Browsing by Author "Biryahwaho, Benon"
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Item Hepatitis B infection is highly endemic in Uganda: findings from a national serosurvey(African health sciences, 2009) Bwogi, Josephine; Braka, Fiona; Makumbi, Issa; Mishra, Vinod; Bakamutumaho, Barnabas; Nanyunja, Miriam; Opio, Alex; Downing, Robert; Biryahwaho, Benon; Lewis, Rosamund F.Infant immunization against hepatitis B began in Uganda in 2002. Objective: To determine the baseline prevalence of hepatitis B virus (HBV) infection and explore risk factors. Methods: A hepatitis B prevalence study was nested in the 2005 national HIV/AIDS serobehavioural survey. Demographic characteristics and risk factors were explored by questionnaire. One third of blood specimens (n=5875) from adults aged 15 to 59 years were tested for hepatitis B core antibodies (HBcAb); positive specimens were tested for hepatitis B surface antigen (HBsAg). Results: HBcAb was present in 52.3% (95% CI: 51.0-53.6) of adults, and HBsAg in 10.3% (9.5-11.1). By 15-19 years of age, 40.0% had been infected with HBV. Prevalence of both markers was significantly higher across northern Uganda, in rural areas, among the poor and least educated, and in uncircumcised men. Other independent predictors of infection were age, ethnic group, occupation, number of sex partners, and HIV and HSV-2 status. Conclusion: Hepatitis B virus infection is highly endemic in Uganda, with transmission occurring in childhood and adulthood. More than 1.4 million adults are chronically infected and some communities disproportionately affected. The hepatitis B infant immunization programme should be sustained and catch-up vaccination considered for older children.Item HIV Risk Perception and Prevalence in a Program for Prevention of Mother-to-Child HIV Transmission Comparison of Women Who Accept Voluntary Counseling and Testing and Those Tested Anonymously(JAIDS Journal of Acquired Immune Deficiency Syndromes, 2005) Mpairwe, Harriet; Muhangi, Lawrence; Namujju, Proscovia B.; Kisitu, Andrew; Tumusiime, Alex; Muwanga, Moses; Whitworth, James A. G.; Onyango, Saul; Biryahwaho, Benon; Elliott, Alison M.To determine whether data from voluntary counseling and testing (VCT)/prevention of mother-to-child transmission (PMTCT) programs can be used for HIV surveillance. Women attending an antenatal clinic at the district hospital in Entebbe, Uganda, from May 2002 to April 2003 were offered counseling and HIV testing with same-day results (VCT) and nevirapine for PMTCT was provided for HIV-positive women and their babies. Those who declined VCT were tested for HIV anonymous Overall, 2635 women accepted VCT; 883 were tested anonymously. HIV prevalence was higher in VCT than in anonymously tested women in the first month of the program (20% vs. 11%, P = 0.05) and in months with <70% VCT uptake (17% vs. 8%, P < 0.001) but was similar in months with high uptake. Uptake of VCT was higher in women who had risk factors for HIV, especially those who believed themselves to have been exposed (84% vs. 73%, P < 0.001). There was a bias to accepting VCT in women with HIV, or risk factors for HIV infection, the former most apparent when there was low coverage. Data from VCT/PMTCT programs cannot replace anonymous surveillance for monitoring of HIV epidemic trends where coverage is incomplete within clinics or communities.Item Human Herpesvirus Type 8 Variants Circulating In Europe, Africa And North America In Classic, Endemic And Epidemic Kaposi's Sarcoma Lesions During Pre-AIDS and AIDS Era(Virology, 2010) Tornesello, Maria Lina; Biryahwaho, Benon; Downing, Robert; Hatzakis, Angelo; Alessi, Elvio; Cusini, Marco; Ruocco, Vincenzo; Mbidde, Edward Katongole; Loquercio, Giovanna; Buonaguro, Luigi; Buonaguro, Franco M.Human herpesvirus-8 (HHV-8) variants have been found heterogeneously distributed among human populations living in diverse geographic regions, but their differential pathogenicity in Kaposi's sarcoma development remains controversial. In the present study, HHV-8 variant distribution has been analyzed in classic, iatrogenic, endemic as well as epidemic Kaposi's sarcoma (KS) during pre-AIDS and AIDS period (1971–2008) in countries with different KS incidence rate. DNA samples from cutaneous KS lesions of 68 patients living in Africa (n = 23, Cameroon, Kenya and Uganda), Europe (n = 34, Greece and Italy) and North America (n = 11) have been subjected to PCR amplification of HHV-8 ORF 26, T0.7, K1 and K14.1/15, followed by direct nucleotide sequencing and phylogenetic analysis. Among the 23 African samples, the majority of HHV-8 ORF 26 variants clustered with the subtype R (n = 12) and B (n = 5). Conversely, the viral sequences obtained from 45 European and North European tumors belonged mainly to subtype A/C (n = 36). In general, HHV-8 and K1 