Observations on trichinosis in the rhesus monkey

Area of Science:

• Veterinary Pathology
• Parasitology
• Infectious Diseases

Background:

• Trichinosis is a parasitic disease caused by roundworm nematodes of the genus Trichinella.
• Understanding the pathogenesis of trichinosis in animal models is crucial for developing effective treatments and prevention strategies.
• Rhesus monkeys are a relevant model for studying human diseases due to physiological similarities.

Purpose of the Study:

• To investigate the clinical, pathological, and morphological manifestations of trichinosis in rhesus monkeys.
• To assess the dose-dependent effects of Trichinella infection in this primate model.
• To compare the induced disease in monkeys to human trichinosis.

Main Methods:

• Rhesus monkeys were experimentally infected with varying doses of Trichinella larvae.
• Clinical signs, including edema and myalgia, were monitored post-infection (PI).
• Pathological changes in muscle and intestine were examined, and adult worms were recovered.

Main Results:

• Infection with 2.0 larvae/g body weight resulted in mortality between 31-41 days PI.
• Monkeys infected with 1.0 larva/g showed varied outcomes, with some succumbing and others remaining healthy long-term.
• Clinical signs included periorbital edema, eosinophilia, myalgia, and joint stiffness, with adult worms found in the intestine by 49 days PI.

Conclusions:

• Rhesus monkeys develop trichinosis that closely resembles human disease clinically and pathologically.
• The study confirms rhesus monkeys as a suitable model for studying Trichinella infections.
• Morphological changes observed were consistent with human trichinosis, without generalized lymphoid hyperplasia.