No abstract

Mycotoxin-producing fungi contaminate food and feeds before, during and after harvest. Aflatoxins are important mycotoxins and aflatoxin B1 (AFB1) is a class 1 human carcinogen (definitely carcinogenic). Aflatoxin M1 (AFM1) is a class 2B (possible) human carcinogen. Aflatoxin B1 in feeds can decrease milk production, reduce fertility and increase susceptibility to infections. A cross-sectional study of aflatoxin contamination of milk and dairy feeds was carried out in five counties in Kenya representing different agro-ecological zones: Kwale, Isiolo, Tharaka-Nithi, Kisii and Bungoma. Dairy feed concentrates and cattle milk were collected twice (dry season and rainy season) from 285 dairy farmers in the five counties and analysed for AFB1 and AFM1, using competitive enzyme-linked immunosorbent assay (ELISA). In the five counties, the proportion of farmers who fed cattle with dairy concentrates varied from zero to 68%. The dairy feed concentrates from farmers had AFB1 levels ranging from less than one part per billion (ppb) to 9661 ppb and the positive samples ranged from 47.8 to 90.3%. The percentages of dairy feeds from farmers with AFB1 above the World Health Organization/Food and Agriculture Organization of the United Nations (WHO/FAO) limit of 5 ppb varied from 33.3% to 87.5 % while 83.3% to 100% of the feeds from retailers and 28.6% to 100% of the feeds from manufacturers exceeded the WHO/FAO limit. Aflatoxin M1 prevalence in milk was lowest in Kwale (13.6%) and highest in Tharaka-Nithi (65.1%). The proportion of milk samples with AFM1 above the WHO/FAO standard of 50 parts per trillion (ppt) varied from 3.4% (Kwale) to 26.2% (Tharaka-Nithi); the highest was 6999ppt. This study shows that aflatoxin contamination is common in dairy feeds and in milk and concentrations may be high. This may contribute to ill health effects in both humans and animals and, therefore, there is need for better understanding of the impacts of aflatoxins in the feed-dairy value chain and appropriate interventions to control aflatoxin contamination in animal feeds.

In the tropics, staples such as maize are often contaminated with mycotoxins, harmful by-products of fungal metabolism. In particular, high exposure to aflatoxins may cause fatal illness in people and animals, while chronic exposure can cause liver cancer in humans and, in domestic animals, growth depression and immune suppression. However, little is known about the potential health risks of milk contaminated with aflatoxins. Moreover, because of different consumption patterns and biology, men, women, boys and girls may experience different levels of risk, while because of gender roles, men and women may have different capacity to mitigate risk; yet, there are few gendered analyses of aflatoxins. This study conducts a qualitative, gendered study on awareness and perceptions of mycotoxins and how these influence risk of dietary exposure to mycotoxins among dairy farmers in Kenya. First, a risk map was developed based on previous occurrence of aflatoxicosis and relevant factors such as farming systems and dairy cattle density. This resulted in three risk categories: high risk with historical outbreaks of human aflatoxicosis, high risk without historical outbreaks and low risk with historical outbreaks. From each category, three districts were randomly selected and from each district, three villages. A focus group discussion (FGD) tool was developed and used for interviews to assess factors related to the potential risk of exposure to mycotoxins in identified risk regions and how perception of risk and risk management differed by gender. In each village, two sex-disaggregated FGDs were conducted, yielding a total of 54 FGDs. This study found that overall risk categories, awareness of mycotoxicosis and carcinogenic effects was generally low, but awareness that eating mouldy food is harmful was high. Women were more cautious than men about feeding spoilt maize to cattle. Preventive measures against fungal contamination were more common post-harvest than pre-harvest. With respect to dairy cow diets and disposal of mouldy foods, women were key decision-makers. Although commercial feeds are expensive and may be contaminated with mycotoxins, farmers regularly fed them to their cattle in low quantities to potentiate milk production. Milk was mainly sold for income generation. The farmer families consumed milk mainly in tea, which was not given to children below school-going age, thus reducing exposure to mycotoxins but also the nutritional benefits of milk. Meat was considered safe even if the cattle had been fed mouldy feeds. This study shows that there is a low understanding of the dangers of mycotoxins in food, and that certain practices among farmers may increase the risk for exposure. Gender analysis reveals that groups having knowledge are not always responsible for risk mitigation.

This investigation was initiated as a consequence of several cases of diarrhea in a nursery ward for preterm babies in Nairobi, Kenya. Ten lactose-positive colonies were isolated from the stools of each of 30 neonates, regardless of whether they had diarrhea; 229 strains were identified as Escherichia coli and 65 strains were identified as Klebsiella pneumoniae. Six strains were lost during laboratory handling. No other bacterial, viral, or parasitic enteropathogens were identified. Using synthetic alkaline phosphatase-labeled probes, the bacterial isolates were found to be negative for the presence of genes coding for heat-stable and heat-labile enterotoxins. Seventy-eight E. coli strains isolated from a total of 13 neonates possessed the E. coli enteropathogenic adhesion factor (EAF) gene, as demonstrated by the use of a cloned radiolabeled DNA fragment probe. These strains possessed similar plasmid profiles constituting a core plasmid profile, and while all adhered to HeLa cells, none produced Vero cell cytotoxins. The EAF gene was located on a 65-megadalton plasmid. Serotyping showed the strains to be of serogroup 0111 and serotype H nontypable, a well known enteropathogenic type. Five neonates died during the outbreak, and the fatality rate was 30.7% (4 of 13) for neonates infected with EAF-positive E. coli strains compared with 7.7% (1 of 13) for neonates from whom only EAF-negative E. coli strains were isolated. K. pneumoniae only was isolated from five neonates.

M. & Olsvik, 0. Antimicrobial resistance of enteropathogenic Escherichia coli strains from a nosocomial outbreak in Kenya. APMIS 99: 728-734, 1991.The majority of the 78 enteropathogenic (EPEC) and the 151 non-EPEC Escherichia coli strains isolated from preterm neonates during an outbreak of gastroenteritis in a hospital in Nairobi, Kenya, were resistant to trimethoprim-sulfamethoxaxole, chloramphenicol, oxytetracycline and ampicillin, but only a few strains were resistant to cefazolin, cefamandole, cefotaxime, amikacin and nalidixic acid. Fourteen different antimicrobial resistance patterns were observed in the 229 strains of E. coli analysed. Eighty-two percent of the EPEC strains belonged to two resistance patterns compared with 79% of non-EPEC strains which exhibited three resistance patterns. There was no consistent relationship between plasmid profile group and antimicrobial resistance pattern, although one resistance pattern was more frequently observed in EAF-positive strains belonging to the dominant plasmid profile group. Nine percent of the EPEC strains were resistant to gentamicin compared to 37% in the non-EPEC group. No correlation was observed between administration of gentamicin and percentage of resistant strains isolated. None of the nine neonates receiving gentamicin died during the outbreak. Gentamicin resistance was observed in E. coli strains from six out of these nine neonates. Five out of fourteen neonates who received other antimicrobials, or no antibiotic treatment at all, died.Enteropathogenic Escherichia coli (EPEC) was the first E. coli t o be identified as a major cause of diarrheal disease (1 2). Recent reports indicate EPEC to be the first o r second most important bacterial cause of infantile diarrhea in some developing countries (1,5), and a cause of sporadic outbreaks of diarrhea in the developed countries (12,19,22). Although serogrouping and serotyping have remained the standard reference ~ ~