Understanding Chandipura Vesiculovirus: A Deadly Encephalitic Virus in India

Chandipura Vesiculovirus: Insights into a Deadly Encephalitic Threat in India

Chandipura vesiculovirus (CHPV), a member of the Rhabdoviridae family, is associated with a severe encephalitic illness known as Chandipura encephalitis or Chandipura viral encephalitis. First identified in 1965 from the blood of two patients in Chandipura village, Maharashtra, India, this virus has since been linked to several unexplained outbreaks of encephalitic illness in central India.

A Historical Overview of Chandipura Vesiculovirus

The virus gained significant attention between June and August 2003 when 329 children were infected in Andhra Pradesh and Maharashtra, resulting in 183 fatalities. The following year, Gujarat saw further sporadic cases and deaths among children.

Transmission and Virology of Chandipura Vesiculovirus

Chandipura vesiculovirus is primarily spread through sandflies, which have been identified as carriers of the virus in both India and West Africa. Despite its presence in Africa, human cases have only been reported in India.

Virological Characteristics

• Genome: The Chandipura vesiculovirus is an enveloped RNA virus with a genome length of approximately 11 kilobases.
• Proteins: The viral genome encodes five polypeptides:
• Nucleocapsid protein (N)
• Phosphoprotein (P)
• Matrix protein (M)
• Glycoprotein (G)
• Large protein (L)

The N protein encases the genome RNA, protecting it from cellular RNase. The L and P proteins form the viral RNA-dependent RNA polymerase. The M protein links the nucleocapsid with the viral envelope, while the G protein, which protrudes from the envelope, serves as the major antigenic determinant.

Life Cycle

The viral life cycle is cytosolic. During transcription, the viral polymerase produces five mRNAs, adhering to stop signals at gene boundaries. The accumulation of viral proteins initiates the viral replicative cycle, generating a polycistronic anti-genomic analogue used for further replication. These progeny genome RNAs, upon packaging, bud out as mature virus particles. The exact mechanism behind the polymerase function switch during replication remains unknown.

Symptoms and Treatment of Chandipura Encephalitis

Symptoms:

• High fever
• Convulsions
• Confusion
• Diarrhea
• Vomiting
• Headache
• Unconsciousness
• Coma

Treatment:
There is currently no specific treatment or vaccine for Chandipura virus infection. Management focuses on supportive care and preventive measures, such as mosquito control.

Past and Recent Outbreaks

• 2003 Outbreak: In Andhra Pradesh and Maharashtra, 329 children were infected, resulting in 189 deaths.
• 2009-2011: There were 110 positive cases and three fatalities.
• 2010 Gujarat Outbreak: 17 fatalities were reported in Kheda, Vadodara, and Panchmahal districts.
• Recent Outbreaks: Sporadic cases in Gujarat in 2014, 2016, and 2019, with fatalities reported.

In July 2024, a suspected outbreak in the Sabarkantha district of Gujarat raised significant public health concerns. The rapid spread and severity of symptoms in affected children have been alarming, with one confirmed death and a suspected death toll of 15.

Conclusion

Chandipura vesiculovirus poses a significant public health threat, particularly in India. The lack of specific treatment or vaccines underscores the importance of preventive measures and rapid response to outbreaks. Continued research and public health initiatives are crucial in mitigating the impact of this deadly virus.

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