Epidemiology of Strongylus vulgaris infection of the horse in Morocco.

The study investigates the infection rate of Strongylus vulgaris, a parasitic worm, in horses in Morocco. The findings highlight that the highest infection rates occur during rainy seasons and the infection is lowest in December and January.

Study Overview

• The research took place between August 1978 and July 1979, where researchers examined the anterior mesenteric artery and its branches from adult horses for the presence of Strongylus vulgaris larvae.
• The incidence of infection ranged from 55% to 100%, with an annual average of 80%. This indicates a high prevalence of the parasitic infection among horses in the studied area.

Infection Dynamics

• The average monthly number of larvae varied from 3 to 22, with an annual mean of 13. This suggests the infection rates may vary significantly from month to month.
• The lowest infection was observed in December and January, whereas the highest occurred in June. Thus, the infection rate peaks in the middle of the year.
• The month-to-month changes in infection rates indicate the lifecycle dynamics of this parasite within its horse hosts in the local climatic conditions of Morocco.

Annual Infection Patterns and Seasonality

• The study findings suggest that S. vulgaris demonstrates annual lifecycle patterns in Morocco, with infection occurring primarily during the rainy season (November-April).
• A surge in the arterial population of the parasite tends to happen in spring, followed by a decline into summer. This implies a seasonality to the lifecycle of the parasite and its impact on horse health.
• The population of adult parasites increased during autumn and winter, indicating the parasite’s lifecycle progression and maturity during the colder months.