Format

Send to

Choose Destination
Int J Infect Dis. 2016 Aug;49:161-9. doi: 10.1016/j.ijid.2016.06.019. Epub 2016 Jun 24.

Subclinical Plasmodium falciparum infections act as year-round reservoir for malaria in the hypoendemic Chittagong Hill districts of Bangladesh.

Author information

1
Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
2
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
3
Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615N. Wolfe St, Rm W4612, Baltimore, MD 21205, USA; Department of Geography, University of Florida, Gainesville, Florida, USA.
4
Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615N. Wolfe St, Rm W4612, Baltimore, MD 21205, USA.
5
Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA; University of Maryland School of Medicine, Baltimore, Maryland, USA.
6
Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615N. Wolfe St, Rm W4612, Baltimore, MD 21205, USA. Electronic address: dsulliv7@jhmi.edu.

Abstract

OBJECTIVES:

An analysis of the risk factors and seasonal and spatial distribution of individuals with subclinical malaria in hypoendemic Bangladesh was performed.

METHODS:

From 2009 to 2012, active malaria surveillance without regard to symptoms was conducted on a random sample (n=3971) and pregnant women (n=589) during a cohort malaria study in a population of 24000.

RESULTS:

The overall subclinical Plasmodium falciparum malaria point prevalence was 1.0% (n=35), but was 3.2% (n=18) for pregnant women. The estimated incidence was 39.9 per 1000 person-years for the overall population. Unlike symptomatic malaria, with a marked seasonal pattern, subclinical infections did not show a seasonal increase during the rainy season. Sixty-nine percent of those with subclinical P. falciparum infections reported symptoms commonly associated with malaria compared to 18% without infection. Males, pregnant women, jhum cultivators, and those living closer to forests and at higher elevations had a higher prevalence of subclinical infection.

CONCLUSIONS:

Hypoendemic subclinical malaria infections were associated with a number of household and demographic factors, similar to symptomatic cases. Unlike clinical symptomatic malaria, which is highly seasonal, these actively detected infections were present year-round, made up the vast majority of infections at any given time, and likely acted as reservoirs for continued transmission.

KEYWORDS:

Asymptomatic; Epidemiology; Malaria; Rapid diagnostic test; Subclinical

PMID:
27350586
DOI:
10.1016/j.ijid.2016.06.019
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center