恙虫病48例临床分析

目的探讨恙虫病的早期诊断,提高医务人员对恙虫病的认识,减少误诊率。方法对本院2006年1月～2009年12月收治的48例恙虫病患者进行回顾性分析。结果 48例均有发热,以弛张热多见,占70.83%,焦痂或溃疡37例（77.08%）,外斐反应OXK阳性29例（60.41%）。经氯霉素或强力霉素治疗,体温48～96h恢复正常,治愈48例,无一例死亡。结论恙虫病在本地区是季节性常见病,突发性高热、特征性焦痂或溃疡伴局部淋巴结肿大需考虑本病可能,早期诊治预后良好。     

恙虫病48例临床分析

目的 探讨恙虫病的早期诊断,提高医务人员对恙虫病的认识,减少误诊率.方法 对本院2006年1月～2009年12月收治的48例恙虫病患者进行回顾性分析.结果 48例均有发热,以弛张热多见,占70.83%,焦痂或溃疡37例(77.08%),外斐反应OXK阳性29例(60.41%).经氯霉素或强力霉素治疗,体温48～96h恢复正常,治愈48例,无一例死亡.结论 恙虫病在本地区是季节性常见病,突发性高热、特征性焦痂或溃疡伴局部淋巴结肿大需考虑本病可能,早期诊治预后良好.     

小儿恙虫病115例临床分析

目的 探讨小儿恙虫病临床表现,诊断要点及治疗方法.方法 分析115例我院儿科恙虫病住院病例资料.结果 小儿恙虫病持续发热,局部皮肤表现,淋巴结及肝脾肿大,血清学异常及外斐OXK阳性为特征.结论 小儿恙虫病临床表现复杂,合并症多,易多器官损害,明确诊断后氯霉素治疗效果明显.     

恙虫病临床诊治特点及预防

恙虫病是由恙螨叮咬,感染恙虫病东方体引起的一种自然疫源性传染病。它常常以急性发热、常伴皮疹或焦痂、对抗生素治疗敏感为特征,若救治不及时可能导致严重的多器官衰竭甚至高达70%的死亡率。延迟救治是导致恙虫病患者高死亡率的主要原因。恙虫病往往无典型症状,易与其他地区性疾病混淆,且临床诊断手段相对落后,易被忽视。本文针对恙虫病的病原体、临床诊治特点及防控策略进行文献综述,以加强公众和临床医生对恙虫病的认识,提高该疾病的诊断水平,降低恙虫病的重症率和死亡率。     

鹤山市恙虫病流行病学特征分析

目的了解鹤山市恙虫病的流行病学特征。为疫情防控提供依据。方法回顾性分析了2008—2012年在鹤山市人民医院住院的75例恙虫病病例资料,分析其流行病学特征。结果恙虫病的发生季节性明显,病例分布于2-11月,5～10月为发病高峰期,病例数占88．00％,近2年发病例数较前上升,尤其是2012年病例数明显增加,较2011年增加了113％。发病年龄以50～70岁年龄段最多,占53．33％。宅梧镇为发病例数最多的地区,病例数27例,占36．00％。职业构成以农民最多,占73．33％。结论鹤山市恙虫病发病呈现上升趋势。在恙虫病流行季节,尤其是高发地区,需做好高危人群的健康教育,以减少恙虫病的发生及流行。     

广州老年人恙虫病50例临床分析

目的分析广州地区老年人恙虫病临床特点，以期降低老年人恙虫病的误诊率、漏诊率及病死率。方法将1983年5月至2008年1月收治的50例广州地区老年人恙虫病从流行病学、主要临床表现、实验室及辅助检查、预后等方面进行回顾性分析研究。结果广州地区老年人恙虫病仍具有发热、焦痂溃疡、淋巴结肿大的特点，但皮疹少见，外周血白细胞数多升高，血小板降低多见，起病隐匿，临床表现趋向多样化、复杂化，多脏器损害多见，易发生误诊、漏诊，病死率达14％。结论老年人恙虫病从流行病学、临床特征、实验室检查方面趋向不典型，极易造成误诊、漏诊，且病死率高，尤其是对病程超过两周的患者，应引起临床医师的高度重视。     

