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Introduction: This study aimed to assess Trichuris species infection and evaluate the anthelmintic efficacy of fenbendazole and ivermectin against natural trichurid infections in non-human primates (NHPs), kept at Mahendra Chaudhury (MC) Zoological Park, Chhatbir, India., Materials and Methods: Molecular confirmation of Trichuris infection was carried out using polymerase chain reaction targeting internal transcribed spacer sequences, and anthelmintic efficacy was assessed by fecal egg count reduction test, respectively., Results: A 710 base pair product confirmed Trichuris species infection in NHPs. Fenbendazole, 10 mg/kg body weight orally for 5 consecutive days and ivermectin, 100 μg/kg body weight orally for 3 alternate days proved effective and showed a maximum fecal egg reduction of 99.20% and 100% (P < .05) at day 7 post-treatment., Conclusions: This study highlighted the molecular confirmation of Trichuris species in non-human primates and its management using fenbendazole and ivermectin., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

In 1997, an outbreak of alveolar echinococcosis in Japanese monkeys (Macaca fuscata) occurred in a zoo in Hokkaido, Japan. Twelve infected monkeys from a colony (n = 57) were diagnosed serologically by Western blotting, and ultrasonography showed the presence of tumor-like tissue in the livers of nine monkeys. The 12 infected monkeys have been treated with albendazole for 10 years without surgical resection. Ten of these monkeys have died so far; diagnoses were confirmed histopathologically through autopsy. Two of these monkeys are still alive. Recently, a significant difference between the two living monkeys was recognized. A difference in curative effect was demonstrated between the two living monkeys by radiography, contrast enhanced computed tomography, and contrast ultrasound. One showed metastasis to various organs, and the other appeared to be almost cured, as demonstrated by size reduction and calcification of the lesion after albendazole treatment for 10 years. This time, serological reexamination was performed to corroborate this apparent difference. The serological tests supported the preliminary imaging findings. In addition, the presence of albendazole metabolites in sera was confirmed by high-performance liquid chromatography. In this study, it was demonstrated that tests which have been used in human cases were also effective for diagnosing alveolar echinococcosis and for assessing curative effects in nonhuman primates such as M. fuscata.

Experimental Trichinella zimbabwensis infections were established in three baboons (Papio sp.) and four vervet monkeys (Cercopithecus aethiops) and the clinical-pathological manifestations assessed. The infected animals showed clinical signs ranging from fever, diarrhoea, periorbital oedema and muscular pain in varying degrees. One baboon became blind due to the infection. Levels of creatinine phosphokinase and lactate dehydrogenase increased to reach a peak on Day 42 post-infection (pi) for both baboons and monkeys. Blood parameters such as packed cell volume, levels of red blood cells and white blood cells did not change significantly from the normal ranges except for the levels of eosinophils which peaked above the normal ranges at Day 28 and 56 pi in baboons and at Day 56 pi in monkeys. Two baboons and two monkeys died during the course of the experiment. They were emaciated and showed lesions such as ascites, hydropericardium, congested liver and enlarged gall bladder. Histopathological findings of various muscles included a basophilic transformation of muscle cells, the disappearance of sarcomere myofibrils and basophilic sarcoplasm with the presence of Trichinella larvae in the sarcoplasm. These changes were mainly in the massetter and were of various intensities in the tail, gastrocnemius and biceps muscles. Five consecutive treatments with an oxfendazole-levamisole combination on surviving animals failed to clear the infection whereas ivermectin cleared the infection after one treatment in two monkeys and after two treatments in a baboon.

Numerous cases of Gongylonema spp. infection with associated pathological lesions and clinical signs were identified in a collection of Goeldi's monkeys (Callimico goeldii) (GMs) at a zoological park during a 3-yr period. An increase in the incidence of clinical signs in the GMs and other callitrichid species prompted an investigation to determine the prevalence of infection within the collection and evaluate treatment protocols. Twenty-one callitrichids [nine GMs, four golden lion tamarins (Leontopithecus rosalia), six cotton-top tamarins (Saguinus oedipus), and two golden-headed lion tamarins (Leontopithecus chrysomelas)] were included in this study. Many of the animals had been positively diagnosed on past examinations. Repeated cytological evaluations of scrapings taken from the mucosa of the tongue were performed to diagnose infection. The animals were randomly divided into two groups and treated with either ivermectin (290 microg/kg p.o., q7 days for four doses) or mebendazole (70 mg/kg p.o. q24 hr for three doses). Follow-up scrapings were performed on all animals at days 35, 64, and 156. Numerous animals displayed clinical signs (facial pruritus, inflammation, and ptyalism) before and throughout the investigation; however, Gongylonema spp. infections were only confirmed by tongue scrapings in two animals. Fecal floatation by using a sodium nitrate solution for recovery of spirurid eggs also was performed, but it yielded no positive results. The low number of confirmed cases precluded comparative evaluation of the efficacy of the anthelmintic treatment protocols. However, both regimes seemed subjectively similar in decreasing clinical signs and were safe with no adverse effects. Diagnosis of Gongylonema spp. infection is challenging, even when severe clinical signs are present. This investigation further demonstrates the lack of a reliable ante-mortem test for the parasite and underscores the importance of treatment based on clinical signs. Until a more sensitive test is available, further comparison studies on treatment regimes will be difficult and likely unrewarding.

Ten cotton-topped tamarins (Saguinus oedipus) were infected with Moniliformis clarki a parasitic acanthocephalan. One animal died of intestinal perforation and peritonitis before treatment was initiated. Five of the remaining tamarins were treated successfully with oral albendazole at either 50 mg/kg b.i.d. for 16 days or 100 mg/kg b.i.d. for 3 days, then repeated biweekly for four treatments. A less-intensive treatment regime of 50 mg/kg albendazole orally s.i.d. for 3 days and monthly repeated treatments was unsuccessful. Parasites were removed via surgical enterotomy from two animals, both of which continued to shed acanthocephalan eggs postoperatively.

The effect of some known antifilarial drugs on naturally-occurring filariae in squirrel monkeys, Saimiri sciureus, was evaluated. Four drugs, dithiazanine iodide, naphuride sodium, thiacetarsamide sodium, and diethylcarbamazine were tested against Dipetalonema gracile and Tetrapetalonema marmosetae. Dipetalonema caudispina was included in some of the studies using diethylcarbamazine. These are the three most commonly encountered filarial species in squirrel monkeys. Dithiazanine iodide proved to be unsuitable for use because of lack of acceptance by the monkeys. Naphuride sodium (10 mg/kg/week for 5 weeks) did not exert filaricidal activity against the species tested during a 7-month evaluation period. Thiacetarsamide sodium (0.22 ml/kg twice daily for 2 days) had lethal effects on the adult parasites, but not the microfilariae, of all species tested. Diethylcarbamazine (50 mg/kg/day for 10 days) was found to be effective against both microfilaria and adults of all filarial species tested. Monkeys given this regimen were microfilaria-negative for 12-24 weeks following treatment.