Assessing malaria risk at night-time venues in a low-transmission setting: a time-location sampling study in Zambezi, Namibia

Jerry O. Jacobson, Jennifer L. Smith, Carmen Cueto, Mukosha Chisenga, Kathryn Roberts, Michelle S Hsiang, Roly Gosling, Davis Mumbengegwi, Adam Bennett

Research output: Contribution to journalArticle

Abstract

BACKGROUND: Identifying efficient and effective strategies to reach and monitor populations at greatest risk of malaria in low-transmission settings is a key challenge for malaria elimination. In Namibia's Zambezi Region, transmission is ongoing yet its drivers remain poorly understood. A growing literature suggests that night-time social activities may lead to malaria exposure that is beyond the reach of conventional preventive interventions, such as insecticide treated bed nets and indoor residual spraying. METHODS: Formative research was conducted with community members in March, 2015 in the catchment areas of six randomly selected health facilities in the western Zambezi Region to identify night-time locations where large numbers of individuals regularly congregate. Using time-location sampling, a survey was conducted between March and May, 2015 at community-identified venues (bars and evening church services) to develop representative estimates of the prevalence of parasite infection and risk factors among venue-goers. RESULTS: When compared to a contemporaneous household survey of the general population aged 15 and older (N = 1160), venue-goers (N = 480) were more likely to have spent the night away from their home recently (17.3% vs. 8.9%, P = 0.008), report recent fever (65.2% vs. 36.9%, P < 0.001), and were less likely to have sought care for fever (37.9% vs. 52.1%, P = 0.011). Venue-goers had higher, but not significantly different, rates of malaria infection (4.7% vs. 2.8%, P = 0.740). Risk factors for malaria infection among venue-goers could not be determined due to the small number of infections identified, however self-reported fever was positively associated with outdoor livelihood activities (adjusted odds ratio [AOR] = 1.9, 95% CI 1.0-3.3), not wearing protective measures at the time of the survey (AOR = 6.8, 9% CI 1.4-33.6) and having been bothered by mosquitos at the venue (AOR = 2.7, 95% CI 1.5-4). CONCLUSIONS: Prevention measures and continued surveillance at night-time venues may be a useful complement to existing malaria elimination efforts.

Original languageEnglish (US)
Number of pages1
JournalMalaria journal
Volume18
Issue number1
DOIs
StatePublished - May 22 2019

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Keywords

  • High-risk populations
  • Malaria
  • Namibia
  • Surveillance
  • Time-location sampling

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases

Cite this

Jacobson, J. O., Smith, J. L., Cueto, C., Chisenga, M., Roberts, K., Hsiang, M. S., Gosling, R., Mumbengegwi, D., & Bennett, A. (2019). Assessing malaria risk at night-time venues in a low-transmission setting: a time-location sampling study in Zambezi, Namibia. Malaria journal, 18(1). https://doi.org/10.1186/s12936-019-2807-x