The usefulness of rapid diagnostic tests in the new context of low malaria transmission in Zanzibar

• Published in: PloS one Vol. 8; no. 9; p. e72912
• Main Authors: Shakely, Delér, Elfving, Kristina, Aydin-Schmidt, Berit, Msellem, Mwinyi I, Morris, Ulrika, Omar, Rahila, Weiping, Xu, Petzold, Max, Greenhouse, Bryan, Baltzell, Kimberly A, Ali, Abdullah S, Björkman, Anders, Mårtensson, Andreas
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 04-09-2013; Public Library of Science (PLoS)
• Subjects: Adhesion; Adolescent; Algorithms; AMODIAQUINE; Child; Child, Preschool; Children; Clinical Medicine; COMBINATION THERAPY; Diagnosis; Diagnostic software; Diagnostic systems; Diagnostic tests; Diagnostic Tests, Routine - methods; Disease transmission; Epidemiology; FEBRILE; Female; Fever; Health care; Health care facilities; Health care reform; Health facilities; Histidine; Humans; Hälso- och sjukvårdsorganisation, hälsopolitik och hälsoekonomi; Hälsovetenskap; Illnesses; INFECTIONS; Infectious diseases; Infektionsmedicin; Klinisk medicin; Malaria; Malaria - diagnosis; Malaria - transmission; Male; Medical diagnosis; Medical personnel; Medical research; Medical tests; Medicin och hälsovetenskap; Medicine; Microscopy; MICROSCOPY scigloo; Mutation; Observational studies; PARASITE; PATIENTS; Pediatric diseases; Plasmodium falciparum - pathogenicity; PLASMODIUM-FALCIPARUM; Polymerase Chain Reaction; Primary care; Primary health care; Product testing; Public health; Quality control; RANDOMIZED-TRIAL; Sensitivity; Sensitivity and Specificity; Smear; TANZANIA; Vector-borne diseases; Tanzania; Sweden; San Francisco California; California; United States > US; Zanzibar
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0072912

We assessed if histidine-rich-protein-2 (HRP2) based rapid diagnostic test (RDT) remains an efficient tool for Plasmodium falciparum case detection among fever patients in Zanzibar and if primary health care workers continue to adhere to RDT results in the new epidemiological context of low malaria transmission. Further, we evaluated the performance of RDT within the newly adopted integrated management of childhood illness (IMCI) algorithm in Zanzibar.
We enrolled 3890 patients aged ≥ 2 months with uncomplicated febrile illness in this health facility based observational study conducted in 12 primary health care facilities in Zanzibar, between May-July 2010. One patient had an inconclusive RDT result. Overall 121/3889 (3.1%) patients were RDT positive. The highest RDT positivity rate, 32/528 (6.1%), was found in children aged 5-14 years. RDT sensitivity and specificity against PCR was 76.5% (95% CI 69.0-83.9%) and 99.9% (95% CI 99.7-100%), and against blood smear microscopy 78.6% (95% CI 70.8-85.1%) and 99.7% (95% CI 99.6-99.9%), respectively. All RDT positive, but only 3/3768 RDT negative patients received anti-malarial treatment. Adherence to RDT results was thus 3887/3889 (99.9%). RDT performed well in the IMCI algorithm with equally high adherence among children <5 years as compared with other age groups.
The sensitivity of HRP-2 based RDT in the hands of health care workers compared with both PCR and microscopy for P. falciparum case detection was relatively low, whereas adherence to test results with anti-malarial treatment was excellent. Moreover, the results provide evidence that RDT can be reliably integrated in IMCI as a tool for improved childhood fever management. However, the relatively low RDT sensitivity highlights the need for improved quality control of RDT use in primary health care facilities, but also for more sensitive point-of-care malaria diagnostic tools in the new epidemiological context of low malaria transmission in Zanzibar.
ClinicalTrials.gov NCT01002066.