PEARLS No. 216, December 2009, written by Brian R McAvoy

Clinical question
How effective are antibiotics for treating Shigella dysentery?  

Bottom line
There was limited evidence that antibiotics reduce the duration of diarrhoea and the duration of fever compared to no antibiotic. There was inadequate evidence regarding the role of antibiotics in preventing relapses. There were no serious adverse events reported for any of the 13 antibiotics studied. The choice of antibiotic to use as first line against Shigella dysentery should be governed by periodically updated local antibiotic sensitivity patterns of Shigella isolates. Other supportive and preventive measures recommended by the WHO should also be instituted along with antibiotics (eg, health education and hand washing).  

Caveat
There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. Most of the trials had methodological limitations. These included inadequate reporting of the generation of allocation sequence, inadequate allocation concealment, and lack of blinding. The most common source of bias was failure to report outcome details for participants who were randomised but in whom Shigella could not be isolated from stool culture.  

Context
Shigellosis is a bacterial infection of the colon that can cause diarrhoea and dysentery and may lead to death. It occurs mainly in low and middle-income countries where overcrowding and poor sanitation exist, and may lead to around 1.1 million deaths per year globally, mostly in children under five years. Mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for eradication and preventing relapse.  

Cochrane Systematic Review
Christopher PRH et al. Antibiotic therapy for Shigella dysentery. Cochrane Reviews 2009, Issue 4. Article No. CD006784. DOI: 10.1002/14651858.CD006784.pub2. This review contains 16 studies involving 1748 participants.