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Abstract：
BACKGROUND: Leptospirosis is a neglected emerging and zoonotic disease reported worldwide. This study sought to determine the molecular and serological prevalence of Leptospira spp. and the associated risk factors in slaughtered cattle from the Bahr El Ghazal region of South Sudan.
METHODS: Between January 16th and February 25th, 2023, blood and urine samples were collected from 402 cattle at the Lokoloko Municipal Slaughterhouse in Western Bahr El-Ghazal State. Serum samples were tested using the microscopic agglutination test (MAT), with a panel of 12 serovars (sv) from 12 serogroups (sg) and 4 species (spp) of Leptospira spp. These serovars had been previously identified in Sudan and the East African region. Simultaneously, 400 corresponding urine samples were screened using qualitative real-time polymerase chain reaction (PCR) to detect the shedding of Leptospira spp. in urine. To identify the associated risk factors, the age, sex, breed and body condition score of each sampled cattle was noted at the time of sampling and subsequently analysed using logistic regression models.
RESULTS: Among the 402 serum samples screened, a substantial 81.8% (329/402, 95% CI 77.9-85.3) displayed seropositivity for Leptospira spp. with a MAT titre ≥ 100. The prevalence of urine shedding determined by PCR was 6% (23/400, 95% CI 3.8-8.4), while probable recent leptospirosis with a MAT ≥ 1:800 was observed in 33.1% (133/402, 95% CI 28.6-37.8) of the cattle. Multiple reactions were detected in 34.8% (140/402, 95% CI 30.6-39.5) serum samples. The seropositivity was against L. borgpetersenii sg. Tarassovi (78.6%; 316/402, 95% CI 74.4-82.3), followed by L. borgpetersenii sg. Ballum at 20.4% (82/402, 95% CI, 16.7-24.4%), L. kirschneri sg. Autumnalis At 8.7% (35/402, 95% CI 5.7-11.7), L. interrogans sg. of Pomona at 7.0% (28/402, 95% CI 4.5-9.5), and L. interrogans sg. Hebdomadis was 5.0% (20/402, 95% CI 2.8-7.2). Several risk factors are associated with seropositivity. Older animals (≥ 2 years) had 2.0 times greater odds (95% CI 1.14-3.5) of being seropositive than younger animals (< 2 years), P-value = 0.016. Female animals demonstrated 2.1 times greater odds (95% CI 1.2-3.6) of seropositivity than males did (P-value = 0.008). Additionally, Felata/Mbororo cattle exhibited 2.4 times greater odds (95% CI 1.3-4.5) of being seropositive than did local Nilotic cattle (P-value = 0.005). The agreement between the MAT and PCR results was poor, as indicated by a kappa statistic value of 0.001 and a P-value of 0.913. But there was a moderate agreement between MAT high titres ≥ 800 and PCR positivity with a kappa statistic value = 0.501 and a P-value < 0.001.
CONCLUSIONS: In addition to the high seroprevalence, Leptospira spp. were found in the urine of slaughtered cattle, suggesting that leptospirosis is endemic to the study area. This finding underscores the significance of cattle as potential sources of infection for slaughterhouse workers, the general public, and other animal species. To address this issue effectively in the Bahr El Ghazal Region and South Sudan, a comprehensive strategy involving a multidisciplinary approach is essential to minimize disease among animals, hence reducing potential zoonotic risks to humans.
METHODS: Between January 16th and February 25th, 2023, blood and urine samples were collected from 402 cattle at the Lokoloko Municipal Slaughterhouse in Western Bahr El-Ghazal State. Serum samples were tested using the microscopic agglutination test (MAT), with a panel of 12 serovars (sv) from 12 serogroups (sg) and 4 species (spp) of Leptospira spp. These serovars had been previously identified in Sudan and the East African region. Simultaneously, 400 corresponding urine samples were screened using qualitative real-time polymerase chain reaction (PCR) to detect the shedding of Leptospira spp. in urine. To identify the associated risk factors, the age, sex, breed and body condition score of each sampled cattle was noted at the time of sampling and subsequently analysed using logistic regression models.
