,88% (2/34) dos casos. Alergia por Cladosporium sp. teve um registro. De acordo com as incidências calculadas entre 1990 e 2014 a pitiose teve incidência mediana (IM) 2,98 e distância interquartil (DI) =3,82, as fêmeas tiveram chance 4,18 vezes maiores de desenvolver a doença, a enfermidade ocorre independente das estações climáticas. A leucoencefalomalácia teve IM=0,0; DI 1,00 e equinos machos tiveram 3,4 vezes mais chance de desenvolver a doença que fêmeas, no inverno a possibilidade de ocorrência dessa enfermidade foi seis vezes maior. O ergotismo teve IM = 0,00; DI = 0,000, rinosporidiose IM=0,00; DI=0,088 e dermatofitose IM=0,00; DI=0,935. A pitiose foi mais prevalente entre as doenças encontradas, podendo ser considerada endêmica na região. Considera-se que a magnitude das doenças possa ser ainda maior dentro do rebanho equino, uma vez que as doenças descritas não são de notificação obrigatória e algumas são bem conhecidas por veterinários e proprietários, que muitas vezes não fazem a confirmação laboratorial do diagnóstico.(AU)

The epidemiological aspects of diseases caused by fungi and oomycetes in horses in southeastern Rio Grande do Sul, Brazil, is described. The epidemiological rates, their causes, and health importance in the region were established. A descriptive epidemiology study was carried out in relation of potential risk factors. The impact on these diseases in the region was measured. From 1978 to 2014, pythiosis had a prevalence of 49.71% (86/173), and mycotoxicoses of 30.05% (52/173), with 45 cases of leukoencephalomalacia and 7 of ergotism. The prevalence of fungal infections was 19.65% (34/173) of cases. Dermatophytosis was the most prevalent fungal infection with 58.82% (20/34) of cases. The most isolated dermatophyte species were Trichophyton mentagrophytes 60% (12/20), Trichophyton equinum 25% (5/20) and Microsporum gypseum, Microsporum canis, and Trichophyton verrucosum, both responsible for 5% (1/20) of infections. Rhinosporidose was diagnosed in 35.29% (12/34) of cases. Uterine mycosis caused by Candida albicans and Cryptococcus laurentii was observed at 5.88% (2/34) of cases. Cladosporium sp. allergy was noted in one record. According to the incidence from 1990 to 2014, pythiosis had median incidence (MI) of 2.98 and interquartile range (DI) of 3.82. Mares were 4.18 times likely to develop the disease then males. The disease occurs in the region in every season. Leukoencephalomalacia had MI of 0.0; DI 1.00 and male horses were 3.4 times more likely than mares to develop the disease. Leukoencephalomalacia was 6 times more likely to occur during winter. Ergotism had MI of 0.00; DI of 0.000, rhinosporidiosis MI of 0.00, DI of 0.088 and ringworm MI of 0.00, and DI of 0.935. In the study pythiosis had the highest prevalence among the diseases observed, and may be considered endemic in the region. The magnitude of the diseases observed may be even greater within the equine herd, since these diseases are not of obligatory notification and some are well known by veterinarians and owners, who often do not obtain a laboratory confirmation of the diagnosis.(AU)

Prevalence of Degnala disease in bovine along with screening of toxigenic fungi isolated from contaminated rice straw.

Toxigenic potential of different candidate fungi, isolated from rice straw feed of Degnala disease affected bovines was analyzed along with species, age, gender and seasonal prevalence. Of 1,536 cases, 104 (6.77%) showed positive signs with a significant association (p less than 0.05) between this disease and rice straw feeding, in buffaloes, and bovine aged over 1 year in the winter season. Complete blood count showed a marked increase in erythrocyte sedimentation rate and all white blood cells numbers, except lymphocytes in positive cases. There was a significant increase (p less than 0.05) in alanine amino transferase, aspirate amino transferase and alkaline phosphatase in the liver function test. At the same time, an increased value of creatinine was noted in the renal function test. For isolation and screening of toxigenic fungi, rice straw samples (n=40) being fed to the positive cases were processed further, and 85 fungal isolates were found, mainly of Aspergillus (57), Penicillium (10), Fusarium (04), Zygomycetes (03), Curvularia (01) and unidentified (10). All isolated fungi were subjected for mycotoxin production and only 11 showed mycotoxin-producing capability (including Aspergillus, Penicillium and Fusarium isolates) analyzed by thin layer chromatography and quantified through high performance liquid chromatography. It is concluded that all the fungi contaminating rice straw feed of Degnala affected animals were not toxigenic. This work will help in establishing major mycotoxin-producing fungi leading to the probable cause of Degnala disease in bovine.

