Battling disease

Why wildlife conservation is good for our collective health

From providing lifesaving drugs to buffering humans from disease, protection of wildlife habitat is key to human well-being.

What if we could reduce diseases and discover life-saving drugs by conserving natural habitat? Would saving ecosystems become more appealing if human health were on the line?

Well, although an underreported dimension of the destruction of wildlife habitat, human health is exactly what is at stake. Habitat destruction has played a role in the emergence of disease organisms that move between humans and other animals, such as Ebola, and even, some scientists argue, in the increase of incidences of Lyme disease. Loss of habitat has also had the unintended consequence of eliminating access to potentially lifesaving drugs by destroying the very places where those drugs originate.

Whether or not people care about nature for its own sake, these implications for human well-being should galvanise them toward habitat and wildlife conservation, and elevate conservation to the same level of importance as things such as cancer or stem cell research or efforts to eradicate malaria or HIV.

Disease emergence

Undisturbed, wild animals and their habitats can serve as a barrier preventing the spillover of emerging infectious diseases – EIDs – from animals to humans. Because the diseases and the animals have evolved together, the diseases have little to no effect on those animals. When transmitted to humans, however, those pathogens can result in EIDs. It has been estimated that 60% of recent EIDs have been zoonoses, and close to three-quarters of these originated in wildlife. The clearing of undisturbed habitat to pave way for human activities such as agriculture has created blurred boundaries between wild and domestic animals, helping to facilitate the jump to humans.

This is what happened in the cases of Nipah and Hendra viruses, among others. The clearing of forests in Southeast Asia and Australia, respectively, led certain types of flying fox fruit bats to move closer to farm animals (pigs in the case of Nipah; horses in the case of Hendra). The farm animals ate virus-ridden bat saliva or urine, became ill, and transmitted the disease to humans who came into contact with them. Neither virus was new, but both were kept from humans until habitat destruction facilitated the jump.

Zoonotic diseases exact an enormous human toll – identified diseases account for at least 2.7 million deaths and 2.5 billion cases of human sickness annually. In the developing world, zoonotic EIDs can exacerbate other public health challenges, such as lack of infrastructure and malnutrition resulting in increased bushmeat consumption, which can in turn introduce new varieties of EIDs. And zoonotic EIDs can have huge economic and social implications as well, such as loss of employment and business – familiar outcomes during outbreaks. For example, pig farmers in Malaysia incurred a loss of $244 million during a Nipah outbreak in 1998 and 1999 due to mass culling of pigs.

Almost half of human medicines come directly or indirectly from the natural world, even as less than 10 percent of all of the world’s biodiversity has been evaluated for potential drugs.

Surveillance, detection and responses to these outbreaks are unfortunately low in developing countries, which are often particularly vulnerable to the emergence of EIDs due to their proximity to areas of high biodiversity. As they develop, those countries and their people face higher exposure to zoonotic pathogens. Meanwhile, population density and increased global travel means transmission of these diseases will be effective, even in the developed world.

The tremendous harm zoonotic EIDs wreak globally points to a powerful need to improve our understanding of the role of wildlife ecology and the wildlife-livestock interface in their emergence. Increasing research in this area would offer tremendous benefit by improving our ability to predict which regions are most at risk and to prepare and respond to these threats. The recent surges in EIDs across the world underscore the importance of protecting wildlife habitat, both with speed and in scale.

Nature’s medicine

And then there’s medication: Almost half of human medicines come directly or indirectly from the natural world, even as less than 10% of all of the world’s biodiversity has been evaluated for potential drugs. Many lifesaving drugs, including some recent anti-cancer drugs, have originated in nature.

Yet all of this progress is likely just scratching the surface of nature’s incredible potential to yield health-promoting substances. New species are continually being found. Discoveries of bacteria that survive in the unlikeliest of places have opened possibilities for even more new drug discoveries. And scientists have recently begun tapping into potential drug discoveries from other members of the microbial world, too.

Meanwhile, 60% of people worldwide depend almost exclusively on plants for their primary medication. Animals are also used in parts of the developing world for traditional medicines. Yet, we are allowing the natural world to disappear without fully understanding what will be lost – or knowing at all, since we can only assume that some species are becoming extinct before humans even know about them. To protect these current and future sources of medicines, we need to protect the nature that provides them.

Studying and conserving nature is as important as any other human health initiative, and the health benefits of conservation need to be included alongside other discussions about saving nature. It is time to make the case that wildlife science and conservation are relevant to everyone’s life. Too many people’s health will be in jeopardy if we don’t.

Rashmi Bhat is a wildlife researcher in and participant in the Ensia Mentor Program. This article was first published in Ensia.

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Relying on the power of habits to solve India’s mammoth sanitation problem

Adopting three simple habits can help maximise the benefits of existing sanitation infrastructure.