RESULTS: Among the 402 serum samples screened, a substantial 81.8% (329/402, 95% CI 77.9-85.3) displayed seropositivity for Leptospira spp. with a MAT titre ≥ 100. The prevalence of urine shedding determined by PCR was 6% (23/400, 95% CI 3.8-8.4), while probable recent leptospirosis with a MAT ≥ 1:800 was observed in 33.1% (133/402, 95% CI 28.6-37.8) of the cattle. Multiple reactions were detected in 34.8% (140/402, 95% CI 30.6-39.5) serum samples. The seropositivity was against L. borgpetersenii sg. Tarassovi (78.6%; 316/402, 95% CI 74.4-82.3), followed by L. borgpetersenii sg. Ballum at 20.4% (82/402, 95% CI, 16.7-24.4%), L. kirschneri sg. Autumnalis At 8.7% (35/402, 95% CI 5.7-11.7), L. interrogans sg. of Pomona at 7.0% (28/402, 95% CI 4.5-9.5), and L. interrogans sg. Hebdomadis was 5.0% (20/402, 95% CI 2.8-7.2). Several risk factors are associated with seropositivity. Older animals (≥ 2 years) had 2.0 times greater odds (95% CI 1.14-3.5) of being seropositive than younger animals (< 2 years), P-value = 0.016. Female animals demonstrated 2.1 times greater odds (95% CI 1.2-3.6) of seropositivity than males did (P-value = 0.008). Additionally, Felata/Mbororo cattle exhibited 2.4 times greater odds (95% CI 1.3-4.5) of being seropositive than did local Nilotic cattle (P-value = 0.005). The agreement between the MAT and PCR results was poor, as indicated by a kappa statistic value of 0.001 and a P-value of 0.913. But there was a moderate agreement between MAT high titres ≥ 800 and PCR positivity with a kappa statistic value = 0.501 and a P-value < 0.001.
CONCLUSIONS: In addition to the high seroprevalence, Leptospira spp. were found in the urine of slaughtered cattle, suggesting that leptospirosis is endemic to the study area. This finding underscores the significance of cattle as potential sources of infection for slaughterhouse workers, the general public, and other animal species. To address this issue effectively in the Bahr El Ghazal Region and South Sudan, a comprehensive strategy involving a multidisciplinary approach is essential to minimize disease among animals, hence reducing potential zoonotic risks to humans.
摘要：
背景：钩端螺旋体病是一种被忽视的新兴和人畜共患疾病。这项研究旨在确定钩端螺旋体的分子和血清学患病率。以及南苏丹BahrElGhazal地区屠宰牛的相关危险因素。
