Scrub typhus strikes back: Are we ready?

Scrub typhus has struck back, albeit with renewed vigour, impacting areas with previously known endemicity as also impressing newer expanses. It is not surprising, therefore, that Scrub typhus has emerged as a leading cause of public health concern globally as well as in India, but are we ready to take on the challenge?Over the last decade, there has been a global increase in the number of outbreaks of Scrub typhus, be it the military occupied areas or the civil population at large. The innumerable outbreaks of Scrub typhus, although disconcerting, have nonetheless contributed phenomenally towards better understanding of the dynamics of scrub typhus. There have been significant contributions to awareness of the disease amongst medical professionals, scrub typhus as a cause of Acute Undifferentiated Febrile Illness (AUFI) and newer clinical manifestation – Acute Encephalitis Syndrome (AES), availability and advances in diagnostics and management, man-vector-pathogen interactions, new records of Leptotrombidium species, newer vectors and Orientia species.Antigenic diversity and the varied clinical presentation of scrub typhus, absence of scrub typhus surveillance system and a lack of political will to recognize the disease as one of the important reemerging public health problem are areas seeking concerted deliberations and actions so that the challenges posed by scrub typhus can be addressed.     

Outbreak of Scrub Typhus in Jammu – A Report

Background

Jammu is scrub typhus prone. Scrub typhus is often seen when troops move out of permanent locations.

Methods

In a prospective study cases of fever reporting to the local military hospital from July to October 2002 were examined clinically, investigated and categorised as scrub typhus when Weil Felix readings were above 1:160.

Results

Twelve cases of scrub typhus were diagnosed during the period of study. The clinical features included fever, malaise and conjunctival congestion. However rashes were rare and only one had an eschar. Multisystem complications occurred in one patient. There was a spatial and temporal clustering of cases. Control of outbreak was carried out by 25% benzyl benzoate impregnation of clothing, clearing of scrub, residual spray with malathion and antirodent measures.

Conclusion

Scrub typhus outbreaks have been noted whenever troops move out of permanent locations to scrub areas.Key Words: Scrub typhus, Mites, Eschar     

云南省肾综合征出血热监测结果分析

目的:调查肾综合征出血热(HFRS)在人及啮齿动物中自然感染的情况,为制定相应的预防控制措施提供科学依据。方法:2005年在云南省的监测点泸西、寻甸和永胜县共采集健康人血清329份,在居民区捕获活鼠3种285只并取血清,用间接免疫荧光法测HFRS的IgG抗体。结果:监测区以褐家鼠和黄胸鼠为优势鼠种。人群抗体阳性率为3.04%(10/329)。鼠血清抗体阳性率为5.61%(16/285)。结论:监测区褐家鼠和黄胸鼠中HFRS病毒感染较为普遍,人群中也存在隐性感染。     

Scrub typhus mimicking the clinical course of infectious mononucleosis: a case report

Objective: Scrub typhus is a relatively common life-threating disease; its symptoms are non-specific and similar to those of other viral infections. Therefore, scrub typhus might be underdiagnosed.Patient: Herein, we report a patient with scrub typhus whose clinical course mimicked that of infectious mononucleosis. A 63-year-old male patient with hypertension presented to our hospital complaining of symptoms including prolonged fever, pharyngeal discomfort, and a mild headache. He showed the appearance of a rash after amoxicillin administration. At the same time, he did not show a crusted rash on his body surface.Results: After a comprehensive examination, Epstein-Barr virus and cytomegalovirus infections were ruled out. We suspected that this patient suffered from scrub typhus on the basis of his usual lifestyle. Finally, polymerase chain reaction analysis showed a positive result for deoxyribonucleic acid of Orientia tsutsugamushi in his blood sample. Fortunately, he recovered naturally with only supportive treatment during his hospitalization.Conclusion: We should observe and monitor patients with infectious mononucleosis-like symptoms and emphasize the importance of a clinical interview.     

云南省2008年肾综合征出血热监测研究

目的对云南省肾综合征出血热人间和鼠间疫情进行监测,分析流行病学特点,提供防治参考。方法收集监测点本病疫情资料,并在监测县采集人血清以及鼠肺脏和鼠血清作汉坦病毒抗原或抗体检查。结果2008年全省共报告出血热病例20例。主要发病地区为大理州12例和楚雄州4例。2008年在红河州泸西县、昆明市五华区、大理州祥云县、文山州文山县、曲靖市罗平县、昭通市昭阳区和绥江县的居民区和野外共捕获鼠类19种880只。其中居民区以黄胸鼠和褐家鼠为优势鼠种,野外以大绒鼠、高山姬鼠为优势鼠种,鼠间汉坦病毒总带毒率为3.66%(30/819),阳性鼠种为黄胸鼠、褐家鼠、大绒鼠、社鼠、臭鼩鼱,带病毒率依次为3.09%(10/324)、2.45%(5/204)、10.43%(12/115)、10.00%(1/10)、100.00%(2/2)。结论滇中和滇西北地区为本病主要发病地区。调查地区广泛存在以褐家鼠为主要传染源的家鼠型HFRS疫源地,泸西县还存在以大绒鼠为主要传染源的野鼠型HFRS疫源地。     

