Prevalence and Genotype Distribution of Human Papilloma Virus (HPV) among Women in Karachi, Pakistan

ABSTRACT We performed a population-based study in densely populated areas of the largest city of Pakistan (Karachi) to determine the overall type- and age-specific prevalence of human papillomavirus (HPV) in the setting of an unscreened and non-vaccinated female population between May 2022 and November 2023. Women (n=3,119) were invited to participate in the study from whom a total of 497 women gave consent and provided cervical samples. HPV positivity was determined and specific HPV genotypes were identified using the INNO LiPa Extra II-line probe assay. Total HPV positivity among all age groups was 16.7%. High risk HPV types (groups 1 and 2) were found in 11.9% whereas low risk types and unclassified types were 4.8% in all samples. Fourteen HR types were detected as single infections (8.4%), highest prevalent types are HPV-31 and HPV-53 (each 1.2%) followed by HPV-68 (1.0%), HPV-16 (0.8%), HPV-33, -39 and -51 (each 0.6%). While HPV-35, HPV-52, HPV-70, HPV-73 and HPV-82 were the least prevalent types. The most prevalent (1.2%) low-risk HPV type detected was HPV-6 of all samples. The highest HPV prevalence (21.3%) was observed in subjects aged 25–34 years (n=220), whereas in the age group above 54 years (n=24) we detected HPV in 12.5% of samples tested. Single HR HPV infections were observed in 8.4%, while multiple HR infections were detected in 4.02% of the 497 women tested. Extrapolating this data to the total female population of Pakistan allows to estimate that about 20 million women are HPV positive. This rough estimation forms a strong basis of an organized cervical cancer screening program using high precision HPV tests for early detection of HPV infections and related diseases including cervical cancer. In addition, this also establish the need of implementation of immunization program with the recently licensed nonavalent human papillomavirus vaccine. This can significantly reduce the future morbidity and mortality from cervical and oral cancer, pre-cancerous lesions and other HPV-related cancers in the female and male population of Pakistan. The current study, therefore, provide a credible basis of further research, and follow-up action on HPV-related disease burden.