Nipah virus.docx
- 1. Nipah virus (NiV) Key facts
- 2. Nipah virus (NiV) causes the deadly viral zoonotic infectious disease called Nipah, that can transmit from animals to humans. Animals such as bats, most commonly the fruit bats called as flying fox and pigs were the acting carriers of Niv. Nipah viral infection in humans results in range of clinical presentations such as asymptomatic infection (subclinical) to acute respiratory infection and fatal encephalitis. This infection has about 40 to 75% fatality rate, which can be varied depending on the local capabilities for epidemiological surveillance and clinical management. Presently approved treatment or vaccination is unavailable for infected rather than supportive care. Therefore, the disease calls out for an urgent need for an approved treatment regimen for a proper cure of the disease. As stated by the 2018 annual review of the WHO R&D Blueprint list of priority diseases. What is Nipah Virus? Nipah virus (Niv) is a zoonotic virus that can spread between animals and people. Fruit bats, also called flying foxes, are the NIV reservoir among animals in nature. Spread of disease occurs from the infected fruit bats to other animals, such as pigs, and from infected animals to humans. The infection occurs through contaminated fruits by the animal's body fluids such as saliva, urine, or blood. Therefore, the initial spread is from animals to humans and then within humans. Thus, the infection caused by Niv results in milder to severe illness ranging from acute respiratory tract infection to severe brain encephalitis (swelling of the brain). The Nipah outbreaks were most commonly observed in parts of Asia, primarily India and Bangladesh. This outbreak reported 40-75% of deaths in 1998 and 2018.
- 3. Past outbreaks Nipah virus (NiV) was first identified in Malaysia and Singapore following an outbreak of disease in pigs and people in 1999. This outbreak resulted in more than 100 deaths and nearly 300 infected cases in people. More than a million pigs were killed to control further outbreaks of disease, and there have been no outbreaks in both countries since 1999. In 2001, an annual outbreak of the disease was observed in Bangladesh. It was also periodically identified in India. The quick spread of the virus from animals to humans raised concern about NIV and made it a global pandemic. Transmission The first known outbreak in Singapore and Malaysia was through direct contact with the Nipah (Niv) infected pigs or their body fluids. It identified that the infected pigs got the Niv strain from bats, which subsequently resulted in transmission of the viral strains from pigs to humans by their unprotected exposure to infected animal species, which in turn led to a severe health issue in contact with humans that was even fatal due to unavailability of proper medications or vaccinations. There was no report of person- person transmission of disease in the outbreak. Whereas person- person transmission was first reported in India (2001) and Bangladesh (2001-2008) by consumption of fruits and vegetables contaminated by the body fluids of infected animals caused Nipah virus infection. The spread of the Nipah virus (NiV) from people was through the following causes:
- 4. Direct contact with infected animals or their body fluids (such as bats or pigs). Consumption of fruits or vegetables contaminated by the body fluids of infected animals (such as palm sap). Close or direct contact with Niv infected person infected their body fluids (such as nasal droplets, blood, or urine). Signs and Symptoms The symptoms commonly appear 4-14 days after exposure to the virus. However, in many cases incubation period as long as 45 days has been reported. Symptoms may initially include one or several of the following for 3-14days: • Fever • Headache • Vomiting Signs of respiratory illness: • Sore throat • Cough • Difficulty breathing In the later phase, brain encephalitis with the following symptoms observed within 24-48 hours: • Disorientation, drowsiness, or mental confusion • Seizures • Coma Approximately 20% of patients have residual neurological consequences such as personality changes and seizure disorders. Chances of relapse or developing delayed onset encephalitis are most common in cured persons.
- 5. An estimated rate of 40% to 75% of fatality cases was reported. The rate can vary depending on local capabilities for epidemiological surveillance and clinical management of the outbreak. Diagnosis NiV can be diagnosed during illness or after recovery. Different tests are available to diagnose NiV infection. During the early stages, laboratory tests such as real-time polymerase chain reaction (RT-PCR) using swabs from the throat and nasal, cerebrospinal fluid, urine, and blood collected for the test. At later stages and after recovery of the disease, an enzyme- linked immunosorbent assay (ELISA) is done for antibody determination. Other tests such as polymerase chain reaction (PCR) assay, Seroneutralization (plaque reduction neutralization test (PRNT))and virus isolation by cell culture were also conducted for detection. Handling and processing specimens require suitably equipped laboratories under maximum biological containment conditions and well-trained staff for collecting samples. Treatment Currently, no approved treatment regimens are available for Nipah virus (NiV) infection. WHO has identified Nipah as a priority disease for the WHO Research and Development Blueprint in the 2018 annual review. Treatment is limited to intensive supportive care, including rest, hydration, and treatment of symptoms as they occur. However, a few immunotherapeutic treatments (monoclonal antibody therapies) are currently under development and evaluation for treating NiV infections.
