Effectiveness of a commercial leptospiral vaccine on urinary shedding in naturally exposed sheep in New Zealand

L. borgpetersenii serovar Hardjo and L. interrogans serovar Pomona are endemic in New Zealand sheep. An effective vaccine and vaccination strategy would protect both humans and livestock.Four to 12 lambs were selected from each of eight farms (total = 84, vaccinated group), while four to 16 lambs (total = 98) served as unvaccinated controls. A commercial Hardjo/Pomona vaccine was given at 1–6 weeks of age, 5–11 weeks later and 33–67 weeks later on seven farms and at 18 weeks of age and 5 weeks later on the eighth farm. Vaccinates and controls were grazed together. Blood was regularly collected from the control group to assess flock exposure. Urine was collected from both groups 26–82 weeks after the second vaccination and tested by quantitative PCR.Seroprevalence in controls at the time of urine sampling ranged from 2.7 to 98.2% for Hardjo and from 0 to 54.1% for Pomona with seroconversion occurring 13 to 67 weeks after the second vaccination in all but one farm where exposure had happened by the time of vaccination. The shedding prevalence adjusted for clustering in farms was 45.1% [95% CI 17.6–72.7] (for an observed number of 50/98) in the control animals and 1.8% [95% CI 0.0–10.1] (for an observed number of 5/84) in the vaccinated animals. The vaccine was 100% effective on five farms where animals were vaccinated before 12 weeks of age and before natural exposure occurred, but the effectiveness was 80% [0–97] on one farm where the lambs were exposed before vaccination and 65% [9–87] to 80% [0–97] on one farm where the animals were fully vaccinated by 24 weeks of age. The overall vaccine effectiveness was 86.3% [63.6–94.8%] despite maternal antibodies in some flocks at first vaccination. Vaccination timing seemed to be crucial in achieving optimum reduction in shedding in urine in vaccinated sheep.     

A comparison of two molecular methods for diagnosing leptospirosis from three different sample types in patients presenting with fever in Laos

ObjectivesTo compare two molecular assays (rrs quantitative PCR (qPCR) versus a combined 16SrRNA and LipL32 qPCR) on different sample types for diagnosing leptospirosis in febrile patients presenting to Mahosot Hospital, Vientiane, Laos.MethodsSerum, buffy coat and urine samples were collected on admission, and follow-up serum ∼10 days later. Leptospira spp. culture and microscopic agglutination tests (MAT) were performed as reference standards. Bayesian latent class modelling was performed to estimate sensitivity and specificity of each diagnostic test.ResultsIn all, 787 patients were included in the analysis: 4/787 (0.5%) were Leptospira culture positive, 30/787 (3.8%) were MAT positive, 76/787 (9.7%) were rrs qPCR positive and 20/787 (2.5%) were 16SrRNA/LipL32 qPCR positive for pathogenic Leptospira spp. in at least one sample. Estimated sensitivity and specificity (with 95% CI) of 16SrRNA/LipL32 qPCR on serum (53.9% (33.3%–81.8%); 99.6% (99.2%–100%)), buffy coat (58.8% (34.4%–90.9%); 99.9% (99.6%–100%)) and urine samples (45.0% (27.0%–66.7%); 99.6% (99.3%–100%)) were comparable with those of rrs qPCR, except specificity of 16SrRNA/LipL32 qPCR on urine samples was significantly higher (99.6% (99.3%–100%) vs. 92.5% (92.3%–92.8%), p <0.001). Sensitivities of MAT (16% (95% CI 6.3%–29.4%)) and culture (25% (95% CI 13.3%–44.4%)) were low. Mean positive Cq values showed that buffy coat samples were more frequently inhibitory to qPCR than either serum or urine (p <0.001).ConclusionsSerum and urine are better samples for qPCR than buffy coat, and 16SrRNA/LipL32 qPCR performs better than rrs qPCR on urine. Quantitative PCR on admission is a reliable rapid diagnostic tool, performing better than MAT or culture, with significant implications for clinical and epidemiological investigations of this global neglected disease.     

