Salmonella infections: why India needs to look beyond typhoid and diarrhoea, Pg II

Key Highlights:

• Salmonella infections extend beyond typhoid and diarrhea, encompassing a range of illnesses from mild gastroenteritis to serious bloodstream infections.
• Non-typhoidal Salmonella (NTS) infections are a significant concern, often undiagnosed due to self-recovery, but can become invasive and life-threatening, especially in vulnerable populations.
• A major challenge is the growing Antimicrobial Resistance (AMR) in Salmonella, with a study indicating fluoroquinolone resistance in S. Typhi reaching 85% in India by 2015-19.
• The World Health Organization (WHO) recommends Typhoid Conjugate Vaccines (TCV) for children from six months, but it is not yet part of India’s Universal Immunisation Programme.
• Food Safety and Standards Authority of India (FSSAI) has surveillance systems, but gaps remain, particularly in the large informal food sector.

Salmonella.jpg

Detailed Insights:

• Salmonella is a group of bacteria, with Salmonella Typhi and Salmonella Paratyphi causing typhoid and paratyphoid (enteric fever), while other serotypes cause NTS.
• NTS commonly causes gastroenteritis and is often linked to contaminated poultry, eggs, and other animal-based foods.
• The actual burden of NTS is difficult to estimate due to many mild infections going undiagnosed, highlighting a public health data gap.
• Both typhoid and NTS spread via the faecal-oral route, but typhoid's reservoir is primarily humans, whereas NTS has a wider ecology involving animals, food, and the environment.
• Contamination can occur at multiple points in the food supply chain, from farms to household kitchens, making Salmonella a One Health problem.
• The emergence of extensively drug-resistant typhoid underscores the critical need for judicious antibiotic use and effective prevention strategies.
• Proper diagnosis, such as blood culture, is crucial before initiating antibiotic treatment, as the Widal test has limitations for typhoid diagnosis.
• Prevention measures include hand washing, safe water, thorough cooking of poultry and eggs, proper refrigeration, and separating raw meat from ready-to-eat food.

Key Concepts Involved:

• Salmonella: A genus of rod-shaped, Gram-negative bacteria that can cause various infections in humans and animals.
• Non-typhoidal Salmonella (NTS): Serotypes of Salmonella that typically cause gastroenteritis but can lead to invasive, life-threatening infections.
• Antimicrobial Resistance (AMR): The ability of microorganisms to resist the effects of an antimicrobial drug to which they were once sensitive.
• One Health: A collaborative, multisectoral, and transdisciplinary approach recognizing the interconnectedness of human, animal, and environmental health.
• Typhoid Conjugate Vaccines (TCV): Advanced vaccines that provide longer-lasting immunity against typhoid and are suitable for young children.