Normally, diseases that break out during the rainy season tend to fade away on the withdrawal of the monsoon. That hasn’t happened this year. Infections typical of hot and humid weather, such as dengue, malaria, encephalitis, meningitis and chikungunya, have tended to persist despite the onset of winter. Meanwhile, cold-weather maladies like various types of influenza, including the dreaded swine flu and bird flu, have also surfaced. Delhi alone has recorded more than 1,800 cases of dengue – the count of unreported cases must be much higher – causing scores of deaths. Mumbai, too, has seen over 700 cases of dengue, including some deaths, the most famed victim being filmmaker Yash Chopra. The situation in other cities and villages is no different. And over a dozen cases of swine flu, caused by the H1N1 virus, have come to light in areas around Delhi.
These diseases may not abate soon due to the laxity of civic administrations in undertaking adequate preventive measures and the emergence of newer forms of pathogens and of infection carriers that are hardier and more difficult to control. For example, the mosquito species Aedes albopictus, known commonly as the tiger mosquito, has now begun to spread the dengue virus. Unlike the more common dengue-carrier Aedes aegypti, which breeds in stagnant water and stops multiplying in cold weather, the tiger mosquito can reproduce even in fresh water found indoors and can withstand the cold. The coexistence of several species of mosquitoes, including the malaria-carrying Aedes anopheles, makes diagnosis of the exact infection difficult for the doctors to begin the treatment in time. Meanwhile, encephalitis, which has killed nearly 400 people – mostly children – in Uttar Pradesh alone, continues to rage out of season. An unseasonably warm early winter in many parts of India, related perhaps to climate change, can also be considered partly responsible. Nor is India alone in seeing diseases that seem out of time and place. Greece, which had declared malaria eliminated in 1974, is suffering an epidemic of the disease this year.
Given that no vaccine is yet available for many of these diseases, preventing the proliferation of vectors, notably mosquitoes, by breaking their breeding cycle seems the best way to tame them. Though civic administrations often tend to put the onus of doing so on the public, asking people to avoid accumulation of water in their premises, this action alone will not suffice. Stagnant water in drains and accumulated leaves in public places need to be cleared regularly. Bird flu and swine flu infections, which spread through air and not through vectors, are known to respond to some of the available prophylactic and curative medicines, including Tamiflu, which need to be stocked and made available to the public at affordable prices. Meanwhile, the battle against climate change must continue. To be effective, the combat against these diseases needs to be carried out on many fronts.