This study describes the potential HR/HR-HPV women attending reproductive health Clinics in Kisumu County (JOOTRH), an urban setting and Siaya County (Gobei Health Centre) a rural setting in Kenya. The two clinics support routine reproductive health services which include cervical cancer screening program. They are in western part of Kenya known to harbor a high burden of HIV. Of these women, potential HR/HR HPV prevalence of 36.3% is reported in this study. Past studies conducted in Kenya focus on overall HPV-DNA prevalence (High risk and low risk) without specific emphasis on potential HR and HR HPV only. A study conducted at a reproductive health clinic in Nairobi revealed a HPV prevalence of 31.3% (16). Similar studies conducted in the Nairobi region Tigoni reported a HPV prevalence of 32.7% (17). Another study done among female sex workers in Kenya reported a baseline HPV prevalence of 23.6%(18). Comparing the current and previous statistics, it is a clear indication that HPV and more specifically potential HR/HR HPV remains a common infection in LVB thus a potential indicator of possible rise in cervical cancer morbidity and mortality in the region. The prevalence of potential HR/HR-HPV genotypes among women attending reproductive health clinic in the rural setting (Gobei Health Center) and JOOTRH-Urban setting was 41.4% and 34.5% respectively. Past studies have reported varying trends of HPV prevalence in urban and rural areas (19, 20). In a study conducted in Burundi, Urban areas reported a high prevalence of HR HPV associated with having multiple sex partners (20). However, in this study, differences in prevalence could be attributed to the settings of the two facilities. JOOTRH- in the urban setting is a referral hospital that enjoys efficient services and resource coverage. By contrast, Gobei Health Center has limited resources and is in a rural setting. The two facilities attract varying numbers of women attending clinics hence the differences in sample sizes.
HPV 52, 67, 16, 31, 39, 45, 31 were the most prevalent potential HR/HR HPV types in this study. HPV 52 was highest at 14.8%. A systematic review and meta-analysis on genotype distribution of potential HR/HR HPV among women in Sub-Saharan Africa reveal HPV 16 and 52 as the main genotypes causing high-risk infection in Eastern and Southern Africa which includes Kenya (21).The prevalence of specific HPV types in the population does not have to equal the HPV types that cause cancer. However, the epidemiological knowledge of the specific types can be very interesting when evaluating the efficacy of vaccines and public health campains. Further, the high prevalence of other potential HR/HR HPVs such as HPV 67, 16, 31, 39 and 45 has been demonstrated previously in Sub-Saharan Africa and Kenya in particular (18, 21–24). HPV 52 and 16 were the most prevalent HR-HPV covered by the nonvalent vaccine. This study builds on the body of knowledge on the predominance of mixed potential HR/HR HPV types other than those in the HPV vaccines licensed and adopted in Kenya. For instance, the bivalent HPV vaccine (Cervarix) protects against HPV 16 and 18, the quadrivalent vaccine (Gardasil) protects against 6,11,16,18 and the Gardasil-9 against (6,11,16,18,31,33,45,52,58) This raises questions on the effectiveness of the current vaccines implemented in protection against HR HPV, particularly considering the HPV epidemiology in Kenya.
Further, the distribution of potential HR/HR HPV among HIV-positive and HIV-negative women in both reproductive health clinics was distinct. HPV 67, a potential HR HPV was noted as the most prevalent among HIV-positive patients. In a study done among Japanese women with cervical lesions, the genome analysis of HPV 67 suggested the carcinogenic potential of this rare genotype (25). The high prevalence of HPV among HIV-positive patients indicates the need for further clinical and epidemiological follow-up study on the role of other HR and potential HR HPV in cervical diseases especially among immune-compromised population. Moreover, there is a need for development and adoption of commercial assays to make the detection of potential HR HPVs part of the HR HPV detection kits.
The bivariate analysis showed age, marital status, and parity as predictors of potential HR/HR HPV infection among women in this region (Table 4). However, on multivariate regression, only age remained as a significant risk factor. Infection with potential HR/HR HPV was highest among women between the age 30–39 years then decreased as the age of the women advanced to 40 + years. Most evaluations have established that the prevalence of HPV is highest in the younger age groups.(26, 27). Past research has shown that the first HPV infection is often acquired shortly after a woman becomes sexually active (28, 29). HR HPV infection among younger women of less than 30 years often tends to be transient and screening in this age is likely to lead to detection of lesions that never progress to cervical cancer. However, as woman advances, the age-related HPV reduction has likely been attributed to a variety of factors including a decrease in involvement of sexual activity, clearance of HPV over a period and acquired immunity likely from previous infection. Supported by this evidence, it becomes necessary for Kenya to adhere to the WHO recommendations on the implementation of the two screenings in a woman’s lifetime, first by age 35 years and second by age 45 (WHO, 2020).
Similarly, in the age-adjusted model of statistical analysis, being married was the only significant factor. The relationship status of women has often been considered a key determinant in HPV infection(30, 31). The results of the current study are similar to the study findings in rural Uganda (32) where married women reported a high prevalence of HR HPV. However, being married has in the past drawn divergent results of HPV prevalence among women depending on the number of life partners that the woman or his partner has. Stable marital status, for instance, has often been viewed to protect an individual from HPV infection(33). Nevertheless, this study did not consider the type of marriages of the women and the potential number of sex partners of their spouses. However, it is very common for men in Kenya both married and unmarried to have non-regular sex partners outside their monogamous setting (24).
Strength and Limitations
This is the first study in the region to report extended genotyping data for both potential HR and HR HPV among women in rural and Urban settings in the post-pandemic era. Our findings add to the epidemiological knowledge on burden, genotypic distribution and potential factors associated with potential HR/HR HPV infection and disease progression among women in LVB.
The main limitation of this study is the source of study participants from facilities only. Given the fact that JOOTRH is a Referral hospital (level 5), it offers more specialized services and resources than health centers (level 3). This leads to discrepancies in cervical screening uptake, diagnoses treatment options, and outcomes, hence impacting the study results.
Further, the urban and rural populations differ in demographics, health needs, and access to healthcare. This can lead to significant differences in the patient populations at the two health facilities, potentially causing bias in the study results.
It is necessary to obtain more precise data on prevalence rates of potential HR/HR HPV in the entire Lake Victoria Region.