Prevalence data on chicken diseases in low-resource settings.

Area of Science:

• Veterinary Epidemiology
• Animal Health Economics
• Global Public Health

Background:

• Transmissible livestock diseases significantly impact animal welfare, public health, and economies.
• Limited data availability in low-resource settings impedes informed decision-making for disease prevention and control.
• Data scarcity in low- and middle-income countries (LMICs) transforms disease surveillance into a development challenge.

Purpose of the Study:

• To compile and analyze existing prevalence and seroprevalence data for viral, bacterial, and parasitic diseases in backyard chickens across LMICs.
• To identify data gaps in disease occurrence for backyard chickens in LMICs.
• To assess the suitability of existing data for estimating disease prevalence.

Main Methods:

• Conducted a systematic literature review to identify relevant studies.
• Collected prevalence and seroprevalence estimates from 306 studies (n=997), covering viral, bacterial, and parasitic diseases.
• Classified studies based on Food and Agriculture Organization of the United Nations' family poultry production systems and analyzed data reporting on chicken breed and sampling methods.

Main Results:

• A dataset of 997 estimates from 306 studies on backyard chicken diseases in LMICs was compiled.
• Significant data gaps exist, with no relevant disease data for 56.9% of LMICs.
• Most studies (85.4%) focused on extensive scavenging production systems, and 52% lacked breed information.
• 71.0% of estimates were for diseases notifiable to the World Organisation for Animal Health, potentially not producer priorities.
• 72.3% of estimates originated from random samples, suitable for imputation methods.

Conclusions:

• There is a critical need to improve disease surveillance and data collection for backyard chickens in LMICs.
• Existing data, particularly from random samples, can be leveraged using imputation methods to bridge data gaps.
• Addressing data gaps is crucial for effective disease management, enhancing animal welfare, and safeguarding public health in these regions.