Cases Of Scrub Typhus Research Articles

Aftermath Earthquake in Nepal: Burden of Scrub Typhus Cases and their Presentations

Background: Scrub typhus, also known as tsutsugamushi disease, is an infectious illness caused by Orientia (Rickettsia) tsutsugamushi. It is widely found in Asian counztries and human beings of all ages including children are influenced by it. It can cause death due to late presentation, delayed diagnosis and drug resistance. The clinical features and complications of scrub typhus vary from mild to fatal illness. We describe the epidemiology, clinical features and treatment outcome among scrub typhus cases admitted in Sukraraj Tropical and Infectious Disease Hospital (STIDH), a tertiary center in Kathmandu, Nepal following the massive earthquake of 2015. Material and methods: Serum samples of twenty-three patients with acute undifferentiated fever admitted to the STIDH were tested positive for orientia tsutsugamushi by IgM ELISA. These patients were admitted between August to October 2015. Detail history taking, clinical evaluation and laboratory parameters of these patients were collected. Most of the patients were from the earthquake effected district and staying in temporary shelter with history of rodent infestation of the environment. Verbal consent was taken from each patient. The data were entered in SPSS version 16 and descriptive statistics was used to analyze the data. Results: In the study, more than half of the patients (52.2%) were female and the mean (±SD) age of the patients was 37.6 (±13.3) years. Most of the patients (82.7%) were engaged in farm work. About three fifths (60.8%) of the patients were from Dhading district followed by Nuwakot, Sarlahi, Kavre and Parsa. Except Sarlahi district, all other were affected by earthquake 2015. Majority (87%) of the patients were living in the temporary shelter following devastating earthquake and had history of environmental infestation by rodents. All the patients had fever and anorexia. The mean fever duration before admission was 10.1(±4.0) days. Clinical features of arthralgia and myalgia (91.3%); nausea, headache and chills or rigors (82.6%) and retroorbital pain (60.9%) among the commonest. Abdominal pain and cough was complained by 47.8% and 43.5% patients respectively. Eschar formation, red eye and lymphadenopathy were the commonest physical finding and noted in 30.4, 30.4% and 26.1% patients respectively. Lymphadenopathy was localized. Most common laboratory parameter was increased in alanine transaminase level and thrombocytopenia and was seen in 73.9% and 60.9% patients respectively. Leukocytosis was seen in 21.7% of patients. Azithromycin or doxycycline was added on ceftriaxone once the diagnosis of scrub typhus was made. The mean fever response time was 1.7 (±1.2) days. All patients were discharged after fever subsides. Clinical recovery and hospital stay was uneventful. Conclusion: From the study, it can be concluded that scrub typhus has emerged as an important cause of febrile illness in Nepal after massive earthquake of 2015 so; it demands the continuous surveillance in the health care setting. Scrub typhus should be considered in the patient presenting with acute undifferentiated fever and can be confirmed by sensitive test as characteristic clinical findings seen only in small number of cases. Rodent infestation of the environment around temporary shelter increases the risk of acquiring scrub typhus and such history increases clinical suspicion in the diagnosis. Azithromycin and doxycycline are the effective antibiotics. Appropriate diagnosis and treatment can reduce the complication of scrub typhus even in resource-limited environment.

Where’s the Eschar?: Non-Eschar Cases and Eschar Distribution between the Serotypes of Karp, Irie/Kawasaki and Hirano/Kuroki Causing Scrub Typhus in Fukushima, Japan

