Browsing by Author "Mirembe, Florence M"

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    Epidemiology of HPV genotypes in Uganda and the role of the current preventive vaccines: A systematic review
    (Infectious Agents and Cancer, 2011-06-11) Banura, Cecily; Mirembe, Florence M; Kataoire, Anne R; Namujju, Proscovia B; Namujju, AnthonProscovia B; Mbonye, Anthony K; Wabwire, Fred M
    Abstract Background: Limited data are available on the distribution of human papillomavirus (HPV) genotypes in the general population and in invasive cervical cancer (ICC) in Uganda. Yet, with the advent of preventive HPV vaccines that target HPV 16 and 18 responsible for causing about 70% of ICC cases in the world, such information is crucial to predict how vaccination and HPV-based screening will influence prevention of ICC. Methods: To review the distribution of HPV infection and prevalent genotypes, electronic databases (e.g. PubMed/ MEDLINE and HINARI) were searched for peer reviewed English articles on HPV infection up to November 30, 2010. Eligible studies were selected according to the following criteria: DNA-confirmed cervical or male genital HPV prevalence and genotypes, HPV incidence estimates and HPV seroprevalence among participants. Results: Twenty studies were included in the review. Among HIV negative adult women, the prevalence of HR-HPV infections ranged from 10.2% -40.0% compared to 37.0% -100.0% among HIV positive women. Among HIV positive young women aged below 25 years, the prevalence of HR-HPV genotypes ranged from 41.6% -75.0% compared to 23.7% -67.1% among HIV negative women. Multiple infections with non vaccine HR-HPV genotypes were frequent in both HIV positive and HIV negative women. The main risk factors for prevalent HPV infections were age, lifetime number of sexual partners and HIV infection. Incident infections with HR-HPV genotypes were more frequent among adult HIV positive than HIV negative women estimated at 17.3 and 7.0 per 100 person-years, respectively. Similarly, incident HR-HPV among young women aged below 25 years were more frequent among HIV positive (40.0 per 100 person-years) than HIV negative women (20.3 per 100 person-years) women. The main risk factor for incident infection was HIV infection. HPV 16 and 18 were the most common genotypes in ICC with HPV 16/18 contributing up to 73.5% of cases with single infections. Among uncircumcised adult HIV positive males, HR-HPV prevalence ranged from 55.3% -76.6% compared to 38.6% -47.6% in HIV negative males. Incident and multiple HR-HPV infections were frequent in HIV positive males. Being uncircumcised was the main risk factor for both prevalent and incident HPV infection. Conclusion: Infections with HR-HPV genotypes were very common particularly among HIV positive individuals and young women irrespective of HIV status. Given the high prevalence of HIV infection, HPV-associated conditions represent a major public health burden in Uganda. However, although the most common HPV genotypes in ICC cases in Uganda were those targeted by current preventive vaccines, there were a large number of individuals infected with other HR-HPV genotypes. Technology allowing, these other HR-HPV types should be considered in the development of the next generation of vaccines
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    The levels of anti-HPV16/18 and anti-HPV31/33/ 35/45/52/58 antibodies among AS04-adjuvanted HPV16/18 vaccinated and non-vaccinated Ugandan girls aged 10–16 years
    (Infectious Agents and Cancer, 2014-09-01) Nakalembe, Miriam; Banura, Cecily; Namujju, Proscovia B; Mirembe, Florence M
    Abstract Background: Data on Human Papilloma virus (HPV) vaccine immune response in sub-Saharan Africa is still sparse yet such knowledge is critical for optimal implementation and monitoring of HPV vaccines. Our primary objective was to evaluate levels of anti-HPV-16/18 antibodies and six other ‘high risk’ HPV (hrHPV) types among the vaccinated and unvaccinated Ugandan girls. Methods: We conducted a cross sectional study among AS04-adjuvanted HPV-16/18 vaccinated and unvaccinated school girls aged 10–16 years in Western Uganda using purposive sampling. The vaccinated girls were at 18 months post vaccination. After consenting and assenting, data was collected using interviewer administered questionnaires for demographics and sexual history. Blood was drawn from which serum samples were analysed by the multiplex HPV serology technology to determine anti-HPV antibody levels to HPV-16/18 and six other hrHPV types (31, 33, 35, 45, 52 and 58). The antibody levels were expressed as Median Fluorescent Intensity (MFI). A total of 207 vaccinated [mean age 13.1 years (SD 1.5); range 10-16 years] and 197 unvaccinated girls [mean age 13.6 years (SD 1.3); range 10-16 years] participated in the study. Sexual activity was self reported among 14/207 (6.8%) vaccinated and 5/197 (2.5%) unvaccinated girls. The MFI levels for HPV-16 and HPV-18 were 15 and 20 times higher respectively in the vaccinated girls than in the unvaccinated girls. HPV-16 mean MFI level was 4691 (SD 1812; 95% CI: 4438-4958) among the vaccinated compared to 218 (SD 685; 95% CI: 190-252) among the unvaccinated girls. For HPV-18 the mean MFI level was 1615 (SD 1326; 95% CI: 1470-1776) among the vaccinated compared to MFI 103 (SD 506; 95% CI: 88 -121) among unvaccinated girls. In addition antibody levels to non vaccine hrHPV types (31, 33, 35, 45, 52 and 58) were all significantly higher in the vaccinated group than in the unvaccinated group (p<0.01). Conclusion: The AS04-Adjuvanted HPV-16/18 vaccinated girls showed a higher level of antibodies to HPV-16/18 and other non-vaccine hrHPV types compared to the unvaccinated girls. This may translate into protection against HPV-16/18 and other hrHPV types. Keywords: Human Papilloma Virus, Bivalent HPV vaccine, Immune response, Uganda, Adolescents
