On September 5 this year, Sri Lanka was declared malaria-free at the 69th Session of the World Health Organisation (WHO) Regional Committee for South-East Asia held in Colombo. This is another milestone in Sri Lanka’s outstanding achievements in public health, also reflected in standard health indicators such as life expectancy, infant mortality and average family size.
The only other country to have achieved malaria eradication in the WHO’s South-East Asian region consisting of 11 countries is the Maldives. It is no accident that these two countries have a long history of effective public health interventions and a well-developed health infrastructure. While these malaria-free countries do provide an important breakthrough for the South Asia region as a whole, it is important to note that the long-term viability of malaria-free status in countries that have already achieved this status depends on gradual advances in malaria control and eradication in the region as a whole. This is because malarial parasites can be easily reintroduced from malaria-endemic countries to malaria-free countries through human migration across national boundaries; these can be in the form of flows of tourists, pilgrims, workers, investors and refugees. This should caution us about being unduly optimistic about consolidating malaria eradication in selected countries without containing malaria in the region as a whole. Moreover, it is essential that the WHO regional office works closely with other donors and national governments to fight the remaining malaria outposts in the region.
Sri Lanka’s battle
Sri Lanka’s struggle against malaria has been a long and arduous one. The use of DDT as a vector control measure started in British Ceylon in the 1940s; the introduction of western antimalarials began in the 1930s. As pointed out by Fernando and Warusavithana in ‘100 Years of Malaria Control Efforts in Sri Lanka, 1911 to 2011’, the story of malaria control in Sri Lanka has been characterised by periods of spectacular advances and, equally, setbacks. Sri Lanka experienced one of the worst malaria epidemics ever recorded (1934-1935) after a triple disaster — a severe drought, food shortages and a malarial outbreak in the densely populated wet zone regions which are generally malaria-free.
The development of a comprehensive welfare state in Sri Lanka, inclusive of free education, free health care and subsidised food rations provided by the state to all citizens with effect from the 1940s, was in part a response to this massive epidemic that broke out a few years after universal franchise was introduced to the country in 1931. Confirming Amartya Sen’s view that famines rarely occur in functioning democracies, the elected political leaders in the affected areas highlighted the misery of malaria victims and pushed for health care and welfare reforms. Many in the first generation of political leadership in independent Ceylon saw the devastation caused by the 1934-35 malaria epidemic, and had directly participated in the relief work provided to populations affected by the epidemic. Therefore, they were determined to campaign for expanding health services and making them accessible to the population at large at state expense. Regular DDT spraying in malaria endemic regions began in 1945 and the number of malaria cases reported dropped from 2.7 million in 1946 to 17 in 1963 —a spectacular success in containing the spread of malaria. At that time the health authorities in Sri Lanka were optimistic about achieving malaria eradication in the near future.
However, optimism was short-lived as a full-scale malaria epidemic broke out again in 1968. Vector resistance to DDT and parasitic resistance to antimalarials were first reported in the 1970s, posing a serious threat to Sri Lanka’s progress. along with the malaria eradication strategy. New development projects such as the Accelerated Mahaweli Development Programme (1977) further complicated the task of malaria control due to development-induced population movements from the malaria-free wet zone to the malaria-endemic dry zone as well as due to enhanced vector breeding following environmental changes triggered by development schemes. By the 1980s, malaria infections were back to the levels seen in the pre-DDT era. An increase in P. falciparum malaria was the new challenge even though malaria mortality had declined due to improved health services in the country by this time.
The Anti-Malaria Campaign (AMC)responded to these challenges by switching from DDT to malathion, changing the drug regime administered to malaria patients, changing the approach from malaria eradication to control, and integration of malaria control with other health services in the country. Health volunteers were deployed to educate the public about the disease, its treatment and prevention. A variety of measures such as insecticide-impregnated bed nets and mosquito repellents were introduced in a multi-pronged attack on malaria vectors and parasites. By the early 1990s, there were signs that the interventions being used at the time had the effect of containing the disease and were limiting it to certain pockets where increased surveillance was necessary.
The struggle against malaria in Sri Lanka experienced a major setback due to the civil war between the Sri Lankan security forces and the LTTE, with Vanni, the primary theatre of war, being a malaria-endemic region and a large civilian population in the Northern Province being displaced into this region. An epidemic broke out in Vanni from 1998 to 2002, affecting civilians, LTTE cadres and Sri Lankan security forces. Despite the raging hostilities between the security forces and the LTTE since 1983, there is no evidence of any manipulation of malaria interventions for military purposes either by the state or the LTTE. On the contrary, the two warring parties opted to stop fighting when anti-malaria work was being carried out by the AMC, perhaps realising that malaria was a common enemy for combatants and civilians on both sides of the ethnic divide. The peace accord signed between the government and the LTTE under Norwegian mediation also facilitated the gradual containment of the war-induced malaria epidemic in the affected regions. Even though successful malaria containment in Sri Lanka was achieved prior to the last phase of the war, it is significant that Sri Lanka achieved malaria-free status in the aftermath of the war when the dust had settled and the resettlement of war-displaced population had been largely accomplished.
Malaria is by and large under control in much of South Asia. The remaining hotbeds of malaria transmission in the region are in conflict-affected and frontier regions in Afghanistan, northeast India and Myanmar and require a long-term focal attention in the form of surveillance of the vector, parasite and human behaviour conducive to malaria transmission, a multi-pronged approach inclusive of increased community participation in malaria control activities, livelihood development and poverty reduction, conflict prevention and reconciliation among rival parties. If we are to ensure that the disease burden is to not become an obstacle to future developments in the South Asia region, efforts must be made to rollback these diseases as we seek to roll-out broad-based development in the region as a whole. As elaborated in my recent book, ‘Decolonisation, Development and Disease: A Social History of Malaria in Sri Lanka’ (2014), successful eradication of malaria calls for a shift from a narrow biomedical to a human-centric approach. (The Hindu)