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OUTBREAK ALERT: Nipah Virus, India

Jade Patel, Sam Shames, Alyssa Schmidt, Emergency Management, Health and Hazards (EMH2) Team

Week of Monday September 6, 2021

Nipah Virus (NiV)[1]

Multiple cases of Nipah Virus (NiV) have been detected in Kerala, India, with the first death recorded on September 5, 2021.[2] With hundreds in isolation in an attempt to contain the untreatable, highly transmissible zoonotic virus, authorities are on high alert for an outbreak. Concurrent SARS-CoV-2 (COVID-19) and Black Fungus outbreaks in India have created an environment where the number of patients facing life-threatening illnesses greatly outnumbers healthcare capacity. As a result, preventing viruses from spreading to additional jurisdictions is essential for public health. It is advised that travel in areas with high case rates is limited, and that residents follow local public health and medical guidance to reduce further transmission of NiV.

Description of Pathogen

NiV is a zoonotic disease that can be transmitted through contact with bodily fluids from an infected human or animal, or through ingestion of contaminated substances.[3] The virus is found most commonly in bats and pigs, with fruit bats being the main reservoir host of the NiV strain in Kerala.[4] Additionally, increased rates of spillover are linked to rapid urbanization and associated deforestation in India, as it displaces reservoir hosts.[5] While public health officials in Kerala have not yet determined the cause of the most recent cases of NiV, the most likely cause of infection in India is consumption of fruit products contaminated with fluids from infected bats.[6]

Symptoms of NiV vary, from asymptomatic infection to acute respiratory illness, seizures, and fatal encephalitis (inflammation of brain tissue). Initial symptoms are often confused with influenza presentation, and may include headaches, muscle pain, fever, sore throat, and vomiting. Currently, symptoms may also be confused with the presentation of the COVID-19 Delta variant. In more severe cases, patients can experience respiratory issues similar to those exhibited with pneumonia. Additionally, those infected may also experience drowsiness and spells of dizziness, altered consciousness and may present other neurological issues. Symptoms are likely to differ between each individual along with the severity of the infection.[7]

The fatality rate for NiV ranges from 40% and 70% with no immediate correlation to underlying health issues.[8] Those who survive acute encephalitis are more likely to make a full recovery but are also extremely likely to be left with neurological problems such as seizures and personality changes. [9] Asymptomatic individuals are more likely to transmit the virus than those with symptoms due to not knowing they are infected and continuing to have contact with others. There is no treatment or vaccine, creating response challenges. The virus can also cause severe disease in animals which could be fatal, resulting in significant economic losses for farmers.[10]

NiV has a high mutation rate with an incubation period as long as 45 days, making the virus dangerous as it is extremely likely that an infected person could spread the virus for well over a month before becoming showing a symptom(s) and realizing they are ill.[11] The long incubation period in conjunction with common early symptoms increases the chance of spread as initial diagnoses during an outbreak may be incorrect. Despite the incubation window, it is advised to remain vigilant for symptom development within 4-14 days of potential exposure. The length of an outbreak is dependent on when the virus is detected and how quickly preventative measures are implemented. The virus does not show patterns of who becomes infected, placing all demographics at risk of contracting NiV. Due to the current outbreak, a 12 year old has succumbed to the virus, with more fatalities likely over the coming weeks.

Although most of the individuals that had acute encephalitis were able to make a full recovery, there are chances that there will be long- term consequences from this disease. Neurological problems such as seizures and changes in personality are seen in 20% of people that are infected.[12] There is also a chance that someone may relapse or experience delayed onset encephalitis in the future. This emphasizes the importance of monitoring symptoms and isolating if infected.


Kerala, India[13]

Nipah Virus was first detected among pig populations in Malaysia in 1999. The virus is currently endemic in a number of Southeast Asian nations, and there have been a total of three reported outbreaks in India. The most recent outbreak in India occurred in Kerala in 2018, characterized by high fatality rates and high rates of nosocomial (hospital originating) transmission.[14] Although those outbreaks were contained, new cases of NiV are detected every few years with increasing incidence in Kerala.