Background Scrub typhus (ST) is endemic in Fukushima, where the highest number has been reported from 2006 to 2011 in Japan. Lack of the triad (fever, rash and eschar) in the clinical features of ST makes the diagnosis difficult especially without eschar. Although genitalia or axillae must be examined carefully as overlooked part of physical examination, the distributions of eschars in the serotypes of ST remain unclear.Methods We reviewed the clinical features of the patients diagnosed as ST in adults from 2008 to 2016 at Ohta Nishinouchi General Hospital, a major teaching hospital in Fukushima, Japan.ResultsTotal 51 cases (serotype Karp 24, Irie/Kawasaki 19, Hirano/Kuroki 8) of ST were confirmed by elevated specific IgM and IgG in the paired sera and the positivity by real-time PCR analysis of eschars. Non-eschar cases were found in 5/51 (9.8%): one of Karp, one of Irie/Kawasaki and three of Hirano/Kuroki. Two eschars were found in a case of Irie/Kawasaki. Total 47 eschars were found in the diagnosed cases. In terms of sex differences, eschars from abdomen to thighs including genitalia were found 4/17 (24%) in men and 17/30 (57%) in women, which is more than twice as high than men. In contrast, eschars in lower extremities from calves to feet were found 5/17(29%) in men and 1/30 (3%) in women. There was no eschar in genitalia and hips in men. In terms of serological type differences, eschars of Karp were found in all of parts of bodies (head, neck, upper extremities, chest, back, abdomen, genitalia, hips, knees/popliteal fossae, and feet). In contrast, no eschar was found in genitalia and hips in Irie/Kawasaki and Hirano/Kuroki. No eschar was found in head, neck and feet in Hirano/Kuroki as well. The contact body sites by vectors, behavior pattern of the patients (passage in women, etc.) and preference to human, such as slow-biter with migration to genitalia or axillae as Leptotrombidium pallidum (L. pallidum; vector of Karp) or quick-biter as L. scutellare (vector of Irie/Kawasaki and Hirano/Kuroki) would be the causes of eschar distribution.Conclusion Eschar is the key feature of ST, so we should not be missed the finding with the high index of suspicion in regards to eschar distribution of the sexes and the serotypes. Atypical presentation such as eschar negative ST should be concerned in this endemic area.Disclosures All authors: No reported disclosures.

Validation of a clinical score to differentiate scrub typhus and dengue

Background: Scrub typhus and dengue are two major causes of acute undifferentiated febrile illness in many parts of India and are difficult to differentiate at initial presentation. Materials and Methods: This retrospective observational study was conducted in a large emergency department (ED) between September 2014 and December 2014. The clinical score to differentiate scrub typhus and dengue (CSSD) was validated on confirmed cases of scrub typhus and dengue who presented during the study period. The six variables used in CSSD were SpO2, hemoglobin, total white blood cell count, serum glutamic oxaloacetic transaminase level, serum bilirubin, and sensorium. Results: During the study period, 134 confirmed cases of scrub typhus and dengue were included in the analysis, of which 68 were scrub typhus and 66 were dengue. A male predominance was seen in dengue (60.6%), whereas females comprised the majority in scrub typhus (58.8%). Among 68 confirmed cases of scrub typhus, 32 patients have CSSD score

Clinical Score to Differentiate Scrub Typhus and Dengue: A Tool to Differentiate Scrub Typhus and Dengue.

Background:Dengue and scrub typhus share similar clinical and epidemiological features, and are difficult to differentiate at initial presentation. Many places are endemic to both these infections where they comprise the majority of acute undifferentiated febrile illnesses.Materials and Methods:We aimed to develop a score that can differentiate scrub typhus from dengue. In this cross-sectional study, 188 cases of scrub typhus and 201 cases of dengue infection who presented to the emergency department or medicine outpatient clinic from September 2012 to April 2013 were included. Univariate followed by multivariate logistic regression analysis was performed to identify clinical features and laboratory results that were significantly different between the two groups. Each variable was assigned scores based on the strength of association and receiver operating characteristics area under the curve (ROC-AUC) was generated and compared. Six scoring models were explored to ascertain the model with the best fit.Results:Model 2 was developed using the following six variables: oxygen saturation (>90%, ≤90%), total white blood cell count (<4000, 4001–7000 and >7000 cells/cumm), hemoglobin (≤14 and >14 g/dL), total bilirubin (<2 and ≥2 mg/dL), serum glutamic oxaloacetic transaminase (>200 and ≥200 IU/dL), and altered sensorium (present or absent). Each variable was assigned scores based on its strength of association. The AUC-ROC curve (95% confidence interval) for model 2 was 0.84 (0.79–0.89). At the cut off score of 13, the sensitivity and specificity were 85% and 77% respectively, with a higher score favoring dengue.Conclusion:In areas of high burden of ST and dengue, model 2 (the “clinical score to differentiate scrub typhus and dengue fever”) is a simple and rapid clinical scoring system that may be used to differentiate scrub typhus and dengue at initial presentation.