新疆伊犁那拉提草原啮齿动物感染恙虫病东方体调查

为了解新疆伊犁那拉提草原啮齿动物中自然感染恙虫病东方体(Ot)的情况,在那拉提草原捕获鼠和旱獭,分别取其脾组织提取DNA,应用巢式PCR(nPCR)方法检测Ot-Sta56基因;基因分型引物扩增阳性片段,判断该地区存在的Ot基因型,部分阳性标本测序,通过NCBI网站对序列进行BLAST比较分析.结果显示,在该地区共捕获...     

36例恙虫病的脑电图表现

恙虫病是由恙虫病立克次体引起的自然疫源性疾病。我县为恙虫病疫区。我院脑电图室 1993- 1998年五年间 ,共对 36例确诊为恙虫病的患者进行脑电图检查 ,现总结如下。1　 资料和方法临床资料 :本组 36例 ,男 2 1例 ,女 15例。年龄 9～ 6 3岁 ,平均 30 6岁 ,其中 2 0～ 5 0岁共 2 9例。主要临床表现 :36例均有发热 ,剧烈头痛、恙螨叮咬处原发性焦痂 ,局部淋巴结肿大。其中 5例出现嗜睡、神志恍惚 ,颈稍有抵抗。实验室检查 :36例血象白细胞正常或偏低 ,ＯＸｋ均在 1:16 0以上。脑电图检查 :本组 36例均在患病后 5日 - 2 6日内。采用上海产ＮＤ…     

Epidemiological,clinical and genetic characterization of scrub typhus in patients presenting with acute febrile illness in New Delhi

PurposeScrub typhus (ST) is a zoonotic disease, caused by O. tsutsugamushi is a major cause of acute febrile illness (AFI) in India. There is a need to study the prevalence and risk factors in various regions of India.MethodsA study to estimate the prevalence and study the risk factors of ST in patients presenting with acute febrile illness (AFI) was performed. All patients underwent serology for IgM antibodies to Orientia tsutsugamushi (In Bios International Inc, Seattle, WA) as per the manufacturers’ protocol. Following this, Polymerase Chain reaction (PCR) (real time SYBR green based targeting groEL gene and conventional PCR targeting 56 ?kDa type specific antigen gene) was performed from stored serum samples.ResultsDuring the study period, 473 patients were admitted. Of these 56 (11.8%) patients were ST positive by IgM serology. The conventional PCR targeting 56 ?kDa type specific antigen gene of O. tsutsugamushi was positive in six patients while Ot groEL SYBR green based PCR) was positive in five. PCR was positive in patients who had demonstrated a higher OD value in ELISA. Conventional PCR positive amplicons were sent for Sanger sequencing and confirmed to be O. tsutsugamushi. The mean age of the patients was 49 ?± ?18.3 years and males constituted a higher number of patients (67.9%, n ?= ?38). The pathognomonic eschar was present in 7 (12.5%) patients. Phylogenetic analysis revealed that sequences clustered close to Kato-like Hualein-20 strain and Karp-like Linh DT strains. All patients were administered doxycycline in our study. Mortality was recorded in 8.9% of the patients.ConclusionsIn patients presenting with acute febrile illness, ST should be considered as a differential diagnosis, especially in post-monsoon season. Along with serology, serum can also be used as sample for PCR in an intracellular bacterium like O. tsutsugamushi.     

