Overview
Shigella infections, commonly known as shigellosis, represent a significant global health concern, particularly in developing regions where sanitation and hygiene standards are suboptimal. These infections are primarily transmitted through the fecal-oral route, often via contaminated food or water, and person-to-person contact. The genus Shigella comprises several species, with S. flexneri and S. dysenteriae being the most prevalent, contributing substantially to the morbidity and mortality associated with bacillary dysentery worldwide [PMID:39827134]. The clinical presentation typically includes bloody diarrhea, fever, abdominal pain, and tenesmus, with severe cases potentially leading to dehydration, sepsis, and, in rare instances, death, especially in vulnerable populations such as children and immunocompromised individuals.
Epidemiology
The epidemiology of Shigella infections underscores a disproportionate burden in low- and middle-income countries, where inadequate sanitation and limited access to clean water exacerbate transmission rates [PMID:39827134]. S. flexneri and S. dysenteriae are predominant, with S. dysenteriae type 1 particularly notable for its ability to cause severe complications due to its production of Shiga toxin, which can lead to hemolytic uremic syndrome (HUS) and other systemic manifestations. This regional disparity highlights the need for targeted public health interventions focused on improving sanitation and hygiene practices in these areas.
Moreover, there is a growing concern over the emergence and spread of multidrug-resistant (MDR) Shigella strains, particularly in Africa [PMID:39827134]. These resistant strains pose significant challenges to treatment efficacy, necessitating enhanced surveillance systems to monitor resistance patterns and guide appropriate antibiotic stewardship. The rise of extended-spectrum beta-lactamase (ESBL) and carbapenemase-producing Shigella further complicates management, underscoring the urgent need for robust surveillance and tailored public health responses to mitigate the spread of these resistant pathogens.
Diagnosis
Diagnosing Shigella infections typically involves a combination of clinical symptoms and laboratory confirmation. Clinicians often rely on the presence of bloody diarrhea, fever, and abdominal pain as key clinical indicators. Laboratory diagnosis commonly includes stool cultures to identify Shigella species, with sensitivity enhanced by using selective media such as Hektoen enteric agar or SS Agar [Evidence: Limited]. Molecular techniques, such as PCR, have also become increasingly valuable for rapid and accurate identification, particularly in detecting specific virulence factors and resistance genes [Evidence: Limited]. Serotyping is crucial for distinguishing between different Shigella species and subtypes, aiding in epidemiological tracking and understanding transmission dynamics [Evidence: Limited].
In clinical practice, early diagnosis is critical for timely intervention and to prevent nosocomial spread, especially in healthcare settings. However, the reliance on stool cultures can sometimes delay diagnosis due to the time required for culture growth and susceptibility testing. Therefore, integrating rapid molecular diagnostics into routine clinical practice can significantly improve diagnostic accuracy and patient management [Evidence: Limited].
Management
The management of Shigella infections primarily focuses on supportive care and targeted antimicrobial therapy, depending on the severity of the infection and local resistance patterns. For uncomplicated cases, supportive measures such as fluid and electrolyte replacement are essential to manage dehydration and maintain hydration status [Evidence: Limited]. Oral rehydration solutions (ORS) are particularly effective in preventing severe dehydration and reducing mortality rates, especially in pediatric populations [Evidence: Limited].
In cases of severe or MDR Shigella infections, empirical antibiotic therapy must be guided by local resistance patterns. Traditionally, fluoroquinolones and trimethoprim-sulfamethoxazole have been first-line treatments; however, the increasing prevalence of resistance necessitates a shift towards alternative agents [PMID:39827134]. Carbapenems, particularly in settings where resistance to other antibiotics is prevalent, have emerged as critical options for treating severe, multidrug-resistant infections [PMID:39827134]. However, the use of carbapenems must be carefully monitored to prevent the further spread of carbapenem-resistant Enterobacterales (CRE) and to preserve their efficacy for treating other serious infections [PMID:39827134].
Emerging therapeutic strategies include the use of probiotics and bacteriophage therapy. A notable example is the encapsulation of Lactobacillus plantarum ZGP-Lpl.19 in alginate-pectin-chitosan microcapsules, which has shown promise in improving survival through the gastrointestinal tract and attenuating S. flexneri growth and pathogenicity [PMID:41042270]. This approach not only supports gut health but also demonstrates potential as a preventive or adjunct therapeutic measure, reducing reliance on antibiotics and mitigating resistance development [PMID:41042270].
Key Recommendations
By adhering to these recommendations, healthcare providers can better manage Shigella infections, mitigate the impact of antibiotic resistance, and improve patient outcomes in both endemic and non-endemic settings.
References
1 Somda NS, Nyarkoh R, Tankoano A, Bonkoungou OJI, Tetteh-Quarcoo PB, Donkor ES. Molecular epidemiology of extended-spectrum beta-lactamases and carbapenemases-producing Shigella in Africa: a systematic review and meta-analysis. BMC infectious diseases 2025. link 2 Ghorbani Z, Shayestehpour M, Shahaboddin ME, Khaledi A, Karimi M, Maleki R et al.. Microencapsulated Lactiplantibacillus plantarum ZGP-Lpl.19 modulates growth and virulence gene expression of Shigella flexneri ATCC 12022 in vitro. Naunyn-Schmiedeberg's archives of pharmacology 2026. link