A thesis submitted in partial fulfilment of the requirement for the degree of Masters of Science in Healthcare Biotechnology

Abstract

Gastroenteritis is a significant public health concern worldwide, causing over 70 million fatalities each year and accounting for 10% of juvenile mortality, making it the second leading cause of death globally. Norovirus infections are common in low-resource countries and have a substantial impact on severe childhood gastroenteritis, leading towards 1.1 million cases of hospitalizations and 218,000 fatalities among children under 5 annually. No data is available on the prevalence and genetic diversity of NoV in KPK region of Pakistan, where NoV can be the possible cause of having high death rate among pediatric population. A total of 803 fecal samples collected from children under the age of 5 years admitted at Saidu Teaching Hospital, Swat (STH) and Khyber Teaching Hospital (KTH) were screened for NoV on the basis of VP1 gene by using one-step conventional RT PCR. The amplified products were separated using Gel Electrophoresis and the positive samples were cycle sequenced. Sequencher was used to edit the raw data obtained from genetic analyzer and FASTA sequences were retrieved which were then analyzed using BLAST followed by construction of phylogenetic tree on MEGA software. This research demonstrated that noroviruses have a substantial role in the episodes of childhood diarrhea, with a 15.69% positivity rate (n=126) among the samples collected from KPK region. Our study revealed that GGII strains were more prevalent with 57.94% (n=73) positive cases as compared to GGI with 42.06% (n=53) positive samples. Among genogroup I, GGI.3 was found to be the most prevalent genotype while GGII.2 was the most prevalent genotype among genogroup II. Gender based analysis demonstrated that NoV infections were more common in females as compared to males. The largest percentage of NoV was found among children less than 2 years. The study's results provide optimism for shaping public health policies to reduce the effects of norovirus-induced gastroenteritis, despite obstacles in resource-constrained regions worldwide.