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Malaria risk factors in northern Namibia: The importance of occupation, age and mobility in characterizing high-risk populations
- Source :
- PLoS ONE, PLoS ONE, Vol 16, Iss 6, p e0252690 (2021)
- Publication Year :
- 2021
- Publisher :
- Public Library of Science (PLoS), 2021.
-
Abstract
- In areas of low and unstable transmission, malaria cases occur in populations with lower access to malaria services and interventions, and in groups with specific malaria risk exposures often away from the household. In support of the Namibian National Vector Borne Disease Program’s drive to better target interventions based upon risk, we implemented a health facility-based case control study aimed to identify risk factors for symptomatic malaria in Zambezi Region, northern Namibia. A total of 770 febrile individuals reporting to 6 health facilities and testing positive by rapid diagnostic test (RDT) between February 2015 and April 2016 were recruited as cases; 641 febrile individuals testing negative by RDT at the same health facilities through June 2016 were recruited as controls. Data on socio-demographics, housing construction, overnight travel, use of malaria prevention and outdoor behaviors at night were collected through interview and recorded on a tablet-based questionnaire. Remotely-sensed environmental data were extracted for geo-located village residence locations. Multivariable logistic regression was conducted to identify risk factors and latent class analyses (LCA) used to identify and characterize high-risk subgroups. The majority of participants (87% of cases and 69% of controls) were recruited during the 2016 transmission season, an outbreak year in Southern Africa. After adjustment, cases were more likely to be cattle herders (Adjusted Odds Ratio (aOR): 4.46 95%CI 1.05–18.96), members of the police or other security personnel (aOR: 4.60 95%CI: 1.16–18.16), and pensioners/unemployed persons (aOR: 2.25 95%CI 1.24–4.08), compared to agricultural workers (most common category). Children (aOR 2.28 95%CI 1.13–4.59) and self-identified students were at higher risk of malaria (aOR: 4.32 95%CI 2.31–8.10). Other actionable risk factors for malaria included housing and behavioral characteristics, including traditional home construction and sleeping in an open structure (versus modern structure: aOR: 2.01 95%CI 1.45–2.79 and aOR: 4.76 95%CI: 2.14–10.57); cross border travel in the prior 30 days (aOR: 10.55 95%CI 2.94–37.84); and outdoor agricultural work at night (aOR: 2.09 95%CI 1.12–3.87). Malaria preventive activities were all protective and included personal use of an insecticide treated net (ITN) (aOR: 0.61 95%CI 0.42–0.87), adequate household ITN coverage (aOR: 0.63 95%CI 0.42–0.94), and household indoor residual spraying (IRS) in the past year (versus never sprayed: (aOR: 0.63 95%CI 0.44–0.90). A number of environmental factors were associated with increased risk of malaria, including lower temperatures, higher rainfall and increased vegetation for the 30 days prior to diagnosis and residing more than 5 minutes from a health facility. LCA identified six classes of cases, with class membership strongly correlated with occupation, age and select behavioral risk factors. Use of ITNs and IRS coverage was similarly low across classes. For malaria elimination these high-risk groups will need targeted and tailored intervention strategies, for example, by implementing alternative delivery methods of interventions through schools and worksites, as well as the use of specific interventions that address outdoor transmission.
- Subjects :
- Male
Epidemiology
Psychological intervention
Indoor residual spraying
Social Sciences
Logistic regression
Geographical Locations
Medical Conditions
Health facility
Risk Factors
Surveys and Questionnaires
Medicine and Health Sciences
Medicine
Public and Occupational Health
Malaria, Falciparum
Child
Mammals
Rapid diagnostic test
Travel
Multidisciplinary
Geography
Incidence
Age Factors
Eukaryota
Ruminants
Middle Aged
Namibia
Socioeconomic Aspects of Health
Professions
Child, Preschool
Vertebrates
Agricultural Workers
Female
Seasons
Research Article
Adult
Adolescent
Science
Plasmodium falciparum
Human Geography
Young Adult
Sex Factors
Bovines
Environmental health
Parasitic Diseases
Humans
Animals
Insecticide-Treated Bednets
Occupations
business.industry
Organisms
Biology and Life Sciences
Odds ratio
medicine.disease
Tropical Diseases
Malaria
Health Care
Health Care Facilities
Case-Control Studies
Medical Risk Factors
People and Places
Africa
Amniotes
Earth Sciences
Housing
Residence
Cattle
Population Groupings
business
Zoology
Subjects
Details
- Language :
- English
- ISSN :
- 19326203
- Database :
- OpenAIRE
- Journal :
- PLoS ONE, PLoS ONE, Vol 16, Iss 6, p e0252690 (2021)
- Accession number :
- edsair.doi.dedup.....ad8a8a801d715d783bd73d6df56dfb92