ASTMH 2018: Session 11 “Malaria Epidemiology – Recent Progress in Advancing Surveillance, Measurement and Modelling for Program Success”

MESA Correspondents bring you cutting-edge coverage from the 67th ASTMH Annual Meeting

Session 11: “Malaria: Epidemiology – Recent Progress in Advancing Surveillance, Measurement and Modelling for Program Success”

The first of two Malaria Epidemiology Scientific Sessions attracted a capacity crowd in the Rodrigue Gallery at the Sheraton on Monday morning 29 October. The session’s theme “Recent progress in advancing surveillance, measurement and modelling for program success,” was addressed by seven presenters. 

Asymptomatic infections of low and high density are key targets during the elimination phase of malaria. Linking routine health facility data and community surveys from 9 countries, Gillian Stresman’s work concluded that as malaria transmission intensity decreases, the proportion of infections detected by routine passive case-reporting of confirmed malaria illness increases. Fitsum Tadesse’s work in Ethiopia showed that a high proportion of asymptomatic low-density infections clustered around the passively detected and routinely reported cases. Ashenafi Assefa explored how multiplex serological studies could be used to distinguish recent and remote infections and enhance data on infecting species. 

Aaron Samuels suggested that tracking malaria infection in pregnant women at antenatal clinics could be a useful adjunct to routine surveillance of symptomatic illness cases. Ursula Dalrymple examined malaria infection and care seeking for childhood febrile illness in Africa and confirmed the need to improve the coverage and monitoring of case management services. 

Epidemiology of drug resistance was discussed at many places during the meeting, with speculation about possible return of drug sensitivity after years of drug withdrawal. In this session, Georgina Humphreys shared recent data on pyrimethamine resistance markers across Africa, concluding that they remain highly prevalent in East and Southern Africa despite policies that have decreased selection pressure. 

Ipsita Sinha explored individual travel survey and cell phone data from malaria patients in the Greater Mekong Subregion to reveal internal and multinational migration patterns that could influence the evolution and spread of drug resistance in those nations and beyond. 

Several of the presenters explored the issue of how low density and asymptomatic infections—mostly missed through passive case detection and routine reporting—can be tracked to improve targeting of interventions. 

Collectively these works demonstrate the highly dynamic scholarship that is contributing to malaria control and elimination efforts and reinforce the value of case-based routine surveillance as well as targeted, more detailed studies, to explore evolving transmission dynamics. 

Co-chairs: Patrick Kachur (Columbia University Medical Center, New York) and Ipsita Sinha (Mahidol Oxford Tropical Research Unit, Bangkok, Thailand)

This report was written by Patrick Kachur with editorial support from Professor Graham Brown.