Drug Resistance in Malaria 2020 Report | UPSC

OVERVIEW

• Fight against this killer is becoming difficult due to the growing resistance against malarial drugs.
• Risk due to antimalarial drug resistance is not high currently, but can lead to a loss of hard-fought gains,

• According to the new WHO report, ACTs remain efficacious across the world, by and large.
• This parasite causes a majority of malarial cases in the WHO’s African and South-East Asian regions, the hubs of the disease.
• Wherever treatment failures were observed, policy changes were introduced.
• The five countries in the Greater Mekong Subregion (GMS) including Cambodia, Laos, Vietnam, Thailand and Myanmar have been epicentres of antimalarial drug resistance.

TITLE

• Drug resistance in malaria

PUBLISHED BY

• World Health Organisation (WHO)
• The report, released as part of the ongoing World Antimicrobial Awareness week, was prepared on the basis of studies conducted from 2010-2019.
• 1,046 studies conducted from 2010-2019 and involving 65,749 patients was analysed for preparing the report.

HIGHLIGHTS

• The report says that some ACTs combinations are no more efficacious in the above mentioned epicentre countries.

• However, the saving grace is that not all ACTs are ineffective yet and at least two are still working.
• The mutations in the malarial parasite have been responsible for artemisinin partial resistance.
• As many as 1,044 studies conducted globally from 2010-2019 confirmed the PfK13 mutation.
• The highest prevalence of PfK13 mutations was found in the GMS.
• ‘C580Y’ is the mutation most frequently identified.

OTHER MALARIA PARASITE

• The other common parasite that causes malaria, especially in India, is P vivax.

• P vivax resistance to chloroquine had been reported from all WHO regions.
• Antimalarial therapies other than CQ had been deployed to treat malaria cases and they had shown effective results.

REPORT ANALYSIS

DISEASE INCIDENCE AND TRENDS

• Malaria occurs in over 90 countries worldwide.

36% of the global population live in areas where there is risk of malaria transmission. 

• Each year an estimated 300 to 500 million clinical cases of malaria occur.
• This makes malaria one of the most common infectious diseases worldwide.

SOURCES : WHO 

• Malaria transmission occurs primarily in tropical and subtropical regions in sub-Saharan Africa, Central and South America.
• The disease is also prevalent in the Middle East, the Indian subcontinent, South-East Asia, and Oceania.

CAUSING AGENTS

• In humans, malaria infection is caused by one or more of four species of intracellular protozoan parasite.

DIAGNOSIS

• Simple light microscopic examination of Giemsastained blood films is the most widely practised
• A second method is a modification of light microscopy called the quantitative buffy coat method is also used.

CURRENT STATUS OF DRUG-RESISTANT MALARIA

• Resistance to antimalarial drugs has been described for two of the four species of malaria parasite that naturally infect humans.

• Although the geographical distribution of resistance to any single antimalarial drug varies greatly.

FACTORS CONTRIBUTING TO THE SPREAD OF RESISTANCE

• Disparate issues as human behaviour
• Vector and parasite biology
• Pharmacokinetics, and economics.
• Conditions leading to malaria treatment failure .

TREATMENT

• Drug resistance is not an all-or-nothing phenomenon, chloroquine still retains adequate efficacy.

INDIAN SCENARIO

• The report noted – Tripura, Arunachal Pradesh and Mizoram had shown that the parasite had become resistant ‘artesunate and sulfadoxine-pyrimethamine (AS+SP) combination’.

• These states have shifted to using artemether-lumefantrine .
• All other states which show resistance to the AS+SP combination will have to make this move.
• In India, 28 different mutations had been detected in the studies conducted in the last ten years.

GLOBAL IMPACT

• A widespread resistance scenario could emerge on the basis of a study of hypothetical scenarios .

• This would result in a yearly excess of 22 million treatment failures, 116,000 deaths .
• The costs include an estimated $130 million to change treatment policy.