Evaluation of Th1 and Th2 immune response in clinical and sub-clinical scrub typhus infection

Scrub typhus (ST), caused by a gram negative intracellular bacteria– Orientia tsutsugamushi, is one among the leading causes of febrile illness across Southeast Asia, including India. Clinical presentation can vary from asymptomatic to severely fatal. Th1-cell mediated immunity has been suggested to play an important role against ST infection in animal models. However, human data on protective immunity are limited. The present study was undertaken to identify host immune correlates that could confer protection in individuals that remain clinically asymptomatic/sub-clinical. Serum cytokine profiling and mRNA expression levels of Th1 (TNF-α, IFN-γ, IL-2) and Th2 (IL-10, IL-6, IL-4) cytokines was studied amongst the clinical and sub-clinical infections. It was observed that a Th1/Th2 pattern is not involved in human ST infection irrespective of being a symptomatic or asymptomatic presentation. However, significant difference was observed in IL-10 serum and gene expression levels. This study suggests a possible role of IL-10 in disease phenotypic presentation. Over-production of IL-10 was found to be a significant factor contributing to the severity of the disease whereas a protective immune mechanism might exist with a low level of IL-10 in ST infection.     

Differential expression of interferon-gamma and interferon-gamma-inducing cytokines in Thai patients with scrub typhus or leptospirosis

Interferon (IFN)-gamma plays an important role in the induction of a type 1 immune response against intracellular pathogens. We compared the plasma levels of IFN-gamma and IFN-gamma-inducing cytokines in adult Thai patients with scrub typhus, caused by the obligate intracellular bacterium Orientia tsutsugamushi, and leptospirosis, caused by extracellular Leptospira interrogans. IFN-gamma, interleukin (IL)-18, and IL-15 levels were elevated only in patients with scrub typhus, whereas IL-12p40 and tumor necrosis factor-alpha concentrations were elevated in both patient groups, although more so in scrub typhus. These data suggest a role for a cell-mediated immune response in host defense against O. tsutsugamushi.     

Pulmonary pathology in patients associated with scrub typhus

AIMS: Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi. Severe cases resulting in mortality from this disease have rarely been reported. We present two scrub typhus cases (a man and a girl) who died of acute respiratory distress syndrome (ARDS). METHODS: Autopsies were performed. Histopathological and immunohistochemical stains were employed using specific antibody for O. tsutsugamushi and inducible nitric oxide synthase (iNOS). RESULTS: These subjects developed respiratory distress shortly after admission, and expired following respiratory failure. At autopsy, generalised lymphadenopathy was observed. The lung weight was about two-fold the normal value. Gross inspection revealed oedematous and haemorrhagic lungs. Microscopic examination revealed diffuse alveolar damage with hyaline membrane formation and interstitial pneumonitis with infiltration of inflammatory cells. Immunohistochemical stain showed O. tsutsugamushi antigen depositions in the endothelial cells. We also demonstrated iNOS in the alveolar macrophages and lung tissue debris in both cases. CONCLUSION: Scrub typhus is usually a mild infectious disease. Our cases present the most dramatic example of sudden death due to ARDS in a short period of time. The clinical investigation and analysis suggest direct endothelial cell invasion of the organism and marked iNOS expression may be involved in the pathogenesis of ARDS associated with scrub typhus.     

Characteristics of scrub typhus,murine typhus,and Q fever among elderly patients: Prolonged prothrombin time as a predictor for severity

Background/purpose

The clinical manifestations of scrub typhus, murine typhus and acute Q fever in the elderly are not clear.

Evaluation of an in-house PCR for diagnosing scrub typhus along with a preliminary study of genotypic characterization of Orientia tsutshugamushi circulating in Chhattisgarh: A prospective clinico-microbiological study

