The Viruses of Microbes 2024 (VoM 2024) conference was held for the first time outside of Europe at the Cairns Convention Centre in Australia. The theme, Expanding Our Viral Frontiers, emphasizes both the geographic expansion of the event and its focus on emerging research directions. The event brought together leading scientists to discuss various aspects of viral research, including bacteriophages, eukaryotic viruses, and their roles in ecosystems and human health.

CHRF was represented by Dr. Yogesh Hooda, who delivered a talk titled “Old tools, new applications: Use of environmental bacteriophages for typhoid surveillance and evaluating vaccine impact.” His presentation focused on the use of environmental bacteriophage surveillance to monitor Salmonella Typhi, the pathogen responsible for typhoid fever.

Typhoid fever remains a critical public health issue in endemic areas. Although Typhoid-conjugate vaccines (TCVs) offer a promising solution to reduce the disease burden, accurate, high-resolution data on disease prevalence is essential to guide effective vaccination strategies. Traditional surveillance methods, such as blood cultures, are often resource-intensive and may not be feasible for widespread use in endemic regions.

As an alternative, CHRF’s research focused on the use of Typhi-specific bacteriophages—viruses that infect Salmonella Typhi—as an effective, low-cost tool for environmental surveillance. In 2021, researchers at CHRF conducted a study in two regions of Bangladesh: Dhaka, the urban capital, and Mirzapur, a rural district. They collected water samples to test for the presence of Salmonella Typhi-specific bacteriophages. The study revealed differences between the two locations. In Dhaka, 31% of the samples tested positive for Typhi-specific bacteriophages, compared to 3% of the samples from Mirzapur.

The researchers also compared these environmental findings with blood culture data from the same year. In Dhaka’s two largest pediatric hospitals, 5% of blood cultures were positive for typhoid fever, while Mirzapur’s largest hospital reported only a 0.05% positivity rate. Notably, 75% of the positive phage samples in Dhaka were found in sewage water, indicating that contamination of water sources may be a critical factor in the transmission of typhoid fever.

In his presentation, Dr. Hooda discussed these findings, which suggest a strong correlation between the presence of Typhi-specific bacteriophages in the environment and the burden of typhoid fever, particularly in urban settings like Dhaka. He highlighted the potential of bacteriophage surveillance as a low-cost, effective tool for monitoring Salmonella Typhi in endemic areas. Additionally, the research examined the diversity of the isolated bacteriophages, which demonstrated a broad spectrum of activity against various Salmonella Typhi genotypes circulating in Bangladesh.

He also emphasizes the promising potential of bacteriophage surveillance as a cost-effective and scalable tool to inform public health strategies and guide policy decisions on typhoid control, especially in resource-limited regions.

To learn more about this research, read the full paper here: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0011822