Shigellosis, an intestinal infection caused by Shigella bacteria, remains a significant public health problem worldwide, particularly in regions where clean water and adequate sanitation are limited. In many developing countries, shigellosis is endemic and contributes substantially to the overall burden of diarrheal disease. Studies estimate that Shigella accounts for 10–20% of all enteric infections in these settings and is responsible for nearly half of all cases of bloody diarrhea, or dysentery, among young children. The disease is especially common in children under five, whose still-developing immune systems make them more vulnerable to infection. After this age, the prevalence drops sharply as immunity builds and exposure patterns change.
In contrast, developed countries experience shigellosis in different epidemiological patterns. While the overall incidence is lower due to better hygiene and sanitation infrastructure, outbreaks still occur sporadically. These typically stem from a single contaminated food or water source, such as improperly handled produce, recreational water exposures, or food prepared under poor sanitary conditions. Because Shigella spreads easily through the fecal–oral route, even small lapses in hygiene can trigger localized outbreaks.
Certain environments in high-income countries can sustain pockets of endemic transmission. Child-care centers, for example, are particularly vulnerable due to close contact among young children and the challenges of maintaining strict hygiene practices. Similar risks are seen in institutional settings such as nursing homes, correctional facilities, and shelters, where crowding and shared amenities can facilitate rapid spread. Remote or marginalized communities with inadequate sanitation infrastructure may also face a higher risk, mirroring conditions more commonly seen in developing regions.
Globally, shigellosis remains a major cause of illness and death among children, although mortality has declined in recent decades due to improved access to treatment and better nutrition. However, the rise of multidrug-resistant Shigella strains poses a growing challenge, complicating treatment and increasing the potential for persistent transmission. Continued investment in sanitation, safe water access, hygiene education, and surveillance is essential to reducing the global burden of this highly contagious disease.
Epidemiology of Shigellosis
