Mysterious Disease, killer virus - ‘Nipah' in Bangladesh

Experts are yet not sure enough to rule out the likelihood of human to human transmission of Nipah virus, which until March this year (2004)has killed 24 people in Faridpur. "We are not sure of human to human transmission, as last time the experts from the centre for disease control and prevention (CDC) of Atlanta, USA did not find any evidence of the virus spreading though man-to-man transmission," said Professor Mizanur Rahman, director general of Health Services.

"Detail studies are required and two experts on community and hospital infection controls from the CDC are here to evaluate the samples. Only after they carry out the studies, we can be sure of the mode of its transmission," Prof Rahman said.

Prof Abul Kalam Azad, director of Institute of Epidemilogy, Disease Control & Research (IEDCR), said, "We are worried about the spread, but are now concentrating on massive awareness-raising programme in the areas where people are becoming sick."

Local members of parliament, imams, doctors and teachers have been involved in the awareness-raising programme to stop spread of the virus.

He, too, said they were yet to find out the actual mode of transmission of the virus and that the scientists from the CDC would confirm it after investigations in Atlanta.

Prof Azad said, since April 16 last, no new case had been reported in the areas, where several expert medical teams were working to find the cause of the disease. The CDC experts would start investigations, mainly sample collection, in the areas of Mallikpur, Guhalaxmipur, C&B Ghat, Ali Char and Kadirpur areas in Faridpur from today.

Meanwhile, the health directorate says a team of experts with a portable device, which instantly identifies virus and its transmission mode, is expected here soon from Health Canada, a specialised centre like the CDC.

"We hope, when Health Canada is here, we will be able to do more close investigations much more quickly," said Prof Azad.

As of April (2004) 20, preliminary reports of one cluster of 30 cases, including 18 deaths, attributed to Nipah virus infection in Faridpur district has been received.

The laboratory testing, done by the CDC, has confirmed Nipah virus infection in 16 of the cases.

Nipah virus

Nipah virus is a newly recognised zoonotic virus, that is, a virus that animals pass to humans. The virus was 'discovered' in 1999. It has caused disease in animals and in humans through contact with infectious animals. It is currently believed that certain species of fruit bats are the natural hosts of it.

Though the exact mode of transmission from animal to animal or from animal to human is uncertain, it appears to require close contact with contaminated tissue or body fluids from infected animals.

Nipah antibodies have been detected in pigs and some other domestic and wild animals. According to the World Health Organisation (WHO), the role of species other than pigs in transmitting the infection to other animals has not yet been determined.

  • The incubation period for the virus is between four and 18 days. In many cases, the infection is mild or non-apparent (sub-clinical). In symptomatic cases, the onset usually comes with 'influenza-like' symptoms, with high fever and muscle pains.

  • The disease may progress to inflammation of the brain (encephalitis), with drowsiness, disorientation, convulsions and coma. Fifty percent of clinically apparent cases of Nipah virus infection die.(Source: The Daily Star, April 26, 2004)

    Virus - ‘Nipah-like’ and a similarity with a disease that hit Malaysia in 1999

    According to the World Health Organisation (WHO), climate change is likely to increase the incidence of diseases such as malaria, diarrhea and malnutrition around the world. As the people of Bangladesh are used to dealing with these illnesses, this thought does not frighten them. What does frighten them is a new disease about which they know nothing and when it proves to be a killer, it can be devastating as people can no longer fall back on past experience to get them through the crisis.

    Of late we have had more than our share of previously unknown diseases like the pneumonia and broncholosis that came our way during the winter. But the latest one, first reported in Meherpur, has frightened people and given rise to wild speculations.

    The panicked villagers have as a result, excommunicated households where people have fallen victim to the disease thinking they can in this way, keep it at bay. As this is an example of the social cost of ignorance we must bring this aspect of disease into greater focus. But the problem is, when the doctors themselves cannot identify the disease, villagers cannot be blamed for their reaction.

    Fortunately the health authorities are concerned and the Institute of Epidemiology, Disease Control and Research (IEDCR) has taken a leading role in advising the people in the affected areas Also blood samples have been taken from the infected and sent to the World Health Organisation (WHO) headquarters at Geneva as well as to other European research laboratories. Scientists of these laboratories have identified the killer virus as ‘Nipah-like’ and have established a similarity with a disease that hit Malaysia in 1999.

    The possible source of the infection is the fruit bat from which people may contract the disease directly, but despite all this information, the doctors still do not know how to cure the disease. Medical experts and doctors have however devised a set of guidelines for combating this new health hazard and we can only hope that in lieu of any specific treatment, the guidelines will work. Areas visited by the mysterious disease are Naogaon, Jaypurhat, Tangail, Faridpur, Rajbari and Manikganj.

