Assessing the potential effects of nevirapine in South African surface water on fish growth: A chronic exposure of Oreochromis mossambicus

Abstract

Aquatic environments around the world have become mixtures of different types of pollutants, including pharmaceuticals. The presence of pharmaceuticals in aquatic environments has raised concerns regarding the possibility of unintended effects on aquatic animals. South Africa is currently the largest consumer of HIV antiretroviral drugs (ARVs) worldwide. Nevirapine (NVP), a first-line ARV, has been associated with serious liver toxicity in humans and has been repeatedly detected in South African surface water. We investigated the potential effect of NVP on the growth of larvae and juveniles of the Mozambique tilapia (Oreochromis mossambicus) through a chronic laboratory exposure. Larval and early juvenile stages were exposed to the highest reported environmental relevant concentration of NVP in South African surface water (1.48 μg/L) for 60 days in a static renewal system. Body mass and total length measurements were recorded and analysed for individuals aged 1, 5, 30 and 60 days. In total, 455 fish were assessed. The growth parameters of larvae exposed to NVP were not statistically significantly different (p>0.05) from those of control larvae. However, the juveniles exposed to NVP showed a slightly lower mean growth rate between the 30th and 60th day compared with the control fish. These results suggest that the concentration of NVP in South African surface water has no significant detrimental effects on fish growth during the first 2 months of their life. Further studies to investigate the effects on all life stages of fish are needed as it is evident that the growth rate of exposed fish could be affected after this stage. Significance: This study was the first to investigate the effect of an antiretroviral drug in surface water on fish growth. Chronic exposure to the highest environmentally relevant concentration of nevirapine in South African waters did not affect the growth of early life stages of Mozambique tilapia. The levels of antiretrovirals in aquatic systems should be monitored closely as their consumption is likely to increase in the future.

Antiretroviral Drugs in African Surface Waters: Prevalence, Analysis, and Potential Remediation

“…The presence of antiretroviral drugs has been reported in surface waters (rivers and man-made lakes (also called dams)), as well as wastewater influents and effluents in Africa (Wood et al 2015;Ngumba et al 2016bNgumba et al , 2020Abafe et al 2018;Nibamureke et al 2019). Surface waters around the globe have scarcely been studied for the Accepted Article presence of antiretroviral drugs, however, ARVDs have been detected in rivers, lakes in South Africa, Kenya, Zambia, and other parts of the world (Aminot et al 2015;Funke et al 2016;K'oreje et al 2016;Wooding et al 2017, Mosekiemang et al 2019Madikizela et al 2020;Ngumba et al 2020).…”

“…Degradation products of nevirapine cause skin rash and liver toxicity and there are growing concerns regarding exposure of nontarget aquatic organisms such as fish to highly specialized compounds such as ARVDs (Kolpin et al 2002, Nibamureke et al 2019). Research has shown that a concentration (1480 ng L –1 ) of nevirapine detected in South African waters did not have significant detrimental effects on Oreochromis mossambicus (Mozambique tilapia fish) juvenile growth in terms of length and body mass initially, but a reduction in growth rate after 1 to 2 mo of exposure was observed (Nibamureke et al 2019).…”

Removal of antiretroviral drugs from wastewater using activated macadamia nutshells: Adsorption kinetics, adsorption isotherms, and thermodynamic studies

“…About 4.9 million of the infected are already in the ARVDs program, thus may increase the volume of ARVDs received by water sources. Nevirapine, abacavir, and efavirenz are commonly used as first‐line treatments against HIV (Abafe et al, 2018; Nibamureke et al, 2019). As a result, these compounds were identified as compounds of interest.…”

The use of zebrafish to assess water quality and remediation efforts.

“…For this reason, the potential impact of ARVs such as nevirapine (NVP) in SA surface water was assessed on the growth of Mozambique tilapia. After a chronic exposure at the laboratory, it was found that NVP detected in SA waters, did not detrimentally affect the early juvenile growth of the tilapia fish being tested (Nibamureke et al,2019). However, further investigation is still needed to test NVP on all life stages of fish (such as zebrafish) to safeguard water systems.…”