Browsing by Author "Muwanika, Richard"

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    Longitudinal evaluation of aflatoxin exposure in two cohorts in south-western Uganda
    (Food Additives & Contaminants: Part A, 2015) Kang, Min-Su; Nkurunziza, Peter; Muwanika, Richard; Qian, Guoqing; Tang, Lili; Songa, Xiao; Xue, Kathy; Nkwata, Allan; Ssempebwa, John; Lutalo, Tom; Asiki, Gershim; Serwadda, David; Seeley, Janet; Kaleebu, Pontiano; Nalugoda, Fred; Newton, Robert; William, Jonathan H.; Wang, Jia-Sheng
    Aflatoxins (AF) are a group of mycotoxins. AF exposure causes acute and chronic adverse health effects such as aflatoxicosis and hepatocellular carcinoma in human populations, especially in the developing world. In this study, AF exposure was evaluated using archived serum samples from human immunodeficiency virus (HIV)-seronegative participants from two cohort studies in south-western Uganda. AFB1–lysine (AFB-Lys) adduct levels were determined via HPLC fluorescence in a total of 713 serum samples from the General Population Cohort (GPC), covering eight time periods between 1989 and 2010. Overall, 90% (642/713) of the samples were positive for AFB-Lys and the median level was 1.58 pg mg−1 albumin (range = 0.40–168 pg mg−1 albumin). AFB-Lys adduct levels were also measured in a total of 374 serum samples from the Rakai Community Cohort Study (RCCS), across four time periods between 1999 and 2003. The averaged detection rate was 92.5% (346/374) and the median level was 1.18 pg mg−1 albumin (range = 0.40–122.5 pg mg−1 albumin). In the GPC study there were no statistically significant differences between demographic parameters, such as age, sex and level of education, and levels of serum AFB-Lys adduct. In the RCCS study, longitudinal analysis using generalised estimating equations revealed significant differences between the adduct levels and residential areas (p = 0.05) and occupations (p = 0.02). This study indicates that AF exposure in people in two populations in south-western Uganda is persistent and has not significantly changed over time. Data from one study, but not the other, indicated that agriculture workers and rural area residents had more AF exposure than those non-agricultural workers and non-rural area residents. These results suggest the need for further study of AF-induced human adverse health effects, especially the predominant diseases in the region.
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    Prevalence Of Protective Tetanus Antibodies And Immunological Response Following Tetanus Toxoid Vaccination Among Men Seeking Medical Circumcision Services In Uganda
    (PloS one, 2018) Makumbi, Fredrick; Byabagambi, John; Muwanika, Richard; Kigozi, Godfrey; Gray, Ronald; Galukande, Moses; Bagaya, Bernard; Ssebagala, Darix; Karamagi, Esther; Rahimzai, Mirwais; Kaggwa, Mugagga; Watya, Stephen; Mbonye, Anthony K.; Aceng, Jane Ruth; Musinguzi, Joshua; Kiggundu, Valerian; Njeuhmeli, Emmanuel; Nanteza, Barbara
    Tetanus infection associated with men who had male circumcision has been reported in East Africa, suggesting a need for tetanus toxoid-containing vaccines (TTCV).To determine the prevalence of tetanus toxoid antibodies following vaccination among men seeking circumcision. We enrolled 620 consenting men who completed a questionnaire and received TTCV at enrollment (day 0) prior to circumcision on day 28. Blood samples were obtained at day 0 from all enrollees and on days 14, 28 and 42 from a random sample of 237 participants. Tetanus toxoid (TT) IgG antibody levels were assayed using EUROIMMUN. Analyses included prevalence of TT antibodies at enrollment and used a mixed effects model to determine the immunological response.Mean age was 21.4 years, 65.2% had knowledge of tetanus, 56.6% knew how tetanus was contracted, 22.8% reported ever receipt of TTCV, and 16.8% had current/recently healed wounds. Insufficient tetanus immunity was 57.1% at enrollment, 7.2% at day 14, 3.8% at day 28, and 0% at day 42. Antibody concentration was 0.44IU/ml (CI 0.35–0.53) on day 0, 3.86IU/ml (CI 3.60–4.11) on day 14, 4.05IU/ml (CI 3.81–4.29) on day 28, and 4.48IU/ml (CI 4.28–4.68) on day 42. TT antibodies increased by 0.24IU/ml (CI 0.23, 0.26) between days 0 and 14 and by 0.023IU/ml (CI 0.015, 0.031) between days 14 and 42 days. Immunological response was poorer in HIV-infected clients and men aged 35+ years.Insufficient immunity was common prior to TTCV, and a protective immunological response was achieved by day 14. Circumcision may safely be provided 14 days after vaccination in HIV-uninfected men aged less than 35 years.