福州口岸及出入境船舶鼠形动物及携带病原的研究

目的掌握福州口岸鼠形动物的种群分布及季节消长变化，以及入出境船舶截获鼠形动物携带病原微生物的差别，对相关疾病的流行风险进行评估。方法在2011年1月到2012年12月之间，实施13岸鼠形动物调查及船舶鼠形动物笼日法监测，并对截获的鼠形动物携带鼠疫菌采用国标法检测抗原、抗体，用RT—PCR方法检测肾综合征出血热病毒（HFRS）RNA，用PCR方法检测钩端螺旋体DNA。结果口岸共捕获鼠形动物373只，年平均密度0．0326只／笼·d，经鉴定隶属2目2科3属5种，褐家鼠为优势种群。7—11月份鼠密度较高，其中9月份达到高峰，12月份最低，鼠形动物活动为单峰型。鼠疫菌抗原、抗体均为阴性，肾综合征出血热RNA阳性55份，阳性率15．90％，钩端螺旋体DNA阳性14份，阳性率3．70％。结论福州口岸鼠体肾综合征出血热、钩端螺旋体阳性率高，有传播相关传染病的风险，有必要对口岸采取灭鼠措施，并对鼠间、人间相应传染病感染情况实施监测。     

A rare case of complicated pancreatitis due to leptospirosis

The COVID-19 pandemic and the actions taken to combat it have greatly impacted the health infrastructure of all nations. Here we present a rare case of leptospirosis with severe acute pancreatitis, bilateral peripheral gangrene, disseminated intravascular coagulopathy and multiorgan failure. This is a rare presentation of leptospirosis wherein the patient had no history suggestive of acquisition of leptospires. The patient was started on doxycycline but still could not be saved due to the multisystem involvement.     

Molecular characterization,serotyping, and antibiotic susceptibility profile of Leptospira interrogans serovar Copenhageni isolates from Brazil

Leptospira interrogans serogroup Icterohaemorrhagiae is the major serogroup infecting humans worldwide, and rodents and dogs are the most significant transmission sources in urban environments. Knowledge of the prevalent serovars and their maintenance hosts is essential to understand the epidemiology of leptospirosis. In this study, 20 Leptospira isolates were evaluated by pulsed-field gel electrophoresis (PFGE), variable number tandem-repeat analysis (VNTR), serotyping, and determination of antimicrobial resistance profile. Isolates, originated from bovine, canine, human, and rodent sources, were characterized by microscopic agglutination test with polyclonal and monoclonal antibodies and were identified as L. interrogans serogroup Icterohaemorrhagiae serovar Copenhageni. MICs of antimicrobials often used in veterinary medicine were determined by broth microdilution test. Most of tested antibiotics were effective against isolates, including penicillin, ampicillin, and ceftiofur. Higher MIC variability was observed for fluoroquinolones and neomycin; all isolates were resistant to trimethoprim/sulfamethoxazole and sulphadimethoxine. Isolates were genotyped by PFGE and VNTR; both techniques were unable to discriminate between serovars Copenhageni and Icterohaemorrhagiae, as expected. PFGE clustered all isolates in 1 pulsotype, indicating that these serovars can be transmitted between species and that bovine, rodent, and dogs can maintain them in the environment endangering the human population.     

Leptospirosis in a Japanese urban area: A case report and literature review

Leptospirosis is not a major disease in urban areas of Japan. We describe a 49-year-old man with leptospirosis, who lived in an urban area and had no history of living in endemic area of leptospirosis. As he worked at a fish market infested with rats, he was suspected of having contracted leptospirosis and received antimicrobial agent treatment. Serum and urinary tests confirmed the diagnosis of leptospirosis. Although it took six days from the onset until treatment initiation, the patient improved in response to receiving ceftriaxone for seven days.Analyzing past reports of Japanese patients with leptospirosis who had no history of overseas travel, we identified 90 patients with courses similar to that of our patient, and the period from onset to treatment initiation was about six days on average (described in 46 cases). Health care providers as well as patients need to recognize that even people with no history of being in an endemic area of leptospirosis may still be at risk of developing this disease depending on occupations and activities.     

Leptospirosis in Reunion Island (Indian Ocean): analysis of factors associated with severity in 147 confirmed cases

Objective Analysis of risk factors associated with severity in patients with confirmed leptospirosis. Design and setting Retrospective study in 147 leptospirosis-confirmed patients at two tertiary nonteaching hospital in Reunion Island. Patients 138 men and 9 women, aged 36 ± 14 years, 80 in the ICU and 67 in medical wards. Measurements and results We collected demographic, clinical, biological, and radiographic data and performed univariate and multivariate analysis to examine risk factors associated with admission in ICU and mortality. Pulmonary forms were more frequent (85%) than in previous reports, with 85 cases (65.3%) on abnormal chest radiography. Among the 38 patients who underwent bronchoalveolar lavage at admission 31 (81.5%) had alveolar hemorrhage. Independent factors related to ICU admission were: age over 46 years (OR 3.02), creatinine higher than 200 μmol/l (6.69), shock (13.87), and acute respiratory failure (20.69). Mortality was 12.9%. The only factor independently related to mortality was need for mechanical ventilation (OR 20.94). Icterohemorrhagiae serogroup was found in 62 cases (42.8%) but was not related to death. Conclusions Pulmonary involvement is a major feature in leptospirosis disease but is not associated with poor outcome. Identification of clinical and laboratory findings on admission may help to better characterize severe cases. Mailing address: Arnaud Bourdin is currently at the Service de Pneumologie, CHU Montpellier, France.     