variant clustering paralleled that of ORF 26 and T0.7. Genotyping of the K14.1/15 loci revealed a large predominance of P subtype in all tumors. In conclusion, comparison of the HHV-8 sequences from classic or endemic versus AIDS-associated KS showed a strong linkage of the HHV-8 variants with specific populations, which has not changed during AIDS epidemic.Item Human Herpesvirus Type 8 Variants In Kaposi’s Sarcoma Before And After AIDS Era(BioMed Central, 2010) Tornesello, Maria Lina; Biryahwaho, Benon; Downing, Robert; Hatzakis, Angelo; Alessi, Elvio; Cusini, Marco; Ruocco, Vincenzo; Loquercio, Giovanna; Mbidde, Edward Katongole; Buonaguro, Luigi; Buonaguro, Franco M.Human herpesvirus 8 (HHV- 8) variants have been found heterogeneously distributed among human populations living in diverse geographic regions, but their differential pathogenicity in Kaposi's sarcoma (KS) development remains controversial. The aim of the present study was to analyze variations of HHV-8 genomes in tumor biopsies collected before and in the course of HIV epidemic (1971 - 2008), from patients with classic, iatrogenic, endemic as well as epidemic KS living in Africa, Europe, and North America.Item Molecular Epidemiology of HIV Type 1 in a Rural Community in Southwest Uganda(AIDS Research and Human Retroviruses, 2000) Kaleebu, Pontiano; Whitworth, James; Hamilton, Laura; Rutebemberwa, Alleluiah; Lyagoba, Fred; Morgan, Dilys; Duffield, Melanie; Biryahwaho, Benon; Magambo, Brian; Oram, JonThe molecular epidemiology of a population-based cohort in a cluster of 15 villages in southwestern Uganda was investigated by sequencing part of the p24 gag gene and performing heteroduplex mobility assays (HMAs) of the V3 region of the env gene. Sequence and HM A data, obtained for 69 and 88 proviruses, respectively, showed that the clade A and D viruses were present at a ratio of about 0.67:1. No other clades were detected. Thirteen (22%) of 59 proviruses for which both gag and env data were obtained appeared to be recombinants. Although both clade A and D viruses were present in 13 of the villages, their distribution was unequal: for example, from env data 59% of clade A viruses were found in the eastern villages, compared with only 27% of clade D viruses. Phylogenetic (maximum likelihood) analysis of the p24 gag sequences showed a total of five clusters supported by bootstrap resampling values above or close to 75%. Four clusters were sexual partners, but there was no known sexual contact between the persons in the other cluster. The DNA sequences showed between 0.5 and 8.3% divergence from the cohort clade A or D consensus sequences. The sequences were not closely related to those published for other clade A or D proviruses.Item Relationship between HIV-1 Env subtypes A and D and disease progression in a rural Ugandan cohort(AIDS, 2001) Kaleebu, Pontiano; Ross, Amanda; Morgan, Dilys; Yirrell, Davida; Oram, Jonb; Rutebemberwa, Alleluiah; Lyagoba, Fred; Hamilton, Laura; Biryahwaho, Benon; Whitworth, JamesTo investigate the role of HIV-1 envelope subtypes on disease progression in a rural cohort of Ugandan adults where two major HIV-1 subtypes (A and D) exist. Participants of a clinical cohort seen between December 1995 and December 1998 had blood collected for HIV-1 subtyping. These included prevalent cases (people already infected with HIV at the start of the study in 1990) and incident cases (those who seroconverted between 1990 and December 1998). HIV-1 subtyping was carried out by heteroduplex mobility assay and DNA sequencing in the V3 env region. Disease progression was measured by the rate of CD4 lymphocyte count decline, clinical progression for the incident cases as time from seroconversion to AIDS or death, to ®rst CD4 lymphocyte count , 200 3 106/l and to the World Health Organization clinical stage 3. All analyses were adjusted for age and sex. One hundred and sixty-four individuals, including 47 prevalent and 117 incident cases, had V3 env subtype data of which 65 (40%) were subtyped as A and 99 as D. In the incident cases, 44 (38%) were subtyped as A and 73 as D. There was a suggestion that for most end-points A had a slower progression than D. The cumulative probability of remaining free from AIDS or death at 6 years post-seroconversion was 0.72 [95% con®dence interval (CI), 0.50 to 0.85] for A and 0.58 (95% CI, 0.42 to 0.71) for D, and the adjusted hazard ratio of subtype D compared to A was estimated to be 1.39 (95% CI, 0.66 to 2.94; P 0.39). The estimated difference in rates of decline in square root CD4 lymphocyte counts was ÿ0.41 per year (95% CI, ÿ0.98 to 0.15; P 0.15). This study suggests that although subtype A may have a slower progression than D, HIV-1 envelope subtype is not a major factor in determining the progression of HIV-1 disease in a rural population in Uganda.