New Delhi: The Union Ministry of Health and Family Welfare said it has sent a National Joint Outbreak Response Team (NJORT) to Gujarat and Rajasthan, where an outbreak of the Chandipura virus is ongoing. The step has been announced in the light of rising cases and child deaths that have been reported owing to the infection during the monsoon.
The Centre has also activated the Public Health Emergency Operations Centre of the National Centre for Disease Control (NCDC) to assist field coordination, surveillance & execution of disease-control measures.
Multidisciplinary team formed
The NJORT includes experts from:
- National Centre for Disease Control.
- Indian Council of Medical Research.
- Department of Animal Husbandry and Dairying.
The team will work with Gujarat and Rajasthan health authorities to investigate suspected cases, assess the epidemiological situation, support clinical management, coordinate laboratory testing and strengthen vector surveillance. It will also review the states’ response and submit recommendations to the Union Health Ministry after completing its field assessment.
Scientific investigation intensified
The rollout is part of a broader, multi-institution compound led by experts in epidemiology, entomology, virology, veterinary science and laboratory diagnostics.
The investigation is being supported by researchers from several national institutions, such as ICMR-National Institute of Epidemiology in Chennai, ICMR-National Institute of Vector Control Research in Puducherry, ICMR-National Institute of Virology in Pune and ICMR-National Institute for Pre-Clinical Research in Hyderabad and ICAR–National Institute of Veterinary Epidemiology and Disease Informatics in Bengaluru.
The study will be conducted with the aim of understanding the entire clinical spectrum of Chandipura virus infection, from mild fever to acute encephalitis syndrome and use results towards prevention & better management.
Active surveillance in affected districts
Active surveillance among patients with acute febrile illness and acute encephalitis syndrome is being strengthened in the districts affected by AES, health authorities said.
They also do community based serosurveys to detect potential asymptomatic infections and measure the real level of transmission. Simultaneously, laboratory teams aim to refine diagnostic tests and establish animal models for the disease mechanisms of the virus.
This level of monitoring can assist health officials in locating cases sooner and establishing whether transmission is happening, as well as find communities needing more public-health assistance.
Transmission cycle under study
Sandflies are known vectors for Chandipura virus, but scientists are investigating if other arthropods could also transmit during the current outbreak. Among the vectors studied are mosquitoes, ticks and mites.
A variety of samples from affected regions continue to be examined in the laboratory. Authorities have warned it is too early to determine the exact vector for the current outbreak before testing is finished.
Implications: An understanding of the transmission cycle is critical to develop targeted control rather than wide spraying of insecticides only.
Animal surveillance expanded
The Dept of Animal Husbandry and Dairying has expanded surveillance in domestic animals to check if they could play a role in the transmission cycle or are reservoirs.
Samples of blood from cattle, buffaloes and goats and milk samples were taken for testing. At the time of the Centre’s update, had about 70 animal blood samples been collected, although authorities said conclusions could not be reached until laboratory analysis was over.
The animal-health probe highlights the government’s One Health scheme, which links human, animal and environmental factors when investigating infectious diseases.
Genetic changes being examined
Scientists are also investigating whether the virus responsible for the current outbreak has changed genetically. The virus samples are undergoing whole-genome sequencing at the Gujarat Biotechnology Research Centre, Gandhinagar.
Initial analyses have revealed small genetic differences, but experts say much more detailed comparative genomic studies are needed before saying whether the current strain is descended from viruses related to those responsible for past outbreaks.
While genomic analysis may be valuable for deciphering changes in transmission, disease severity or geography, such conclusions cannot be made on the basis of genomics alone and require rigorous laboratory and epidemiological data.
Lessons from the 2024 outbreak
The continuing investigation has been building on results from Gujarat’s Chandipura outbreak in 2024. In that study, several vector species were captured and tested for the virus by viral isolation, but all samples were negative for Chandipura and no particular vector was able to be confirmed.
This uncertainty made the present investigation extremely. Investigators are exploring more types of vectors, animals and clinical specimens in an effort to gain a fuller understanding of the route through which the virus is spreading.
Hospital surveillance network activated
The response is also being supported through the hospital based acute encephalitis syndrome surveillance network in India. The programme, which relies upon standardised clinical protocols, serological testing, molecular diagnostics and selective next-generation sequencing spans 15 tertiary-care hospitals.
Further work is expected to use the network to provide further evidence on the causes of encephalitis, improve outbreak detection and facilitate swifter public-health response.
However, the rapid clinical progression of Chandipura infection in children makes routine clinical reports, and early referral to hospitals having paediatric intensive-care facilities, vital.
What is Chandipura virus?
Chandipura virus is an acute encephalitis syndrome and a vector-borne infection. Reported predominantly from western, central & southern India; it tends to occur during monsoon with conducive conditions for vector activity.
Children may present with sudden fever, vomiting, seizures, confusion or extreme degree of drowsiness or loss of consciousness. Severe illness can rapidly progress, therefore urgent medical evaluation is warranted for complications of fever associated with neurologic Symptoms.
At this time, an antiviral treatment or vaccine for Chandipura virus is not available. Intensive supportive measures are the mainstay of medical care, including treatment of seizures, oxygen therapy (if required), intravenous fluids and management of complications.
Public-health measures remain important
Investigations are ongoing, but residents of affected areas should comply with surveillance teams and participate in vector-control activities. Families are trained through mosquito nets, protective clothing or leaving their homes and surrounding areas clean and using insect repellent by following the instructions.
Immediate medical attention must be sought if child develops high fever associated with seizure, repeated vomiting, changes in behaviour, confusion or abnormal sleepiness. Any acute illness may worsen rapidly, and so obtaining hospital treatment as soon as possible is crucial if Chandipura disease becomes severe.
Coordinated national response
The setting takes the central support to Gujarat and Rajasthan with a major expansion of the NJORT. The Centre has following a coordinated approach through a mix of human-health surveillance, animal testing, vector studies/genomic analysis and hospital monitoring to understand and control the outbreak.
The Approach is to Control cases but in such a way, that it also answers the following questions of utmost importance with respect to transmission of disease and severity as well as ways to contain this in the future. Results from the field survey and laboratory studies will be useful in strengthening preparedness of India against Chandipura virus, as well as other novel pathogens.