Single and Synergistic Effects of Fenbendazole and Metronidazole Against Subclinical Infection by in Non-Human Primates in a Zoological Garden in Southern Italy.

The aim of this study was to assess the single and synergistic effects of fenbendazole (Fenb) and metronidazole (Metro) for the treatment of infection in different species of non-human primates (NHPs) housed in a zoological garden of southern Italy. Moreover, the study also aimed to better define the circulation of zoonotic assemblages in NHP and the potential occurrence of zoonotic transmission between the staff from the zoo and NHP. Briefly, six species that belonged to four families (Lemuridae, Cercopithecidae, Atelidae, and Hylobatidae) of NHP and housed in six cages (CG) were identified as positive and divided into two groups. Group F ( = 16 animals) was treated with Fenb (50 mg/kg, every 24 h for 5 consecutive days) and Group M ( = 7 animals) was treated with Metro (25 mg/kg, two times a day for 5 consecutive days). After the first round of therapy, all the animals were retreated for 5 days by inverting the drugs in each group. On each sampling day [study days (SDs) 3-24], the samples were tested for the presence of cysts using the FLOTAC technique. Multiple fecal tests for the antigen detection of , such as rapid ELISA and direct immunofluorescence (IFA), were performed at each sampling point only on samples that resulted in positive for cysts with FLOTAC. The efficacy of Fenb ranged from 30 to 67% and for Metro ranged from 82 to 96%. The results showed the synergistic effects of Metro and Fenb (98-100%) over the combination of Fenb and Metro (52-90%) against the infection by in NHPs. The overall k agreement between FLOTAC and IFA was reached 0.858 ( = 0.0001). In contrast, all the samples had a negative antigen result when using ELISA. At molecular analysis, six samples were confirmed positive for by nested PCR. Only two positive samples were successfully sequenced that showed 100% of identity with assemblage B. All the samples from the humans included in the study resulted in negative for cysts. Overall, the study emphasizes the need for regular monitoring of infections in NHP housed in zoos by traditional diagnostic tools combined with molecular characterization of the parasite.