Acute photosensitisation and mortality in a herd of dairy cattle in Tasmania.

CASE HISTORY: A herd of Holstein, Jersey, or Holstein-Jersey cross lactating cattle of mixed ages presented with a sudden drop in milk yield in 94/678 cows on 3 October 2014 (Day 0). The herd was located in Gretna in the Derwent Valley (Tasmania, Australia) and had been grazing dryland pasture. CLINICAL FINDINGS: On Day 0 the cows variably showed recumbency, peracute photosensitisation, inflamed coronary bands, conjunctival erythema, periauricular oedema, distress indicated by kicking at the flank, bruxism, discomfort, weight shifting, vocalisation indicating pain and depression. Blood samples collected on Day 4 from five clinically affected cows showed high activities of aspartate aminotransferase, glutamate dehydrogenase and gamma-glutamyl transferase. Morbidity, based on the number of treated cases within 72 hours of clinical onset, was estimated at 165/678 cows (24.3%). Mortality over the first 30 days was 19/678 cows (2.8%). PATHOLOGICAL FINDINGS: Necropsies of two cows on Day 4 showed marked distension of the gall bladder and extensive icterus. Necropsies of another two cows on Day 5 showed enlarged livers with severe damage and oedema of the distal abomasum. Severe ulcerative abomasal gastritis was present in both cows. Hepatic histopathology was consistent with chronic cholangiohepatitis. MYCOTOXICOLOGY: Fifty-five different mycotoxins were detected from a barley grass (Hordeum murinum) sample from the presumably contaminated pasture. Concentrations of B-trichothecenes, fumonisins, and zearalenone metabolites from this sample were remarkably high. The leaf smut, Jamesdicksonia dactylidis, that has not been previously reported in Tasmania, was identified from the sample of barley grass, but it is not known whether the smut can produce toxins. DIAGNOSIS: Probably an undescribed peracute mycotoxicosis associated with the ingestion of contaminated dryland pasture. CLINICAL RELEVANCE: A definitive diagnosis could not be reached in this case of acute photosensitisation and mortality in dairy cattle grazing possibly contaminated dryland pasture. The findings differed from both facial eczema and acute bovine liver disease, suggesting an undescribed mycotoxicosis.

Current Understanding of Acute Bovine Liver Disease in Australia.

Acute bovine liver disease (ABLD) is a hepatotoxicity principally of cattle which occurs in southern regions of Australia. Severely affected animals undergo rapid clinical progression with mortalities often occurring prior to the recognition of clinical signs. Less severely affected animals develop photosensitization and a proportion can develop liver failure. The characteristic histopathological lesion in acute fatal cases is severe, with acute necrosis of periportal hepatocytes with hemorrhage into the necrotic areas. Currently there are a small number of toxins that are known to cause periportal necrosis in cattle, although none of these have so far been linked to ABLD. Furthermore, ABLD has frequently been associated with the presence of rough dog's tail grass (Cynosurus echinatus) and Drechslera spp. fungi in the pasture system, but it is currently unknown if these are etiological factors. Much of the knowledge about ABLD is contained within case reports, with very little experimental research investigating the specific cause(s). This review provides an overview of the current and most recently published knowledge of ABLD. It also draws on wider research and unpublished reports to suggest possible fungi and mycotoxins that may give rise to ABLD.

Hepatotoxicidad por Amanita lilloi, reporte de primeros casos / Amanita lilloi hepatotoxicity, first cases report

Se presentan dos casos clínicos de intoxicación por A. lilloi, hongos silvestres, que fueron recolectados por quienes los consumieron. Ambas pacientes desarrollaron sintomatología digestiva y evolucionaron a la falla hepática. La consulta tardía retrasó el diagnóstico y el tratamiento, pero igualmente la evolución de ambas pacientes fue favorable.

