Nevirapine in African surface waters induces liver histopathology in Oreochromis mossambicus: A laboratory exposure study

Nevirapine (NVP) is one of the HIV antiretrovirals detected recurrently in African surface waters. Liver side effects in humans were reported. Because the effects on fish are unknown, this study investigated the potential effects of NVP on selected biometric indices and liver histology of Oreochromis mossambicus (Mozambique tilapia) in a chronic exposure. Adult fish were exposed to two concentrations of NVP (1.48 and 3.74 µg l⁻¹) in a static renewal system under controlled conditions for 30 days. At the end of the exposure, each fish was weighed, the total length recorded, and blood collected from the caudal vein. A standard necropsy was done, selected organs were sampled and weighed, and biometric indices calculated. Liver tissue was processed for histological assessment. Results showed significant differences (p < 0.001) in hepatosomatic indices between the exposed fish and the control, as well as in spleen indices of the fish exposed to the higher NVP concentration (p = 0.008). Liver tissue of exposed fish showed significant histological changes (p < 0.001), including hepatocyte apoptosis, vacuolation, and a mild fibrosis around some of the veins and bile ducts. Nevirapine in African surface waters could have long-term negative effects on the health of fish.