|Ciprofloxacin||500 mg PO 2× daily for 3 d or 750 mg once daily|
|Levofloxacin||500 mg once daily|
|Trimethoprim–sulfamethoxazole (TMP–SMX)||160 mg TMP/800 mg SMX PO 2× daily for 5 d|
|Azithromycin||500 mg PO daily for 1 day, then 250 mg PO daily for 4 d|
|Ceftriaxone||1–2 g intravenously once daily|
Specific antimicrobial therapy in shigellosis requires the administration of agents that shorten the illness and reduce the mortality. Sometimes antibiotics are used in order to reduce transmission and risk to others. Empiric antibiotic therapy may be wise in some patients, e.g., those who are severely ill, or the elderly, in malnourished individuals, and patients with human immunodeficiency virus (HIV) infection, food handlers, healthcare workers, and individuals in day-care centers
The antibiotic of choice for adults with Shigella infection is an oral fluoroquinolone. The duration of therapy is 3 days; or 5 to 7 days in patients with infection due to S. dysenteriae type 1 or with HIV coinfection. If the patient has a history of travel in the Indian subcontinent, empiric antibiotic therapy may require a third-generation cephalosporin, due to widespread resistance to ciprofloxacin, trimethoprim–sulfamethoxazole, and azithromycin. Once susceptibilities are known treatment can be adjusted as necessary.
In children adequate hydration is critical and as with adults the decision to introduce antibiotics has to be a clinical decision based on the clinical severity, underlying risk (e.g., immunocompromise) and likelihood of spread to others. Empiric therapy may be appropriate in patients with suspected shigellosis if they are also immunocompromised and have symptoms suggestive of bacteremia (Table 155.2).