Therapy and drug resistance in malaria

A systematic review of CQ-resistant Plasmodium vivax malaria infections in India

INTRODUCTION

Chloroquine (CQ) is the drug of choice for treating uncomplicated Plasmodium vivax (P. vivax) malaria in India. The knowledge about the exact burden of CQ resistance in P. vivax in India is scarce. Therefore, this systematic review aimed to assess the prevalence of CQ resistance in reported P. vivax cases from India.

METHODS

PubMed, EMBASE, and Web of Science, were searched using the search string: 'Malaria AND vivax AND chloroquine AND (resistance OR resistant) AND India'. We systematically reviewed in-vivo and in-vitro drug efficacy studies that investigated the CQ efficacy of P. vivax malaria between January 1995 and December 2022. Those studies where patients were followed up for at least 28 days after initiation of treatment were included.

RESULTS

We identified 12 eligible CQ therapeutic efficacy studies involving 2470 patients, Of these 2329 patients were assessed by in-vivo therapeutic efficacy methods and the remaining 141 were assessed by in-vitro methods. CQ resistance was found in 25/1787 (1.39%) patients from in-vivo and in 11/141 (7.8%) patients from in-vitro drug efficacy studies.

CONCLUSION

Based on the available studies, the prevalence of CQ resistance in P. vivax was found to be relatively lower in India. However, continued surveillance and monitoring are crucial to identify the emergence of CQ resistance.

Monitoring the chloroquine sensitivity of Plasmodium vivax from Calcutta and Orissa, India

Chloroquine-resistant Plasmodium vivax malaria was first reported in India in 1995. This report led to the round-the-year monitoring, in Calcutta (West Bengal) and Mayurbhanj district (northern Orissa), of the in-vivo sensitivity of local P. vivax to chloroquine (CQ). Between January 1998 and December 2001, 800 cases with microscopically confirmed P. vivax malaria were enrolled in the study. Each was given CQ in the regimen recommended both by the Government of India and the World Health Organization (i.e. a total of 25 mg/kg, over 3 days). Only six cases, of the 480 who completed the scheduled 28 days of follow-up, failed to clear their parasitaemias by day 5. Even these six cases had only low-level parasitaemias on day 5, and all were aparasitaemic by day 7. In the study area, despite the wide-spread abuse of CQ and the increasingly frequent reports of CQ-resistant P. falciparum, CQ appears to remain an effective drug in the treatment of P. vivax.

Cerebral malaria in rural India

OBJECTIVE

A cross-sectional hospital based study was carried out to investigate clinical features and outcome of cerebral malaria in a rural area.

METHODS

All children fulfilling inclusion criteria, were enrolled and were entered on specially designed proforma. Their peripheral smear (PS) were studied based on which the diagnosis was classified as definite cerebral malaria (DCM) and probable cerebral malaria (PCM).

RESULT

There were 2991 admissions in pediatric ward, of which 1394 (46.6%) were for fever. Of 781 (56.6%) cases with fever no cause was identified. Of the 56 cases positive for malarial parasite on PS 4.3% were Plasmodium vivax (PV) and 2.8% Plasmodium falciparum (PF). Fifteen patients fulfilled the criteria for study of which 7 were DCM and 8 belonged to PCM group. Twelve (80%) were in school-going age group and M : F ratio was 2 : 1. All patients presented with fever, and CNS involvement, 66.6% had convulsion, 7 developed coma, anaemia was seen in 60%, but only 20% required blood transfusion. Splenomegaly and hepatomegaly was seen in 53.3% and 47% cases respectively. Two patients died, one each in DCM and PCM. Cerebral malaria is a serious complication of severe falciparum malaria and is seen in approximately 32% of PF positive cases.

CONCLUSION

PCM is an entity which should be kept in mind when treating fever without definite focus in rural areas, because timely and specific therapy is lifesaving.