Background
Appendicitis is a frequent surgical emergency worldwide. The present study was conducted to determine the prevalence of HIV, and the association of infection with clinical, intraoperative and histological findings and outcome, among patients with appendicitis.

Methods
We performed a cross sectional study at Weill-Bugando Medical Centre in northwest Tanzania. In total, 199 patients undergoing appendectomy were included. Demographic characteristics of patients, clinical features, laboratory, intraoperative and histopathological findings, and HIV serostatus were recorded.

Results
In total, 26/199 (13.1%) were HIV-seropositive. The HIV-positive population was significantly older (mean age: 38.4 years) than the HIV-negative population (25.3 years; p < 0.001). Leukocytosis was present in 87% of seronegative patients, as compared to 34% in seropositive patients (p = 0.0001), and peritonitis was significantly more frequent among HIV-positives (31% vs. 2%; p < 0.001). The mean (SD) length of hospital stay was significantly longer in HIV-positives (7.12 ± 2.94 days vs. 4.02 ± 1.14 days; p < 0.001); 11.5% of HIV patients developed surgical site infections, as compared to 0.6% in the HIV-negative group (p = 0.004).

Conclusion
HIV infections are common among patients with appendicitis in Tanzania, and are associated with severe morbidity, postoperative complications and longer hospital stays. Early diagnosis of appendicitis and prompt appendectomy are crucial in areas with high prevalence of HIV infection. Routine pre-test counseling and HIV screening for appendicitis patients is recommended to detect early cases who may benefit from HAART.