Correlation of avian influenza-H9N2 with high mortality in broiler flocks in the southwest of Tripoli, Libya.

Background: Low pathogenic H9N2 avian influenza (LPAI H9N2) caused by the influenza A virus which belongs to the family Orthomyxoviridae. It caused mild respiratory symptoms and a drop in egg production in poultry. Outbreaks of AI-H9N2 have occurred in poultry since the 1990s in many countries in USA, Europe, and Asia. Recently, outbreaks of H9N2 in commercial chicken were recorded in Morocco, Tunisia, Libya, and Egypt. Furthermore, numerous studies demonstrated that co-infection with AI H9N2 and other pathogens results in severe respiratory illness with high mortality in broiler chickens. Outbreaks of respiratory disease with variations in mortality rate were recorded in broiler flocks growing in the southwest of Tripoli in Libya. Aim: The present study was conducted to explain the variation of mortality rate on broiler flocks growing in the southwest area of Tripoli by detection of AI H9N2 antibodies and antigens. Methods: A total of 453 sera samples, 60 tracheal swabs, and 60 cloacal swabs were collected from unvaccinated broiler flocks against avian influenza. Specific avian influenza type A antibodies were detected by using the Elisa test, and specific AI-H9N2 antibodies were detected by using the HI test, whereas specific AI-H9N2 antigens were detected in tracheal and cloacal swabs by using One-Step RT-PCR (M gene) technique. Results: Respiratory diseases with high variations in mortality rate were recorded in broiler flocks growing in the southwest of Tripoli in Libya; the broiler mortality rate in Twisha farms was higher than other farms (62.2% and 11%, respectively). Whereas avian influenza type A antibodies were detected at a high level in Twisha and other farms (95.2%, and 76.7%, respectively). The positive samples for AI type A were tested for AI H9N2 using the HI test. Interestingly the percentage of AI-H9N2 antibodies was quite similar in high and low mortality regions (53.4% and 46.8%, respectively). Additionally, AI-H9N2 antigens were detected only in tracheal swabs in Twisha farm 3, Al-Maamoura, and Ber Al-Tota districts. Conclusion: This study confirmed the endemic of AI- H9N2 in broiler flocks in the southwest of Tripoli-Libya. Also, it clarified that AI-H9N2 was not responsible for the high mortality rate by itself in broiler flocks. Moreover, this study supported the presence of other subtypes of avian influenza in the studied area.

Prevalence of Salmonella in poultry slaughterhouses located in Tripoli, Libya.

Background: Salmonella is a leading cause of severe economic losses in poultry and foodborne illness in humans worldwide. Aim: The aim of this study was to determine the prevalence and multidrug resistance of Salmonella Enteritidis (S. Enteritidis) in several chicken abattoirs in Tripoli, Libya. The study includes the South, East, and West regions of Tripoli. Methods: Each region was assigned five slaughterhouses. Each chicken slaughterhouse was visited three times to collect samples. Five samples were taken at random from the neck skin, crop, and spleen. The total number of samples collected from all regions was 675. Bacterial isolation and identification, as well as antibiotic sensitivity testing, were performed on these samples. Results: Salmonella spp. was found to be 15% prevalent, and S. Enteritidis was found to be 7% prevalent. The south region of Tripoli had the highest S. Enteritidis (9%), while the west region had the highest Salmonella spp. (22%). Salmonella prevalence increased significantly (p < 0.01) higher in the spleen (13%) as compared with the crop (5%) and neck (7%). Based on bacterial resistance pattern, Salmonella spp. isolated from the spleen had the highest multiple antibiotic resistance (MAR) index of 0.86 in the south region followed by MAR indexes of 0.8 and 0.46 in the West and East, respectively. Conclusion: Isolation of Salmonella from the spleen may indicate chickens' systemic infection and failure to control the most important microbe for public health. Thus, the control measures have to be revised and a national Salmonella control program should be put in place urgently.

Tissue persistence of fumonisin B1 in ducks and after exposure to a diet containing the maximum European tolerance for fumonisins in avian feeds.

Toxicity and persistence of fumonisin B1 (FB1) in liver, kidney and muscle were investigated in ducks fed 5, 10 and 20mg FB1+FB2/kg feed during force-feeding. Mortality and signs of toxicity were only obtained with 20mg/kg, whereas an increased Sa/So ratio was observed from 5mg/kg on. Persistence of FB1 was only found in liver (16 and 20 microg FB1/kg liver in ducks fed 10 and 20 mg FB1+FB2/kg feed, respectively). Toxicokinetic studies were conducted by the intravenous route (IV, single dose: 10mg FB1/kg body weight) and the oral route (single dose: 100mg FB1/kg body weight), in growing ducks and in ducks during force-feeding. After IV administration, serum concentration-time curves were described by a two-compartment open model. Elimination half-life and mean residence time of FB1 were 26 and 24 min, respectively, clearance was 19.3 ml/min/kg. After oral administration, bioavailability, elimination half-life, mean residence time and clearance varied during force-feeding and growth from 2-2.3%, 71-80 min, 200-188 min, 16.7-17 ml/min/kg, respectively. Taken together these results demonstrate that the risk of persistence of FB1 in ducks after force-feeding is very low, Sa/So being a good biomarker which increases before signs of toxicity and risk of persistence of FB1 in tissue (limit of detection 13 microg/kg).