Occurrence of Orientia Tsutsugamushi Genotypes in Areas of Union Territory of Puducherry and Tamil Nadu State, India

Scrub typhus, caused by the proteobacterium, Orientia tsutsugamushi, is re-emerging in several regions of Asia, particularly in India. Severity of infection and clinical presentations are known to vary with the infecting prototype/genotype. Hence genotypic characterization and distribution of various genotypes is of clinical and epidemiological importance. One hundred and forty five suspected scrub typhus cases, reporting to a tertiary care centre in Puducherry, India were investigated for O. tsutsugamushi specific IgM antibodies by ELISA out of which, 135 (93%) were positive. Most cases occurred post-monsoon, peaking in September, and there was a preponderance in young adults. Forty samples tested positive by Nested PCR based on 56kDa gene of O. tsutsugamushi and amplicons from PCR positive samples were sequenced. Phylogenetic tree constructed using 35 sequences (from nt 20 to nt 130) obtained in the study, along with those retrieved from NCBI site, formed two major branches; one comprising 15 sequences from this study, which aligned with Karp genotype, and the other containing 6 sequences which aligned with a sequence from Vellore, India. The second major branch had 12 sequences, which formed an independent group from the Gilliam prototype. Analysis of association of clinical manifestations with genotypes obtained in the present study showed that the sequences that formed an independent group, were associated with a wide spectrum of clinical manifestations involving multiple organs and more severe manifestations like ARDS and hypotension. The sequences, which branched with Karp prototype were associated with hepatitis, meningitis and Multi-organ disorder syndrome (MODS). The present study thus indicated that different genotypes of O. tsutsugamushi occur in southern regions of India, which were associated with various clinical manifestations. Studies on the occurrence of genotypes will help in development of diagnostic methods and vaccines to curtail the infection.

Improving the Diagnosis of Scrub Typhus by Combining groEL Based Polymerase Chain Reaction and IgM ELISA.

Scrub typhus, an acute febrile illness, caused by Orientia tsutsugamushi, is an important cause of pyrexia of unknown origin in regions of endemicity. This disease is mostly underdiagnosed or misdiagnosed, the reasons for this being a combination of factors which include clinical manifestations that can mimic other infections, lack of easy and reliable diagnostic methods and variation among strains in endemic areas. Hence, easy and reliable methods of diagnosis will contribute to rapid identification and treatment of the infection. The aim of the study was to compare four different methods of detection of scrub typhus and to identify one single test or a combination of tests detecting maximum number of cases. One hundred and forty-five suspected scrub typhus cases were included in this study. Duration of fever and presence of eschar in each patient was noted down. Enzyme-Linked Immunosorbent Assay (ELISA) to detect Immunoglobulin M (IgM) antibodies and Polymerase Chain Reaction (PCR) to detect three genes of Orientia, namely, 56 kDa, 16S rRNA, and groEL were done on these samples. The results of each test were analyzed to identify the test picking up maximum number of positive samples. Statistical analysis was performed using Chi-square test. The level of significance was set at p<0.05. These tests showed that IgM ELISA (93%) and PCR (68%) picked up maximum number of positives. Statistical analysis performed using Chi-square test between the diagnostic assays showed that the p - value <0.001 was significant for IgM ELISA. Among the molecular markers, p-value was significant (<0.001) for groEL PCR. Further analysis of eschar positivity and duration of fever also showed that groEL PCR could detect DNA of the bacterium even in cases with 10 days of fever and this PCR was the best among the molecular markers used to detect the infection. This study suggests that IgM detection by ELISA and conventional groEL PCR, either in combination or alone, depending on the duration of fever, would enhance the diagnosis of scrub typhus.

Clinical and Epidemiological Characteristics of Japanese Spotted Fever and Scrub Typhus in Central Japan, 2004–2015

