A 41 year old African American man history presented with 8 months of diarrhea with tenesmus. He had no past medical history and took no home medications. He also complained of cough and 15 pound unintentional weight loss in the past month, but had no nausea or vomiting. He was febrile to 103.7, and had gross blood on digital rectal examination. His lungs were clear to auscultation and exam was otherwise unremarkable. Laboratory results revealed he was HIV-1 positive with a CD-4 count of 20. Stool was positive for lactoferrin. Two blood cultures and a stool culture were both positive for Shigella Sonnei. The patient was initially treated empirically for sepsis with vancomycin and pipercillin-tazobactam. His antibiotics were de-escalated to intravenous ceftriaxone after cultures had resulted and a PICC line was placed for completion of a full 14 day course of ceftriaxone on an outpatient basis.
Discussion:
Internists have a difficult task when working up an infectious complaint in a patient with AIDS. Shigella Sonnei is generally found in the GI tract and is transmitted via fecal-oral route. It is extremely virulent and often infects children, but is also common among men who have sex with men. Symptoms of Shigella infection of the GI tract infection include fevers and frequent loose stools with tenesmus, but usually no nausea or vomiting.
In a very immunosuppressed patient, such as ours, the differential diagnosis for chronic diarrhea includes a broad admixture of the very common and the very rare. Bloody diarrhea in a patient with a CD4 count of less than 50 is often caused by CMV, HSV, or bacterial infections, such as Salmonella, Yersinia, Shigella or Campylobacter. Rarer diseases such as MAC, Cryptosporidium, or Isospora belli infections are also in the differential. A history of recent antibiotics can indicate probability of clostridium difficile, while a recent HAART medication change could suggest medication-induced diarrheal illness. Unprotected receptive anal intercourse is a risk factor for sexually transmitted disease such as HSV, chlamydia, or gonorrhea in the colorectal portion of the GI tract, which can present this way. A history of recent international travel could indicate that Giardia or Entamoeba Histolytica are likely pathogens.
Treatment of shigellosis is typically accomplished with a 3-5 day course of oral ciprofloxacin, levofloxacin, azithromycin, Bactrim or IV ceftriaxone. In the case of Shigella bacteremia, there are too few cases to have a good consensus, but a 14 day course of oral Bactrim or IV ceftriaxone was recommended by the CDC when we contacted them regarding this rare case of Shigella bacteremia.
Conclusions:
Ultimately this case reinforces the importance of obtaining HIV testing and the broad differential of diarrhea in the immuncompromised host. Hospitalists should anticipate bacteria to act unpredictably in the setting of a defenseless host.