云南省2003年肾综合征出血热监测分析

目的 掌握云南省肾综合征出血热流行病学特点，为其防治提供科学依据。方法收集云南省肾综合征出血热各监测点采集的人血清、捕鼠并采取鼠肺脏和鼠血清进行汉坦病毒抗原和抗体检测等相关疫情监测资料，并进行统计分析。结果2003年全省共报告72例，死亡1例，年发病率为0．17／10万，病死率为1．39％。主要发病地区为红河州、大理州、昆明市和楚雄州。监测点县人群隐性感染率为2．94％。在泸西、寻甸和永胜监测点捕获鼠类11种537只，居民区以褐家鼠和黄胸鼠为优势鼠种，野外以高山姬鼠为优势鼠种。鼠间的汉坦病毒带毒率为3．44％，带毒鼠种为褐家鼠、黄胸鼠、小家鼠、大绒鼠、中华姬鼠和臭鼯。结论监测区内存在以褐家鼠和黄胸鼠为主要宿主的家鼠型疫源地，也存在以大绒鼠和中华姬鼠为主的野鼠型疫源地。疫区的进一步扩大是发病率上升重要因素。应在加强监测的同时，采取以灭家鼠和接种家鼠型或两型混合型疫苗的防治措施。     

Serological evidence for the presence of rickettsial infections in parts of Nigeria

Weil-Felix tests using OX19 and OXK proteus antigens reveal high antibody titers to OXK and OX19 antigens in patients reporting at the University of Nigeria Teaching Hospital, Enugu with clinical diagnosis of pyrexia of unknown origin. These findings suggest the presence of either or both scrub typhus fever and Epidemic typhus fever in this community. While the advisablility of using other diagnostic techniques to support and confirm positive Weil-Felix reaction will be useful, it is felt that the above findings are strong evidences for the prevalence of these diseases in this part of Nigeria.     

Scrub typhus as a possible aetiology of Guillain–Barré syndrome: two cases

Neurological complications of scrub typhus are reported to be rare. Peripheral nervous system involvement has been reported in only one case. We present two cases of Guillan–Barré syndrome (GBS) associated with scrub typhus. In both cases, the findings of an elevated indirect immunofluorescent antibody titer for Orientia tsutsugamushi and nerve conduction study showing sensory-motor polyneuropathy, have led us to believe that scrub typhus could be one of the antecedent illnesses associated with GBS.     

我国西沙群岛鼠形动物和吸血昆虫的鉴定并首次记述按蚊和蠓

目的 研究我国西沙群岛有害的鼠形动物和吸血昆虫的种类和分布情况,为当地传染病防控提供资料。 方法 2013年11月至12月和2014年2月至3月两次赴我国海南省西沙群岛的永兴岛和石岛,用鼠笼和诱蚊灯采集鼠形动物和吸血昆虫,结合形态和分子特征进行种类鉴定。 结果 捕获鼠形动物3种共计160只,分别为：褐家鼠、黄胸鼠和鼩鼱,优势种为褐家鼠（61.25%）。捕获的315只蚊成虫隶属4属5种,优势种是骚扰阿蚊（52.38%）,按蚊经分子鉴定为浅色按蚊B。捕获蠓成虫121只,隶属3亚科4属8种,帛琉库蠓为优势种（61.98%）。 结论 共发现西沙群岛的永兴岛和石岛的鼠形动物3种,蚊5种,蠓8种,其中按蚊和蠓均为西沙群岛首次记述,斑美铗蠓和泥泽铗蠓是我国的新记录种。     

媒介恙螨与恙虫病传播关系的研究

目的介绍恙螨与恙虫病传播流行关系的研究新进展。方法通过文献检索,查阅大量相关媒介恙螨与恙虫病传播关系研究的最新的文献资料。结果恙螨对恙虫病传播具有关键作用,其种类分布、种群密度与季节消长和恙虫病的流行密切相关。结论恙螨是恙虫病的唯一传播媒介,控制媒介恙螨是防治恙虫病的重要手段。     

Molecular epidemic survey on co-prevalence of scrub typhus and marine typhus in Yuxi city, Yunnan province of China

