Parasitological, serological, and molecular survey of trypanosomosis (Surra) in camels slaughtered in northwestern Nigeria

Parasitological, Serological and Molecular Prevalence of Trypanosoma evansi among Arabian Camels (Camelus dromedaries) with Evaluation of Antitrypanosomal Drugs

PURPOSE

This study was carried out to assess the prevalence of Trypanosoma evansi infection in naturally diseased Dromedary camels in Dammam, Eastern region of Saudi Arabia. The detection of Trypanosoma evansi was performed using the parasitological, serological, and molecular diagnosis and a comparison between such methods were analyzed. In addition, evaluation of therapeutic efficacy of selected antitrypanosomal drugs, cymelarsan and quinapyrmine (aquin-1.5), was trialed for treatment of diagnosed infected cases.

METHODS

A total 350 randomly selected camels were evaluated using thin blood smear (TBS), RoTat1.2 PCR and CATT/T. evansi techniques.

RESULTS

The total prevalence was 6.9%, 7.7%, and 32.8% by TBS, RoTat1.2 PCR and CATT/T. evansi techniques, respectively. Although PCR detect T. evansi in more samples than TBS, the agreement was good (K = 0.9). Among the CATT/T. evansi results, PCR detect T. evansi in 12 and 15 CATT positive and negative camels, respectively, with low agreement (Kappa = 0.1). The use of cymelarsan and quinapyramine sulfate in the treatment of naturally infected cases demonstrated a very efficient therapeutic response.

CONCLUSION

It was found that 1. Comparing the CATT/T. evansi and PCR results, the positivity of CATT was higher than PCR detection, while the agreement was poor (K = 0.1). 2. Cymelarsan and aquin-1.5 proved to be effective in the treatment of naturally infected camels, but cymelarsan presented with higher effectiveness (100%) than aquin-treated camels (83.3%). a 3. The use of cymelarsan and CATT is recommended for disease treatment and control.

A cross-sectional questionnaire survey on knowledge of anti-protozoal drug use and resistance among AHPs in Kwara State, Nigeria

Antimicrobial resistance is a global public health crisis. However, there is a paucity of data on anti-protozoal resistance (APR), especially in animals. Hence, we assessed the knowledge of prudent antiprotozoal drug usage (APU) and resistance among animal health practitioners (AHPs) in Kwara State, Nigeria.

A cross-sectional survey of 435 AHPs was performed in Kwara State from the 5th of March to the 31st of July 2020 using a structured and validated questionnaire. We used logistic regression analysis to identify socio-demographic factors that are associated with the satisfactory perception of prudent APU and good knowledge of APR among AHPs.

Our findings showed that 80.2% (n = 349) of the AHPs in Kwara state had a good knowledge of APR with a mean knowledge score of 5.8 ± 1.2. In the same vein, 75.6% (n = 329) of the AHPs had a satisfactory perception of prudent APU with a mean score of 3.84 ± 1.21. Only 10.1% of the AHPs had observed treatment failures after the use of anti-protozoal drugs. Most of the AHPs (75.6%) believed that APR poses a significant threat to animal production and health globally. Logistic regression analysis showed that female AHPs were more likely (OR: 2.17; 95% CI: 0.91, 5.20; p < 0.005) to have better knowledge of APR than their male counterparts. AHPs with tertiary education were likely (OR: 2.77; 95% CI: 0.96, 4.99; p < 0.05) to be more knowledgeable about APR and have satisfactory perceptions of APU (OR: 1.57; 95% CI: 1.16, 2.99; p = 0.07) respectively. Finally, veterinarians were 3.76 times (95% CI:1.26, 9.25; p < 0.001) more likely to have good knowledge of APR and better perceptions of APU (OR: 3.28; 95% CI: 1.89, 5.68; p < 0.001) than other AHPs respectively.

To control antimicrobial resistance, continuous training of AHPs especially para-veterinary officers is essential to update their knowledge on prudent antimicrobial usage and prevent the emergence of resistant protozoan parasites.

Prevalence and animal level risk factors associated with Trypanosoma evansi infection in dromedary camels

Surra is a non-cyclic parasitic disease caused by Trypanosoma evansi (T. evansi) and spread by biting flies. The disease has a severe impact on camel health, productivity, and market value, posing a significant threat to food safety and the economy. In a cross-sectional study, 370 blood samples were collected from camels in three Egyptian governorates. Samples were tested using parasitological (thin blood smear (TBS)), card agglutination test for T. evansi (CATT), and PCR to estimate the prevalence of T. evansi infection. Overall, the prevalence of T. evansi among examined camels was 17.3%, 18.9% and 22.7% using TBS, CATT and PCR methods, respectively. The risk of T. evansi infection in older camels (> 10 years) is higher than that in young ones (odds ratio (OR) = 9; 95% CI: 3.5–23.1), particularly during spring (OR = 2.5; 95% CI: 1.1–5.7). Furthermore, females and poor conditioned camels were 2.6 and four times more likely to get infection than males and good conditioned camels, respectively. The level of agreement between diagnostics tests were perfect kappa (> 0.83). Moreover, CATT showed higher sensitivity (0.83; 95% CI: 0.74–0.91) than TBS (0.76; 95% CI: 0.66–0.85) and both had perfect specificity (100%). In conclusion, our findings revealed a high rate of T. evansi infection in camels from the three Egyptian governorates. The CATT is a good test for routine use in control program of trypanosomiasis in camels.