New Delhi/Ahmedabad, Aug 5 (IANS) The Union Health and Family Welfare Ministry has deployed a National Joint Outbreak Response Team (NJORT) to Gujarat and Rajasthan to strengthen the response to the ongoing Chandipura Virus Disease (CHPV) outbreak, as Gujarat continues to report the country's highest caseload with 35 laboratory-confirmed infections and 22 child deaths this monsoon season.
On Monday, State Health Minister Praful Pansheriya said 35 cases had been confirmed from 184 suspected infections, while seven children remain under treatment.
Announcing the deployment on Wednesday, the ministry said the move comes alongside an expanded, multi-institutional scientific investigation into the outbreak, with continuous surveillance being carried out under the Integrated Disease Surveillance Programme (IDSP), coordinated by the National Centre for Disease Control (NCDC) in collaboration with state surveillance units.
According to the ministry, the investigations are aimed at improving understanding of the virus, including its transmission dynamics, clinical spectrum, epidemiology and potential treatment approaches, while guiding evidence-based public health interventions.
The NCDC's Public Health Emergency Operations Centre has also been activated to support the response.
The multidisciplinary NJORT comprises experts from the NCDC, the Indian Council of Medical Research (ICMR) and the Department of Animal Husbandry and Dairying (DAHD).
The team will work with the Gujarat and Rajasthan governments on outbreak investigation, epidemiological assessment, clinical management, laboratory coordination, vector surveillance and implementation of public health measures.
It will also review the response on the ground before submitting its recommendations to the Union Health Ministry.
"One of the most extensive scientific investigations into Chandipura virus in recent years is now underway. Experts from ICMR-National Institute of Epidemiology, Chennai; ICMR-National Institute of Vector Control Research, Puducherry; ICMR-National Institute of Virology, Pune; ICMR-National Institute for Pre-Clinical Research, Hyderabad; and ICAR-National Institute of Veterinary Epidemiology and Disease Informatics, Bengaluru are working with the Gujarat Health Department," officials said.
The investigation brings together specialists in epidemiology, virology, entomology, veterinary sciences and laboratory diagnostics to study the full clinical spectrum of Chandipura virus infection, ranging from mild febrile illness to Acute Encephalitis Syndrome (AES), and to generate evidence for strengthening public health interventions.
Active surveillance has been intensified among patients presenting with Acute Febrile Illness (AFI) and AES in affected districts, while community-based serosurveys are being conducted to estimate asymptomatic infections and assess the true extent of virus transmission.
Laboratory teams are also working to strengthen diagnostic assays and develop improved animal models to better understand the disease's pathogenesis.
The ministry said a major focus of the investigation is to establish the virus transmission cycle.
While sandflies are recognised as the established vectors of Chandipura virus, scientists are also examining whether mosquitoes, ticks and mites may play a role in transmission.
Large numbers of vector samples collected from affected areas are undergoing laboratory analysis, and officials said it would be premature to identify the vector responsible for the current outbreak until the investigations are completed.
Animal surveillance has also been expanded to determine whether the virus is circulating among domestic animals that could serve as reservoirs.
Blood samples from cattle, buffaloes and goats, along with milk samples, have been collected for testing. Around 70 animal blood samples have been collected so far and are being analysed for Chandipura virus and other pathogens.
The ministry said no conclusions should be drawn until laboratory investigations are completed.
The ongoing investigations are drawing on findings from the 2024 Chandipura virus outbreak in Gujarat, when several vector species, including sandflies, were collected and tested but none were found positive for the virus, leaving no specific vector conclusively identified.
Scientists are also examining whether the virus has undergone genetic changes. Whole-genome sequencing of virus samples from the current outbreak is being carried out at the Gujarat Biotechnology Research Centre in Gandhinagar.
Preliminary analysis has identified minor genetic variations, although experts said detailed comparative genomic studies are required before determining whether the circulating strain has evolved from those associated with previous outbreaks.
The ministry also noted that researchers from ICMR-NIV, Pune, in collaboration with ICMR-Rajendra Memorial National Institute of Health Research in Patna, B.J. Medical College in Ahmedabad, the Department of Animal Husbandry and Dairying, and the Gujarat Health and Family Welfare Department have recently published a research paper documenting the multidisciplinary investigations undertaken during the 2024 outbreak.
The current response is further supported by India's Hospital-based Acute Encephalitis Syndrome Surveillance Network, a multicentric prospective programme covering 15 tertiary care hospitals.
"Using standardised clinical protocols, serological and molecular diagnostics and selective next-generation sequencing, the network is generating epidemiological and laboratory evidence to improve outbreak detection, understand the causes of AES and support timely public health action," officials said.
The ministry said the deployment of the National Joint Outbreak Response Team, together with parallel investigations by multiple national institutions, reflects a coordinated 'One Health' approach integrating human, animal and vector surveillance to better understand and contain the Chandipura virus outbreak.
--IANS
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