Get serious about ‘one health’
THE world has not yet gotten over the coronavirus pandemic fully, with new cases still being reported from many countries, including India. Amidst the efforts to end the pandemic has emerged a new health threat — a multi-country outbreak of monkeypox. Some 17,000 cases have been reported from 75 countries. India has recorded four confirmed cases so far.
Given the large livestock and human populations that live close to forests and wildlife habitats, India is a hotspot for zoonotic diseases.
Although not a novel virus like SARS-COV-2, which led to the Covid pandemic, monkeypox has spread rapidly even to countries that have not seen it earlier. The outbreak has been declared an international health emergency because WHO experts see a risk of its further international spread. These are the early days of the outbreak and scientific data about new modes of transmission is still emerging. Surveillance and public health measures have been suggested based on available data, and past knowledge. However, the risk of the virus leading to disruption in travel, etc., remains low, for now, and a vaccine for it exists. So, there is no need to panic.
Yet the frequency with which new health threats are emerging shows that emerging and re-emerging infections, particularly zoonotic diseases, are going to dominate the health discourse. Monkeypox is a re-emerging disease. It has been endemic in about a dozen countries in central and western Africa for close to half a century. It is causing some concern now because the current outbreak has spread to dozens of non-endemic countries.
The monkeypox virus belongs to the same genus as smallpox. Its recent history is intertwined with that of smallpox. The monkeypox virus was first reported in 1959 from long-tailed macaque monkeys used in lab experiments for testing new drugs. It was reported from a lab in Copenhagen that had imported monkeys from Singapore. When WHO launched the smallpox eradication programme, its medical officer-in-charge DA Henderson undertook a study to explore if non-human primates like monkeys were a reservoir of the smallpox virus. This was critical because if there was a large reservoir of smallpox in the wild, it could pose a threat to the smallpox eradication programme in humans.
In the 1960s and 1970s, India used to export monkeys for animal studies in western labs. Henderson surveyed 26 major labs which had colonies of experimental monkeys. Several of them reported the presence of monkeypox but did not find any transmission to humans. The Lederle Laboratories handled some 8,000 monkeys and reported the presence of monkeypox virus in some rhesus monkeys that had arrived from India. Another US drug company, Wyeth Laboratories, also found the monkeypox virus in monkeys sourced from India.
Henderson’s study published in 1968 is a significant pointer to the presence of monkeypox in Indian monkeys, though the study concluded that ‘man may be comparatively insusceptible’ to the virus. He was proved wrong when the first case of monkeypox in humans was reported from Congo in 1970 by WHO’s smallpox eradiation officers. Several monkey species inhabited the region from where the case was reported, and monkey meat was considered a delicacy among local people. The first outbreak outside endemic countries was reported in the US in 2003.
Animals are a reservoir of a range of pathogens and viruses. Sometimes these viruses can jump species and transmit to humans. In recent years, we have seen several outbreaks of zoonotic diseases, such as avian influenza, SARS, pandemic influenza H1N1, MERS-CoV, ebola and SARS-Cov-2. Even commonly reported rabies, which spreads from dogs, is a zoonotic disease. Viruses causing these diseases spread due to an interplay between humans, animals and the environment, and they affect human and animal health, and can potentially impact food supplies. Many factors are responsible for growing contact between humans and animals — from deforestation to a rise in meat consumption and even pet-keeping. In recent years, Indians have taken to the hobby of keeping exotic animals as pets. Livestock and other animals like monkeys and dogs live in proximity in many regions. The threat of new infectious agents is also growing due to increased travel, changing food habits and international trade in animal meat.
In order to prevent and contain zoonotic diseases, it is necessary to take an integrated approach to human and animal infections in what has been dubbed ‘one health’. It means different agencies concerned with animal and human health, food supply, wildlife, etc., should work together. There needs to be constant monitoring of infections shared among humans, livestock and wild animals. In the past few years, a number of inter-sectoral committees, plans and frameworks have been prepared to implement ‘one health’, but the progress is tardy. The National Centre for Disease Control has directed all states and UTs to form state and district-level zoonotic committees, but not all states have this infrastructure in place. Wherever these panels exist, there is ambiguity on aligning the work of animal husbandry, forests and wildlife departments when it comes to carrying out tasks, such as surveillance and monitoring. There is a lack of technical capacity at various levels. In border states in the Northeast, the need is for surveillance of transboundary pathogens. In addition, Integrated Disease Surveillance Programme meant for monitoring new human infections needs further strengthening.
Given the large livestock population and human populations that live close to forests and wildlife habitats, India is a hotspot for zoonotic diseases. The Covid pandemic, and now the monkeypox outbreak, is a reminder of the looming dangers to human health and the need for urgent action. India needs to prioritise investments to strengthen the human and animal health infrastructure at all levels, develop necessary technical workforce and operationalise policies to make ‘one health’ a reality on the ground.
