Nipah (NiV), a zoonotic (transmitted from animals to people) virus, can spread quickly through contaminated foods and between individuals, posing the threat of subclinical infections to, severe respiratory illnesses and fatal encephalitis in infected humans even Nipah virus cause death.
Furthermore, this virus infects animals such as pigs, which causes significant economic losses for farmers.
The has only caused isolated outbreaks across Asia. Yet it can spread quickly among different animals and cause severe illness or even death in humans. And at the moment, We do not have a specific drug or Nipah virus vaccine available.Â
Past Outbreaks
Malaysia saw its initial outbreak of the Nipah virus in 1999 when several pig farmers became infected. Since that time, no additional outbreaks have been reported here.
Since 2001, outbreaks in Bangladesh have occurred frequently, and the disease is sometimes also observed in eastern India.
Risks to other regions exist since the virus was found in a bat natural reservoir and numerous bat species from Cambodia, Ghana and Indonesia.
Transmission
In Malaysia and Singapore, during the initial outbreak of pig-borne disease in 2015, many human infections were caused by direct contact with sick animals or their infected tissue, with unprotected skin contact being one of the main pathways through which the virus was spread – or through exposure to secretions from infected pigs.
Bangladesh and India experienced outbreaks of infection caused by fruit or fruit products contaminated with urine or saliva from fruit bats.
No research has been conducted to ascertain viral persistence in bodily fluids, fruits or the environment.
Nipah virus transmission between people has been documented among family members and caregivers of those infected.
At subsequent outbreaks of Nipah in Bangladesh and India, researchers observed that its spread occurred through direct human-to-person contact through excrement or secretions.
For instance, 75% of cases were among staff and visitors in the Siliguri hospital setting in India. In comparison, between 2001-2008, approximately 50% of reported cases in Bangladesh involved human-to-human transmission due to caring for infected patients.
Signs And Symptoms
Infections in humans can range from mild to severe acute respiratory infections (or encephalitis) that could even prove fatal.
Initial symptoms may include fever, headaches (muscle pain), nausea and sore throat. Other symptoms can include dizziness, drowsiness and altered consciousness.
In severe cases, people may also experience acute respiratory distress as well as pneumonia or severe respiratory problems, with acute respiratory distress being experienced by some individuals.
Further complications include encephalitis and seizures developing within 24 to 48 hours, causing comas to form within this timeframe.
Incubation periods for viruses vary between 4-14 days and have even been reported at up to 45 days in length.
Most survivors of acute brain encephalitis recover completely, though reports of long-term neurological conditions in survivors exist. About 20% have residual neurological effects, such as personality changes and seizure disorders, lasting after treatment.
Other people who initially recover may later relapse with delayed-onset encephalitis. Case fatality rates range between 40%-75%, depending on local capacity for epidemiological surveillance, clinical management and treatment.
Diagnosis
Nipah symptoms are vague and difficult to identify immediately, making accurate diagnosis difficult and leading to issues with outbreak detection, infection control and response activities.
The accuracy of lab results can also be affected by factors like sample collection quantity, quality, timing and type. Also critical are transfer times between the clinic and the laboratory.
Clinical history can be used to diagnose Nipah Virus infection during both acute and convalescent phases of the disease, with real-time polymerase chain reactions (RT-PCRs) and enzyme-linked immunosorbent tests (ELISAs) being the main diagnostic tools.
Additional tests include polymerase chain reaction (PCR) testing and virus isolation using cell culture techniques.
Treatment of nipah virus
Nipah does not have a specific drug or vaccine available to it. However, WHO has prioritised Nipah in its Research and Development Blueprint; intensive supportive care should be administered as necessary for severe neurologic and respiratory complications to be managed effectively. Nipah virus prevention must be followed until a specific drug or vaccine is available.
Natural Host: Fruit Bats
Nipah virus can be found naturally in certain species of fruit bats, such as those belonging to the Pteropus species. However, they do not seem affected by any diseases associated with its transmission.