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    Prevalence, incidence and risk factors for anogenital warts in Sub Saharan Africa: a systematic review and meta analysis
    (Infectious Agents and Cancer, 2013-08-27) Banura, Cecily; Mirembe, Florence M; Orem, Jackson; Mbonye, Anthony K; Kasasa, Simon; Mbidde, Edward K
    Abstract Introduction: The quadrivalent HPV vaccine is highly effective in primary prevention of anogenital warts (AGWs). However, there is lack of systematic review in the literature of the epidemiology of AGWs in Sub Saharan Africa (SSA). Objective: To review the prevalence, incidence and risk factors for AGWs in SSA prior to the introduction of HPV vaccination programs. Methods: PubMed/MEDLINE, Africa Index Medicus and HINARI websites were searched for peer reviewed English language published medical literature on AGWs from January 1, 1984 to June 30, 2012. Relevant additional references cited in published papers were also evaluated for inclusion. For inclusion, the article had to meet the following criteria (1) original studies with estimated prevalence and/or incidence rates among men and/or women (2) detailed description of the study population (3) clinical or self-reported diagnosis of AGWs (4) HPV genotyping of histologically confirmed AGWs. The final analysis included 40 studies. Data across different studies were synthesized using descriptive statistics for various subgroups of females and males by geographical area. A meta - analysis of relative risk was conducted for studies that had data reported by HIV status. Results: The prevalence rates of clinical AGWs among sex workers and women with sexually transmitted diseases (STDs) or at high risk of sexually transmitted infection (STIs) range from 3.3% - 10.7% in East, 2.4% - 14.0% in Central and South, and 3.5% - 10.5% in West African regions. Among pregnant women, the prevalence rates range from 0.4% - 3.0% in East, 0.2% - 7.3% in Central and South and 2.9% in West African regions. Among men, the prevalence rates range from 3.5% - 4.5% in East, 4.8% - 6.0% in Central and South and 4.1% to 7.0% in West African regions. In all regions, the prevalence rates were significantly higher among HIV+ than HIV- women with an overall summary relative risk of 1.62 (95% CI: 143–1.82). The incidence rates range from 1.1 – 2.7 per 100 person-years among women and 1.4 per 100 person years among men. Incidence rate was higher among HIV+ (3.0 per 100 person years) and uncircumcised men (1.7 per 100 person-years) than circumcised men (1.3 per 100 person-years). HIV positivity was a risk factor for AGWs among both men and women. Other risk factors in women include presence of abnormal cervical cytology, co-infection with HPV 52, concurrent bacteria vaginoses and genital ulceration. Among men, other risk factors include cigarette smoking and lack of circumcision. Conclusions: AGWs are common among selected populations particularly HIV infected men and women. However, there is need for population-based studies that will guide policies on effective prevention, treatment and control of AGWs. Keywords: Anogenital warts, Sub Saharan Africa, HIV, HPV vaccination
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    Universal routine HPV vaccination for young girls in Uganda:
    (2012-07) Banura, Cecily; Mirembe, Florence M; Kataoire, Anne R; Namujju, Proscovia B; Mbidde, Edward K
    Abstract This article reviews the existing realities in Uganda to identify opportunities and potential obstacles of providing universal routine HPV vaccination to young adolescent girls. Cervical cancer is a public health priority in Uganda where it contributes to about 50–60% of all female malignancies. It is associated with a dismal 5-year relative survival of approximately 20%. With adequate financial resources, primary prevention through vaccination is feasible using existing education and health infrastructure. Cost-effectiveness studies show that at a cost of US$2 per dose, the current vaccines would be cost effective. With optimal (≥70%) coverage of the target population, the lifetime risk of cervical cancer could be reduced by >50%. Uganda fulfils 4 out of the 5 criteria set by the WHO for the introduction of routine HPV vaccination to young adolescent girls. The existing political commitment, community support for immunization and the favorable laws and policy environment all provide an opportunity that should not be missed to introduce this much needed vaccine to the young adolescent girls. However, sustainable financing by the government without external assistances remains a major obstacle. Also, the existing health delivery systems would require strengthening to cope with the delivery of HPV vaccine to a population that is normally not targeted for routine vaccination. Given the high incidence of cervical cancer and in the absence of a national screening program, universal HPV vaccination of Ugandan adolescent girls is critical for cervical cancer