The repeated outbreaks of dengue and chikungunya reveal our limited ability to prevent vector-borne diseases. At this juncture, it would be expedient to look at yet another threat that looms large on the horizon.
The Zika virus could be India’s next big public health crisis. It is spread by the Aedes mosquito — the same one that is responsible for the spread of diseases like dengue and chikungunya. However, not a single case of Zika has been reported in the past several months. The absence of the disease could actually signal “under-reporting, misdiagnosis or high level of immunity in people”, as has been conjectured in a recent paper published by researchers from the University of Oxford. Further, other studies have shown that India has the perfect climate for the virus to spread exponentially. A recent study published in The Lancet says that India is at high risk for the spread of Zika, as it hosts over 67,000 travellers from areas where there is an active circulation of the virus.
Said to spread through sexual contact, the virus becomes dangerous for young women of child-bearing age. However, the fact that except for pregnant women, Zika causes a mild illness, often indistinguishable from other causes of viral illnesses, could be crucial to understanding one possible reason behind the non-detection of the virus in India. Until and unless more penetrating surveillance systems are put into place, it would be difficult to state with confidence that the virus was actually absent from India.
Globally, there has been a move to pre-empt and contain the spread of the virus and not repeat the mistakes made during the Ebola outbreak, which raged on unchecked for far too long. The creation of data and knowledge sharing platforms, like the WHO’s Zika Open, where research studies on the virus are fast-tracked and published online, has helped the global community deal with the uncertainty that surrounded the pathogen in the early days of its emergence. The increased focus on and funding for the disease has sparked a research race where investigations into diagnostic medical devices and vaccines have been initiated remarkably early — another notable deviation from the Ebola experience.
However, the truth remains that medical devices and vaccines, although they sound like attractive options to counter an emergent disease, are often not the best use of limited resources, especially in the setting of an infection spreading on a global scale. These interventions are resource-intense endeavours that need to go through several levels of animal and human testing before they can be deployed on a mass scale. Not only does this take a long time, but there is also the attendant risk that the intervention will fail at one of the many levels that it needs to navigate. There has to be a larger corpus of funding in basic preventive mechanisms, which have been shown to be the best weapon against vector-borne diseases.
If the crisis that had struck Brazil last year has to be kept at bay in India, the entire public health machinery has to gear up to provide diagnostic aids to vulnerable groups, and supportive therapy to potentially affected mothers. It is an urgent wake-up call for health planners and policy-makers, one that nudges them yet again, to invest in primary and preventive healthcare ahead of tertiary healthcare, well before an epidemic breaks out.
Manish Kakkar, senior public health specialist, Public Health Foundation of India
The views expressed are personal