National 4 (Spotlight Weekly)

‘Vector-borne Diseases Are Very Difficult To Eliminate’

— Dr. Panduka M. Wijeyaratne

Dr. Panduka M. Wijeyaratne is the Program Director of the Environment Health Project (EHP) of USAID in Nepal. He has been in the post for the last three years working on vector-borne diseases like malaria, kala-azar, Japanese encephalitis and so on. These diseases claim hundreds of lives each year in the country and cause severe illness and hardship. The diseases like Japanese encephalitis and kala-azar prevalently appear in summer and monsoon season. He spoke to SANJAYA DHAKAL about the current situation of the diseases in the country and what EHP is doing in this regard. Excerpts:

What is EHP and what does it do?

EHP is a major health project that works globally and is funded by the USAID. It is based in Washington DC, USA. In Nepal, it is mainly concentrating on the vector-borne disease. It has been working with the government of Nepal and other partners for nearly four years in the prevention and control of these diseases. At present, the EHP has focused its operation in districts like Dhanusha, Mahottari, Kanchanpur and Jhapa, based on all the information we have scientifically collected.

What is the situation of vector-borne diseases in Nepal?

Among the vector-borne diseases in Nepal, we are mainly focusing on the three ñ malaria, Japanese encephalitis and kala-azar. Malaria and Japanese encephalitis are transmitted by mosquitoes, whereas kala-azar is transmitted by sandfly. Due to the successful control strategy implemented by the Nepalese government with the help of USAID, malaria had been brought under control some years ago. But there are indications that the control of the disease is not complete. Similarly, kala-azar is also becoming a greater menace, having been reduced earlier with malaria.

How many people are affected every year by these diseases in the country?

The exact number is very difficult to establish, but they are in the thousand range. As we go by the cases reported to the hospital, the total number is grossly underestimated as many go un-reported. It is rather difficult to give an exact number though, but it is very significant for Nepal.

What causes these diseases?

As far as malaria is concerned, it is caused by a parasite called plasmodium. There are two types of malaria, plasmodium vivax and plasmodium falciparum. From disease point of view, plasmodium falciparum is the more dangerous one as it causes most fatalities. Kala-azar is caused by a parasite called leishmania, while Japanese encephalitis is caused by a certain kind of virus. For malaria and Japanese encephalitis, mosquitoes act as vectors, while the vector of kala-azar is sandfly. Kala-azar also causes death, if untreated and Japanese encephalitis is very damaging and causes fatalities also.

Everyone talks about the significance of prevention strategy. But why are the threats of these diseases growing by the years?

In our environment in Nepal, vector-borne diseases are very difficult to eliminate. Though we may control it presently, it may be lying dormant in humans or other vectors and could crop up as and when it finds suitable environment and climate. Therefore, there has to be a sustained effort to root out these diseases, and the methods must be scientific and effective.

How do you find the infrastructure of health services like hospitals, health posts, manpower in controlling these diseases?

For vector-borne diseases, I think the existing health infrastructure of the government is very good. Since it was inherited from the days of malaria eradication program, the health services are well placed and now decentralized. Having said that, there are still some problems of manpower and resources in the peripheral health posts and sub health posts, and these are very important for prevention and control.

There have reports of recent outbreak of typhoid and malaria in Chitwan district. How do you find it?

I happened to recently meet and talk with the team of the health department that had gone to Chitwan. According to their reports, the number of cases of typhoid has been grossly over-estimated by the media and that the case of malaria has not been confirmed yet.

Is it true that malaria is making a comeback?

I wouldnít say it is making a comeback. But definitely the disease exists in pockets and is not fully controlled. Because of ecological changes, population growth and their movement, the transmission of the disease is continuing. Besides, as there are ample cross-border movements between Nepalese Terai people to and fro Assam and West Bengal and other parts in India, the chances of catching malaria is that much higher, and the parasite is often difficult to treat.

What about Japanese encephalitis and kala-azar? How serious are these problems?

Japanese encephalitis is a grave problem and the government is very serious about this disease, especially since the last two years when it emphasized on the prevention of the disease through vaccination. Kala-azar, which is an equally menacing disease, is presently confined to 13 districts in eastern and central Terai region. For reasons yet unknown, the disease has not been seen in western Terai till now. This is a disease that affects the poorest of the poor. In fact, the epicenter of kala-azar is Bihar in India. Thankfully, of late, there have been integrated and cross-border efforts to control this disease; we are helping in this. New oral drugs are also now being explored for treating this disease. And the government is very keen on controlling the disease in a serious and sustainable way.