Treatment for Shigella Infection

Anyone with a suspected Shigella infection should be tested for the presence of Shigella bacteria. Antibiotics can shorten the length of illness.

Although shigellosis is usually a self-limited illness, antibiotics can shorten the course, and in the most serious cases, might be life-saving. [1, 16, 22] Historically, the antibiotics commonly used for treatment of bacterial infections, like those caused by Shigella, are ampicillin, trimethoprim/sulfamethoxazole (TMP-SMZ, also known as Bactrim or Septra), or ceftriaxone (Rocephin). [1, 11, 26] Ciprofloxacin is also used commonly to treat adults who are infected. [11, 26, 30].

Unfortunately, Shigella bacteria have become resistant to one or more of these antibiotics. [16, 30] This means some antibiotics might not be effective for treatment, and that using (or overusing) antibiotics to treat shigellosis can sometimes make the bacteria more resistant. [30] As noted in one recent study:

Of 369 isolates tested, 59% were resistant to TMP-SMZ, 63% were resistant to ampicillin, 1% were resistant to cefixime, and 0.3% were resistant to nalidixic acid; none of the isolates were resistant to ciprofloxacin. Thirteen percent of the isolates had multidrug resistance to ampicillin, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline. Infections due to multidrug-resistant shigellae are endemic in Oregon. [30]

This study therefore suggests that “[n]either ampicillin nor TMP-SMZ should be considered appropriate empirical therapy for shigellosis any longer; when antibiotics are indicated, a quinolone or cefixime should be used.” [30]

About Shigella

Chapter 8