Modelling the migration of Onchocerca volvulus in simuliids, using a simple compartmental process

Area of Science:

• Parasitology
• Mathematical Biology
• Entomology

Background:

• Onchocerca volvulus is a filarial nematode.
• Simuliids (black flies) are vectors for Onchocerca volvulus.
• Understanding parasite migration in vectors is crucial for disease control.

Purpose of the Study:

• To model the early migration of Onchocerca volvulus in simuliids.
• To apply a hierarchical compartmental process to parasite movement.
• To assess the fit of a multinomial distribution to observed migration patterns.

Main Methods:

• Developed a time-homogeneous compartmental model with differing transition rates.
• Utilized a hierarchical structure where individuals enter the first compartment.
• Applied the model to Onchocerca volvulus migration data in simuliids.

Main Results:

• The hierarchical compartmental process results in a multinomial distribution.
• The model successfully represents early Onchocerca volvulus migration from the stomach to the thorax.
• Allowances for engorgement period and peritrophic membrane encapsulation improve model fit.

Conclusions:

• A multinomial distribution derived from a hierarchical compartmental model effectively describes early Onchocerca volvulus migration in simuliids.
• The model provides insights into parasite translocation within the vector.
• This approach can inform strategies for controlling onchocerciasis transmission.