The epidemiology and detectability of asymptomatic plasmodium vivax and plasmodium falciparum infections in low, moderate and high transmission settings in Ethiopia

被引：20

作者：

Hailemeskel, Elifaged ^{[1
,2
,3
,4
]}

Tebeje, Surafel K. ^{[1
,4
]}

Behaksra, Sinknesh W. ^{[1
]}

Shumie, Girma ^{[1
]}

Shitaye, Getasew ^{[6
]}

Keffale, Migbaru ^{[1
]}

Chali, Wakweya ^{[1
]}

Gashaw, Abrham ^{[1
]}

Ashine, Temesgen ^{[1
]}

Drakeley, Chris ^{[7
]}

Bousema, Teun ^{[4
,7
]}

Gadisa, Endalamaw ^{[1
]}

Tadesse, Fitsum G. ^{[1
,4
,5
]}

机构：

[1] Armauer Hansen Res Inst, Malaria & Neglected Trop Dis Directorate, POB 1005, Addis Ababa, Ethiopia

[2] Addis Ababa Univ, Coll Nat & Computat Sci, Dept Biomed Sci, POB 1176, Addis Ababa, Ethiopia

[3] Wollo Univ, Coll Nat & Computat Sci, Dept Biol, POB 1145, Dessie, Ethiopia

[4] Radboud Univ Nijmegen, Med Ctr, Dept Med Microbiol, NL-6525 GA Nijmegen, Netherlands

[5] Addis Ababa Univ, Inst Biotechnol, POB 1176, Addis Ababa, Ethiopia

[6] Bahir Dar Univ, Sch Med Sci, Dept Biomed Sci, Bahir Dar, Ethiopia

[7] London Sch Hyg & Trop Med, Dept Immunol & Infect, London WC1E 7HT, England

来源：

MALARIA JOURNAL | 2021年 / 20卷 / 01期

基金：

欧洲研究理事会; 比尔及梅琳达.盖茨基金会;

关键词：

Plasmodium infection; Elimination; Asymptomatic; Transmission; nPCR; Detectability; Density distribution; MALARIA TRANSMISSION; HIGH-SENSITIVITY; PREVALENCE; PARASITEMIA; MICROSCOPY; AREA; CARRIAGE; DISTRICT; LONG; TIME;

D O I：

10.1186/s12936-021-03587-4

中图分类号：

R51 [传染病];

学科分类号：

100401 ;

摘要：

BackgroundAs countries move to malaria elimination, detecting and targeting asymptomatic malaria infections might be needed. Here, the epidemiology and detectability of asymptomatic Plasmodium falciparum and Plasmodium vivax infections were investigated in different transmission settings in Ethiopia.Method:A total of 1093 dried blood spot (DBS) samples were collected from afebrile and apparently healthy individuals across ten study sites in Ethiopia from 2016 to 2020. Of these, 862 were from community and 231 from school based cross-sectional surveys. Malaria infection status was determined by microscopy or rapid diagnostics tests (RDT) and 18S rRNA-based nested PCR (nPCR). The annual parasite index (API) was used to classify endemicity as low (API>0 and <5), moderate (API<greater than or equal to>5 and <100) and high transmission (API<greater than or equal to>100) and detectability of infections was assessed in these settings.ResultsIn community surveys, the overall prevalence of asymptomatic Plasmodium infections by microscopy/RDT, nPCR and all methods combined was 12.2% (105/860), 21.6% (183/846) and 24.1% (208/862), respectively. The proportion of nPCR positive infections that was detectable by microscopy/RDT was 48.7% (73/150) for P. falciparum and 4.6% (2/44) for P. vivax. Compared to low transmission settings, the likelihood of detecting infections by microscopy/RDT was increased in moderate (Adjusted odds ratio [AOR]: 3.4; 95% confidence interval [95% CI] 1.6-7.2, P=0.002) and high endemic settings (AOR=5.1; 95% CI2.6-9.9, P<0.001). After adjustment for site and correlation between observations from the same survey, the likelihood of detecting asymptomatic infections by microscopy/RDT (AOR per year increase=0.95, 95% CI0.9-1.0, P=0.013) declined with age.ConclusionsConventional diagnostics missed nearly half of the asymptomatic Plasmodium reservoir detected by nPCR. The detectability of infections was particularly low in older age groups and low transmission settings. These findings highlight the need for sensitive diagnostic tools to detect the entire parasite reservoir and potential infection transmitters.

引用

页数：10

共 53 条

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