Background Japanese spotted fever (JSF) and scrub typhus (ST) are endemic rickettsial diseases in Japan. Both diseases potentially have a fatal outcome. Since no studies have specifically compared JSF with ST, we investigated the clinical and epidemiological characteristics of JSF and ST in the area where both are endemic.Methods We systematically collected clinical and epidemiological data from all patients clinically suspected with rickettsial diseases at three medical facilities in Boso Peninsula of Japan between 2004 and 2015. Indirect immunofluorescence assays were used, and eschar PCR/immunoperoxidase assays were also used for identifying the strain. SatScan™ was used for spatial cluster analysis.ResultsIn total, 661 patients were enrolled, 44% were female, and the mean age was 64 years. Thirty-two patients were diagnosed as JSF, 204 were ST, and 97 were non-rickettsial diseases. Only one patient died of ST. Comparing to non-rickettsial diseases, patients with JSF and ST were significantly older, and more of them resided wooded area (P < 0.001). Spatial clusters were identified for both JSF (P < 0.001) and ST (P < 0.05). JSF occurred from April to October with a small peak in July, while 90.2% of ST was diagnosed in November and December. Both rash and eschar were detected in the majority of JSF (97%, 86%) and ST (96%, 87%). When compared with ST, purpura, and the rash on palms/soles were strongly associated with JSF (OR, 29.0, 61.1, respectively). However, patients were much less likely to complain their rash (27% JSF, 44% ST) and eschar (0% JSF, 2.5% ST). Moreover, 26% of JSF and 28% of ST cases did not present with apparent fever (≥37.5°C). All identified ST strains were Irie/Kawasaki (16/22, 73%) or Hirano/Kuroki (6/22, 27%).Conclusion Although clinical picture of JSF and ST are similar, there are some clues to distinguish JSF from ST such as seasonality, geographical region, rash distribution on palms/soles, and the hemorrhagic nature of rash. Rickettsial cases may be underdiagnosed if clinical diagnosis relies on fever, rash, and eschar.Disclosures All authors: No reported disclosures.

Complication profile of scrub typhus and its association with total leucocyte count

Background: Recent reports from several parts of India indicate that there is a resurgence of scrub typhus. There have been a few studies analysing the association of various complications of scrub typhus with leukocyte count. The objective of this study was to study the association of various complications of scrub typhus with leukocyte count in children.Methods: A prospective study done at SPMCHI, SMS Medical College, Jaipur from August 2014 to November 2014. 75 Scrub typhus positive children were included in the study group. A detailed history of signs, symptoms, complications, demographic background was taken and relevant laboratory investigations done. The association between the complications of scrub and the total leukocyte count was studied, statistical analysis was done using Chi Square test.Results: Meningoencephalitis was most commonly seen complication in 14.7% followed by ARDS (9.3%), hepatitis (8%), AKI (6.7%), shock (6.7%) and myocarditis (1.3%). Meningoencephalitis and acute renal failure were more frequent among Scrub Typhus cases with leucopenia (p = 0.006, P = 0.011 respectively). It was observed that hepatitis was more frequent with leukocytosis, but was not statistically significant.Conclusions: Our study revealed that leukopenia has a significant association with meningoencephalitis and acute kidney injury.

The Epidemiology and Characteristics of Q fever and Co‐infections with Scrub Typhus, Murine Typhus or Leptospirosis in Taiwan: A Nationwide Database Study

Q fever (QF) is a worldwide zoonosis associated with outbreaks. Only a few nationwide studies regarding the surveillance and epidemiology of human QF have been reported. Although QF is endemic in Taiwan, a nationwide database investigation of the epidemiology and characteristics of QF and its associations with scrub typhus (ST), murine typhus (MT) and leptospirosis (LS) has never been reported. We analysed nationwide databases of suspected QF, ST, MT and LS cases from October 2007 to December 2014 obtained from the Centers for Disease Control, Taiwan. A total of 468 (4.2%) QF cases were identified among 11109 suspected QF cases. QF cases were mainly distributed in the southern and Kaohsiung-Pingtung regions but rarely in the eastern region. Compared to non-QF cases, QF cases had significantly higher percentages of males (88.7 versus 66.2%) and high-risk occupations (farming, animal husbandry or veterinary medicine) (16.2 versus 10.5%). But the percentages of specific animal contact, including cattle (0.6 versus 0.8%) and goats (0.9 versus 1.0%), were low in both. The majority of suspected QF cases (89.4%) were simultaneously suspected with ST, MT or LS, and the combinations of suspected diseases differed between regions. The number of suspected QF cases from the eastern region decreased since 2009, which was not observed in other regions. A total of 1420 (12.8%) cases had confirmed diseases, including QF (453, 4.1%), QF+ST (7, 0.06%), QF+MT (4, 0.04%), QF+LS (4, 0.04%), MT (186, 1.7%), ST (545, 4.9%), ST+LS (11, 0.1%) and LS (210, 1.9%). Compared to cases of unknown disease, QF cases had larger percentages of high-risk occupations (16.2 versus 9.6%) but similar histories of animal contact (29.8 versus 25.1%). QF is an endemic disease in southern Taiwan. It is difficult to differentiate QF from ST, MT or LS only by high-risk occupations and history of animal contact, and co-infection of QF with these diseases should be considered.