安徽怀远县1970～2003年钩端螺旋体病流行病学分析

目的了解怀远县乃至安徽省钩端螺旋体病(以下简称“钩体病”)其流行趋势,以制定科学有效的控制措施。方法根据怀远县1970-2003年疫情资料及检验结果进行汇总统计,并加以整理分析。结果怀远县1970-2003年平均发病率为1.79/10万,1970～2001年全县发生的钩体病以波摩那群为主,2002～2003年以黄疸出血群为主;流行形式上,以爆发为主,常伴有散发病例,爆发病例共549例,占总报告病例的88.12％;时间分布上,无明显周期性,除3次爆发出现明显的年度高峰外,其余年份病例数无明显差异,呈散发,以7～10月份发病为多,占报告病例总数的93.10％,去除爆发因素,则以1月份和7、8月份相对较多;男性明显高于女性,男女性别发病数之比为2.09∶1,以10～44岁发病数较高,形成较为明显的年龄高峰,75岁以上无发病;地区分布上,除爆发乡镇病例明显高于其它乡镇外,其余乡镇无明显差异,但从河流分布看,涡河以南明显高于涡河以北,若去除爆发因素,两者无明显改变。2003年的8～9月份钩体病现状调查显示,我县涡河以南钩体病感染率明显高于涡河以北(x~2=17.32,P<0.01)。结论我县钩体疫源地类型已由既往的经济疫源地向自然疫源地过渡,为混合型疫源地,流行形式已由洪水型向稻田型过渡,目前与稻田型一致,以黄疸出血群为主,黑线姬鼠为主要动物宿主,流行菌群发生变迁,并从血清学及病原学方面证实了“南黄北移”现象的存在。     

广州市2006-2012年重点媒介传染病流行特征分析

目的 探讨广州市重点媒介传染病流行病学特征,为媒介传染病防控提供科学依据.方法 从国家疾病监测信息报告管理信息系统中收集广州市2006-2012年重点媒介传染病报告病例基本信息以及个案调查流行病学信息,用描述性流行病学方法分析广州市重点媒介传染病的流行病学特征.结果 2006-2012年,广州市共报告6种媒介传染病5828例,其中肾综合征出血热（HFRS）、登革热、钩端螺旋体（钩体）病、疟疾、流行性乙型脑炎（乙脑）和恙虫病年平均发病率分别为1.01/10万、1.37/10万、0.10/10万、0.18/10万、0.02/10万和4.72/10万.登革热和恙虫病发病季节性特征明显,中心城区HFRS和登革热发病构成比较大,钩体病、疟疾、乙脑和恙虫病发病以城乡结合部和农村区域为主,除乙脑发病以儿童为主外,其余各媒介传染病发病职业分布广泛,年龄以中老年为主.结论 广州市媒介传染病发病整体相对平稳,但近年来有小幅上升趋势,发病风险仍然存在,应加强监测和预防控制工作.     

Epizootiological survey of small mammals as Leptospira spp. reservoirs in Eastern Croatia

In this survey we investigated a population of small mammals in Eastern Croatia in order to determine Leptospira carriage rates and identify circulating serovars. Out of 67 trapped animals, 20 (29.9%) isolates were obtained. Identification of isolates using microscopic agglutination test, pulsed field gel electrophoresis and multi locus sequence typing revealed that 10 (50.0%) isolates belong to serogroup Pomona, serovar Mozdok, 6 (30.0%) isolates to serogroup Australis, serovar Jalna, 2 (10.0%) isolates to serogroup Sejroe, serovar Saxkoebing, and 1 (5.0%) isolate to serogroup Grippotyphosa, serovar Grippotyphosa. One isolate from serogroup Bataviae was unable to be identified to the serovar level. Amplification of a 331-bp region of the locus LA0322 using real-time polymerase chain reaction determined that 12 (60.0%) isolates belong to L. kirschneri, 6 (30.0%) isolates to L. interrogans, and 2 (10.0%) isolates to L. borgpetersenii. Leptospira carriage rate was high (29.9%), which corresponds to a high incidence of human and domestic animal leptospirosis in Eastern Croatia. Furthermore, 90.0% of the isolates belong to serogroups Pomona, Australis and Sejroe which are also the most prevalent serogroups in humans in this area. These findings suggest that small mammals might be an important source of Leptospira spp. infection in Eastern Croatia.