Epidemiology of HPV genotypes in Uganda and the role of the current preventive vaccines: A systematic review
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Date
2011-06-11
Journal Title
Journal ISSN
Volume Title
Publisher
Infectious Agents and Cancer
Abstract
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
Description
Keywords
Epidemiology, HPV genotypes, Preventive vaccines