Two clinical cases of poisoning A. lilloi, wild mushrooms, which were collected by those who consumed themdebe, are presented. Both patients developed gastrointestinal symptoms and progressed to liver failure. The late consultation delayed diagnosis and treatment, but nevertheless the evolution of both patients was favorable.

Aflatoxin B1 and total fumonisin contamination and their producing fungi in fresh and stored sorghum grain in East Hararghe, Ethiopia.

Natural contamination of sorghum grains by aflatoxin B1 and total fumonisin and their producing toxigenic fungi has been studied. A total of 90 sorghum grain samples were collected from small-scale farmers' threshing floors and 5-6 months later from underground pits during 2013 harvest from three districts of East Hararghe, Ethiopia. Mycotoxin analysis was done using enzyme-linked immunosorbent assay (ELISA). The limits of detection were in the range 0.01-0.03 µg kg-1. The results revealed that all sorghum grain samples were contaminated with both Aspergillus and Fusarium species. Aflatoxin B1 was detected at levels ranging from

Plant poisonings in livestock in Brazil and South Africa.

Information on intoxication of livestock by plants in Brazil, in terms of cause, clinical signs and pathology, is compared with information on livestock poisoning by plants in South Africa. Plant poisoning, including mycotoxicosis, is considered to be one of three major causes of death in livestock in Brazil, which is one of the top beef producing countries in the world, with a cattle population of more than 200 million. Cattle production in South Africa is on a more modest scale, but with some 600 species of plants and fungi known to cause toxicity in livestock, as opposed to some 130 species in Brazil, the risk to livestock in South Africa appears to be much greater. The comparisons discussed in this communication are largely restricted to ruminants.

Prevalence and effects of mycotoxins on poultry health and performance, and recent development in mycotoxin counteracting strategies.

Extensive research over the last couple of decades has made it obvious that mycotoxins are commonly prevalent in majority of feed ingredients. A worldwide mycotoxin survey in 2013 revealed 81% of around 3,000 grain and feed samples analyzed had at least 1 mycotoxin, which was higher than the 10-year average (from 2004 to 2013) of 76% in a total of 25,944 samples. The considerable increase in the number of positive samples in 2013 may be due to the improvements in detection methods and their sensitivity. The recently developed liquid chromatography coupled to (tandem) mass spectrometry allows the inclusion of a high number of analytes and is the most selective, sensitive, and accurate of all the mycotoxin analytical methods. Mycotoxins can affect the animals either individually or additively in the presence of more than 1 mycotoxin, and may affect various organs such as gastrointestinal tract, liver, and immune system, essentially resulting in reduced productivity of the birds and mortality in extreme cases. While the use of mycotoxin binding agents has been a commonly used counteracting strategy, considering the great diversity in the chemical structures of mycotoxins, it is very obvious that there is no single method that can be used to deactivate mycotoxins in feed. Therefore, different strategies have to be combined in order to specifically target individual mycotoxins without impacting the quality of feed. Enzymatic or microbial detoxification, referred to as "biotransformation" or "biodetoxification," utilizes microorganisms or purified enzymes thereof to catabolize the entire mycotoxin or transform or cleave it to less or non-toxic compounds. However, the awareness on the prevalence of mycotoxins, available modern techniques to analyze them, the effects of mycotoxicoses, and the recent developments in the ways to safely eliminate the mycotoxins from the feed are very minimal among the producers. This symposium review paper comprehensively discusses the above mentioned aspects.

Regional differences in the fescue toxicosis response of Bos taurus cattle.

