Making Pastoralists Count: Geospatial Methods for the Health Surveillance of Nomadic Populations

Abstract

. Nomadic pastoralists are among the world’s hardest-to-reach and least served populations. Pastoralist communities are difficult to capture in household surveys because of factors including their high degree of mobility over remote terrain, fluid domestic arrangements, and cultural barriers. Most surveys use census-based sampling frames which do not accurately capture the demographic and health parameters of nomadic populations. As a result, pastoralists are “invisible” in population data such as the Demographic and Health Surveys (DHS). By combining remote sensing and geospatial analysis, we developed a sampling strategy designed to capture the current distribution of nomadic populations. We then implemented this sampling frame to survey a population of mobile pastoralists in southwest Ethiopia, focusing on maternal and child health (MCH) indicators. Using standardized instruments from DHS questionnaires, we draw comparisons with regional and national data finding disparities with DHS data in core MCH indicators, including vaccination coverage, skilled birth attendance, and nutritional status. Our field validation demonstrates that this method is a logistically feasible alternative to conventional sampling frames and may be used at the population level. Geospatial sampling methods provide cost-affordable and logistically feasible strategies for sampling mobile populations, a crucial first step toward reaching these groups with health services.

Health interventions among mobile pastoralists: a systematic review to guide health service design

“…This challenge led at least one study in our sample to conduct an independent census of the study area prior to their immunisation campaign, which found that only 2.6% of children were current with their immunisation status [51]. Delivery innovations that leverage geospatial analysis and mobile phones have demonstrated promise in improving demographic surveillance among mobile pastoralists, but significant progress remains to be made [2,55].…”

“…Pastoralist populations practise animal husbandry as their primary economic activity and typically practise some degree of mobility, defined in this paper as any type of seasonal transhumance carried out while managing livestock. Systematic underrepresentation in population data further hinders efforts to include pastoralists in health services planning, and demographic information is so incomplete that not even their population is known [1,2]. Estimates are outdated and range from 50 to over 200 million individuals globally, while the African Union estimates there are 268 million pastoralists on the African continent alone [3–5].…”

Health services uptake among nomadic pastoralist populations in Africa: A systematic review of the literature

“…Five broad areas of research were identified among the included papers. The first area included epidemiologic studies that focused primarily on the prevalence of, and biomedical risk factors for, specific diseases or conditions, such as cholera, TB, and rabies (16). A second area comprised studies focused on the knowledge, attitudes and practices specific to certain conditions (e.g., pregnancy) and diseases (e.g., Rift Valley Fever) and the factors determining or correlating with knowledge, attitudes and practices (25).…”

“…Specific human health topics. The health topic foci included reproductive health issues (including antenatal care, maternal mortality and/or childbirth) (21); vaccine-preventable disease/immunization topics (excluding polio) (14); general health service access, uptake or delivery (9); primary health care (4); or disease-specific topics such as tuberculosis (16), neglected tropical diseases (9), polio (9), malaria (8), HIV/AIDS (4) and zoonoses (3) (S2 Fig). Five papers on other unique topics were also reviewed (not listed individually).…”

Mobile pastoralists in Africa: a blind spot in global health surveillance

“…Including pastoralists in household surveys such as the DHS is an essential first step to guide health service planning. Satellite imagery has been used to conduct health assessments among sedentary populations and, more recently, to generate representative sampling frames for conducting health surveys among nomadic pastoralists directly comparable with the DHS over a large geographic scale [17, 18]. Such geospatial methods open up logistically and economically feasible alternatives to census listings and should be used to construct sampling frames capable of accounting for mobility.…”