Human Papillomavirus Epidemiology in Nigeria
Human Papillomavirus Epidemiology in Nigeria
Background:

 -  Cervical cancer is caused by persistent infection of the lining of the cervix with some
 kinds of human papillomaviruses (HPV). These HPV infections are distantly related to the
 viruses that cause warts on the skin. Like common wart viruses, most women who have
 cervical infections with HPV resolve the infections within 2 years without any need for
 treatment. Cervical infections that do not go away may cause disease that can turn into
 cancer after many years.

 -  Only one study has been done in Nigeria to learn how many women have HPV infection. The
 results of the study differed from most other studies in the world because older women
 were much more likely to be infected. This study with learn whether the results found in
 the previous study are true in Irun also, the site of the current study.

 Objectives:

 -  To examine the age distribution of HPV infection and relationship to cancer of the
 cervix among Nigerian women.

 -  To understand how different screening methods, including HPV testing, could best reduce
 the risk of cervical cancer in Nigerian women.

 Eligibility:

 - Women residing in Irun, Nigeria, who are 15 years of age or older.

 Design:

 -  Participants complete a brief questionnaire related to demographics, household and
 living conditions and a longer survey with questions related to reproductive history,
 family history, illnesses, stressful life events and sexual history (U. of Michigan
 collaboration).

 -  Participants have a cervical examination, HPV test, Pap test and blood test.

 -  Women whose tests show they are infected with HPV or have cervical disease will do the
 following:

 -  see a doctor and have cervical biopsies of all white abnormal areas (removal of a small
 tissue sample from the cervix)

 -  have photographs of the cervix taken

 -  have a cervical scraping for a new kind of HPV test.

 -  Some women with normal test results are also asked to see a doctor to check the validity
 of the testing

 -  Women with cervical disease receive treatment by a specialist and remain in the program
 until treatment is successfully completed or a final diagnosis is reached.

 -  Participants may be contacted for followup up to 5 years after the final diagnosis is
 made.
BACKGROUND: Cervical cancer, caused by persistent infection with approximately 15-20
 genotypes of carcinogenic human papillomavirus (HPV) infection, is the second leading cause
 of female cancer. Cytology (Pap smears) and the new HPV vaccines are not widely available in
 poor regions. Immediate treatment of HPV-infected older women by cryotherapy might have
 greater impact.

 Although the same HPV types cause cervical cancer everywhere, and the same stages (infection,
 persistence vs. clearance, progression to precancer, and invasion) typify cervical
 carcinogenesis, the patterns of age-specific prevalence of HPV vary widely. These patterns
 are important for secondary prevention strategies relying on HPV DNA testing.

 In many regions, including the US, HPV infections appear as classical sexually-transmitted
 agents, with peak cervical DNA prevalence at young ages (approximately 20) and low prevalence
 at older ages. However, in Nigeria, HPV prevalence is high (greater than or equal to 15%) at
 all ages according to the one study performed in urban Ibadan by Franceschi s group at IARC
 (n=932 women). This pattern is very uncommon. High prevalence at all ages would preclude use
 of HPV testing in low-cost strategies, due to poor positive predictive value. One possibly
 relevant element is the marital structure in Nigeria; a man often has multiple wives.

 OBJECTIVES: The major objectives are: 1) To estimate age-specific HPV prevalences in Irun,
 Nigeria; 2) To investigate epidemiologic risk factors for HPV and cervical intraepithelial
 neoplasia in this population; 3) To examine the performance of screening options; 4) To
 assess the correlation of HPV among co-wives, comparing households with multiple wives with
 those with single wives; and 5) To validate the performance of rapid HPV, an inexpensive HPV
 test designed for public-sector use in settings like Irun.

 ELIGIBILITY: All non-pregnant women aged 15+, without hysterectomy, will be eligible if they
 can provide written informed consent. Unmarried women less than 21 will be enrolled only with
 parental consent. Sexually active women will be examined and asked for cervical specimens;
 self-reported virginal women will be asked for a 10-ml blood sample only.

 DESIGN: This is a cross-sectional screening study of 1500 women in Irun, a Nigerian village.
 Unlike the IARC study, we will incorporate cytology, visual inspection, and colposcopic
 biopsy of women that test positive by any of the three screening tests. We will determine
 whether HPV infection at various ages is related to risk of cervical abnormalities. The
 analyses will include descriptive trend data, multivariable modeling of HPV determinants, and
 clinical epidemiologic analysis of relative screening test performance in detecting cervical
 neoplasia.
-  INCLUSION CRITERIA:

 -  Females who are 15 years to 99 years of age

 EXCLUSION CRITERIA:

 -  Previous hysterectomy

 -  Current pregnancy

 -  Inability to give informed consent