Cattle of the same breed from different regions of the USA may have altered responses to heat stress and fescue toxicosis. Angus steers from Missouri (MO ANG, n = 10, 513.6 ± 13.6 kg BW) and Oklahoma (OK ANG, n = 10, 552.8 ± 12.0 kg BW) were fed a diet containing either endophyte-infected (E+, 30 µg ergovaline/kg BW/day) or endophyte-uninfected (E-, 0 µg ergovaline/kg BW/day) tall fescue seed for 23 days. Diet treatment began on day 2. Animals were maintained at thermoneutrality (TN, 19-22 °C, days 1-8) and then exposed to heat stress (HS, cycling 26-36 °C, days 9-22). On day 23, ambient temperature was returned to TN and used as a recovery day. Feed intake (FI) was measured daily, with rectal and skin temperatures determined six times daily. Feed intake reduction from pretreatment levels was greater (P < 0.01) for E + (13.9 ± 0.9 versus 11.9 ± 0.3 kg/day) compared to E - (12.6 ± 0.9 versus 12.4 ± 0.3 kg/day) steers over the entire TN period, regardless of Angus group. During HS, E + cattle had reduced FI (P < 0.02; 6.9 ± 0.2 versus 8.4 ± 0.2 kg/day) compared to E - animals, independent of region of origin. A greater decrease in FI (P < 0.01) was observed for OK (12.1 ± 0.3 versus 6.2 ± 0.2 kg/day) compared to MO ANG (12.2 ± 0.3 versus 7.9 ± 0.2 kg/day) when ambient temperature was increased from TN to HS. On day 13 and days 15-22, OK ANG (E+) had reduced FI (P < 0.01, -2.21 kg) compared to OK ANG (E-), while there was no effect on MO ANG. From day 12 to day 22 of HS, daily minimum temperatures for ear, rump, and tail skin were less for E + (P < 0.05) when compared with E-treated steers, signifying peripheral vasoconstriction in E + animals. This was supported by reduced shoulder and lower tail temperatures (P < 0.01) for E + compared to E-treated OK ANG on the recovery day. In summary, regional differences in the response to fescue toxicosis exist, with peripheral vasomotor effects becoming most evident when animals are subjected to rapid changes in their environment.

An overview on mycotoxin contamination of foods in Africa.

Mycotoxins are fungal secondary metabolites that contaminate various feedstuffs and agricultural crops. The contamination of food by mycotoxins can occur before production, during storage, processing, transportation or marketing of the food products. High temperature, moisture content and water activity are among the predisposing factors that facilitate the production of mycotoxins in food. Aflatoxins, ochratoxins, fumonisins, deoxynivalenol and zearalenone are all considered the major mycotoxins produced in food and feedstuffs. In Africa, mycotoxin contamination is considered to be a major problem with implications that affect human and animal health and economy. Aflatoxin-related hepatic diseases are reported in many African countries. Ochratoxin and fumonisin toxicity in humans and animals is widespread in Africa. The available, updated information on the incidence of mycotoxin contamination, decontamination and its public health importance in Africa is lacking. The aim of this review is to highlight, update and discuss the available information on the incidence of mycotoxins in African countries. The public health implications and the recommended strategies for control of mycotoxins in food and agricultural crops are also discussed.

Multitoxin analysis of Aspergillus clavatus-infected feed samples implicated in two outbreaks of neuromycotoxicosis in cattle in South Africa.

Aspergillus clavatus intoxication is a highly fatal neuromycotoxicosis of ruminants, especially cattle. It is caused by the ingestion of infected sprouting grain and sorghum beer residue. Locomotor disturbances, tremors and paralysis are observed. Histologically, degeneration and necrosis of larger neurons in the medulla oblongata, the midbrain, the thalamus and the ventral horns of the spinal cord are observed. Although a range of mycotoxins such as patulin, cytochalasin E and pseurotin A have been isolated, there is limited information on which specific mycotoxin or group of mycotoxins are involved during outbreaks of intoxication in livestock. In the present study, two outbreaks of A. clavatus poisoning in cattle are briefly described. Feed samples were collected for fungal identification, and culture and multitoxin analysis. A range of fungal metabolites were detected, and the estimated concentrations (µg/kg) are provided. Both the sprouting barley and brewer's grain were predominantly infected with A. clavatus and, to a lesser extent, Rhizopus arrhizus. The only common Aspergillus secondary metabolite present in all the samples was pseurotin A. Patulin and cytochalasin E were present in the sprouting barley samples, as well as the A. clavatus isolates cultured on malt extract agar for 2 weeks; however, neither of these mycotoxins could be detected in the brewer's grain sample.

