Jasmin Shrestha: Understanding Rotavirus disease among community children in Nepal.
PhD Candidate Jasmin Shrestha is undertaking a PhD studying the rotavirus disease burden, and the distribution of rotavirus genotypes in children participating in a community-based cohort study in Bhaktapur, Nepal. She also aims to describe any changing patterns of rotavirus genotypes over time, to provide information for increasing vaccine efficacy.
Globally, diarrhoeal / enteric infectious disease is the second leading cause of under 5 mortality, particularly in low- and middle-income countries. It can be caused by a variety of agents. Most have some kind of seasonality. While improving understanding of this seasonality is methodologically challenging, it is critical to informing policy aimed at optimising the timing of preventive measures. This knowledge will also be relevant to attempts to forecast the impact of climate change on future trends in disease burdens.
In an earlier paper involving Shrestha and colleagues, as well as researchers from the Interactions of Malnutrition & Enteric Infections: Consequences for Child Health and Development project (MAL-ED) project, the researchers stressed that improving understanding of the pathogen-specific seasonality of enteric infections is critical to informing policy on the best timing of preventive measures as well as for forecasting trends in the burden of diarrhoeal disease.
Need for a large-scale surveillance system
In Nepal, rotavirus-caused diarrhoea is a winter disease, called winter gastroenteritis. In the research for Shrestha’s first paper, rotavirus infections were observed in the period between December and March. The highest incidence peak occurred in January, which is the coldest month of the year in Nepal. In this community, no cases were seen in month of August. This research also found that in this study population, the high prevalence of disease was due to the G2-type rotavirus strain. This was followed by disease caused by the G1- and G12-strains.
The large diversity of rotavirus genotypes and the seasonal fluctuations in disease burden underline the importance of having a thorough, large-scale surveillance system in the country. Such a system will help to monitor the evolution of any new or unusual rotavirus genotypes and will make it possible to assess the impact of vaccine introduction on any newly emerged strains.
Importance of control groups
In her second paper, Shrestha included a control group for comparison. This enabled the researchers to describe causality and asymptomatic carriage of each disease-causing organism studied. This was an advantage because other previous hospital-based diarrheal studies conducted in Nepal only considered cases with acute gastroenteritis or were focused on specific pathogens only.
Shrestha presented her mid-way evaluation 10 June – via Zoom because of the COVID-19 lockdown. When asked about the challenges she had experienced thus far in her PhD studies, she cited resource limitations in Nepal, including limitations in sequencing capacity for identifying different rotavirus strains. She also cited travel restrictions due to COVID-19, which have prevented her from completing some of the planned PhD coursework. She aims to finish her degree at the end of 2021.