The epidemiology and natural history of HIV/HBV and HIV/HCV co-infections.

Both hepatitis B virus (HBV) and hepatitis C virus (HCV) are more common in HIV-infected individuals than in the general population as a result of shared risk factors for viral acquisition. Populations of injecting drug users are at particularly high risk for HIV/HCV co-infection. Co-infection with HIV results in greater likelihood of chronicity and enhanced viral replication in the setting of both HBV and HCV infections. Current evidence suggests that HIV infection may have a negative impact on HBV-related liver disease progression, although the mechanisms for this are unclear. HBV seems to have little impact on the progression of HIV disease. HIV co-infection hastens HCV-related liver disease with faster progression to cirrhosis, end-stage liver disease and occurrence of hepatocellular carcinoma. There is still conflicting evidence on the impact of HCV on HIV progression with inconsistent results from cohort studies. Long-term follow-up of highly active antiretroviral therapy (HAART)-treated patients will help elucidate this further. Antiretroviral agents have little long-term impact on HCV viraemia, although some have significant anti-HBV activity. Morbidity and mortality from end-stage liver disease in HIV-infected individuals is increasing and every effort should be made to identify, educate and treat as appropriate those with HBV or HCV co-infection.

Abdominal computed tomographic findings of Mycobacterium tuberculosis and Mycobacterium avium intracellulare infection in HIV seropositive patients.

OBJECTIVE: To compare the computed tomographic (CT) findings of abdominal Mycobacterium tuberculosis (MTB) infection and Mycobacterium avium intracellulare (MAI) infection in patients with human immunodeficiency virus (HIV) infection. METHODS: A retrospective review of the CT findings of 30 patients with HIV and proven MTB (n = 9) or MAI (n = 21) infection was conducted. Images were reviewed by a radiologist blinded to the diagnosis, and the radiologic findings involving the abdominal viscera, peritoneum and lymph nodes were compared. RESULTS: The following were more frequent in patients with MAI infection: hepatomegaly (MAI 71% v. MTB 44%, p < 0.05), uniform attenuation of lymph nodes (MAI 90% v. MTB 55%, p < 0.05) and clustered pattern of lymph nodes (MAI 57% v. MTB 22%, p < 0.05). In patients with MTB infection, lymph nodes with low attenuation centrally were more common (MAI 10% v. MTB 44%, p < 0.05), and mesenteric lymph nodes were significantly larger (MAI mean = 20 mm v. MTB mean = 40 mm, p < 0.05). CONCLUSION: Although nonspecific, CT may be useful in the early diagnosis of MTB and MAI infection, allowing for presumptive treatment before microbiologic confirmation.