Chloroquine efficacy for Plasmodium vivax malaria treatment in southern Ethiopia.

Sisay Getachew,Sarah Auburn,Abraham Aseffa,Beyene Petros,Ric N Price,Adugna Abera,Kamala Thriemer,Endalamaw Gadisa

doi:10.1186/s12936-015-1041-4

Abstract

BackgroundChloroquine (CQ) is the first-line treatment for vivax malaria in Ethiopia, but there is evidence for its declining efficacy. Defining the extent and regional distribution of CQ resistance is critical to ensure optimal treatment guidelines. This study aimed to provide data on the therapeutic efficacy of CQ against Plasmodium vivax malaria in southern Ethiopia.MethodsPatients with P. vivax mono-infection aged between 8 months and 65 years were enrolled in a clinical efficacy trial. The study was conducted at four sites in southern Ethiopia. Study participants were treated with a supervised course of CQ (25 mg/kg over three consecutive days), followed by weekly blood film examination and clinical assessment for 28 days. CQ blood concentrations were not assessed. The primary endpoint was the risk of failure at 28 days by survival analysis.ResultsBetween May 2010 and December 2013, 288 patients were enrolled in the study (n = 89 in Shele, n = 52 in Guba, n = 57 in Batu and n = 90 in Shone). Baseline characteristics varied significantly between sites. In total 34 (11.8 %) patients were censored during follow up (five with Plasmodiumfalciparum parasitaemia and 29 lost to follow up). Two (0.7 %) patients experienced early treatment failure and 23 (8 %) late treatment failure. The overall risk of recurrence by day 28 was 9.4 % (95 % CI 6.4–13.6 %) with site-specific estimates of 3.8 % (95 % CI 1.2–11.3) for Shele, 21.9 % (95 % CI 12.2–36.1) for Guba, 5.9 % (95 % CI 1.9–17.3) for Batu and 9.2 % (95 % CI 4.5–17.6) for Shone.ConclusionThere is evidence of reduced CQ efficacy across three of the four study sites, with the degree of resistance severe enough in Guba to suggest that review of treatment policy may be warranted.

Highlights

Chloroquine (CQ) is the first-line treatment for vivax malaria in Ethiopia, but there is evidence for its declining efficacy
The greatest burden of disease is found in South and Southeast Asia, 10–20 % of all P. vivax malaria cases occur in Eastern and Southern Africa [1]
In Ethiopia, P. vivax accounts for approximately 40 % of all malaria infections [5]

Summary

Introduction

Chloroquine (CQ) is the first-line treatment for vivax malaria in Ethiopia, but there is evidence for its declining efficacy. This study aimed to provide data on the therapeutic efficacy of CQ against Plasmodium vivax malaria in southern Ethiopia. An estimated 2.85 billion people live at risk of Plasmodium vivax infection worldwide [1, 2] with the number of annual infections ranging from 19 to 240 million cases [3]. The greatest burden of disease is found in South and Southeast Asia, 10–20 % of all P. vivax malaria cases occur in Eastern and Southern Africa [1]. There have been an estimated 10 million clinical malaria cases annually, numbers have reduced substantially in the past decade. Since 2005, Ethiopia has scaled-up one of the largest and most ambitious malaria control programmes in Africa. The programme is designed to support the country‘s Health Sector Development Plan (HSDP), and the national child survival strategy, in order to reduce under-five mortality rates by two thirds by 2015 [6]

Objectives

Methods

Results

Conclusion