A bridge too near: a major health risk of land-bridging India and Sri Lanka

Many have discussed the benefits and hazards to Sri Lanka of a land bridge which is being proposed between Talaimannar in Sri Lanka and Rameswaram in South India. In an article published in the Island newspaper of September 22, Mr Ashley de Vos has elucidated his concerns about the proposed bridge in which he cites the re-introduction of malaria to Sri Lanka as one of the plausible risks. We write as persons with some technical knowledge on the subject of malaria to endorse Mr de Vos’ warning and explain further that it is not only the malaria parasite which, he points out, that is at risk of being introduced from India, but a type of mosquito that transmits the disease in India, which would magnify the risk many fold and introduce a far more dangerous type of malaria than we ever had in this country.

Today there is no more malaria in Sri Lanka, the country having successfully eliminated the disease three years ago. Malaria in Sri Lanka was transmitted by a mosquitoe Anopheles culicifacies and a few other less important species, all of which breed in rural environments. Thus, malaria was hardly ever endemic in cities and urban environs in this country except during a few rare epidemics in the distant past. In India malaria continues to be a massive public health problem partly because, in southern India in particular, the disease is transmitted by an urban mosquitoe – Anopheles stephensi, which breeds prolifically in and around cities close to human habitations, making malaria more difficult to control there. An.stephensi has never been prevalent in Sri Lanka, and what marks its boundaries and keeps it within the shores of India is the ocean that intercepts the landmasses of the two countries. There is, even now, a minute risk of this mosquitoe being introduced to Sri Lanka through aircrafts but the risk is small, and is mitigated by the WHO recommended strategy of spraying aircrafts with insecticides prior to landing. Similar precautions should, in fact, be taken with respect to sea crafts.

A land bridge would, almost certainly enable An.stephensi to make the jump to Sri Lanka by steadily breeding in suitable sites along the bridge – a possibility that does not exit today because of the ocean buffer zone that intercepts it. If this mosquitoe is introduced to the country the consequences would be nothing short of disastrous – malaria will become endemic in the major cities as well as in the rural areas plunging the country into a public health catastrophe – this time a much more serious one that we have ever experienced, not only because it will spread in cities as well as in rural areas, but because a dangerous type of multi-drug resistant malaria which is prevalent in the Mekong region has made its way to Myanmar and is now at India’s eastern border, with a likelihood of spreading further west and south. Sri Lanka is currently not at risk of multi-drug resistant malaria because the country is free of malaria transmission, but if malaria returns we will be "sitting ducks" for an upheaval –because of an extremely dangerous type of malaria which is to come.

The risk we describe here is not theoretical - another insect-borne disease leishmanasis, particularly of the cutaneous (skin) type which was not endemic in Sri Lanka but endemic in India emerged here a few decades ago, we believe imported from India, and though its impact is not as great as that of malaria, it is now imposing a considerable health burden on the people of this country. If India’s malaria vector mosquito, An.stephensi gets introduced here, which is very likely to happen through a land bridge, malaria of a type that is far more difficult to control because of the urban vector, and more fatal than before because of drug-resistance could be re-introduced.

Articles that one of us has written and published in this newspaper in the past two years, have described the tremendous effort that the Anti-Malaria Campaign of Sri Lanka is mounting to detect and treat every malaria infected person coming into this country - and there are many, mainly from India, so that they do not spread the disease here. The possibility of re-introducing malaria to Sri Lanka exists even now because of extensive travel to and from Sri Lanka bringing malaria infected persons who contracted the disease overseas, mainly in India. This, at present, is a risk which is very manageable through efficient surveillance systems, but if, the numbers of migrant labour from India increases as it will invariably do consequent to a land bridge, and much more importantly, if India’s mosquito vector is introduced, we may not be able to do much, other than watch as the disaster unfolds.

The argument in favour of a bridge is made on the grounds of enhancing human development through removing geographical barriers. We implore authorities to give adequate consideration to the associated risk of re-introducing a disease, malaria, which is intractably linked to human development. It is with the knowledge that malaria thwarts human development that affluent countries are investing billions of dollars to rid the world of malaria through the "Global Fund to fight AIDS, TB and Malaria" – not an easy task, which Sri Lanka has finally achieved to its credit, and for which it is being admired by the world. The country needs now to sustain this achievement. India is, sadly, steeped in a massive burden of malaria with little chance of eliminating it in the near future – to the contrary it is at the doorstep of the extremely dangerous multi-drug resistant malaria at its eastern land border with Myanmar. Let us point out that malaria has, for centuries, impoverished Sri Lanka by stunting both cognitive and physical growth of its people, decreasing productivity and entrenching us in poverty. We are now rid of it, and thus, of a major impediment to human development. We hope we have convinced the public and the relevant authorities of the need to factor this risk of re-introducing malaria to Sri Lanka into the equation of human development – which forms the very basis on which the bridge is being considered.

Dr. Kamini Mendis

Dr. Nihal Abeyesundere

Dr. Pushpa Herath

All three signatories are former WHO malaria experts who also have a wide experience in Sri Lanka

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