Induced Neurocysticercosis in Rhesus Monkeys (Macaca mulatta) Produces Clinical Signs and Lesions Similar to Natural Disease in Man

Abstract

Neurocysticercosis is a serious endemic zoonosis resulting in increased cases of seizure and epilepsy in humans. The genesis of clinical manifestations of the disease through experimental animal models is poorly exploited. The monkeys may prove useful for the purpose due to their behavior and cognitive responses mimicking man. In this study, neurocysticercosis was induced in two rhesus monkeys each with 12,000 and 6,000 eggs, whereas three monkeys were given placebo. The monkeys given higher dose developed hyperexcitability, epileptic seizures, muscular tremors, digital cramps at 10 DPI, and finally paralysis of limbs, followed by death on 67 DPI, whereas the monkeys given lower dose showed delayed and milder clinical signs. On necropsy, all the infected monkeys showed numerous cysticerci in the brain. Histopathologically, heavily infected monkeys revealed liquefactive necrosis and formation of irregular cystic cavities lined by atrophied parenchymal septa with remnants of neuropil of the cerebrum. In contrast, the monkeys infected with lower dose showed formation of typical foreign body granulomas characterized by central liquefaction surrounded by chronic inflammatory response. It was concluded that the inflammatory and immune response exerted by the host against cysticerci, in turn, led to histopathological lesions and the resultant clinical signs thereof.

Causes of organ condemnation, its public health and financial significance in Nekemte municipal abattoir, Wollega, Western Ethiopia

“…Sometimes the tapeworm affects human health, but often it goes undetected. In rare cases the cystic intermediate stage can lodge in the brain of people and cause serious disease (Chowdhury et al, 2014). Factors that increase the risk of cattle being infected with C. bovis include grazing on land that has human faecal contamination, over flowing domestic sewage systems, irrigation with inadequately treated reclaimed sewage water, bird movements to and from a nearby sewage treatment works (Filmer, 1999).…”

Model systems for investigating disease processes in neurocysticercosis

“…NCC can be reliably induced in rhesus monkeys by feeding them large doses of activated T. solium oncospheres. The infected monkeys present with seizures and clinical symptoms very similar to those in humans within a matter of days, and if not treated may eventually die from the infection (Saleque et al ., 1988; Chowdhury et al ., 2014). Symptom presentation is delayed and attenuated in monkeys receiving smaller numbers of oncospheres, which may more closely resemble the human condition (Chowdhury et al ., 2014).…”

“…The infected monkeys present with seizures and clinical symptoms very similar to those in humans within a matter of days, and if not treated may eventually die from the infection (Saleque et al ., 1988; Chowdhury et al ., 2014). Symptom presentation is delayed and attenuated in monkeys receiving smaller numbers of oncospheres, which may more closely resemble the human condition (Chowdhury et al ., 2014). It is interesting to note that symptom onset could be induced within a matter of days, in contrast to a study reporting a case of naturally acquired NCC in an 8-year-old rhesus monkey, which presented with no symptoms (Johnston et al ., 2016).…”

Recent advancements and new perspectives in animal models for Neurocysticercosis immunopathogenesis

“…Recently, one group has used rhesus monkey ( Macaca mulatta ) to develop an animal model for NCC, by simply feeding two monkeys in with 12 000 and 6 000 eggs . All the four infected monkeys developed CNS infection.…”