Pathogens found in 11.1% patient samples in 2025: ICMR surveillance report

Pathogens were detected in 11.1 per cent of the 4.5 lakh patient samples tested this year by the ICMR (Indian Council of Medical Research’s) nationwide laboratory network, indicating a marginal but notable rise in infectious disease activity across India.

The detection rate increased from 10.7 per cent in January–March 2025 to 11.5 per cent in April–June 2025, the latest ICMR surveillance bulletin noted. Officials said that although the increase is modest, it highlights the need for strengthened seasonal surveillance and preparedness.

“This may not appear large, but it should not be underestimated,” a senior scientist associated with the virus surveillance programme said, calling the rise a “warning signal for seasonal diseases and emerging infections.”

Key pathogens detected

ICMR’s VRDL (Virus Research and Diagnostic Laboratory) network identified the top five pathogens circulating during the first half of 2025:

• Influenza-A — acute respiratory infection (ARI)/SARI cases

• Dengue virus — acute fever and haemorrhagic fever cases

• Hepatitis-A — jaundice cases

• Norovirus — acute diarrhoeal outbreaks

• Herpes simplex virus — acute encephalitis syndrome cases

These infections are consistent with seasonal transmission patterns, ICMR said.

Quarterly cluster investigations

The VRDL network investigated 191 disease clusters between April–June 2025, identifying mumps, measles, rubella, dengue, chikungunya, rotavirus, norovirus, varicella-zoster virus, Epstein-Barr virus, and astrovirus.

Between January–March 2025, 389 clusters were probed, detecting pathogens including mumps, measles, rubella, viral hepatitis, dengue, chikungunya, influenza, rotavirus, Leptospira, varicella-zoster virus, and sexually transmitted infections.

Growing national health surveillance network

Established in 2014, the VRDL network has expanded from 27 labs to 165 labs across 31 states and UTs by 2025. Over 40 lakh samples have been tested since inception, with pathogens detected in 18.8 per cent of cases overall. The network has so far flagged 2,534 disease clusters, serving as an early-warning system for potential outbreaks.

The scientist added that continued quarterly analysis will help pre-empt epidemics:

“The VRDL network functions as the country’s early-warning system. Consistent monitoring is key to preventing future outbreaks.”

(With inputs from PTI)