Web-Based Passive Surveillance: Multifactorial Assessment of Sonali Chicken Diseases and Antimicrobial Prescription Pattern in Bangladesh

Despite the significant growth in Sonali chicken production across Bangladesh, inadequate disease surveillance and control measures along with indiscriminate antimicrobial use remain major challenges to the sector. In this study, we evaluated the disease burden and antimicrobial prescription patterns of Sonali chickens in Bangladesh using a web-based data recording system from 2020 to 2021 and analyzed 1690 cases. The diagnoses recorded in the system were presumptive, as they were based on clinico-epidemiological history, clinical signs, and gross necropsy findings noted by registered veterinarians. We conducted this study in Bogura, a district renowned for its high concentration of Sonali chicken farms. We estimated a higher prevalence of infection among grower chickens (69.0%) compared to starter chickens (31.0%). Small- to medium-sized flocks (63%) were more frequently infected than larger flocks (37.0%). Most disease cases occurred during the summer season (43.0%), followed by winter (27%), the rainy season (15%), and autumn (14%). Overall, climatic factors contributed to 51% of disease occurrence at temperatures below 25°C, 55% at high humidity (≥75%), and 57% during heavy rainfall (≥29 mm). The most prevalent disease was Newcastle disease (ND) (19.5%), followed by Marek's disease (9.8%), coccidiosis (7.4%), necrotic enteritis (4.7%), infectious bursal disease (3.2%), and infectious laryngotracheitis (3.2%). The odds of ND were 1.4 (grower chickens vs. starter chickens), 11.4 (summer vs. winter), 4.1 (autumn vs. winter), 3.9 (rainy vs. winter), 3.5 (≥25 °C vs. <25 °C), and 2.6 (≥75% vs. <75%). Tylvalosin (38.0%) was the most frequently prescribed antibiotic, followed by fluoroquinolones (9.0%), aminoglycosides (8.0%), and colistin sulphate (4.0%). These findings suggest that a web-based disease record could be an important tool for a centralized poultry disease surveillance system in low- and middle-income countries like Bangladesh.

Quantitative and qualitative analysis of antimicrobial usage and biosecurity on broiler and Sonali farms in Bangladesh

Antimicrobial use (AMU) is a major contributing factor to the rising threat of antimicrobial resistance (AMR) in human and animals. To control AMR, indiscriminate antibiotic use needs to be restricted, preventive measures such as biosecurity must be prioritized and proper action plans must be implemented. This study aimed to quantify and associate AMU and biosecurity status of broiler and Sonali farms in Bangladesh. Data on all antimicrobial treatments administered during a batch production cycle and antimicrobials purchased over a year were collected from 94 conventional broiler and 51 Sonali (cross-breed) farms from the northern and southeast regions of Bangladesh. Flock-level AMU was quantified using Treatment Incidence (TI) per 100 days based on the Defined Daily Dose (TI_DDDvet) expressing the number of days per 100 animal-days at risk that the flock receives a standard dose of antimicrobials. The biosecurity status (external and internal) of these farms was assessed by means of the Biocheck.UGent scoring system and the correlation between biosecurity and TI_DDDvet were assessed by Pearson's correlation coefficients. Median flock TI_DDDvet was 60 and 58 for broilers and Sonali flocks, indicating that the birds were treated around 60% and 58% of their lifetime with an antimicrobial dose, respectively. Minimum and maximum values of TI_DDDvet ranged from 18 -188 and 31-212 in broilers and Sonali, respectively. Fluoroquinolones, sulfonamides, tetracyclines and aminopenicillins were the most frequently used antimicrobial classes. The mean external and internal biosecurity scores were 39% and 61% for broilers and 44% and 61% for Sonali, respectively. There was a statistically significant difference in the external biosecurity score in broiler farms in the two regions (p ≤ 0.001), whereas, the internal biosecurity score was borderline not statistically significantly different (p = 0.065). The biosecurity score was negatively correlated with AMU in broiler and sonali farms both for external (R² =-0.38; -0.36) and internal biosecurity (R² =-0.33; -0.32), respectively. As most of the farmers treated their birds with antimicrobials for a very large part of the production, it could be concluded that there is a high overuse of antimicrobials both in broiler and Sonali poultry production in Bangladesh. This study also highlighted a low level of farm biosecurity practices. Overuse of antimicrobials and low level of biosecurity practice may be due to a lack of knowledge, ignorance, avoid loss and/or lack of monitoring by governmental agencies. Therefore, urgent action is required to increase awareness and biosecurity levels and to reduce AMU in these production systems.

Epidemiological assessment of clinical poultry cases through the government veterinary hospital-based passive surveillance system in Bangladesh: a case study

An epidemiological assessment of clinical poultry cases recorded through the existing passive surveillance at Kishoreganj District Veterinary Hospital during February-March 2016 was performed. A total of 200 cases (87 layers, 80 broilers, 21 ducks, and 12 pigeons) were included in this evaluation. The present study attempted to demonstrate the usefulness of passive surveillance data in quantifying the relative burden of poultry cases and their distribution along with drug prescription patterns. The cases were diagnosed based on clinical history, clinical signs, and observable post-mortem lesions by the registered veterinarian or intern veterinarian. The most prevalent diseases in chickens were infectious bursal disease (IBD) (31.7%; CI (confidence interval) 24.7-39.3%), coccidiosis (22.8%; CI 16.6-29.8%), Newcastle disease (ND) (21.6%; CI 15.5-28.5%), and coli-enteritis (8.4%; CI 4.6-13.6%). The most prevalent disease in ducks was duck plague (DP) (76.6%; CI 52.8-91.7%). Newcastle disease was most prevalent (66.7%; CI 34.8-90.0%) in pigeons. Infectious bursal disease, aspergillosis, and colibacillosis respectively were seen in a higher proportion of cases in broiler chickens than in layer chickens (58.7%, 12.5%, and 11.2% vs. 6.9%, 1.1%, and 3.4%; p ≤ 0.05). Contrarily, ND was seen in greater proportion of cases in layer chickens (32.1%) than in broiler chickens (10.0%) (p < 0.001). Infectious bursal disease, ND, coccidiosis, and aspergillosis were higher in older age broilers than in younger broilers (p ≤ 0.05). Antibiotics were often used to treat the poultry diseases such as trimethoprim with sulpha drugs (41%), ciprofloxacin (39%), sulphadiazine (27.5%), and erythromycin (26%). Through the present study, we can see how a passive surveillance system would be an effective tool for delineating disease distributions and common treatment regimens, thus helping to mitigate disease prevalence.