As of September 11, 2021, the virus is only present in the southwestern province of Kerala; this area has gone on high alert in response. The impacted area is not central, making it likely that this region can be isolated easier to help combat the spread of NiV within the country. However, surrounding areas are likely to be impacted if the virus is not contained. The likelihood of the virus spreading throughout the entirety of India is less likely if domestic travel in and out of Kerala is paused until the virus is controlled. The origin of the outbreak is unclear as there is no pattern to when the virus spreads from the reservoir host. Currently, India is the only country experiencing an outbreak. This outbreak is not impacted by terrain, climate or weather.

Response Challenges

It is difficult to respond to NiV outbreaks due to the lack of approved vaccines or medications. The best form of treatment is supportive care, and ensuring those infected remain isolated. As a result, health officials are engaging in rigorous contact tracing and immediate isolation of identified contacts. Another challenge is diagnosing the virus as initial symptoms may be mistaken for influenza or COVID-19, which may delay detection. However, now that health officials are aware of increased virus transmission, healthcare workers have been notified.

The most pressing concern is that India is currently experiencing its fourth wave of COVID-19 infections, which is correlated with increased cases of Black Fungus in COVID-19 patients. Since the Delta Variant of SARS CoV-2 was first detected in India in April 2021, the healthcare system has collapsed. Lack of resources, overcrowding of hospitals, and uncontrollable transmission have left thousands without access to treatment. Healthcare workers will now have to work to distinguish patients infected with NiV and prioritize their treatment. This may cause more patients with COVID-19 to be turned away from hospitals, leaving them without care. As a result, in an effort to contain NiV, cases and deaths due to COVID-19 may increase.

Travel Warnings

It is recommended that travel to and from Kerala, and infected areas, is paused until the virus is controlled to deter from a mass outbreak throughout the country. Travel could increase the spread of the virus and with no vaccinations available, there is no way to protect or prevent the spread. Alongside recommending people not travel into infected areas, it is also advised that people refrain from consuming foods where contamination is likely or confirmed, with consideration made to farmers, food production companies, and transportation around the country.

Political Effects/Effects on Terrorism

The outbreak does not pose an immediate threat of political instability and/or terror opportunity. Without intervention, this could lead to high numbers of people becoming infected across multiple regions of India, which would likely result in mass fatalities. A sharp increase of fatalities will most likely put India into a health crisis (alongside the ongoing crisis from COVID-19, hazards etc.) which could weaken the countries defense, short and long term. This takes a combination of events, and not just due to this specific outbreak.

Recommendations for AOCs

The Emergency Management, Health and Hazards (EMH2) Team recommends that agencies, organizations and companies monitor the number of cases of the virus in Kerala as well as surrounding areas. It is advised that food products be washed before consumption and date palm juice should be boiled before consumption.[15] Health officials should employ a One Health approach to improve animal disease surveillance systems and ensure that the food they are distributing is uncontaminated. Identifying the location of bat populations that are known to carry the virus is crucial so they can be tracked and monitored for future early detection of the disease. World Health Organization (WHO) assistance is essential in order to make sure that this illness is being handled appropriately. It is recommended that travel in and out of infected areas is reduced where possible in efforts to constrain NiV, with health officials providing information on what to do if exposed to NiV and where to seek help if needed. Personal Protective Equipment (PPE) should be utilized especially in areas that have high cases in order to limit the transmission of this illness as well as many others that are prominent such as COVID-19. Individuals should continue to follow protocols that were used to reduce the spread of COVID-19, such as mask wearing, social distancing, and hand washing, since they should similarly slow the spread of NiV.


[2] Outbreak Surveillance, Travel Health Pro, September 2021,

[3] Nipah Virus, World Health Organization (WHO), May 2018,

[4] Ibid

[5] Nipah Virus Infection, World Health Organization (WHO), June 2009,

[6] Nipah virus, World Health Organization (WHO), May 2018,

[7] Ibid

[8] Ibid

[9] What is Nipah Virus, and should we be worried?, Wales Online, September 2021,

[10] Nipah Virus, World Health Organization (WHO), May 2018,

[11] What is Nipah Virus, and should we be worried?, Wales Online, September 2021,

[12] Nipah Virus, World Health Organization (WHO), May 2018,

[15] Nipah Virus, World Health Organization (WHO), May 2018,



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