Outbreaks of the deadly Nipah virus has been recorded almost every year in selected districts of Bangladesh since 2001.

Pteropus fruit bat Image/Video Screen Shot
Pteropus fruit bat
Image/Video Screen Shot

Since the outbreak in Meherpur in April-May 2001, Bangladesh has seen 260 cases through 2015, including 197 deaths, for a case fatality of nearly 76 percent, according to accumulated data from the World Health Organization and the Bangladesh Institute of Epidemiology, Disease Control and Research (IEDCR).

In addition, sporadic cases of Nipah virus encephalitis have been reported, mostly from the west and north-western regions of Bangladesh almost every year, with high mortality and constituting a public health threat.

However, in 2016 to date, no outbreaks have been reported, according to country health officials. This has prompted health officials to proclaim success with their Nipah awareness campaigns.

“Our extensive awareness program worked,” Line Director Prof Abul Khair Mohammad Shamsuzzaman said recently.

According to the World Health Organization (WHO), in the Bangladesh and also in India outbreaks, consumption of fruits or fruit products (e.g. raw date palm juice) contaminated with urine or saliva from infected fruitbats was the most likely source of infection. Fruit bats of the family Pteropodidae – particularly species belonging to the Pteropus genus – are the natural hosts for Nipah virus. There is no apparent disease in fruit bats.

In more recent outbreaks of the disease, person-to-person transmission has been seen in Bangladesh and India.

The disease in humans can range from asymptomatic infection to fatal encephalitis. Encephalitis and seizures occur in severe cases, progressing to coma within 24 to 48 hours.

The case fatality rate is estimated at 40% to 75%; however, this rate can vary by outbreak depending on local capabilities for surveillance investigations, according to the WHO.

Those who survive acute encephalitis make a full recovery, but around 20% are left with residualneurologicalconsequences such as persistent convulsions and personality changes.

There is no treatment or vaccine available for either people or animals.

Nipah virus was first detected in Malaysia in 1998 but at present Bangladesh, a hotspot for infectious diseases, is the only country in the world that reports the disease.

Related: The World’s Deadliest Viruses

“I think our program has succeeded. People did not drink raw date sap,”Shamsuzzaman said.