An Anopheles stephensi mosquito obtains a blood meal from a human host through its pointed proboscis in this undated handout photo obtained by Reuters, November 2015. Photo: Reuters/Jim Gathany/CDC.

The latest World Malaria Report released in December 2019 said there were 228 million malaria cases in 2018, down 3 million from 2017. In 2018, an estimated 405,000 people died of malaria, down about 2.6% from 2017. While African nations accounted for most cases as well as deaths, South Asia including India has one of the worlds highest malaria burdens.

According to the WHO, 19 countries in sub-Saharan Africa plus India bore almost 85% of the global malaria burden in 2019. Of them, only India reported any progress in reducing the number of malaria cases. (Interestingly, Algeria was declared malaria-free last year.)

According to the WHO, Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. Importantly, it is preventable as well as curable.

There are thousands of mosquito species in the world that are vectors for diseases like dengue, filariasis, chikungunya, yellow fever, elephantiasis, Japanese encephalitis and brain fever.

In 1897, a British medical doctor named Ronald Ross discovered that the female Anopheles mosquitoes are responsible for spreading malaria. Ross was born in the Almora district of Indias Uttarakhand. He studied in London and came back to India to work on malaria from 1882 to 1889. He found the link between mosquitoes and malaria transmission 15 years into his studies, and was awarded the medicine Nobel Prize in 1902 for describing the complete life cycle of the malarial parasite.

World Mosquito Day is observed every year on August 20 in recognition of his work, and even then the eradication of malaria is a major part of its awareness campaign.

In humans, malaria is caused by five species of parasites of the genus Plasmodium. Of these, P. falciparum accounts for the majority of malaria cases and deaths because of the severity of the infections it can cause (although infections of P. vivax have also been known to be dangerous). When a female Anopheles mosquito carrying a Plasmodium parasite bites a human, the parasite is transmitted through the skin. First, it invades first the liver through asexual reproduction and then targets the red blood cells. As a result, the human develops symptoms like fever with chills and anaemia, etc. If left untreated, malaria can kill.

At present, a major barrier to eradicating malaria is that malarial parasites have developed resistance against commonly used drugs to treat them, including chloroquine, sulfadoxine/pyrimethamine and even to the newer artesunate-based combination therapies. In the absence of an effective vaccine, its crucial that we find a way to restore these drugs potency against the parasite or develop new drugs that can be effective.

The ongoing novel coronavirus pandemic hasnt made matters easier, even if the world has developed (even temporarily) a heightened awareness of the effects of infectious diseases.

Since the virus is new, were still discovering more about it even as were working towards a vaccine. So in the meantime, researchers have been repurposing vaccines and other fever-curing drugs already approved by various regulatory bodies to resist COVID-19. This is how hydroxychloroquine, a very important antimalarial drug, hit the limelight and which Indias apex medical research body has recommended to the countrys healthcare workers as a prophylaxis, even if there is no evidence that it can effectively prevent COVID-19.

On the flip side, however, hydroxychloroquine tablets have become harder to find and use in places where chloroquine still remains effective against malarial parasites.

Additionally, and even though the current pandemic situation is serious, controlling malaria is also very important but has often been sidelined in the headlong rush to avoid the novel coronavirus. Both COVID-19 and malaria patients have fever, but more people with fever get tested for COVID-19 first before malaria. As a result, malaria diagnosis and treatment may get delayed.

There is no vaccine to prevent or cure malaria. One, designated RTS,S/AS01 and named Mosquirix, is currently undergoing clinical trials, after having displayed partial protection against malaria in young children.

Even though its easier said than done in the throes of a pandemic, its important that we keep up precaution, prevention, early detection and effective treatment, together with mosquito control efforts, to vanquish malaria.

Brief note on prevention

To lower your chances of getting malaria, considering the following steps:

G. Lakshmi is a life-sciences research scholar. Shilpi Garg is affiliated with BITS Pilani.

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World Malaria Day a Good Time to Remember COVID-19 Isn't the Only Crisis - The Wire