By Dr Rouchelle Tellis

Mangaluru, May 24: As all of us are aware that Kerala is put on high alert, following the mysterious deaths of about 10 persons from the so called mysterious viral disease. Seven of these victims are from Kozhikode district, including the first three victims from a single family, and three from the neighbouring Malappuram district. The samples of these patients have tested positive for Nipah virus at National Institute of Virology, Pune where the tests were done.

Nipah viral infection is a newly emerging viral infection that causes severe disease in both animals and humans. This virus first came into limelight when it caused an outbreak in humans that took place in a small village of Kampung Sungai Nipah in Malaysia in 1998 and the virus was named after this place. In Malaysia people got the infection from infected pigs. Since 2004 to 2012 almost every year this infection has been reported from Bangladesh. A total of 209 human cases were reported from Bangladesh and 161 (77%) of them died. In the past two decades India has seen two previous outbreaks of Nipah viral infection (2001 in Siliguri in West Bengal & 2007 in Nadia in West Bengal). Seventy one cases with 50 deaths (70%) were reported in these two outbreaks. The present outbreak is the third one reported from India. From the above figures it appears to be a highly infectious and dangerous disease. Here are a few questions or doubts that most of us have about the disease:

Where does the infection come from?

Research has shown that human infection is directly or indirectly related to fruit eating bats of the genus Pteropus. Nipah virus is commonly found in the saliva and urine of these bats. This virus does not make the bats sick, which means that they coexist and have co evolved.

How does the infection spread? 

This is a disease that goes from bats to other animals and people and then it can go from person to person. There are 3 ways in which this virus can get transmitted from bats to humans:

a) The most common route is by consuming fresh date palm sap or toddy. As we know toddy is harvested by a cut that is made into the trunk of the palm tree and sap flows slowly overnight into an open clay pot. Studies have confirmed that bats frequently visit date palm sap trees and lick the toddy that is getting collected in the pot or may even urinate in it. During this time the virus in the bats saliva or urine gets into the toddy. Nipah virus can survive for many days in sugar-rich solutions such as fruit pulp and toddy. Drinking this toddy or consuming bat-bitten fruits can also cause human infection.

b) Second common route of infection from bats to humans is through domestic animals. Fruit bats commonly drop partially eaten saliva-laden fruits which are consumed by domesticated animals such as cows, pigs, goats etc. Close contact with these infected animals can cause human infection.

c) Some people especially tree climbers may come into direct contact with the secretions of fruit bats and can get infected.

Can the Nipah virus spread from one person to another?

Human-to-human transmission of Nipah virus is seen among those in close contact with sick patient, family and caregivers of Nipah virus-infected patients. Respiratory secretions appear to be source of transmission as this virus is seen in the saliva of the infected patients. Experts also say that this infection has airborne transmission and can affect those who come in direct contact with contaminated bodies of infected animals and humans.

What are the signs and symptoms of Nipah viral infection?

Infection in humans can have various presentations. Some infected people may be aymptomatic, some may develop severe respiratory distress and few may have severe infection of the brain (fatal encephalitis). Some common signs and symptoms of are headache, fever, nausea, dizziness, drowsiness, neck stiffness and mental confusion.

What is the treatment for human infection?

There is no specific treatment to kill the virus. Only supportive treatment is given to keep the patient comfortable. Ventilator breathing support may be required if the person has respiratory distress.

Is there a vaccine to prevent this disease?

Currently there is no vaccine for either humans or animals.

Should I be worried?

It is better to be well informed rather than be worried. DO NOT CREATE PANIC. There is however scope for a little worry as the disease can get transmitted from person to person and there is no effective antiviral therapy for the infection nor vaccine.

Who are at high risk of getting infected with Nipah virus?

• Consuming fruits which are already bitten by bats
• People drinking toddy contaminated by bats.
• People working with pigs
• Tree climbers or others who come in contact with bats
• Persons taking care of already infected patients

How do we protect ourselves from the disease?

• Avoiding direct contact with infected pigs and bats
• Do not eat fruits already bitten by bats. Fruits should be thoroughly washed and peeled before consumption.
• Do not consume toddy that is collected in open pots. (Pots can be kept covered using a lid made of bamboo)
• Avoid travel to the affected region until the outbreak subsides
• If you have travelled to the affected region recently and are having any symptoms of the disease visit your doctor immediately.
• Health professionals attending to such patients should take precautionary measures, such as wearing N95 masks and gloves.

How to take care of infected patient?

• Close unprotected physical contact with Nipah virus-infected people should be avoided. Wear protective gear like N95 mask as the disease spreads by air borne transmission
• Do not share eating utensils and drinking glasses with sick patients.
• Leftovers of food offered to ill Nipah patients should be discarded. Not be consumed by any other family member.
• Avoid close contact like hugging and kissing the sick patient.
• Regular hand washing should be carried out after caring for or visiting sick people.

(Dr Rouchelle Tellis is Associate Professor at Yenepoya Medical College Hospital, Deralakatte Mangaluru)