Abstract
<title>Abstract</title> <p>Human adenoviruses are recognized as significant viral pathogens associated with a wide range of clinical manifestations, including acute gastroenteritis, particularly among pediatric populations. Enteric adenoviruses belonging to species F (types 40 and 41) are well established as the primary causative agents of adenoviral diarrhea, whereas the clinical significance of other adenovirus species detected in stool samples remains controversial. In this study, stool samples were obtained from children presenting with acute diarrhea at hospitals in Najaf Governorate between March and July 2025. The samples were analyzed using multiplex polymerase chain reaction (PCR) for the detection of adenovirus species A–F. Adenovirus species F was the most frequently detected species (29%), confirming its dominant etiological role in diarrheal disease. Other adenovirus species were also identified, including species C (15.9%), D (13.6%), E (11.3%), B (6.8%), and A (6.8%). Co-detection of adenovirus species F and B was observed in 13.6% of samples, suggesting either true co-infection or prolonged asymptomatic shedding of non-enteric adenoviruses. The detection of non-enteric adenovirus species in diarrheal samples is likely attributable to incidental gastrointestinal passage or persistent viral shedding following previous respiratory or systemic infections, rather than a direct causative role in acute diarrhea. These findings emphasize the predominance of adenovirus species F in gastroenteritis and highlight the necessity for cautious interpretation of highly sensitive multiplex PCR results in clinical and epidemiological studies.</p>