AUTHOR=Ahmad Nisar , Khan Saeed A. , Majid Hafiz A. , Ali Rehman , Ullah Riaz , Bari Ahmed , Akbar Noor Ul , Majid Abdul 

TITLE=Epidemiology and phylogeny of Haemonchus contortus through internal transcribed spacer 2 gene in small ruminants

JOURNAL=Frontiers in Veterinary Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1380203

DOI=10.3389/fvets.2024.1380203

ISSN=2297-1769

ABSTRACT=<sec><title>Introduction</title><p><italic>Haemonchus contortus</italic> (<italic>H. contortus</italic>) is a blood-feeding nematode causing infectious disease haemonchosis in small ruminants of tropical and subtropical regions around the world. This study aimed to explore the prevalence and phylogeny of <italic>H. contortus</italic> in small ruminants using the internal transcribed spacer-2 (ITS-2) gene. In addition, a comprehensive review of the available literature on the status of <italic>H. contortus</italic> in Pakistan was conducted.</p></sec><sec><title>Methods</title><p>Fecal samples were collected from sheep and goats (<italic>n</italic> = 180). Microscopically positive samples were subjected to DNA extraction followed by PCR using species-specific primers.</p></sec><sec><title>Results</title><p>The overall prevalence of <italic>H. contortus</italic> was 25.55% in small ruminants. The prevalence of <italic>H. contortus</italic> was significantly associated with months and area. The highest occurrence of haemonchosis was documented in July (38.70%), whereas the lowest occurred in December (11.11%), with significant difference. The prevalence was highest in the Ghamkol camp (29.4%) and lowest in the arid zone of the Small Ruminant Research Institute (17.5%) (<italic>p</italic> = 0.01). The results of the systematic review revealed the highest prevalence of haemonchosis (34.4%) in Khyber Pakhtunkhwa (<italic>p</italic> = 0.001).</p></sec><sec><title>Discussion</title><p>Phylogenetic analysis revealed a close relationship between <italic>H. contortus</italic> and isolates from Asia (China, India, Iran, Bangladesh, Malaysia, and Mongolia) and European countries (Italy and the United Kingdom). It has been concluded that <italic>H. contortus</italic> is prevalent in small ruminants of Kohat district and all over Pakistan, which could be a potential threat to food-producing animals, farmers, dairy, and the meat industry. Phylogenetic analysis indicates that <italic>H. contortus</italic> isolates share close phylogenetic relationships with species from Asia and Europe.</p></sec>