Henipaviruses appear to be spread geographically along with Pteropus bats, and this hypothesis was further strengthened when evidence was discovered of Henipavirus in Papua New Guinea bats.
Pteropodidae of African fruit bats belonging to Eidolon were found to contain antibodies for Nipah and Hendra viruses, suggesting their possible presence across their geographic distribution in Africa.
Nipah Virus Infections In Domestic Animals
Malaysia reported its first Nipah outbreaks among domestic animals such as horses, goats, cats, and dog cats during its initial outbreak in 1999.
Pigs can be highly infectious during incubation, typically lasting 4-14 days. They are contagious throughout this period.
Pigs infected with Nipah may show no symptoms at first. Later, some will experience fever, difficulty breathing and neurological symptoms like trembling and muscle spasms. Mortality rates tend to be low except among young piglets.
Nipah symptoms resemble other respiratory and neurologic diseases in pigs. So if barking and coughing piglets exist or there are human cases of encephalitis, this should be suspected as Nipah disease.
Nipah Kills Two in Kerala
On 19 May 2018, a Nipah virus disease (NiV) outbreak was reported in Kozhikode district of Kerala, India. This is the first NiV outbreak in South India. There have been 17 deaths and 18 confirmed cases as of 1 June 2018. The two affected districts are Kozhikode and Malappuram.
Two deaths have been confirmed from Nipah virus in Kerala of Kozhikode District, prompting medical personnel to treat two additional people aged 9 and 24 who are related to one who passed away on 30 August.
The family members of those who died will likely recover as they go into recovery themselves.
On Tuesday morning, Kerala Health Minister Veena Georgie led a meeting at an expert level to assess the situation in Kozhikode. Union Health Minister Mansukh Mandaviya announced that an expert team from their central office had been sent directly to Kozhikode.
Nipah virus is more lethal than COVID-19 despite spreading slower; estimates by WHO place its global death rate between 40%-75%.
Reduce The Risk Of Infection Among People
Without access to a vaccine, raising awareness about risks and educating people on how to decrease exposure to Nipah is the only effective way to lower or prevent infection risks.
Reducing The Risk Of Bat-To-Human Transmission
To prevent transmission, efforts should focus on restricting bat access to fresh food and date palm sap, using protective covers (such as bamboo skirts) against bats collecting sap.
Date palm juice freshly collected must be boiled before consumption. At the same time, fruits must be thoroughly washed and peeled before eating them – any fruits showing signs of bat bites must be disposed of immediately.
Reduce The Risk Of Animal-To-Human Transmission
Use gloves and other protective clothing when handling sick animals’ tissues, slaughtering, or culling. People should try to avoid direct contact with infected animals. When setting up a new pig farm in an endemic area, one must take note of fruit bat presence; feed storage and sheds must also be secured from them.
Reducing Risk From Human To Human
Avoid unprotected contact with those infected by the Nipah virus and wash hands frequently after visiting or caring for sick individuals.
Controlling Infections In Healthcare Settings
All healthcare workers providing care or handling samples from patients suspected or confirmed with infections should always adhere to standard infection control measures.
Contact and droplet precautions, in addition to standard precautions, should be used whenever there has been any report of human-to-human spread, for example, in healthcare environments. In certain instances, airborne precautions might also be necessary.
Laboratory staff with the appropriate equipment must process samples taken from animals and people suspected to be infected with the Nipah virus.
What Response Has The Who Taken
In response to Nipah outbreaks or those at risk, to help control them and avoid future outbreaks? With that goal in mind, WHO provides technical advice and support services for countries dealing with outbreaks or at risk from future ones.
Washing and peeling fruits before consumption can reduce the risk of international dissemination by eating fruits or fruit-based products contaminated with saliva or urine from infected fruit bats and fruit with bat bites that should be discarded immediately.
