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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Namibia
Sampling Studies
Malaria
Fever
Odds Ratio
Insecticide-Treated Bednets
Infection
Parasitic Diseases
Health Facilities
Culicidae
Research
Population
Surveys and Questionnaires

Keywords

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

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases

Cite this

Assessing malaria risk at night-time venues in a low-transmission setting : a time-location sampling study in Zambezi, Namibia. / Jacobson, Jerry O.; Smith, Jennifer L.; Cueto, Carmen; Chisenga, Mukosha; Roberts, Kathryn; Hsiang, Michelle S; Gosling, Roly; Mumbengegwi, Davis; Bennett, Adam.

In: Malaria journal, Vol. 18, No. 1, 22.05.2019.

Research output: Contribution to journalArticle

Jacobson, Jerry O. ; Smith, Jennifer L. ; Cueto, Carmen ; Chisenga, Mukosha ; Roberts, Kathryn ; Hsiang, Michelle S ; Gosling, Roly ; Mumbengegwi, Davis ; Bennett, Adam. / Assessing malaria risk at night-time venues in a low-transmission setting : a time-location sampling study in Zambezi, Namibia. In: Malaria journal. 2019 ; Vol. 18, No. 1.
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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.",
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AU - Cueto, Carmen

AU - Chisenga, Mukosha

AU - Roberts, Kathryn

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AU - Gosling, Roly

AU - Mumbengegwi, Davis

AU - Bennett, Adam

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