PurposeScrub typhus, caused by Orientia tsutsugamushi (O. tsutsugamushi) present nonspecific clinical features during manifestation of acute undifferentiated febrile illness (AUFI) to render its early diagnosis difficult. Accordingly, this study was undertaken to assess an in-house groEL PCR versus IgM ELISA for the diagnosis of scrub typhus and to genotypically characterise the randomly selected scrub typhus positive cases.MethodsBlood samples, collected from two hundred twenty one (221) AUFI cases were subjected to groEL PCR and IgM ELISA for diagnosis of scrub typhus. Eleven randomly selected PCR positive cases were processed for DNA sequencing to determine the genetic diversity of O. tsutsugamushi in Chhattisgarh.ResultsScrub typhus prevalence of 35.2% were detected among AUFI cases using both in-house groEL PCR and IgM ELISA. PCR alone showed sensitivity, specificity, positive and negative predictive values of 66.6% (CI: 55.08–76.94), 100% (CI: 90 to 100),100% (CI: 93.15 to 100) and 57.37% (CI: 44.05 to 69.96) while for IgM ELISA, these parameters were 62.8% (CI: 51.13–73.50), 100% (CI: 90 to 100), 100% (CI: 92.75 to 100) and 54.68% (CI: 41.75 to 67.18) respectively. PCR and ELISA could detect scrub typhus in 37.2% and 33.3% cases, when tested alone. groEL PCR detected the O. tsutsugamushi throughout the course of infection. Phylogenetic analysis depicted 5 of 11 positive cases belonged to Kuroki, Japan strain of O. tsutsugamushi, followed by Gilliam and Karp strain in 4 and 2 cases respectively.ConclusionScrub typhus should be considered in differential diagnosis of AUFI. groEL PCR may aid on to IgM ELISA test for optimum laboratory diagnosis of scrub typhus by its implementation especially in seronegative cases. Predominance of Kuroki-like strain followed by Gillian and Karp strains of O. tsutsugamushi in Chhattisgarh confirm variable geographical distribution of O. tsutsugamushi and provide the baseline epidemiological data which will eventually be used to help the researchers for developing better diagnostic tests and vaccine covering the predominant genotypes.     

Possibility of scrub typhus in fever of unknown origin (FUO) cases: An experience from Rajasthan

Purpose: Fever of unknown origin (FUO) has multiple causes. Scrub typhus is less known cause of FUO in India. The present study reports a recent epidemic of scrub typhus amongst cases of FUO from different areas of Rajasthan, India. There was high mortality in undiagnosed cases of FUO which lead to the diagnosis of scrub typhus. Objective: To study the possibility of scrub typhus as a causative factor in FUO cases by qualitative detection of IgM antibodies with ELISA. Materials and Methods: From September 2012 to December 2012, 271 serum samples of FUO cases were analysed for IgM antibodies to Orientia tsutsugamushi along with dengue, malaria, typhoid, tuberculosis and brucellosis. Results: Scrub typhus IgM antibodies by ELISA were detected in 133 (49.1%) patients. Scrub typhus positivity was significantly higher among female in comparison to males (P < 0.05). Maximum positivity of scrub typhus was found in females of 46-60 years age group. The laboratory parameters were abnormal in most of the patients as evident by thrombocytopenia (63%), deranged liver functions (56%) and renal functions (25%). Conclusion: The present study emphasises the importance of scrub typhus among cases of FUO especially after rainy season and during early cooler months. The study also highlights the significance of ELISA method for rapid and early reporting and ruling out scrub typhus in FUO cases.     

A serosurvey of Orientia tsutsugamushi from patients with scrub typhus

Many countries where scrub typhus is endemic use their own cutoff values for antibody titres to differentiate between cured cases and current infections. To establish an antibody titre cutoff value, one needs to investigate the seroprevalence in endemic areas, and the duration of the increase in titre after complete cure. We conducted a follow-up study of anti-Orientia tsutsugamushi antibody titres using indirect immunofluorescence assays (IFA) and passive haemagglutination assays (PHA) in patients with scrub typhus. After the onset of symptoms, IgM antibody titres increased gradually over 2–3 weeks, peaked at about 4 weeks, and started to decrease rapidly between 4 and 5 weeks. At 1-year follow-up, the median IgM value was 1:10. Out of 77 patients who were tested at that time, 36 (47%) had IgM titres ≥1:20, and none had titres exceeding 1:80. Over the first 2 weeks, IgG antibody titres increased sharply, peaked at about 4 weeks and decreased rather gradually thereafter, with a median titre of 1:128 maintained up to the 18th month. At 1-year follow-up, five out of 77 patients (6.5%) had titres ≥1:1,024 and 57% had titres ≥1:128. Based on these results, a cutoff value of ≥1:160 for IgM antibody should differentiate between previous and current infections in endemic areas such as Korea and Japan, where scrub typhus occurs mainly in the autumn.