More than a billion people across the world, mostly in low and lower- Middle income countries, are affected by neglected tropical diseases, according to World Health Organisation. Among the six WHO regions, South-East Asia region bears the second highest burden of these debilitating infections and at least one neglected tropical disease is endemic in each of the region’s member states. In this backdrop, Sabitri Dhakal of The Himalayan Times talked to Dr Anup Bastola, chief consultant, Tropical Medicine, and spokesperson for Sukraraj Tropical and Infectious Disease Hospital, Teku, about the status of tropical diseases and preventive measures. Excerpts:
What is the current scenario of tropical disease in Nepal?
There are various tropical diseases in Nepal. Dengue, rabies, lymphatic filariaris, kala-azar and malaria are some of them. Apart from neglected tropical diseases such as malaria, kala-azar, lymphatic filariaris, we don’t have proper information about other tropical diseases. Information is also not available on zoonoses — infectious disease caused by bacteria, virus and parasites that spread between animals and humans.
Dengue is spreading in the country. Along with dengue, seasonal flu — Hong Kong flu (H3N2) and Flu A/Pdm H1N1 09 cases are up. Scrub typhus has re-emerged. It is also said that trypanosomiasis, a disease caused by parasitic protozoan trypanosomes has been seen in the country, but no information has been provided yet. Many of the diseases are under-reported such as in Taeniasis — acquired by humans through the inadvertent ingestion of tapeworm larvae. Dog tapeworm is also there. Though various doctors and surgeons are treating patients, there is no data for such diseases.
This could be because of lack of budget or lack of knowledge about the disease. We are trying to eliminate diseases such as malaria, kala-azar and lymphatic filariasis.
Does global warming impact tropical and infectious disease?
Rising global temperature increases the distribution range and virus transmission. Malaria and dengue are Sensitive to climate change. Both have been reported in hilly districts and high altitude areas such as Kalikot, Darchula and Dolpa. Kala-azar and cutaneous leishmaniasis — diseases transmitted by infected female phlebotomine sand fly — have been reported in areas where they were not found earlier, such as in Dolpa. After 2016, the number of cutaneous leishmaniasis patients has increased. Rise in temperature and change in rainfall pattern provide breeding ground for vectors.
Rainfall influences transport and dissemination of infectious agents. Temperature affects their growth.
Why has dengue spread in the capital this year?
Last year, dengue cases were seen in Sano Bharyang when Dashain was approaching. As the disease spread slowly, the temperature fell. Eggs of the Aedes Aegypti might have survived in unfavourable conditions. With the pre-monsoon this year, the mosquitoes were able to breed and spread.
Aedes Aegypti lays eggs in new places where there is clean water. It only takes a very small amount of water to breed. Bowls, cups, fountains, tyres, vases, any container storing water provides space for the mosquitoes to breed. The adult female Aedes Aegypti mosquito lays eggs on the wet surface of any container above the waterline. The eggs can resist desiccation and survive in unfavourable environments for up to over a year. These mosquitoes spread to new areas when materials containing dormant eggs are transported. Also, infected people, eggs and mosquitoes can travel from one place to another quickly. Besides, the high population density in the capital allows such diseases to spread.
What are the ways to prevent dengue?
Integrated vector management, including vector control, search and destroy campaigns and public education are extremely important. Mass awareness campaign should be carried out. Fogging should be done only when the habitats of mosquitoes are destroyed and mosquitoes living in homes and inner spaces are destroyed.
Is Nepal vulnerable to globally emerging diseases? What are the ways to control them?
Nepal is vulnerable to globally emerging diseases because of climate change, rise in temperature and migration. There are high chances of other tropical and infectious diseases which have broken out in other countries reaching the country. The authorities concerned must be informed about such diseases. Surveillance is also necessary to know about the possibility of emergence and re-emergence of diseases. It is also necessary to know about changes occurring in the pathogens.
What is the role of vector control inspectors?
Vector control inspectors have knowledge of habitat, nature of vectors, ways to control them and how they contribute to transmission of diseases. They are also responsible for scheduling inspections and operations. Using a variety of strategies they help prevent the spread of both the vector and the disease.
It’s sad that the government has removed the post of vector control inspectors at a time when dengue has spread across the country, the government must give them more responsibilities and help them learn through trainings as they are needed during such outbreaks. Each province should have at least four to five vector control inspectors.
Is collaboration necessary in the health sector?
There are various international organisations collaborating and cooperating with the government. Some organisations are helping us make guidelines, while some support us financially. World Health Organisation is providing technical assistance.
Until we have knowledge about the diseases, back-up plans to prevent and control their spread, investigation capabilities and skilled technical human resource we can’t do much on our own.
Are we prepared to combat health emergencies?
We have preparedness plans for cholera, influenza and other diseases. But we are not in a position to implement them.
How can communication and social mobilisation tools be useful for eradicating tropical and infectious diseases?
The public should be made aware. Whenever there is an outbreak there are rumours as we have seen with dengue this year. Risks should be communicated so that people don’t panic. Various volunteer groups can be mobilised to help prevent the disease from spreading. These groups reduce panic by disseminating right information and supporting the government in its technical works. If the government can’t control the outbreak it could lead to various other social problems. In situations when the government closes everything and stops mobility of people during health emergencies there could be problems of food crisis. Vaccines could be limited. To help prevent such situations, the government needs help from people.
What programmes should the government bring?
Firstly, the government should work with proper plans. For instance, the government came up with mass drug administration programmes to combat soil transmitted ailments and cases of leprosy, lymphatic filariasis and many other diseases have declined. If there are plans and strategies, it won’t be difficult to eliminate tropical and infectious diseases. With the country adopting the three-tier government system, there has been confusion regarding duties and responsibilities within the system. The government can come up with a central disease control division to contain infectious and tropical diseases. Dengue has given us a great lesson. Strategies should be worked out to prevent dengue spread. Action-oriented planning is necessary.
The government should make plans in such a way that eggs and larvae of mosquitoes are destroyed immediately after rainfall. The government should classify diseases on the basis of risks, severity and casualties. It also should specify diseases on the basis of geographical location, maintain proper data and deploy technical manpower with financial assistance for surveillance.
Such measures will help us prepare for the emergence of diseases.
A version of this article appears in print on September 23, 2019 of The Himalayan Times.