Malaria infection prevalence and sensitivity of reactive case detection in Zanzibar

International Journal of Infectious Diseases

Bakar S. Fakih¹  Chris Cotter²  Benjamin Grossenbacher²  Abdullah Ali²  Abdul-wahid H. Al-mafazy³  Ingrid Felger⁴  Tina van der Horst⁴  Adam Bennett⁵  Aurel Holzschuh⁵  Erik Reaves⁵  Logan Stuck⁶  Manuel W. Hetzel⁷  Joshua Yukich⁸  Natalie E. Hofmann⁸ 

[1] Corresponding Author;University of Basel, Basel, Switzerland;Ifakara Health Institute, Dar es Salaam, United Republic of Tanzania;Malaria Elimination Initiative, Global Health Group, University of California, San Francisco, CA, USA;Swiss Tropical and Public Health Institute, Basel, Switzerland;Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA;U.S. President's Malaria Initiative, Malaria Branch, U.S. Centers for Disease Control and Prevention, Atlanta, GA, USA;Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania;

关键词: malaria;    surveillance;    elimination;    reactive case detection;    focal mass drug administration;    RCD;   

DOI  :  

来源: DOAJ

【 摘 要 】

Background: Reactive case detection (RCD) is a commonly used strategy for malaria surveillance and response in elimination settings. Many approaches to RCD assume detectable infections are clustered within and around homes of passively detected cases (index households), which has been evaluated in a number of settings with disparate results. Methods: Household questionnaires and diagnostic testing were conducted following RCD investigations in Zanzibar, Tanzania, including the index household and up to 9 additional neighboring households. Results: Of 12,487 participants tested by malaria rapid diagnostic test (RDT), 3·2% of those residing in index households and 0·4% of those residing in non-index households tested positive (OR = 8·4; 95%CI: 5·7, 12·5). Of 6,281 participants tested by quantitative polymerase chain reaction (qPCR), 8·4% of those residing in index households and 1·3% of those residing in non-index households tested positive (OR = 7·1; 95%CI: 6·1, 10·9). Within households of index cases defined as imported, odds of qPCR-positivity amongst members reporting recent travel were 1·4 times higher than among those without travel history (95%CI: 0·2, 4·4). Amongst non-index households, odds of qPCR-detectable infection were no different between households located within 50 m of the index household as compared with those located farther away (OR = 0·8, 95%CI: 0·5, 1·4). Sensitivity of RDT to detect qPCR-detectable infections was 34% (95%CI: 26·4, 42·3). Conclusions: Malaria prevalence in index households in Zanzibar is much higher than in non-index households, in which prevalence is very low. Travelers represent a high-risk population. Low sensitivity of RDTs due to a high prevalence of low-density infections results in an RCD system missing a large proportion of the parasite reservoir.

【 授权许可】

Unknown