Epidemiology &Surveillance Bill Brieger | 24 Apr 2013 07:37 am
Household Survey Used to Study Human Population Movement on Malaria Transmission in Southern Zambia
Karen E. Kirk, a MSPH-Internal Health Candidate at the Johns Hopkins Bloomberg School of Public Health has written this guest posting based on a poster she presented at the School’s Global Health Day earlier this month.
The inability to eliminate malaria in low endemic settings due to importation by infected individuals is considered a potential barrier in the fight to eradicate malaria worldwide. Individuals living in the rural Choma District, Southern Province, Zambia have seen a dramatic decline in malaria since 2007 with the implementation of malaria control programs that include active case detection; mass distribution of insecticidal treated nets (ITNs); and widespread use of indoor residual spraying (IRS). However, malaria elimination has still not been achieved in this region of the country.
The first photo shows field staff collecting blood samples from household members to test for malaria parasitemia in Choma District
A household survey was conducted in the Choma District to assess human population movement (HPM) and its association with confirmed or suspected malaria cases of individuals living in the district. The survey looked at travel history of 196 individuals from 42 randomly selected households between December 2012 and March 2013. It collected data on travel patterns of individuals from the previous 4 weeks who stayed overnight for at least one night outside of their village. In addition, it collected blood sample for the testing of malaria parasitemia. This survey was included in both the longitudinal and cross-sectional household surveys being conducted by the International Centers of Excellence in Malaria Research (ICEMR).
The second photo shows Field staff conducting malaria community health and HPM survey with mother in Choma District
Of the 196 individuals surveyed there were 97 (49.5%) adults (ages >17), and 99 (51.5%) children (<17). There were a total of 34 trips taken by 31 (15.8%) individuals, 18 adults and 13 children. The majority of these individuals (59.3%) traveled for 7 days or less and 27 (87.1%) individuals traveled within the Choma District. No malaria cases were detected in this study and therefore the results of this preliminary data were not able to show an association between HPM and malaria incidence rates. However, with an increase in data collected over time, trends could be ascertained to determine seasonal patterns with HPM and its impact on malaria incidence rates in this hypoendemic setting. The hope is that with adequate funding in malaria research with HPM, these types of studies can contribute important information on malaria transmission and help achieve the goal of regional elimination and ultimately eradication of this harmful disease.
[Bill Moss of JHSPH served as Principal Investor of this project]