    Certainly the Government of Bangladesh and its partners who are working together to improve the health of the people over the past must be congratulated for their efforts but knowledge about any new disease must be widely circulated lest people panic. This means that poor people need to be the focus of health workers. Thankfully WHO and others are giving serious thought to this matter and is trying to discover a curative treatment. The challenge is to first find the source and then find a treatment. Once that is settled medicines must be made freely available to those in need to reduce fatalities. If the disease is, as reported, affecting people with respiratory problems, this information must be disseminated to the public so that they can be on their guard as ignorance can do more harm that the disease itself.
    Source: The Bangladesh Observer, April 17, 2004

    Centre for Disease Control, Atlanta, and World Health

    Foreign and local experts who worked during the epidemic only speculated but could not specify how the disease spread. They are now leaving the country in groups. An extensive research carried out by the Institute of Epidemiology, Disease Control and Research found that pregnant bats harboured the virus and possibly transmitted it to humans.

    Pregnant bats harboured the virus - November to April

    The experts were also of the opinion that human to human transmission of the disease could not be ruled out. A rickshaw puller who carried a patient to the hospital became infected and later died. The research found that usually a group of people were infected at a time and the victims were relat

    The latest finding was the presence of a viral genetic material in the beds of two patients in Faridpur General Hospital. It means that the virus is capable of spilling out of the patients’ body, but it is questionable whether it is infectious or not.

    Disease Control and Research found that pregnant bats harboured the virus and possibly transmitted it to humans. The bats become pregnant from November to April and most of the Nipah-like infection cases were reported during the period. . About 17 per cent of the bats were found carrying antibodies against Nipah in their blood and surprisingly all were pregnant. Tests on other domestic and wild animals proved negative.

    A cluster of some 3,000 indigenous people living in Faridpur eat bats but none of them were infected. Dr M Abdur Rahim Molla, assistant professor of virology of the IEDCR, said these people may have escaped the infection as they normally avoid hunting bats from August to July, the bat breeding season. Dr K. B. Chua, consultant virologist of the National Public Health Laboratory of Malaysia, who first discovered the Nipah virus in 1999, said the virus spread from animal sources during a particular time of the year and people and public health authority of Bangladesh should be aware of that to contain a major outbreak. (The Daily Star, May 05, 2004).

    Experts fear another nipah outbreak in south-west

    Nipah, a seasonal viral disease that causes encephalitis and claimed 45 lives last winter, may show its deadly face this winter as well, experts fear. A study shows that the outbreak of the virus has been limited to south-western districts of Bangladesh in the past three years, with a mortality rate of 50-100 per cent in different areas. The study, conducted by local and foreign virologists, traced the virus to fruit bats. "Date and palm juices, contaminated by urine of nipah-infected bats, transmit nipah virus to humans, so do fruits, half-eaten by the infected bats," said Dr AKM Shahidul. Islam, an associate professor of microbiology at the Sir Salimullah Medical College.

    "Strong evidences were also there that the virus had been transmitted from one person to another." Shahid, who was part of the team that had conducted the survey, said people should not eat fruits bitten or half-eaten by bats, or drink raw juices of palm and date in a nipah-prevalent area. About 17 per cent of the bats tested between January and April 2004 were found carrying antibody against nipah, suggesting that they were infected by the virus either then or previously. The bats were pregnant as well, he said.

    Most cases of nipah outbreak so far have taken place between November and April, coinciding with the reproductive period of bats, said Shahid. He added that no domestic or wild animal was found to be carriers of the virus during the study. "Erratic cases of nipah occur in the south-western district through the year with its seasonal peak during winter, but they are not detected as there is no laboratory in Bangladesh that can detect the virus," he said. An extensive research on the nipah virus was conducted between January and April 2004 by the Institute of Epidemiology, Disease Control and Research, involving local and foreign experts.

    Experts from the US Centre for Disease Control, World Health Organisation headquarters in Geneva, Health Canada and University of Malaya have come to Bangladesh to from time to time to investigate the nipah outbreak. The experts observed that although the disease had been prevalent in the south-western districts for years, it had only recently been detected. Some experts are of the opinion that the virus-prone belt stretches along the course of the Padma up to south-west India, causing death to an uncounted number of people every year.

    Scientists at the International Centre for Diarrhoeal Diseases Research, Bangladesh have documented two previous nipah outbreaks in Bangladesh. The first outbreak of nipah encephalitis occurred between April 25 and May 26 2002 when nine died in village Chandpur in Meherpur. Between January 11 and 28, 2003, another outbreak occurred at villages Chalksita and Biljoania in Naogaon, killing eight of the seventeen affected (K. K. Das,The Independent, November 12, 2004).

    Last Modified: November 15, 2004

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