Introduction And Socio-Ecological Drivers

• India constitutes a mega-biodiverse country hosting approximately 11% of global flora within 2.4% of the global landmass, presenting a complex biological matrix for infectious disease transmission.
• Over 60% of human pathogens are zoonotic, and over 70% of emerging infectious diseases originate from wildlife species.
• Pediatric populations, specifically children under 15 years and infants under 5 years, represent the most vulnerable demographic to emerging zoonotic threats.
• Pediatric susceptibility results from frequent hand-to-mouth contact, immature hygiene practices, and exposure to high-risk environments like public sandboxes, petting zoos, and livestock areas.
• Developing immune systems and underlying malnutrition in resource-limited sectors degrade mucosal defenses, limiting a child's capacity to restrict pathogen replication.
• Key socio-ecological drivers include rapid urbanization, agricultural intensification, deforestation, and changing climate variables, which increase the human-animal-wildlife interface.
• Expanding irrigation networks create standing-water habitats that amplify vector populations, while forest fragmentation drives wildlife reservoirs like fruit bats into domestic proximity.

Epidemiological Burden And Surveillance

• The Integrated Disease Surveillance Program - Integrated Health Information Platform records a rising national trajectory of zoonotic infections, particularly rickettsial, leptospiral, and arboviral pathogens.

High-Priority Pediatric Zoonotic Viral Pathogens

Chandipura Virus Encephalitis

• Caused by Chandipura virus, a member of the Rhabdoviridae family and Vesiculovirus genus, emerging as a devastating pediatric pathogen restricted almost entirely to India.
• Highly monsoonal transmission peaking from May to September.
• Transmitted by the sandfly Phlebotomus papatasi, mosquitoes, and ticks harboring the virus in salivary glands.
• Plastering walls and floors with cow dung in rural housing draws sandflies into close proximity with children sleeping indoors.
• Induces acute, rapid-onset encephalitis targeting children under 15 years, with a high case fatality rate ranging from 28.6% to 78.3%.
• Clinical manifestations include high fever, vomiting, and abdominal pain, escalating precipitously to altered sensorium, decerebrate posturing, seizures, coma, and death within 24 to 48 hours.
• The 2024 outbreak involved 245 cases of acute encephalitis syndrome and 82 deaths (case fatality rate ~33.5%), predominantly in Gujarat and Rajasthan.

Nipah Virus Disease

• Nipah virus is an enveloped RNA virus of the Paramyxoviridae family, representing a high-priority emerging zoonotic threat with pandemic potential.
• The natural reservoir is the fruit bat of the Pteropus genus (flying foxes).
• Spillover occurs via direct bat contact, exposure to intermediate amplifiers like pigs, or consumption of raw date palm sap contaminated with bat saliva or urine.
• Pediatric impact includes a fatal case in a 12-year-old child in Kozhikode (2021) and a 9-year-old child (2023) presenting with rapid encephalitis.
• Nosocomial amplification is a major risk, recently infecting healthcare workers in West Bengal in January 2026.
• Clinical presentation features biphasic fever, acute respiratory distress syndrome, and fatal encephalitis, with case fatality rates ranging from 40% to 75%.

Kyasanur Forest Disease

• A tick-borne viral hemorrhagic fever caused by the Kyasanur Forest Disease virus (flavivirus), endemic to the Western Ghats (Karnataka, Kerala, Tamil Nadu, Goa, Maharashtra).
• Transmitted by hard ticks (Haemaphysalis spinigera); small rodents and monkeys serve as natural hosts.
• Monkey deaths act as sentinel events for local outbreaks.
• Exhibits a biphasic clinical course: an initial 5 to 12-day severe febrile illness followed by hemorrhagic manifestations (epistaxis, hematemesis, bleeding gums).

High-Priority Pediatric Zoonotic Bacterial Pathogens

Scrub Typhus

• A rickettsial zoonosis caused by Orientia tsutsugamushi, transmitted via the bite of larval trombiculid mites (chiggers).
• Represents a leading cause of acute undifferentiated febrile illness in pediatric wards during monsoon and post-monsoon months.
• The classic diagnostic necrotic skin lesion (eschar) is highly variable in children, appearing in 11% to 75% of cases.
• Infantile scrub typhus (<12 months) presents distinctively with atypical facial eschars, severe pallor, generalized edema, crackles, and severe transaminitis.
• Severe complications include pneumonia, acute respiratory distress syndrome, hypovolemic shock, and meningoencephalitis.

Pediatric Brucellosis

• A systemic, chronic zoonotic bacterial infection caused primarily by Brucella melitensis (sheep/goats) and Brucella abortus (cattle).
• Transmission occurs via ingestion of unpasteurized milk and cheese or inhalation of infectious aerosols on family farms.
• Presents with undulant fever, severe fatigue, nocturnal sweating, and hepatosplenomegaly.
• Osteoarticular involvement occurs in 83% of cases, presenting as chronic bone pain or monoarthritis of the hip, knee, or ankle.
• Frequently misdiagnosed as tuberculosis or pyrexia of unknown origin.

Leptospirosis

• A widespread zoonosis caused by pathogenic spirochetes of the genus Leptospira, transmitted through contact of abraded skin with water contaminated by rodent or cattle urine.
• Epidemics are strongly associated with post-monsoon flooding and waterlogging.
• Anicteric Leptospirosis: The most common form, presenting with high remittent fever, intense calf muscle myalgia, and characteristic non-purulent conjunctival suffusion.
• Weil Syndrome: The severe form featuring profound jaundice, acute renal failure, and hemorrhagic manifestations.

Diagnostic And Management Protocols

National One Health Mission And Interventions

• The Government of India established the National One Health Mission, coordinated by the National Centre for Disease Control and the Indian Council of Medical Research.
• Surveillance Integration: The Integrated Disease Surveillance Program is evolving to link human, animal, and environmental data streams to detect spillover events early.
• Laboratory Capacity: The Indian Council of Medical Research is expanding Infectious Disease Research and Diagnostic Laboratories and BSL-3/BSL-4 facilities in government medical colleges to enable metagenomic pathogen discovery.
• Vaccine Development: The Biotechnology Research and Innovation Council leads indigenous vaccine development for zoonoses, including candidates for Nipah virus, Japanese Encephalitis, Dengue, and Brucellosis.
• Grassroots Empowerment: Integrating ASHA, ANM, Anganwadi workers, and veterinary field assistants to facilitate joint reporting of animal illness and human symptoms.
• Environmental Management: Vector control around forest-plantation mosaics, upgrading water sanitation in peri-urban zones, and educating communities against consuming unpasteurized dairy and raw date palm sap.