West Nile virus found in Bangladesh!

Mohammad Al Amin

26 September, 2019 12:00 AM printer

A new mosquito-borne virus ‘West Nile Virus (WNV)’ has been found in Bangladesh.

However, detailed information about the virus has not been available yet as the government’s concerned department didn’t investigate to know its origin.

According to the experts, the West Nile Virus (WNV) is a potentially life-threatening viral infection which can pass to animals and humans if they are bitten by an infected mosquito.

WNV is a virus of the Flaviviridae family, which includes the viruses responsible for Japanese encephalitis and dengue fever. It mainly affects birds, but it can also be experienced by mammals and reptiles. Between 70 and 80 per cent of people have no symptoms. Up to one per cent of those who become ill have serious and potentially fatal complications, they added.

“We have asked the Institute of Epidemiology Disease Control and Research (IEDCR) to investigate the West Nile Virus,” said Dr Sanya Tahmina Jhora, Director of Disease Control unit of Directorate General of Health Services (DGHS) told the Daily Sun on Wednesday.

Asked about the West Nile Virus, Prof. Dr Meerjady Sabrina Flora, Director of Institute of Epidemiology of the IEDCR said “A report about the West Nile Virus has come to us. A study of the icddr,b has mentioned about detecting the virus in Bangladesh.”

“Our team will go to the spot and carry out investigation about the West Nile Virus. We can say details about it after the investigation,” she added.

The DGHS sources said the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) has detected the West Nile Virus infected patient in an area near Dhaka city and informed the concerned authorities of the government to this end.

However, talking to Daily Sun the ICDDR,B communication unit refused to comment about this. 

According to the Centers for Disease Control and Prevention of the United States (U.S), the West Nile virus (WNV) is the leading cause of mosquito-borne disease in the continental United States.

It is most commonly spread to people by the bite of an infected mosquito. Cases of WNV occur during mosquito season, which starts in the summer and continues through fall. There are no vaccines to prevent or medications to treat WNV in people,” it said.

The report also said “most people infected with WNV do not feel sick as about 1 in 5 people who are infected develop a fever and other symptoms. About 1 out of 150 infected people develop a serious, sometimes fatal, illness. You can reduce your risk of WNV by using insect repellent and wearing long-sleeved shirts and long pants to prevent mosquito bites.”

The World Health Organisation (WHO) said the West Nile virus can cause a fatal neurological disease in humans while approximately 80 per cent of people who are infected will not show any symptoms.

“West Nile virus is mainly transmitted to people through the bites of infected mosquitoes. The virus can cause severe disease and death in horses. Vaccines are available for use in horses but not yet available for people. Birds are the natural hosts of West Nile virus,” it said.

The WHO statement said West Nile Virus (WNV) can cause neurological disease and death in people. “WNV is a member of the flavivirus genus and belongs to the Japanese encephalitis antigenic complex of the family Flaviviridae. WNV is maintained in nature in a cycle involving transmission between birds and mosquitoes. Humans, horses and other mammals can be infected,” it added. The WHO statement said human infection is most often the result of bites from infected mosquitoes. Mosquitoes become infected when they feed on infected birds, which circulate the virus in their blood for a few days. The virus eventually gets into the mosquito’s salivary glands. During later blood meals (when mosquitoes bite), the virus may be injected into humans and animals, where it can multiply and possibly cause illness.

It said the virus may also be transmitted through contact with other infected animals, their blood, or other tissues. A very small proportion of human infections have occurred through organ transplant, blood transfusions and breast milk.

The WHO report further said infection with WNV is either asymptomatic (no symptoms) in around 80 per cent of infected people or can lead to West Nile fever or severe West Nile disease. About 20 per cent of people who become infected with WNV will develop West Nile fever.

It said symptoms include fever, headache, tiredness, and body aches, nausea, vomiting, occasionally with a skin rash (on the trunk of the body) and swollen lymph glands.

The report said the symptoms of severe disease (also called neuroinvasive diseases, such as West Nile encephalitis or meningitis or West Nile poliomyelitis) include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis.

It is estimated that approximately 1 in 150 persons infected with the West Nile virus will develop a more severe form of the disease. Serious illness can occur in people of any age, however people over the age of 50 and some immunocompromised persons (for example, transplant patients) are at the highest risk for getting severely ill when infected with WNV. The incubation period is usually 3 to 14 days, it added.

The WHO further said treatment is supportive for patients with neuro-invasive West Nile virus, often involving hospitalization, intravenous fluids, respiratory support, and prevention of secondary infections. No vaccine is available for humans.