India’s sanitation problem is well documented – the country was recently declared as having the highest number of people living without basic sanitation facilities. Sanitation encompasses all conditions relating to public health - especially sewage disposal and access to clean drinking water. Due to associated losses in productivity caused by sickness, increased healthcare costs and increased mortality, India recorded a loss of 5.2% of its GDP to poor sanitation in 2015. As tremendous as the economic losses are, the on-ground, human consequences of poor sanitation are grim - about one in 10 deaths, according to the World Bank.

Poor sanitation contributes to about 10% of the world’s disease burden and is linked to even those diseases that may not present any correlation at first. For example, while lack of nutrition is a direct cause of anaemia, poor sanitation can contribute to the problem by causing intestinal diseases which prevent people from absorbing nutrition from their food. In fact, a study found a correlation between improved sanitation and reduced prevalence of anaemia in 14 Indian states. Diarrhoeal diseases, the most well-known consequence of poor sanitation, are the third largest cause of child mortality in India. They are also linked to undernutrition and stunting in children - 38% of Indian children exhibit stunted growth. Improved sanitation can also help reduce prevalence of neglected tropical diseases (NTDs). Though not a cause of high mortality rate, NTDs impair physical and cognitive development, contribute to mother and child illness and death and affect overall productivity. NTDs caused by parasitic worms - such as hookworms, whipworms etc. - infect millions every year and spread through open defecation. Improving toilet access and access to clean drinking water can significantly boost disease control programmes for diarrhoea, NTDs and other correlated conditions.

Unfortunately, with about 732 million people who have no access to toilets, India currently accounts for more than half of the world population that defecates in the open. India also accounts for the largest rural population living without access to clean water. Only 16% of India’s rural population is currently served by piped water.

However, there is cause for optimism. In the three years of Swachh Bharat Abhiyan, the country’s sanitation coverage has risen from 39% to 65% and eight states and Union Territories have been declared open defecation free. But lasting change cannot be ensured by the proliferation of sanitation infrastructure alone. Ensuring the usage of toilets is as important as building them, more so due to the cultural preference for open defecation in rural India.

According to the World Bank, hygiene promotion is essential to realise the potential of infrastructure investments in sanitation. Behavioural intervention is most successful when it targets few behaviours with the most potential for impact. An area of public health where behavioural training has made an impact is WASH - water, sanitation and hygiene - a key issue of UN Sustainable Development Goal 6. Compliance to WASH practices has the potential to reduce illness and death, poverty and improve overall socio-economic development. The UN has even marked observance days for each - World Water Day for water (22 March), World Toilet Day for sanitation (19 November) and Global Handwashing Day for hygiene (15 October).

At its simplest, the benefits of WASH can be availed through three simple habits that safeguard against disease - washing hands before eating, drinking clean water and using a clean toilet. Handwashing and use of toilets are some of the most important behavioural interventions that keep diarrhoeal diseases from spreading, while clean drinking water is essential to prevent water-borne diseases and adverse health effects of toxic contaminants. In India, Hindustan Unilever Limited launched the Swachh Aadat Swachh Bharat initiative, a WASH behaviour change programme, to complement the Swachh Bharat Abhiyan. Through its on-ground behaviour change model, SASB seeks to promote the three basic WASH habits to create long-lasting personal hygiene compliance among the populations it serves.

This touching film made as a part of SASB’s awareness campaign shows how lack of knowledge of basic hygiene practices means children miss out on developmental milestones due to preventable diseases.


SASB created the Swachhata curriculum, a textbook to encourage adoption of personal hygiene among school going children. It makes use of conceptual learning to teach primary school students about cleanliness, germs and clean habits in an engaging manner. Swachh Basti is an extensive urban outreach programme for sensitising urban slum residents about WASH habits through demos, skits and etc. in partnership with key local stakeholders such as doctors, anganwadi workers and support groups. In Ghatkopar, Mumbai, HUL built the first-of-its-kind Suvidha Centre - an urban water, hygiene and sanitation community centre. It provides toilets, handwashing and shower facilities, safe drinking water and state-of-the-art laundry operations at an affordable cost to about 1,500 residents of the area.

HUL’s factory workers also act as Swachhata Doots, or messengers of change who teach the three habits of WASH in their own villages. This mobile-led rural behaviour change communication model also provides a volunteering opportunity to those who are busy but wish to make a difference. A toolkit especially designed for this purpose helps volunteers approach, explain and teach people in their immediate vicinity - their drivers, cooks, domestic helps etc. - about the three simple habits for better hygiene. This helps cast the net of awareness wider as regular interaction is conducive to habit formation. To learn more about their volunteering programme, click here. To learn more about the Swachh Aadat Swachh Bharat initiative, click here.

This article was produced by the Scroll marketing team on behalf of Hindustan Unilever and not by the Scroll editorial team.