Background Human rickettsioses are worldwide zoonoses and it is not easy to differentiate them from other infectious diseases because of their atypical manifestation. In recent years the number of patients with fever of unknown causes from Hongta District CDC, Yuxi city of Yunnan Province has been increasing significantly in the summer. Diagnosis of scrub typhus was made by local clinicians. In order to ascertain the disease, we undertook a laboratory investigation for such patients from August 18 to 26, 2005.Methods Active surveillance was conducted by Hongta District CDC Yuxi city of Yunnan Province from 2002 to 2004 and basic data were obtained from cases confirmed according to clinical definitions. Average incidences and town-level incidences were calculated during the study periods. Blood samples were analyzed by PCR and serological test. Based on the groEL gene sequences a paired general outer primers (Gro-1 and Gro-2) targeting typhus, spotted fever as well as scrub typhus and two paired inner primers (SF1, SR2 and TF1, TR2) for typhus together with spotted fever and scrub typhus, respectively, were designed to perform a multiplex-nested PCR. Serological assay was carried out by indirect immunofluorescence assay with 7 different rickettsial antigens, i.e., R.mossori, R.sibirica, R.conorii, O.tsutsugamushi, B.quintana, B.henselae and Coxilella burnetii phase II Ag.Results Epidemiological surveillance showed that from 2002 to 2004, the average incidences of the scrub typhus or scrub typhus with murine typhus were 222.1/10(5), 204.3/10(5) and 109.6/10(5), respectively. Of 13 blood samples taken during acute stage of illness, 6 showed the amplified products for scrub typhus and the sequenced products showed 100%, 99%, 99%, 99%, 99%, 99% similarity to O.tsutsugamushi Karp but they shared the same deduced amino acid sequences, which indicated 100% identity with the heat shock protein of the O.tsutsugamushi Karp strain. Five yielded PCR products for murine typhus and their corresponding nucleotide sequences exhibited 100%, 100%, 99%, 99% and 99% similarity to R. mossori Wilmington and the analyses of predicted amino acid sequences indicated 100%, 100%, 98%, 98% and 98% identity with the heat shock protein of R. mossori Wilmington strain. Of the 8 PCR positive patients, 3 showed a co-infection of scrub typhus with murine typhus. All the 13 serum samples from febrile patients were positive against O. tsutsugamushi and 8 of them were positive against R. mossori. All of the 8 paired specimens had four-fold elevation of antibody against O. tsutsugamushi, and seroconversion for typhus was demonstrated in 3 paired serum samples. Another finding in the study was that a high seropositive prevalence (76.9%) of Q fever was detected.Conclusion It’s confirmed that co-prevalence of scrub typhus with murine typhus are occurring in Yuxi city of Yunnan province, China. Other rickettsial diseases also need to be investigated in these areas.     

小儿恙虫病的皮损与临床-附26例报告

皮肤焦痂及皮疹是恙虫病的重要临床特征之一，对本病的早期诊断与鉴别诊断有一定意义。本文对２６例小儿恙虫病进行了临床分析，结果：入院时有焦痂者１１例（４２．３％），出现过皮疹者１０例（３８．５％），双下肢有出血点３例（１１．５％），误诊１４例。同时提示焦痂与皮疹的发生率较低可能与部份患者求诊时间较晚及焦痂多位于身体隐蔽部位而易漏诊、误诊有关。氯霉素对本病有特效。     

恙虫病流行病学研究新进展

恙虫病又称丛林斑疹伤寒,是一种由恙虫病立克次体引起的急性自然疫源性传染病,是我国法定报告传染病之一.现要求医疗机构一旦确诊恙虫病病例,应在24h内向国家监测系统报告.世界卫生组织曾指出恙虫病可能是世界上最流行、被严重忽视但容易治疗的一种发热性疾病之一.据我国CDC疫情报告显示,随着我国绿化工程的不断实施,恙虫病病例数持...     

海南省680例不明原因发热患者恙虫病东方体感染调查

目的 了解海南省不明原因发热患者的恙虫病东方体检感染情况,为不明原因发热患者恙虫病防治提供指导。方法 收集2018—2021年海南医学院第一附属医院、海南医学院第二附属医院、海口市人民医院和琼中黎族苗族自治县人民医院临床诊断为不明原因发热患者血液样本,利用胶体金免疫层析法和PCR方法分别对样本进行恙虫病东方体特异性IgM、IgG抗体和恙虫病东方体56kD型特异性抗原基因检测,同时收集样本的临床及流行病学信息,并进行流行病学分析。结果 共收集临床不明原因发热患者血样680份,恙虫病东方体IgM、IgG抗体和56kD型特异性抗原PCR阳性率分别为23.97%(163/680)、36.62%(249/680)和20.88%(142/680),焦痂或皮疹率为12.06%(82/680)。根据诊断标准,最终诊断为恙虫病的患者为223例,其中男性111例（49.78%）,女性109例（48.88%）,平均年龄（53.14±15.12）岁,其中40～<60岁98例（占43.95%）,感染人群民族中汉族136例（占60.99%）,农民93例（41.70%）,秋季发病114例（51.12%）。临床...     