Mycotoxicoses in children.

Mycotoxicoses are acute and chronic poisonings caused by mould toxins called mycotoxins. Although acute mycotoxicoses, caused by high mycotoxin levels in food are rare nowadays, they need to be described in order to inform physicians and other health care workers about their symptoms. Children are more sensitive to mycotoxins because of their lower body mass, higher metabolic rate, and underdeveloped organ functions and detoxication mechanisms. Some mycotoxicoses appear only in children, and some are more pronounced in children than in adults. Acute mycotoxicoses in children are reported poorly, mostly because they occur in the tropical regions with poor healthcare coverage. In developed countries healthcare authorities are more concerned about child exposure to low levels of mycotoxins with immunotoxic, genotoxic or carcinogenic properties.

Mycotoxicoses of ruminants and horses.

In the current study, mycotoxicoses of ruminants and horses are reviewed, with an emphasis on the occurrence of these diseases in South America. The main mycotoxicoses observed in grazing cattle include intoxications by indole-diterpenoid mycotoxins (Paspalum spp. contaminated by Claviceps paspali, Lolium perenne infected by Neotyphodium lolii, Cynodon dactylon infected by Claviceps cynodontis, and Poa huecu), gangrenous ergotism and dysthermic syndrome (hyperthermia) caused by Festuca arundinacea (syn. Festuca elatior) infected by Neotyphodium coenophialum (syn. Acremonium coenophialum), and photosensitization in pastures contaminated by toxigenic Pithomyces chartarum. Other mycotoxicoses in grazing cattle include slaframine toxicity in clover pastures infected by Rhizoctonia leguminicola and diplodiosis in cattle grazing in corn stubbles. The mycotoxicoses caused by contaminated concentrated food or byproducts in cattle include poisoning by toxins of Aspergillus clavatus, which contaminate barley or sugar beetroot by-products, gangrenous ergotism or dysthermic syndrome caused by wheat bran or wheat screenings contaminated with Claviceps purpurea, and acute respiratory distress caused by damaged sweet potatoes (Ipomoea batatas). The main mycotoxicosis of horses is leukoencephalomalacia caused by the fumonisins B1 and B2 produced by Fusarium spp. Poisoning by C. purpurea and F. elatior infected by N. coenophialum has also been reported as a cause of agalactia and neonatal mortality in mares. Slaframine toxicosis caused by the ingestion of alfalfa hay contaminated by R. leguminicola has also been reported in horses.

Sago haemolytic disease: towards understanding a novel food-borne toxicosis.

Sago haemolytic disease is a rare but sometimes fatal disease found primarily in the coastal regions of Papua New Guinea and among groups in which sago is a primary source of carbohydrate. It has been known since 1961 and fungi consistently have been suspected of being involved. Investigations carried out on stored sago and samples recovered from poisoning episodes have failed to indicate the consistent presence of mycotoxins. However, fungi (especially Aspergillus, Fusarium, Penicillium, Trichoderma) with strong haemolytic activity have been associated with sago, particularly when stored in open-weave baskets and sago-leaf-wrapped bundles. The haemolytic activity has been attributed to fatty acids (principally oleic, palmitic, linoleic) contained primarily in the fungal hyphae. It is hypothesized that when these acids are released through hyphal breakdown during digestion and are present in individuals with a low serum albumin level, free fatty acid excess occurs resulting in red cell membrane destruction and intravascular haemolysis. In extreme cases, blood transfusion is required. Methods of storage providing high levels of access to oxygen favour the development of fungi: eg, leaf-encased bundles and open-weave storage favour growth over that seen in starch stored under water, such as in earthen vessels. Ensuring storage does not exceed 3-4 weeks, encouraging anaerobic conditions of the starch and maintaining protein nutrition in communities where sago is relied upon should alleviate outbreak episodes.

Zearalenone and deoxynivalenol mycotoxicosis in dairy cattle herds.

