The Prevalence And Predictors Of Human Papilloma Virus Infection Of The Cervix At A University Teaching Hospital In Northern Nigeria.
E Ojiyi, C Okeudo, E Dike, F Anolue, U Onyeka, B Audu, H Ngadda
hpv, maiduguri., pap smear, predictors, prevalence
E Ojiyi, C Okeudo, E Dike, F Anolue, U Onyeka, B Audu, H Ngadda. The Prevalence And Predictors Of Human Papilloma Virus Infection Of The Cervix At A University Teaching Hospital In Northern Nigeria.. The Internet Journal of Gynecology and Obstetrics. 2012 Volume 16 Number 2.
As of 2000, cervical carcinoma was responsible for 466,000 deaths per annum worldwide and is the leading cause of deaths per annum in women aged 35-45 years.1 It was the most common malignancy among women in Nigeria and the rest of sub-Saharan Africa with a very poor survivalrate.1-4
In Benin, Nigeria, carcinoma of the cervix made up of 74.6% of all cases of malignant gynaecological tumours, with stage IIb and above constituting 67.6% of the cases.2 It accounted for 66.2% of all gynaecological malignancies in Zaria, Nigeria with advanced carcinoma of the cervix, stage IIb andabove, making up 88.7% of the cases.3 In Kenya, 55% of women with cancer of the cervix presented with stage III disease and beyond.4
In 1842, Rigoni-Stern formally hypothesized that cervical cancer had an infective sexually transmitted aetiology.5 Many studies since then confirmed the veneral nature of cervical cancer and identified other risk factors. The most exciting development has been the finding that infection with Human Papilloma Virus is casually associated with cervical cancer.6,7 The HPV has been shown to be a determinant of the natural history of cervical intraepithelial neoplasia (CIN). The progression rate to cervical cancer when HPV coexists with CIN is about 21% but only 5.6% when CIN lesions occur alone.8
Many studies have tried to show some kind of association between age, reproductive factors, marital factors, educational level, religion, occupation and sexual behaviors with the risk of developing HPV and cervical cancer.9 Such socio-demographic factors may be useful in risk scoring. This is important because risk scoring systems have the potential for assisting the targeting of screening resources, as broad risk targeting of all sexually active women is not a viable option for developing countries due to paucity of both human and financial resources. Even in industrialized nations of the West the need for more precise targeting of high risk groups in order to improve the efficiency of cytology programmes and conserve funds has become a major issue.10
Sub-clinical HPV infections of the cervix may be diagnosed by colposcopy, viral DNA hybridization, polymerase chain reaction (PCR) amplification, histology or by the characteristic HPV changes on Papanicolaou smear.9,11 The Papanicolaou smear for cervical cytology fulfills all the criteria for an ideal screening test. Not only is it cost effective, acceptable to most patients and adoptable to wide spread screenings, it is specific enough to detect changes and subsequent progression to CIN resulting in decreased morbidity and mortality from invasive cervical cancer.12 DNA hybridization and PCR amplification can detect both productive and non-productive infection, but appear to be of limited value in predicting the risk of developing CIN or invasive carcinoma.11
Although cervical cytology, histology and colposcopy are less sensitive, they are capable of detecting significant pathological changes associated with productive HPV infection.
Subjects And Methods
The subjects were 450 randomly selected sexually active women attending the antenatal, postnatal, gynaecology and family planning clinics in the Department of Obstetrics and Gynaecology of the University of Maiduguri Teaching Hospital, Nigeria between April 2001 and May 2002. They were recruited after consenting to participate and a formal approval had been given by the institution’s Ethics and Research Committee. The recruitment continued until a sample size of 450 was reached.
This was calculated using the WHO Epi Info Version 6 programme for population sampling.
It was based on a population of 4,342 patients/clients attending the recruiting clinics from April 2001 to May 2002. The purpose and value of the procedure were explained to each prospective patient and her consent sought. All consenting patients had their pap smears taken using a moistened and unlubricated Cusco’s bivalve speculum and an Ayre’s wooden spatula after a questionnaire containing age, marital and reproductive factors, educational level, religion, occupation and sexual attitudes had been filled. The smears were transported to the histopathology laboratory immersed in 95% ethanol for Preparation, staining and reading. The smears were examined microscopically by a pathologist at the Magnifications of 4, 10 and 100.
