In the past two decades, path-breaking achievements have been made to eliminate malaria. Globally, with scientific advancement new knowledge on malaria parasites, insights into vector biology and newer control strategies have helped target interventions resulting in substantial transmission reduction leading to disease elimination.
As per the Global Malaria Report 2020 by the World Health Organization (WHO), in 2019 an estimated 229 million malaria cases and 409,000 deaths in 87 malaria-endemic countries are recorded, with a large concentration of the total malaria burden (94%) in Africa. India shared 2% of the total global malaria cases in 2019.
Global Malaria Elimination scenario: How many countries have successfully eliminated malaria?
Since 1900, 127 countries have registered malaria elimination. In 2021, two countries El Salvador on February 25 and China on June 29 were declared malaria-free by the WHO.
This is definitely not an easy task. It needs proper planning and a strategic action plan based on the local situations. All these countries followed the existing tools and strategies to achieve the malaria elimination goal. The main focus was on surveillance.
China followed some specific strategies, namely strong surveillance following the ‘1-3-7’system: malaria diagnosis within 1 day, 3 days for case investigation and by day 7 for public health responses.
Molecular Malaria Surveillance for drug resistance and genome-based approaches to distinguish between indigenous and imported cases was conducted. All borders to the neighbouring countries were thoroughly screened to prevent the entry of unwanted malaria into the country.
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India has a great history of malaria control. The highest incidence of malaria occurred in the 1950s, with an estimated 75 million cases with 0.8 million deaths per year.
The launch of National Malaria Control Programme in 1953 and the National Malaria Eradication Programme in 1958 made it possible to bring down malaria cases to 100,000 with no reported deaths by 1961. This is no doubt a great achievement has been made so far.
But from a nearing stage of elimination, malaria resurged to approximately 6.4 million cases in 1976. Since then, confirmed cases have decreased to 1.6 million cases, approximately 1100 deaths in 2009 to less than 0.4 million cases and below 80 deaths in 2019.
India accounted for 88% of malaria cases and 86% of all malaria deaths in the WHO South-East Asia Region in 2019 and is the only country outside Africa among the world’s 11 `high burden to high impact’ countries.
The road ahead for India:
India is a signatory to National Framework for Malaria Elimination (NFME) 2016-2030 aiming for malaria elimination by 2030. This framework has been outlined with a vision to eliminate the disease from the country which would contribute to improved health with quality of life and poverty alleviation.
India stands at a very crucial stage. The present challenge is the detection of asymptomatic/afebrile cases in most endemic areas.
The current approach for mass screening with Rapid Diagnostic Tests (RDTs) would not fulfil the basic purpose because these tests fail to detect <100 parasites/µL blood and also the problem of deletion of certain diagnostic genes in the Plasmodium falciparum dominated areas. To overcome this, a microPCR-based point-of-care device that detects <5 parasites/µL blood can be used. The same technology is being used in Tuberculosis and COVID-19 diagnosis.
Molecular Malaria Surveillance must be used to find out the drug-resistant variants and genetic-relatedness studies to find out the imported or indigenous cases.
Finding active and functional gametocyte carriage of P. falciparum in endemic areas should get priority. It has been found that when transmission decreases malaria becomes focal and residual. The surveillance must be strengthened and using smart digital surveillance devices would be an important step. Real-time and organic surveillance is needed even in remote areas.
The results of each malaria case can be registered in a central dashboard at the National Vector Borne Disease Control Programme, as it is done for COVID-19 cases by Indian Council of Medical Research. All intervention activities must strictly be monitored. Vector biology, site of actual vector mosquito bite, host shifting behaviour, feeding time, feeding behaviour and insecticide resistance studies need to be carried out to support the elimination efforts. Medical entomologists who would help accelerate elimination plans should be appointed at both Central and State levels.
China collaborated with Harvard University and the Massachusetts Institute of Technology, USA for Molecular Malaria Surveillance. In India, there are very dedicated expert scientists who can take up such assignments.
The entire world is now facing the once in a century pandemic of COVID-19. This has resulted in an over 32% decline in total blood smear collection for malaria surveillance in 2020 in India compared to 2019. India has to quickly overcome this and make the elimination process back on track and put all efforts to make India malaria-free by 2030.
The author is a former scientist G, National Institute of Malaria Research, ICMR, Bengaluru Field Unit