Global and regional prevalence of helminth infection in chickens over time: a systematic review and meta-analysis

Abstract

Gastrointestinal helminth parasites are a concern for the poultry industry worldwide as they can affect the health, welfare, and production performance. A systematic review of the prevalence over time in different countries may improve our understanding of gastrointestinal helminthiasis in chickens and subsequently lead to improved poultry health. The aim of this systematic review and meta-analysis was to provide an overview of the published information regarding the epidemiology and the diagnostic approaches of chicken helminth infection. Six databases were searched for studies, and a total of 2,985 articles published between 1942 and 2019 were identified and subsequently screened for eligibility using title or abstract and full text assessment, resulting in 191 publications to be used in the study. Postmortem diagnostics (73.8%) and the flotation technique (28.8%) were commonly used to detect helminth infections with a pooled prevalence of 79.4% ranging from 4 to 100%. More than 30 helminth species in chicken populations were identified including Ascaridia galli (35.9%), Heterakis gallinarum (28.5%), Capillaria spp. (5.90%), and Raillietina spp. (19.0%) being the most prevalent. The reported prevalence of helminth infection decreased over time in developing countries while it increased in the developed world. Chicken kept in backyard and free-range systems had a markedly higher pooled prevalence of helminth infection (82.6 and 84.8%, respectively) than those housed in cage production systems (63.6%). This may indicate the need for more rigorous control and prevention measures in free-range and backyard production systems using regular deworming coupled with access to early and accurate diagnosis allowing for early intervention.

Prevalence of gastrointestinal parasites in three groups of domestic poultry managed under backyard system in the Savanna subregion, Department of Sucre, Colombia

“…The prevalence of gastrointestinal parasite infections varies between regions and countries [ 15 ]. For example, prevalences between 97.6% and 99.2% were reported in Germany [ 16 ], 99.3% in Italy [ 17 ], 72% in Iran [ 18 , 19 ], 73.9% in Thailand [ 20 ], and 95.8% in Zambia [ 21 ], with environmental conditions, age of birds, and availability of intermediate hosts being the main determinants for the variability of parasite prevalence [ 22 ].…”

Commercial Free-Range Laying Hens’ Preferences for Shelters with Different Sunlight Filtering Percentages

“…The important positive attributes of free-range (including organic) layer farming are the birds' access to an outdoor range, exposure to natural daylight (sunlight), ability to move freely, increased space to better regulate social interactions, and opportunities for expression of natural behaviours [1,2]. Free-range systems may also have some potential risks such as parasitic infections [3], increased disease exposure [4], heat stress [5], and predation [6,7]. However, welfare benefits such as reduced plumage damage and reduced footpad dermatitis can be seen in individuals that range more [8,9].…”

Identification of the main intestinal helminths of local breed chickens (Gallus gallus domesticusLinnaeus, 1758) reared in traditional mode in the Oran region

“…In particular, 2 species of nematodes were recovered during the study include Ascaridia galli and Heterakis gallinarum with a prevalence of (39.53 %) and (41.86 %) respectively (Raza et al, 2016). Shifaw et al, (2021) and according to a metaanalysis instead showed a high prevalence in favor of Ascaridia galli (35.9 %), followed by Heterakis gallinarum (28.5 %). Likewise, Zada et al (2015) showed a relatively low overall prevalence rate of A. galli by about 21.44 %, however A. galli was the most common and prevalent nematode in chickens in Mardan district of Pakistan.…”

“…Acanthocephali are exceptional in chickens (Reid & Mc Dougald, 1978). The reported prevalence of helminth species varied among species and ranged from 30 to 100 % (Shifaw et al, 2021). The parasitic species of helminths in the digestive tract are very common.…”