Nipah Viral Disease in Malaysia: A Comprehensive Review

All about nipah virus

1. NIPAH VIRAL DISEASE IN MALAYSIA: A COMPREHENSIVE REVIEW VMIC 114 Veterinary Virology VMIC 114 Veterinary Virology Charlton Cerenio & Franz Lyndon Paligpig

2. Introduction Malaysia has experienced 18 of the reported zoonotic pathogens (Fig.1). The Nipah Virus is one of the recognized zoonotic pathogens that caused devastation in Malaysia in 1980. The Nipah Virus ( NiV ) has started in Perak, Malaysia in 1998. Fig.1. Geographical data showing 18 reported zoonotic pathogens in Malaysia. The acronyms for the viruses are shown, along with the year that each location in Malaysia observed their first appearance (Tee et al., 2009).

3. Morphology and Structure It is a negative sense, non-segmented, single-stranded, enveloped RNA virus with helical symmetry. The RNA genome is composed of six genes: N, P, M, F, G, and L, arranged sequentially from 3 to 5. The vRNP is formed when the N, P, and L proteins connect to the viral RNA. F and G proteins are responsible for the virion's cellular adhesion and subsequent host-cell invasion.

4. Nipah Virus Strains The first NiV outbreak occurred in Malaysia and Singapore in 1998–1999, and it was caused by the Malaysia strain ( NiVM ). It resulted in an infection to over 270 individuals and a case fatality rate (CFR) of almost 40%. The Bangladesh strain ( NiVB ) is responsible for recurring outbreaks in Bangladesh and northeast India, with outbreaks recorded every year from 2001 to 2015. The CFR recorded is roughly 75% and human-to-human transmission has also been noted. 01 02 Malaysian Strain Bangladesh Strain

5. Transmission Routes Schematic diagram of transmission from reservoir host to final host.

6. primarily occurred in Bangladesh and India. Malaysia and Singapore experienced outbreaks in 1999. P otential risk Indonesia, Cambodia, and the Philippines. Countries Affected Nipah virus primarily affects humans. Pteropus fruit bats serve as the natural reservoir , commonly transmitted in pigs and less common in monkey, horses, goats, dogs, and cats Animals Affected Epidemiology

7. Epidemiology primarily occurred in Bangladesh and India. Malaysia and Singapore experienced outbreaks in 1999. P otential risk Indonesia, Cambodia, and the Philippines. Countries Affected Nipah virus primarily affects humans. Pteropus fruit bats serve as the natural reservoir , commonly transmitted in pigs and less common in monkey, horses, goats, dogs, and cats Animals Affected

8. Pathogenesis

9. Clinical Symptoms in Humans Early Stage Fever, Headache , Muscle pain, Fatigue 01 Respiratory Symptoms Cough, Sore throat 02 Neurological Symptoms Altered mental state, Seizures, Coma 03 Respiratory Distress Severe respiratory issues 04 High Mortality Many cases result in death 05 Incubation Period Typically 5 to 14 days 06 Person-to-Person Transmission Possible in close contact 07 Supportive Care No specific treatment, Focus on symptom management and respiratory support 08

10. Clinical Signs in Animals Early Stage D yspnea and muscle tremors 01 Respiratory Symptoms fever, and respiratory symptoms that include dry cough 02 Neurological Symptoms tremors, muscle fasciculations, tetanic tremors, motor lack of coordination, posterior weakness, and paraplegia 03 Adult Neurological Symptoms corner, biting the bar, tonic- clonic muscle spasms, and seizures 04 High Mortality Certain animals that are older than six months old pass away quickly often in less than a day and show no symptoms. 05

11. Laboratory and Radiologic Diagnosis Routine Hematological Test Cerebrospinal Fluid Analysis NiV Specific Tests Radiological Imaging

12. Differential Diagnosis Leptospirosis Scrub Typhus Scrub Typhus Cerebral Malaria Herpes Meningoencephalitis Bacterial Meningitis Japanese Encephalitis Measles Dengue Encephalitis Rabies

13. Postmortem Lesions Postmortem macroscopic lesions observed in severe Nipah viral infection in African Green Monkeys. (A) Sanguineous froth flowing from the nares; (B) Enlarged mottled lungs with multifocal areas of congestion and hemorrhage that failed to completely collapse; (C) Moderate congestion of the meninges (black arrows); (D) Extensive petechiae in the lungs; (E) Moderate and diffused congestion of the brain. ( Rockx , 2010) Macroscopic Lesions

14. Postmortem Lesions Postmortem microscopic lesions of the lungs observed in severe Nipah viral infection in African Green Monkeys. (A) Alveolar lumina contains blood. (B) Minor bleeding and edema in the alveolar lumina. (C) The pulmonary artery's tunica media, intima, and neighboring alveolar septa are all infiltrated by NiV . (D) NiV labeling is present in the neighboring alveolar septa and in the tunica intima of a tiny vessel (Cline et al., 2022). Microscopic Lesions Postmortem microscopic lesions of the brain observed in severe Nipah viral infection in African Green Monkeys. (A) Lesions in the neuropil (B),(D),(E) NiV labeling in the brain. (C) Different kinds of cells are present in the brain (F) Positive NiV labeling in neighboring neuropils and neurons (Cline et al., 2022)

15. Treatment and Post Exposure Prophylaxis Ribavirin 36% decrease in mortality with 45 fatalities in the treated group (32%) and 29 in the control group (54%). Favipiravir D emonstrated to have strong antiviral action against henipaviruses by blocking Nipah and Hendra's transcription and replication m102.4 Monoclonal Antibodies strong cross-reactive neutralizing antibody in vitro that targets the ephrin-B2 and ephrin-B3 receptor binding domain of the Henipavirus G envelope glycoprotein.

16. Prevention and Control S top the transmission of the disease from person to person A pplication of infection control measures M esh netting in the pig sheds to keep the bats away from them, clothe and glove the workers in protective gear, and keep the herd of pigs away from fruit trees. Isolation and strict infection control to prevent transmission, especially in healthcare. S top date palm sap from becoming contaminated

17. Possibility of Nipah Viral Disease in the Philippines There is a possibility for Nipah Virus to occur in the Philippines. There is a reported case for Nipah Viral Disease in the southern Philippines both humans and horses. The possibility of Nipah Virus directly emerging from the Philippines without any transmission from other countries is unlikely

18. Insights in Problems Encountered During the 1999 Malaysian Nipah Virus Outbreak E pidemics should handled by qualified experts like scientists and medical specialists. Scientists and physicians freely shared knowledge and collaborated with one another both domestically and globally. The virus would not have been identified and efficient surveillance and control methods would not have been developed so swiftly without this desire to share and assist

19. Conclusion Nipah Virus has become known to be a fatal zoonotic disease. South and Southeast Asian nations must immediately cooperate to improve their surveillance capacity. Research is needed into the ecology of bats and the factors that lead to spill-over occurrences Effective treatments and prophylactics for both humans and animals must be developed, and detection mechanisms must be strengthened to stop outbreaks.

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