Malaria makes comeback amidst COVID-19 surge
By Dilanthi Jayamanne
While the entire country keeps count on the number of rapidly increasing COVID-19 cases and its death toll during the past few days, Sri Lanka may be faced with another danger from one of its old friends – named Anopheles; the mosquito that is very much alive and is seen in several dry areas of the country even after the World Health Organisation awarded Sri Lanka the certification for Malaria elimination in 2016.
Director of the Anti Malaria Campaign (AMC), Dr. Prasad Ranaweera said that at the time the main epidemiological aim had been elimination of the disease, there had been a steady reduction of case incidence and the simultaneous elimination of both Plasmodium Falciparum and Plasmodium Vivax - the disease causing parasites.
But since 2016, after the country received the certification, even qualified medical practitioners failed to recall that Sri Lanka had a disease called Malaria and that the mosquito only needs to transmit the virus from one body to another while feeding. But as the campaign focused on preventing local transmission of malaria, the possibility of imported infections was overlooked.
Dr. Ranaweera said, the Government spent over Rs. 7 billion rupees annually to prevent a re-emergence of malaria in the country. Last year alone the AMC received USD 1 million to assist the programme. With the ability of the Malaria causing parasite to remain hidden in the human liver for a period of one year the campaign had to stay vigilant – especially with regard to those who tour malaria endemic countries such as India and Haiti.
Towards December 2016 and early 2017 Entomologists engaged in surveillance identified a new malaria causing mosquito. Anopheles Stephensi was vastly detected in the Districts of Mannar, and spread out to the areas of Vavuniya, Jaffna and Mullaitivu.
The particular species of mosquito is a major vector of urban malaria in India and has been found in the areas of Madras and Kerala. Therefore, it is similar to its dengue causing counterpart which also thrives in urban surroundings. “Measures have been taken by the AMC surveillance teams and the Regional Medical Officers to spray chemicals in those areas in a bid to rid the Northern Province of what was possible to turn into a colossal issue in the future. But unfortunately Anopheles Stephensi is chemical resistant. Therefore, surveillance teams have taken measures to choose a biological method of getting rid of the mosquito by introducing guppy fish into wells and other places where clean water collects.
Containing the spread
Dr. Ranaweera explained that earlier the Malaria issue had been highly prevalent in the dry zone which was more conducive for its existence. It was once known as jungle fever by colonials – especially the British. However, as Stephensis is an urban mosquito, the AMC is doing its best to prevent the mosquitoes from spreading to Colombo, Gampaha, Kalutara and Kandy and other areas which have high population densities.
The AMC is also faced with another issue with the setting up of quarantine centres in several areas of the Northern Province last year with the onset of COVID-19. The AMC Director said that last year alone there had been 30 cases of malaria recorded; 11 of them were detected from quarantine centres. There were 125 persons who had returned from India in those centres for a period of three weeks which posed a severe risk to their lives since India was endemic to the infection. From January till date there have been seven cases of Malaria; one of them was detected from a quarantine centre in Puttalam, he said.
The Regional Medical Officers have been instructed to maintain surveillance of one kilometre range surrounding quarantine centres to prevent such crises.
There was also surveillance which should be maintained to prevent all possibilities of importing cases. According to the AMC’s website, travellers to sub-Saharan Africa have the greatest risk of both contracting malaria and dying from infection. “Many countries in South Asia and South East Asia neighbouring Sri Lanka were also endemic to the infection. Travellers to these countries were also at risk of contracting the disease. Some groups of travellers, especially young children, pregnant women and individuals with a weakened immune systems are at increased risk of developing serious illness if they become infected with malaria.,” the campaign’s website states.
Taking these facts into consideration Sri Lanka cannot just sit back and relax thinking that it had been able to overcome one mosquito-borne disease. It took the country a painstaking 45 years to overcome malaria. The debacle would be doubled should Anopheles Stephensi, the urban mosquito, invade Colombo - where population density is the highest with 13,364 persons per square kilometre. The country’s average population density is 325 persons per square kilometre. Therefore, one can only imagine that the mosquito is bound to have a field day should that happen.