The WHO Epi Info statistical programme was used to compute and analyze the results. These included frequency distribution and tests of significance using Chi-square). P value of <0.05 was taken as being significant.
Four hundred and fifty sexually active women attending various clinics at the Department of Obstetrics and Gynaecology, University of Maiduguri Teaching Hospital had their Pap smears taken and questionnaires on sexual attitudes, reproductive and marital factors, occupation, religion, educational status and symptomatolgy filled.
Table I shows the cytology results of the Papanicolaou smears. Abnormal smears occurred in 245 (54.5%) of the patients screened. Forty-eight women (10.7%) had HPV associated with changes, constituting 19.7% of all abnormal smears.
Table II depicts the demographic and social characteristics of the women screened. The ages of the patients ranged between 15 and 64 years, with a mean of 26.3years. Majority of the patients (65.8%)were aged between 20-29 years. They were mostly married (65.8%) and parous (69.6%), but 24.9% had no formal education. There were 246 (54.7%) Moslems while 32.7% either had no occupation or were simply housewives.
Most (69.3%) of the patients did not practice any form of contraception; the 30.7% who did virtually used hormones (combined pills, progesterone only pills, implants, injectables) or intra-uterine contraceptive device only.
When the various factors studied were individually matched with human papilloma virus associated changes, variable patterns of association were observed. Table III shows that there was no significant association between the patients’ age and human papilloma virus infection (P>0.05).
Table IV shows the association between various sexual attitudes and human papilloma virus infection. There was a statistically significant association between multiple sexual partners, coital frequency per week and the occurrence of genital HPV infection. On table V, statistically significant association is shown to exist between multiparity, contraceptive use, duration of contraceptive use and genital HPV infection (P<0.01).
Table VI shows that there was a statistically significant association between marital status, occupation and genital HPV infection (P<0.01).
HPV infection was significantly associated with abnormal vaginal discharge and irregular menstruation (P<0.01), as well as postmenopausal and postcoital bleeding (P<0.05) as shown in table VII. There was no significant association with vaginal itching (P>0.05).
The prevalence rate of Human Papilloma Virus infection of the cervix of 10.7% (107 per 1000) in this study is fairly high. It is higher than the 4.01%,13 1.8%14 and 1.2%11 reported in Ibadan, Maiduguri and Enugu respectively, but lower than the 48% 15 and 32%16 reported in Brazil and Tanzania respectively. The differences in all these prevalence rates may be because of differences in the socio-cultural factors of the studied populations and the different diagnostic methods employed.
The absence of any significant difference in the prevalence of HPV between the age groups in this study may be accounted for by the fact that the study population was predominantly young, 79.1% being 29 years-old or younger.
Multiple sexual partners and coital frequency were the coital factors significantly associated with HPV infection in this study. The absence of any significant association between HPV and past sexually transmitted diseases might be accounted for by the fact that most women are very reluctant to disclose the details of previously sexually transmitted diseased or their treatment17.
There was significant association between contraception, duration of contraception use and cervical HPV infection.
Multiparous patients in this study stand a statistically significant risk of acquiring genital HPV infection compared to their non-parous counterparts. This is in agreement with the works of
There was a statistically significant association between marital status, occupation and cervical HPV infection. Among occupation groups, those with secured means of livelihood such as housewives (2.3%), business executives (3.7%) and civil servants (3.9%) were at least risk of HPV infection compared to students (37.5%), apprentices (33.3%) and petty traders (18.9%). Married women were 25 times less prone to develop HPV infection of the cervix compared to single sexually active women.
There is a high prevalence rate of Human Papilloma Virus infection among women attending the various clinics of the Department of Obstetrics and Gynaecology, University of Maiduguri Teaching Hospital. This is reflected among teenagers. There is an association with multiple sexual partners, coital frequency, multiparity, contraceptive use, marital status, abnormal vaginal discharge, postcoital bleeding and menopausal bleeding. These associations may allow for targeting of a high risk group in an organized systematic cervical screening programme, without discriminating other sexually active women.