Data scarcity and ecological complexity: the cutaneous leishmaniasis dynamics in Ecuador.

Area of Science:

• * Tropical Medicine
• * Epidemiology
• * Vector-borne Diseases

Background:

• * Cutaneous leishmaniasis (CL) is a neglected tropical disease transmitted by sand flies, with over 1000 reported cases annually in Ecuador.
• * Ecological factors, including host diversity and sand fly abundance, influence CL transmission in Ecuador.
• * Passive surveillance systems lead to underreporting of CL cases, obscuring the true incidence.

Purpose of the Study:

• * To develop and analyze an epidemic model for CL transmission dynamics in Ecuador's coastal ecosystems, incorporating non-human hosts.
• * To estimate key epidemiological parameters, including transmission rates and case reporting levels.
• * To assess the effectiveness of current surveillance and identify control strategies.

Main Methods:

• * An epidemic model was developed to simulate CL transmission dynamics.
• * The model was fitted to data from a 2010 CL outbreak in Valle Hermoso, Ecuador.
• * Parameters such as transmission rates, reproduction numbers, and reporting levels were estimated.

Main Results:

• * Ecuador's current surveillance system misses an estimated 38% of actual CL cases.
• * The mean CL reproduction number (R0) in Valle Hermoso was estimated at 3.9 during the 2010 outbreak.
• * Transmission probabilities between alternative hosts, sand flies, and humans were quantified.

Conclusions:

• * Major CL outbreaks in Ecuador's coastal regions are likely without improved surveillance and alternative host management.
• * Vector control and alternative host management must be implemented concurrently for effective outbreak prevention.
• * Accurate CL incidence data is essential for targeted public health interventions.