方法：1月16日至2月25日，2023年，从西加扎勒河州Lokoloko市政屠宰场的402头牛中收集了血液和尿液样本。使用显微镜凝集试验（MAT）测试血清样品，具有来自12个血清群（sg）和4个钩端螺旋体属物种（spp）的12个血清变型（sv）。这些血清型先前已在苏丹和东非地区确定。同时,使用定性实时聚合酶链反应（PCR）筛选400份相应的尿液样品，以检测钩端螺旋体的脱落。在尿液中。为了识别相关的风险因素，年龄,性别,在取样时记录每只取样牛的品种和身体状况评分，随后使用逻辑回归模型进行分析。
结果：在筛选的402份血清样本中，81.8%(329/402,95%CI77.9-85.3)的钩端螺旋体属显示血清阳性。MAT滴度≥100。通过PCR确定的尿液脱落的患病率为6％（23/400，95％CI3.8-8.4），而在33.1%(133/402,95%CI28.6-37.8)的牛中观察到MAT≥1:800的近期钩端螺旋体病。在34.8％（140/402，95％CI30.6-39.5）的血清样本中检测到多个反应。血清阳性是针对L.borgpeterseniisg。塔拉索维（78.6%；316/402，95%CI74.4-82.3），其次是L.borgpeterseniisg。Ballum为20.4%（82/402，95%CI，16.7-24.4%），L.kirschnerisg.Autumnalis为8.7%（35/402，95%CI5.7-11.7），L.审问sg.波莫纳的7.0%（28/402，95%CI4.5-9.5），和L.审问sg。Hebdomadis为5.0%（20/402，95%CI2.8-7.2）。几个危险因素与血清阳性相关。老年动物（≥2岁）的血清反应阳性几率（95％CI1.14-3.5）是年轻动物（<2岁）的2.0倍，P值=0.016。雌性动物的血清阳性几率（95％CI1.2-3.6）是雄性动物的2.1倍（P值=0.008）。此外,Felata/Mbororo牛的血清阳性几率（95％CI1.3-4.5）是当地Nilotic牛的2.4倍（P值=0.005）。MAT和PCR结果的一致性较差，如kappa统计值为0.001和P值为0.913所示。但是MAT高滴度≥800与PCR阳性之间存在中度一致性，kappa统计值=0.501，P值<0.001。
结论：除了高血清阳性率外，钩端螺旋体。在屠宰牛的尿液中发现，这表明钩端螺旋体病是研究区域特有的。这一发现强调了牛作为屠宰场工人潜在感染源的重要性，广大市民,和其他动物物种。为了在加扎勒河地区和南苏丹有效解决这一问题，涉及多学科方法的综合战略对于最大程度地减少动物疾病至关重要，从而降低人类潜在的人畜共患风险。
方法：1月16日至2月25日，2023年，从西加扎勒河州Lokoloko市政屠宰场的402头牛中收集了血液和尿液样本。使用显微镜凝集试验（MAT）测试血清样品，具有来自12个血清群（sg）和4个钩端螺旋体属物种（spp）的12个血清变型（sv）。这些血清型先前已在苏丹和东非地区确定。同时,使用定性实时聚合酶链反应（PCR）筛选400份相应的尿液样品，以检测钩端螺旋体的脱落。在尿液中。为了识别相关的风险因素，年龄,性别,在取样时记录每只取样牛的品种和身体状况评分，随后使用逻辑回归模型进行分析。
结果：在筛选的402份血清样本中，81.8%(329/402,95%CI77.9-85.3)的钩端螺旋体属显示血清阳性。MAT滴度≥100。通过PCR确定的尿液脱落的患病率为6％（23/400，95％CI3.8-8.4），而在33.1%(133/402,95%CI28.6-37.8)的牛中观察到MAT≥1:800的近期钩端螺旋体病。在34.8％（140/402，95％CI30.6-39.5）的血清样本中检测到多个反应。血清阳性是针对L.borgpeterseniisg。塔拉索维（78.6%；316/402，95%CI74.4-82.3），其次是L.borgpeterseniisg。Ballum为20.4%（82/402，95%CI，16.7-24.4%），L.kirschnerisg.Autumnalis为8.7%（35/402，95%CI5.7-11.7），L.审问sg.波莫纳的7.0%（28/402，95%CI4.5-9.5），和L.审问sg。Hebdomadis为5.0%（20/402，95%CI2.8-7.2）。几个危险因素与血清阳性相关。老年动物（≥2岁）的血清反应阳性几率（95％CI1.14-3.5）是年轻动物（<2岁）的2.0倍，P值=0.016。雌性动物的血清阳性几率（95％CI1.2-3.6）是雄性动物的2.1倍（P值=0.008）。此外,Felata/Mbororo牛的血清阳性几率（95％CI1.3-4.5）是当地Nilotic牛的2.4倍（P值=0.005）。MAT和PCR结果的一致性较差，如kappa统计值为0.001和P值为0.913所示。但是MAT高滴度≥800与PCR阳性之间存在中度一致性，kappa统计值=0.501，P值<0.001。
结论：除了高血清阳性率外，钩端螺旋体。在屠宰牛的尿液中发现，这表明钩端螺旋体病是研究区域特有的。这一发现强调了牛作为屠宰场工人潜在感染源的重要性，广大市民,和其他动物物种。为了在加扎勒河地区和南苏丹有效解决这一问题，涉及多学科方法的综合战略对于最大程度地减少动物疾病至关重要，从而降低人类潜在的人畜共患风险。