盐城市2006-2010年恙虫病流行病学研究

目的研究2006-2010年盐城市恙虫病流行病学及病原学特点,探讨防制对策。方法系统收集恙虫病疫情,检测病人血液中恙虫病东方体及进行相关分子生物学研究,开展人群及动物恙虫病血清流行病学调查。结果盐城市2006-2010年共报告399例恙虫病病例,各县(市)均有疫情发生。每年疫情始于10月,11月为高峰,终于12月。病人以中老年为主。从1例病人血液中分离出恙虫病东方体,经分子技术测定及目的基因同源性比较,基因型别属Kawasaki。15岁以上人群血清抗恙虫病东方体IgG阳性率为1.85%,牛的血清阳线率为3.40%。结论盐城市各县(市)均发现恙虫病疫源地,疫情将持续流行,病原体基因型别未发生变化。     

山东省东南地区142例恙虫病病例分析

本文对１４２例恙虫病进行了分析。发现山东省东南地区的恙虫病患者在临床上具备焦痂、发热、皮疹和淋巴结肿大等四个特征；但临床表现比较轻缓，可能与该地区恙虫病立克次体的毒力较弱有关。治疗以四环素、氯霉素为主，疗效明显。     

105例恙虫病疑似患者巢式PCR检测结果分析

目的对泰州市靖江105例恙虫病疑似患者全血进行恙虫病东方体(Ot)检测,分析该地区恙虫病感染情况,为恙虫病预防控制提供科学依据。方法采集靖江市2013年10~11月的105例恙虫病疑似患者全血样品进行巢式PCR检测,并进行个案调查,记录结果,用描述性分析方法对检测结果及个案资料进行分析。结果 105例疑似患者中62例检出恙虫病东方体核酸阳性(阳性率59.0%)。发病人群年龄以50~80岁为主,占69.4%,实验室诊断病例中农民占82.3%,男女性别之比1:1.7。结论靖江市恙虫病发病率较高,应针对流行特征采取综合防制措施。     

云南省某大学新生中莱姆病和恙虫病的血清流行病学调查

目的 分析云南省某大学新生莱姆病和恙虫病感染情况,间接了解两种虫媒传染病在云南省的分布.方法 采集来自云南滇中及滇东北2地区大学新生血样标本,以ELISA方法检测莱姆病和恙虫病IgG抗体,计算抗体阳性率.结果 共检测大学新生血清标本42份,检出莱姆病IgG抗体阳性率为2.4％;恙虫病IgG抗体阳性率为4.8％.结论 云南省存在莱姆病和恙虫病散发,应进一步加强对这2种虫媒传染病的监测与控制.     

成人恙虫病心电图改变及其临床价值研究

目的 探讨成人恙虫病患者心电图异常情况及其临床价值。方法 回顾性分析233例成人恙虫病病例（恙虫病组）,选取同期220例健康体检者为对照组,对比两组心电图异常情况;收集心电图异常患者临床资料,分析心电图异常与器官损害的关系。结果 恙虫病组心电图异常的患者比例（56.7%,132/233）高于对照组（40.0%,88/220）（P<0.001）。恙虫病组异常心电图发生频率高于对照组的有窦性心动过速（15.5%,36/233）、胸和（或）肢体导联低电压（10.7%,25/233）、房性早搏（6.0%,14/233）、U波改变（2.6%,6/233）（P_均<0.05）。恙虫病组心律失常发生频率（38.2%,89/233）高于对照组（P<0.001）,但两组严重心律失常发生频率均很低且无统计学差异（P=0.659）。低电压患者发生胸膜炎或心脏增大者比例（68.0%,17/25）高于非低电压患者（41.8%,87/208）（P<0.05）,并发器官功能障碍综合征（MODS）比例（20.0%,5/25）亦高于非低电压患者（5.3%,11/208）（P<0.05）。结论 成人恙虫病心电图异常非常普遍,心律失常常见但严重心律失常罕见;低电压患者需注意胸膜或心脏病变,甚至MODS可能,需密切监护和积极治疗。     

珠海市恙虫病流行病学特征分析

目的了解珠海市恙虫病的流行特点,为防控疫情提供依据。方法回顾性分析2003~2012年在珠海市某医院住院的88例恙虫病确诊病例资料,描述其流行病学特征。结果珠海市恙虫病的发生存在明显的季节性,病例分布于4～12月份,5~7月份为发病高峰,病例数占60.22%。近年来发病例数整体呈上升趋势,尤其是2012年病例数增长显著,较2011年增加了50%。发病年龄以40~60岁年龄段最多,占45.46%,职业构成以农（渔）民最多,占35.23%。香洲区是发病例数最多的地区,病例数47例,占53.41%。结论恙虫病流行季节需做好高危人群的健康教育,以预防、控制恙虫病的发生及流行。