Efficacy of Chloroquine for the Treatment of <i>Vivax malaria</i> in Northwest Ethiopia

<div><p>Background</p><p>Resistance to anti-malarials is a major challenge for effective malaria control in sub-Saharan Africa. This triggered a need for routine monitoring of the efficacy of the antimalarial drugs every two years in all malaria endemic countries. Chloroquine remained the drug of choice for the treatment of vivax malaria in Ethiopia. Though, a strong scientific evidence of chloroquine resistance to <i>P</i>.<i>vivax</i> that could have brought change of treatment regimen is yet to be established in Ethiopia, continuous and regular monitoring of drug’s efficacy is critical for establishing rational anti-malarial drug policies. This study therefore, assessed the therapeutic efficacy of Chloroquine (CQ) for the treatment of <i>Plasmodium vivax</i> infections in Northwestern Ethiopia.</p><p>Methods</p><p>An observational, 28- day therapeutic clinical efficacy study was conducted from August to December, 2014, in Northwest Ethiopia. Patients confirmed to have monoinfection of vivax malaria, aged above 6 months were included. All subjects were treated with standard chloroquine dose of 25 mg/kg for three (3) days. Parasitological and clinical outcomes of treated patients were then evaluated on days 1, 2, 3, 7, 14, 21, and 28 during the entire 28-day follow-up period. A portable spectrophotometer (HemoCue Hb 301 System, Sweden) was used to estimate hemoglobin concentration.</p><p>Results</p><p>A total of 69 subjects had completed follow up. Some 57/69 (82.6%) had fever at enrolment and the rest 12 patients 48 hours before enrollment. Out of total, 65/69 (94.2%) and 66/69 (95.6%) of the study subjects were free of fever by day 1 and day 2 respectively but fever was cleared in all subjects by day 3. At base line the mean asexual parasitemia was 3540 parasites/μL of blood. Parasite carriage on day 3 was 3%. The overall cure rate (an adequate and clinical parasitological response) was very high (97%) [(95% CI = 93.1–99.4)]. The time to parasite, fever and gametocyte clearance as expressed in mean (SD) was 35 (3), 25 (4.6), 28 (3.2) hours respectively. Mean hemoglobin was significantly increased (P<0.001) from 12.2 (7–15) g/dl at day 0 to 13.3 (10–16) g/dl on day 28.</p><p>Conclusions</p><p>In view of our findings, CQ remains efficacious for the treatment of vivax malaria in the study area. However, there is a need to monitor CQR regularly using molecular and or biochemical tools for better evaluation of treatment outcomes.</p></div

Pattern of parasite, gametocyte and fever clearance in <i>P</i>. <i>vivax</i> monoinfected patients treated with Chloroquine in Northwest Ethiopia.

<p>Pattern of parasite, gametocyte and fever clearance in <i>P</i>. <i>vivax</i> monoinfected patients treated with Chloroquine in Northwest Ethiopia.</p

Hemoglobin concentrations and degree of anemia in <i>P</i>. <i>vivax</i> infected patients before CQ treatment and at the end of treatment follow up, with respect to age, Northwest Ethiopia (August–December, 2015).

<p>Hemoglobin concentrations and degree of anemia in <i>P</i>. <i>vivax</i> infected patients before CQ treatment and at the end of treatment follow up, with respect to age, Northwest Ethiopia (August–December, 2015).</p

Map of the study site.

<p>Metekel Zone, Bullen District.</p

Patient recruitment and follow-up for the trial of CQ efficacy against <i>P</i>. <i>vivax</i> malaria in Bullen Health Centre Northwest Ethiopia (17 August to 19 December, 2014).

<p>Patient recruitment and follow-up for the trial of CQ efficacy against <i>P</i>. <i>vivax</i> malaria in Bullen Health Centre Northwest Ethiopia (17 August to 19 December, 2014).</p

Parasite and fever clearance rate and hemoglobin recovery in study participants Bullen Health center, Northwest Ethiopia.

<p>Parasite and fever clearance rate and hemoglobin recovery in study participants Bullen Health center, Northwest Ethiopia.</p

Baseline characteristics of the study participants, Bullen Health Center, August-December, 2014, Bullen, Ethiopia.

<p>Baseline characteristics of the study participants, Bullen Health Center, August-December, 2014, Bullen, Ethiopia.</p