Mycotoxin contaminations pose a growing problem in animal production from the economic and toxicological point of view. Clinical symptoms of mycotoxicosis are relatively unspecific, making the disease difficult to diagnose. This study presents a clinical case of dairy cattle infected with natural mycotoxins produced by fungi of the genus Fusarium (zearalenone [ZEA] and deoxynivalenol [DON]) in eastern Poland. In dead and infected cows, the presence of ZEA and DON was determined in the blood serum, significant changes were observed in blood morphological and biochemical profiles, extravasations and bowel inflammations were also observed. The results reported testify to an acute autoimmune process in the intestines as well as immunosuppression.

Mold growth in on-reserve homes in Canada: the need for research, education, policy, and funding.

The impact of mold growth in homes located on First Nations reserves in Canada is part of a national housing crisis that has not been adequately studied. Nearly half of the homes on reserves contain mold at levels of contamination associated with high rates of respiratory and other illnesses to residents. Mold thrives due to increased moisture levels in building envelopes and interior spaces. Increased moisture stems from several deficiencies in housing conditions, including structural damage to the building envelope, overcrowding and insufficient use of ventilation systems, and other moisture-control strategies. These deficiencies have developed due to a series of historical and socioeconomic factors, including disenfranchisement from traditional territory, environmentally inappropriate construction, high unemployment rates, lack of home ownership, and insufficient federal funding for on-reserve housing and socioeconomic improvements. The successful, long-term reduction of mold growth requires increased activity in several research and policy areas. First, the actual impacts on health need to be studied and associated with comprehensive experimental data on mold growth to understand the unique environmental conditions that permit the germination and growth of toxic mold species. Second, field data documenting the extent of mold growth in on-reserve homes do not exist but are essential in understanding the full extent of the crisis. Third, current government initiatives to educate homeowners in mold remediation and prevention techniques must be long lasting and effective. Finally, and most importantly, the federal government must make a renewed and lasting commitment to improve the socioeconomic conditions on reserves that perpetuate mold growth in homes. Without such improvement, the mold crisis will surely persist and likely worsen.

Mycotoxins and human health.

Mycotoxins have been investigated in relation to a wide range of adverse human health effects, but the evidence for all but a small number of associations is limited. Thus, the full impact on human health of the widespread exposure to mycotoxins remains to be defined. The main exception is for aflatoxins; epidemiological, experimental, and mechanistic studies have contributed to establishing aflatoxins as a cause of human liver cancer, with a particularly elevated risk in people chronically infected with hepatitis B virus. In addition, acute aflatoxicosis after exposure to high dietary toxin levels has been demonstrated. The impairment of child growth by aflatoxin exposure early in life remains an important subject of study. More information is also required on the potential immune effects of aflatoxins, especially in vulnerable populations. For fumonisins, studies indicate a possible role in oesophageal cancer and in neural tube defects, although no definitive conclusions can be drawn at present. For deoxynivalenol and other trichothecenes, exposure has been linked to acute poisoning outbreaks in large numbers of subjects. For ochratoxin A and zearalenone, the human health effects remain undefined. The limited tools available to accurately assess human exposure to mycotoxins and the relative paucity of epidemiological studies need to be addressed if the full extent of the adverse effects of these common dietary contaminants is to be understood and adequate public health measures taken. In this respect, newly established biomarkers of exposure at the individual level are proving valuable in improving exposure assessment in epidemiological studies.

The impact of mycotoxicoses on human history.

Mycotoxicoses are acute or chronic diseases of humans and animals caused by mycotoxins, toxic compounds produced by moulds. Of about 400 known mycotoxins only a small number are known to cause mycotoxicoses in humans. Organs that are most targeted are those in which mycotoxins are metabolised, that is, the liver and kidneys, but the lesions may affect the neurological, respiratory, digestive, haematological, endocrine, and immune systems as well. The epidemics of mycotoxicoses are often connected with times of famine, when population consumes food that would not be consumed in normal circumstances. Mycotoxicoses have influenced human history, causing demographic changes, migrations, or even influencing the outcomes of wars. Fortunately, epidemics affecting so many persons and with so many fatalities belong to the past. Today they only appear in small communities such as schools and factory canteens. This paper presents epidemics and pandemics of mycotoxicoses that influenced human history.