Medical Microbiology

Permanent URI for this collection

http://etd.aau.edu.et/handle/123456789/69

Browse

Browsing Medical Microbiology by Author "AbebeTamrat"

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    Human Papillomavirus Genotype Distribution, Persistence, Clearance, and Characterizing Cervicovaginal Microbiota: A Population- Based Follow up Study
    (Addis Ababa University, 2023-04) Endallew Brhanu ; AbebeTamrat ; Kaufmann Andreas ; Kantelhardt Eva ; Mihret Adane
    Background: Human papillomaviruses (HPVs) are a group of small, non-enveloped, naked icosahedral (55nm) viruses that can cause cervical cancer (CC) and other cancers. Cervical cancer is by far the most common HPV-related disease, and it is the second leading cause of morbidity and mortality from all cancers in Ethiopian women. Persistent infection with hr-HPVs and progression to precancerous lesions are the most important steps in the carcinogenesis process. However, most infections are transient and rarely persist implying development of CC is a multifactorial and step by step process and may require other co-factors like cervicovaginal microbiome within the local microenvironment for its development. Objective: To determine the prevalence of HPV infection, genotype distribution, the persistence and clearance rates within two years and compare the performance of different HPV tests. Furthermore, it aimed to characterize the cervicovaginal microbiota in women with premalignant dysplasia or invasive cervical cancer compared with that of healthy women. Methods: The study was conducted in two cohorts; a population-based cohort from rural women in Butajira, south-central Ethiopia and women attending gynaecological clinic at Tikur Anbessa Specialized Hospital from October 2017 to February 2020. From Butajira, a total of 893 samples were tested at baseline. A self-sampling brush (Evalyn Brush®, RoversOss The Netherlands) was used for cervical specimen collection and HPV testing was performed using multiplexed genotyping (MPG) by BSGP5+/6+ PCR with Luminex read out. Follow-up testing was done at 6 and 24 months for baseline hr-HPV positive women. Moreover, three HPV DNA testing assays (MPG-Luminex Assay, Anyplex II HPV HR Detection, and EUROArray HPV) were compared and the analytical sensitivity and specificity of the assays in detecting hr-HPV infections was computed. At Tikur Anbessa Specialized Hospital, cervicovaginal microbiota of 120 women was characterised using the 16S rRNA cervical microbiome sequencing. Shannon and Simpson diversity indexes were used to evaluate alpha diversity. Beta diversity was examined using principal coordinate analysis (PCoA) of unweighted Unifrac distances. Results: At baseline screening, the population-based HPV positivity rate was 23.2% (95% CI: 23.54‐22.86%), of these 20.5% (95% CI=20.79‐20.21), and 10.3% (95% CI=10.52‐10.08) women were hr‐ and lr‐ HPV positives, respectively. Age‐specific hr‐HPV infection peaked in the agegroup 30‐34 years old (58.6%) and decreased in 35‐39, 40‐44, and 45‐49 years to 20.4%, 4.5% and 3.8% respectively. The top five prevalent hr‐HPV genotypes were HPV16 (57.1%), 35 (20.3%), 52 (15.8%), 31 (14.1%), and 45 (9.6%) in the Butajira district. hr-HPV infection clearance was observed in 70 women (73.7%) within 6 months and among 77 women (84.6%) within 2 years. In the control women (negatives at baseline), the hr-HPV incidence was 4.1%.