Human papillomavirus types causing recurrent respiratory papillomatosis in Zimbabwe

Recurrent respiratory papillomatosis (RRP) caused by human papillomavirus (HPV) is preventable through vaccination. This study was motivated by the recent thrust of the Zimbabwean government to reduce incidence of HPV related cervical cancer in Zimbabwe through vaccination against HPV. We therefore set out to type HPV genotypes causing RRP in Zimbabwe. We also describe for the first time, the demographics of Zimbabwean RRP patients, the characteristics of patients with different HPV types and possible risk factors of HPV infection in our setting.

We conducted a prospective, hospital based study were patients were recruited from two national otorhinolaryngology hospitals in Zimbabwe. All patients diagnosed with RRP during a twenty four month period were included in the study. A questionnaire was administered per patient to collect both demographic and clinical variables. HPV DNA was extracted from formalin fixed paraffin embedded laryngeal tissue. The extracted HPV DNA was amplified using polymerase chain reaction and next generation sequencing was used to genotype the HPV types.

A total of 52 patients all aged 14 years and under were recruited into the study. Only Juvenile onset RRP cases were observed over the two year period and 64% of the patients were HPV positive. HPV types 6 and 11 were the dominant types observed constituting 85% of all HPV types. The remaining 15% constituted of HPV 16 and HPV 18. 27% of the patients had coinfection with at least two different HPV types. There were no statistically significant differences between the characteristics of HPV positive and HPV negative patients. No statistically significant risk factors were observed.

HPV types 6 and 11 were the predominant genotypes causing RRP in Zimbabwe. Thus the use of quadrivalent or even nonavalent HPV vaccines may play an important role in the prevention and management of RRP in Zimbabwe.