Key Points:
- A group of pathogens called the TORCH complex cause mild symptoms in expecting mothers, but in fetuses can lead to birth defects or death.
- TORCH surveillance data from India remain limited.
- Researchers analyzed blood samples from patients tested for TORCH pathogens between 2019 and 2025.
- Some pathogens remain a serious risk, highlighting the need for more effective public health strategies.
Washington, D.C. — The TORCH complex is a group of pathogens that can cause infections with mild or silent symptoms in an expecting mother, but in a developing fetus can lead to serious complications that include stillbirth, lifelong disability, or birth defects. Researchers from the All India Institute of Medical Sciences (AIIMS), New Delhi, recently assessed long-term trends in TORCH infections in a region where reliable data have been lacking. TORCH includes pathogens that cause toxoplasmosis, rubella, cytomegalovirus (CMV), herpes simplex virus and other infections.
They found that that these infections remain a risk in the region, even though vaccination rates have been improving, said Sudhahar Tamizhan, M.D., a physician at AIIMS who led the study. Microbiologist Suneeta Meena, M.D., was senior author on the study. Tamizhan presented the study's findings at ASM Microbe 2026 in Washington, D.C.
"We hope this work contributes to more informed public-health policies and better prevention of congenital infections in India and other resource-limited settings," Tamizhan said. "Our findings support the importance of sustained surveillance, targeted public health education and evidence-based screening approaches tailored to regional epidemiological patterns. Studying these TORCH microbes collectively, Tamizhan said, gives researchers broad perspectives on infectious risks and exposure patterns, which can inform strategies for prevention.
He and his collaborators, which included Meena and microbiologist Rojaleen Das, M.D., analyzed lab records of individuals who had undergone testing for TORCH pathogens between 2019 and 2025 at a tertiary care teaching hospital in North India. They evaluated patterns of antibodies associated with exposure or immunity to the pathogens.
They found distinct epidemiological patterns. Exposure to CMV remained constant throughout the study period, showing that the virus circulated widely in the community. Its high prevalence highlights the need for greater awareness of this infection, which often receives less attention than other TORCH pathogens, the authors noted.
The researchers also found consistently high immunity to rubella among patients. Rubella is preventable by a vaccine, and the data suggest that vaccination initiatives in the region are having a positive impact, he added. However, a significant minority of patients remained susceptible, not only to rubella but also to toxoplasmosis, which is preventable through safe food preparation, hand washing and careful handling of cat litter.
The findings suggest TORCH pathogens may require different prevention strategies. "A 'one-size-fits-all' approach to TORCH testing may not always be the most effective strategy," Tamizhan said. While maintaining high vaccine coverage remains important for rubella prevention, public health education regarding food hygiene, environmental exposure and prenatal care may help reduce the risk of toxoplasmosis and other congenital infections.
The team is now planning follow-up studies to explore age-specific and pregnancy-related risk factors, with particular emphasis on improving awareness and early identification of CMV and other congenital infections.
The new findings represent observations from a single-center, retrospective study, Tamizhan cautioned. Larger, multicenter investigations are needed to better understand regional variations and evolving trends in congenital infection risk across India.
