Kerry L Shannon1, Wasif A Khan2, David A Sack1, M Shafiul Alam2, Sabeena Ahmed2, Chai Shwai Prue2, Jacob Khyang2, Malathi Ram1, M Zahirul Haq2, Jasmin Akter2, Gregory E Glass3, Timothy M Shields4, Sean R Galagan1, Myaing M Nyunt5, David J Sullivan6. 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.
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.
Authors: Mohammad Shafiul Alam; Mohammad Moktadir Kabir; Mohammad Sharif Hossain; Shamsun Naher; Nur E Naznin Ferdous; Wasif Ali Khan; Dinesh Mondal; Jahirul Karim; A K M Shamsuzzaman; Be-Nazir Ahmed; Akramul Islam; Rashidul Haque Journal: Malar J Date: 2016-11-11 Impact factor: 2.979
Authors: Mohammad Abdul Matin; Nandini D P Sarkar; Ching Swe Phru; Benedikt Ley; Kamala Thriemer; Ric N Price; Koen Peeters Grietens; Wasif Ali Khan; Mohammad Shafiul Alam; Charlotte Gryseels Journal: Pathogens Date: 2020-10-14
Authors: Rebecca C Christofferson; Daniel M Parker; Hans J Overgaard; Jeffrey Hii; Gregor Devine; Bruce A Wilcox; Vu Sinh Nam; Sazaly Abubakar; Sebastien Boyer; Kobporn Boonnak; Stephen S Whitehead; Rekol Huy; Leang Rithea; Tho Sochantha; Thomas E Wellems; Jesus G Valenzuela; Jessica E Manning Journal: PLoS Negl Trop Dis Date: 2020-07-30
Authors: Ipsita Sinha; Abdullah Abu Sayeed; Didar Uddin; Amy Wesolowski; Sazid Ibna Zaman; M Abul Faiz; Aniruddha Ghose; M Ridwanur Rahman; Akramul Islam; Mohammad Jahirul Karim; Anjan Saha; M Kamar Rezwan; Abul Khair Mohammad Shamsuzzaman; Sanya Tahmina Jhora; M M Aktaruzzaman; Hsiao-Han Chang; Olivo Miotto; Dominic Kwiatkowski; Arjen M Dondorp; Nicholas P J Day; M Amir Hossain; Caroline Buckee; Richard J Maude Journal: BMC Med Date: 2020-03-04 Impact factor: 8.775