Early Detection of Histomoniasis in Blood Samples by PCR and Sequencing

• Published in: Avian diseases Vol. 67; no. 4; p. 340
• Main Authors: Durairaj, Vijay, Barber, Emily, Veen, Ryan Vander
• Format: Journal Article
• Language: English
• Published: United States 19.12.2023
• Subjects: Animals; Disease Outbreaks; Polymerase Chain Reaction - veterinary; Poultry Diseases - diagnosis; Protozoan Infections; Turkeys; histomoniasis; histomonosis; blood samples; early detection; blackhead disease; Histomonas meleagridis; PCR; sequencing
• ISSN: 1938-4351
• DOI: 10.1637/aviandiseases-D-23-00026

Histomoniasis is a deadly disease of turkeys causing devastating economic losses to the poultry industry. In field outbreaks, a presumptive diagnosis is made based on gross pathology lesions and confirmed by histopathology. An early detection tool with quick turnaround time is needed to prevent the spread of histomoniasis. With this objective, two studies were conducted in turkeys. In Study 1, 40 poults were housed in two pens (20 poults/pen) and challenged at 14 days of age with by intracloacal route. Blood samples were collected 4 days postchallenge. Fifty-five percent (22/40) of the blood samples tested positive for based on PCR using primers targeted against the 18S rRNA gene and confirmed by sequencing. In Study 2, 40 poults were housed in two groups and raised in floor pens. Groups 1 and 2 served as negative and challenge controls, respectively. At 14 days of age, the birds in Group 2 were challenged with by intracloacal route. Blood samples were collected 2 days postchallenge. Five percent (1/20) of the blood samples tested positive for , based on PCR and confirmed by sequencing. The results from both studies indicate that DNA can be detected in the blood samples by PCR and confirmed by sequencing as early as 4 days postchallenge. This early detection method could be applied in field outbreaks to detect and confirm histomoniasis as early as possible.