- 6. 1. Ribavirin: During the NiV outbreak in Malaysia in 1998/99, ribavirin was given empirically to treat 140 patients. The trial is non-randomized. Mortality was lower in the treated group (32%) compared to the controls (54%), corresponding to a 36% reduction. 2. Convalescent plasma has not been investigated clinically during outbreaks of NiV infections. 3. Monoclonal antibodies targeting the surface glycoproteins showed efficacy against both Hendra and Nipah viruses as pre-and post-exposure prophylaxis on animal models for the experiment. Monoclonal Antibodies m102.4 have potent neutralizing and cross-neutralizing activity against both Hendra virus and Nipah viruses has been demonstrated in both ferrets and NHPs infected with either Hendra or Nipah viruses. In humans, m102.4 has been used in Australia (10 people exposed to Hendra virus) at high-dose therapy under compassionate protocol where all survived with no associated adverse events. The double-blind, placebo-controlled, single-center, and dose-escalation phase 1 trial of m102.4 was all implemented in Australia in 2015-16. Dosing was well tolerated and safe, displayed linear pharmacokinetics, and showed no evidence of an immunogenic response. Prevention
- 7. In areas where Nipah virus (NiV) outbreaks have occurred people should: Practice regular handwashing with soap and water Avoid contact with sick bats and pigs and their geographic location Avoid areas where bats are known to roost Avoid contaminated fruits and vegetables by bats Avoid contact with the body fluids of Niv infected Using face mask and Personal Protective Equipment (PPE) to avoid infection while working in a healthcare setting where infection is suspected or detected. Taking proper measures of standard infection control practices and proper barrier nursing techniques are important in preventing hospital-acquired infections (nosocomial transmission) in settings where a patient has confirmed or suspected of NiV infection. In addition to the above steps, it will be critical for scientists, researchers, and communities at risk to continue learning about NiV to prevent future outbreaks. Broader prevention efforts include: Increasing surveillance of animals and people in areas where NiV is known to exist. Increasing research on the ecology of fruit bats to understand where they live and how they spread the virus to other animals and people. Evaluation of novel technologies or methods to minimize spread of the virus within bat populations. Improving tools to detect the virus early in communities and livestock. Reinforcing protocols for healthcare settings on standard infection control practices to prevent person-to-person spread. Public health educational messages should focus on: Reducing the risk of bat-to-human transmission.
- 8. Reducing the risk of animal-to-human transmission. Reducing the risk of human- to-human transmission. Pteropus Bats Presence and Nipah Virus Outbreaks
- 9. Pteropus Bats Presence and Previous Nipah Virus Infections: Asia, South Pacific, and Australia Region Countries with previously reported Nipah virus outbreaks in people: Bangladesh, India, Malaysia, Philippines, Singapore Countries where Pteropus bat species are known or likely present: Australia, Bangladesh, Bhutan, Brunei, Burma, Cambodia, China, Guam, India, Indonesia, Laos, Mariana Islands, Malaysia, Nepal, Pakistan, Palau, Papua New Guinea, Philippines, Singapore, Sri Lanka, Taiwan, Thailand, Timor-Leste, Vietnam This map shows areas where outbreaks of Nipah virus (NiV) in people have already occurred, including cases of illness and death. It also highlights where multiple species of bats of the genus Pteropus, which can spread NiV, are known or are thought to live in the Asia, South Pacific, and Australia region. Pteropus bats are also found in locations in Asia and Africa that are not shown here. References: WHO's work on Nipah virus disease
- 10. R&D Blueprint and Nipah virus https://www.who.int/news-room/fact-sheets/detail/nipah-virus https://www.cdc.gov/vhf/nipah/index.html