Review Question - QID 221292

This patient with a history of a solid organ transplant on immunosuppression who presents with abdominal pain, bloody stools, and colonoscopy findings of linear ulcers most likely has cytomegalovirus infection. The most appropriate treatment for this infection is ganciclovir.

In immunocompetent hosts, cytolomegalovirus (CMV) infections are typically asymptomatic. Immunocompromised hosts such as those with post-transplant immunosuppression and acquired immunodeficiency syndrome can present with severe disease with wide-ranging manifestations. Clinical presentations include CMV pneumonitis, which would present with cough, dyspnea, and fever, CMV retinitis, which would present with visual field defects, CMV colitis, which would present with bloody stools, abdominal pain, and linear colonic ulcers, and CMV encephalitis, which would present with altered mental status and focal neurologic deficits. Treatment with ganciclovir or valganciclovir is the primary pharmacotherapy for CMV infection and should be started immediately upon clinical suspicion of an infection.

Yerushalmy-Feler et al. reviewed the diagnosis and management of CMV colitis. They found that ganciclovir for a 2-3 week course is an effective treatment for CMV colitis. They recommended a longer course of parenteral therapy of 14-21 days in pediatric patients as early switching to oral treatment could promote CMV reactivation.

Figure/Illustration A is a clinical photograph demonstrating linear ulcerations in the colon (blue circle). These findings are consistent with CMV colitis.

Incorrect Answers:
Answer 1: Azithromycin is an antibiotic therapy that can be used to treat Shigella infections in adults. Shigella infections can present with bloody diarrhea, fevers, and abdominal cramps. Shigella gastroenteritis is usually self-limited in immunocompetent hosts. In immunocompromised hosts, Shigella would still not be likely to cause linear ulcerations seen on colonoscopy.

Answer 3: Neuraminidase inhibitors like oseltamivir are used to treat influenza, a seasonal respiratory infection that presents with malaise, fever, myalgias, and sore throat. Influenza does not present with bloody stools and colonoscopy findings of ulcerations.

Answer 4: Rifampin, isoniazid, pyrazinamide, and ethambutol are used to treat tuberculosis, which presents with fever, malaise, hemoptysis, and weight loss. Tuberculosis can lead to enteritis and diarrhea, especially in immunocompromised patients.

Answer 5: TMP-SMX is the first-line treatment for Pneumocystis pneumonia which presents with subacute dyspnea, hypoxia, and dry cough in patients with advanced AIDS. Chest radiograph frequently reveals bilateral pulmonary infiltrates.

Bullet Summary:
In post-transplant patients, cytomegalovirus is a common cause of colitis and should be treated with ganciclovir.