Abstract

Family poultry production systems (FPPSs) in Chile and Argentina produce high-quality and nutritious food. However, little is known about chicken coccidiosis in these production systems. This work aimed to determine the Eimeria sp. positivity rate, circulating species, general farm management, and knowledge of the disease in FPPSs by gaining access to peri-urban markets in these two countries. The overall Eimeria sp. positivity rate, determined in 88 fecal samples, was 85.1%. Oocysts per gram in Argentinean meat-producing FPPSs were significantly higher than in Argentinean and Chilean egg-producing FPPSs. Multiplex-PCR based on seven Eimeria spp. Sequence-Characterized Amplified Region (SCAR) markers showed a great diversity of circulating species, with E. mitis (70.3%), E. acervulina (62.2%), and E. tenella (59.5%), followed by E. maxima (43.2%), E. praecox (32.4%), E. necatrix (18.9%), and E. brunetti (5.4%). Low awareness among family producers and low implementation of control measures were found. Importantly, pathogenic species were found even in asymptomatic chickens, which represents a potential chicken health threat. Furthermore, the administration of sulfonamides to broilers with clinical signs poses a risk of environmental contamination. This is the first comprehensive cross-sectional study showing that Eimeria sp. is a persistent parasite in peri-urban FPPSs in Argentina and Chile.; The relevance of coccidiosis, a parasitic disease of chickens, in family poultry production systems (FPPSs) was assessed in Buenos Aires, Argentina, and Santiago, Chile, by analyzing samples obtained from chicken pens in the laboratory, and by a survey addressed to producers. We found that coccidiosis is a prevalent disease in FPPSs, disseminating parasitic species of these coccidia in the environment. We also estimated a low awareness of coccidiosis and its association with other diseases and a lack of prevention strategies to avoid outbreaks among family producers. This descriptive study is the first conducted in FPPSs in this region. Its findings can help the introduction of sanitary improvements to attenuate the parasite’s dissemination and improve chicken health, as well as aid in diminishing the use of chemical anticoccidials, contributing to food safety and a minimal environmental impact of anticoccidials used in poultry production. © 2025 by the authors.; © 2025 by the authors.