Browsing by Author "Chengo, Nelson Menza"

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    Aflatoxins in peanuts and the prevalence of aflatoxin induced hepatocellular carcinoma in Busia and Kisii Central Districts, Kenya
    (Kenyatta University, 2015-12) Chengo, Nelson Menza
    Aflatoxin is a carcinogenic toxin produced mainly by Aspergillus jlavus and contaminates foods including peanuts. Aflatoxin is associated with liver failure, hepatocellular carcinoma (HCC) and death. Many people are exposed to chronic levels of aflatoxins through consumption of contaminated foods. In Kenya, most efforts have been focused on aflatoxin in maize while other highly predisposed foods such as peanuts have received little attention. Also limited studies have been done to link aflatoxin to HCC. This study identified aflatoxin producing Aspergillus species and the type and levels of aflatoxin contamination of various varieties of peanuts (Arachis hypogaea L.) in Busia and Kisii Central districts. It also determined the peanut producers' exposure to aflatoxins and the prevalence of aflatoxin induced HCC among patients from the study districts. Cross-sectional and retrospective study designs with systematic random sampling technique were adopted. One hundred and two (102) peanut and urine samples were collected from peanut growers in each district and transported to Cooppers Labs, Nairobi for analysis. Aspergillus species' were identified using plate technique of serially diluted samples on modified Rose Bengal agar. Types and levels of aflatoxins were analyzed using high performance liquid chromatography (HPLC) technique while aflatoxin B (AFB) gual in urine was determined using fluorescence Spectrophotometer. Analysis of records for patients from Busia and Kisii Central districts who attended Moi Teaching and Referral Hospital in January 2010 to December 2012 was done to determine the prevalence of HCC among the study population. The diagnosis of HCC was confirmed by the presence of AFB 1 guanine adducts in urine or AFB 1 albumin adduct in blood. The levels of total aflatoxin ranges were 0.1 to 2681lg/kg and 1.63 to 591.11lg/kg in peanuts from Busia and Kisii Central respectively. Majority of peanuts samples had levels within Kenya Bureau of Standards (KEBS) and European Union (EU) regulatory limits for total aflatoxins. Aflatoxin type Bl was the most dominant (t = 12.4, df= 3, P = 0.034). Overall, the occurrence of Aspergillus jlavus L strain and A. flavus S strain were significantly higher than other species identified (H = 15.55, df= 4, P = 0.004) in peanuts from the two districts. However, A. jlavus S-strain was the most dominant species (F=3.15, df=25, P=0.031) with an overall mean occurrence of 45.1%. Oil content in peanuts decreased with an increase in aflatoxin levels (r = -0.496, P = 0.031) except in peanuts of Uganda local red variety from Kisii Central. Overall, males in both districts had slightly higher incidences (9.8%) of exposure to urinary Aflatoxin B than females at 5.4%. The prevalence of aflatoxin induced HCC among the patients was 19.73%. There is need for urgent awareness through campaign among the peanuts producers on the aflatoxin levels and promote sound practices when handling peanuts. Continuous screening of patients with liver disorders should be done for early detection of HCC. The high levels of aflatoxins in peanuts suggest the necessity to screen other foods consumed in the study areas. The findings will form basis of policy development for aflatoxin contamination control and management of aflatoxin induced HCC in Kenya.
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    Isolation, identification and susceptibility profile of candida species to antifungal agents in pregnant women in Thika District Hospital, Kenya
    (2012-04-13) Chengo, Nelson Menza; Margaret W. Muturi; M.W.Wanyoike
    Vaginal candidiasis is relatively higher in pregnant women particularly inthe third trimester compared to nonpregnant women. Infection with Candida species causes choriomnionitis which is associated with pre-term delivery and death of the infant. Therefore, epidemiological monitoring of vaginal candidiasis infections is highly desirable for continuous determination of the existing causative species and the disease trends. Determination of susceptibility profile will be of importance in the appropriate selection of drugs for effective treatment of the infection in pregnant women. The objectives of the study were to determine the prevalence of vaginal candidiasis and identify the Candida species. The study also aimed at determining the susceptibility profile of the Candida species to antifungal drugs prescribed to the pregnant women with symptoms of the infection. A cross sectional study design and purposive sampling techniques were adopted in this study. Vaginal swabs were collected from the pregnant women attending the antenatal clinic of Thika District hospital between the months of June and August, 2010. The samples were gram stained and inoculated on Sabourands Dextrose Agar (SDA). Isolates from SDA were plated on CHROMagar for detection of mixed cultures. Germ tube, chlamydospore formation and sugar assimilation tests were performed for identification of isolates. Susceptibility profile was done using broth microdilution minimum inhibiting concentration method based on the approved NCCLS, 2002. The prevalence of vaginal candidiasis was 42.7%. The distribution of vaginal candidiasis had the highest incidence of 60% in women aged 26-35years followed by those aged 15-25years who were 26%. Twelve per cent (12%) of the women infected were aged 36-45 years. The women aged 46 and above years were the least infected (2%). This study showed that Candida albicans was the most common vaginal Candida species causing vaginal candidiasis in all the age groups. It was also found to be the most abundant species of all Candida species isolated. The women in their 3rd trimester had the highest infection occurrence of 68.09% followed by those in the 2nd trimester with 21.28% while those in their first trimester of pregnancy (10.63%) were least infected. Candida albieans was the most isolated species with 63.8%, followed by Candida glabrata 29.79%, Candida tropicalis 3.19%, Candida krusei 2.13% and Candida parapsilosis was the least with 1.06%. Most of the vaginal Candida species were isolated in 60% women who were 26-35 years, followed by 26% of those between 15-25 years. Only 2% of the women with 46years and above years were infected. The azole antifungal agents (fluconazole, ketoconazole, itraconazole and c1otrimazole) used showed high efficacy against all the vaginal Candida species isolated except Candida krusei. Candida krusei showed 100% resistance to fluconazole, c1otrimazole and a 50% resistance to ketoconazole. It was only susceptible (100%) to itraconazole. The other non-albieans Candida species were susceptible to the azole antifungal drugs. Candida albicans, Candida glabrata and Candida krusei showed moderate susceptibility (66.67%, 57.14% and 50%) respectively to topical nystatin. Candida parapsilosis was 100% susceptible to the drug. Nonetheless, the susceptibility of vaginal Candida species to the azole drugs and topical nystatin observed in this study supports the continued use of azole drugs but not topical nystatin for the treatment of vaginal candidiasis in the pregnant women attending the Thika District Hospital.