Meteorological factors affecting scrub typhus occurrence: a retrospective study of Yamagata Prefecture, Japan, 1984-2014.

Climate change, by its influence on the ecology of vectors might affect the occurrence of vector-borne diseases. This study examines the effects of meteorological factors in Japan on the occurrence of scrub typhus, a mite-borne zoonosis caused by Orientia tsutsugamushi. Using negative binomial regression, we analysed the relationships between meteorological factors (including temperature, rainfall, snowfall) and spring-early summer cases of scrub typhus in Yamagata Prefecture, Japan, during 1984-2014. The average temperature in July and August of the previous year, cumulative rainfall in September of the previous year, snowfall throughout the winter, and maximum depth of snow cover in January and February were positively correlated with the number of scrub typhus cases. By contrast, cumulative rainfall in July of the previous year showed a negative relationship to the number of cases. These associations can be explained by the life-cycle of Leptotrombidium pallidum, a predominant vector of spring-early summer cases of scrub typhus in northern Japan. Our findings show that several meteorological factors are useful to estimate the number of scrub typhus cases before the endemic period. They are applicable to establish an early warning system for scrub typhus in northern Japan.

Clinical and paraclinical profile, and predictors of outcome in 90 cases of scrub typhus, Meghalaya, India.

BackgroundIndia is an integral component of “tsutsugamushi triangle” which depicts a part of the globe endemic to scrub typhus. Owing to frequent outbreaks witnessed in different parts of the country in the recent past, scrub typhus is described as a re-emerging infectious disease in India. The present study aimed to study the clinical and paraclinical profile, complications and predictors of outcome among 90 cases of scrub typhus diagnosed in a hospital of north-eastern India from Sept 2011 to Aug 2012.MethodsA longitudinal study was conducted in a hospital of Meghalaya, India between Sept 2011 and Aug 2012. Diagnosis of scrub typhus was arrived by SD BIOLINE tsutsugamushi (solid phase immunochromatographic assay) rapid diagnostic test for antibodies (IgM, IgG or IgA). Descriptive analyses of age, gender, geographic area, symptoms and signs, treatment, laboratory findings, complications, and outcome were conducted. Relative risk (RR) with 95 % confidence interval (CI) was computed for Multiple Organ Dysfunction Syndrome (MODS) and mortality. Binary logistic regression was applied to the significant correlates (P < 0.05) on univariate analysis to identify the predictors of MODS and mortality in scrub typhus.ResultsAs many as 662 clinically suspected scrub typhus patients were tested and 90 (13.6 %) were diagnosed to have scrub typhus. Out of 90 patients, 52.2 % (n = 47) were males and their mean (SD) age was 36.29 (13.38) years. Fever of <7 days (n = 75, 83.3 %), myalgia (n = 56, 62.2 %), pain abdomen (n = 24, 26.7 %), headache (n = 24, 26.7 %), nausea/vomiting (n = 21, 23.3 %), dry cough (n = 21, 23.3 %), hepatomegaly (n = 24, 26.7 %), splenomegaly (n = 22, 24.4 %), and lymphadenopathy (n = 20, 22.2 %) were the predominant clinical features. Eschar was seen in 10 patients (11.1 %). One third (n = 30) of the patients developed at least one systemic complication. Acute hepatitis (n = 15, 16.7 %), pneumonitis (n = 14, 15.6 %), and acute kidney injury (n = 11, 12.2 %) were the common complications. MODS was seen in 14.4 % (n = 13) and 38.5 % (n = 5) of the patients with MODS died. Overall, case fatality rate was 5.15 % (n = 5). On univariate analysis, platelets <100 000/mm3, serum creatinine >1.5 mg/dl, and transaminase (AST, ALT or both) >500 U/L were associated with MODS (P < 0.001) and mortality (P < 0.05). In addition, serum bilirubin >3 mg/dl was also associated with MODS (P < 0.001). On applying binary logistic regression, serum creatinine >1.5 mg/dl was a predictor of MODS (OR: 76.1, 95 % CI: 4.9–1175.6) and mortality (OR: 18.03, 95 % CI: 1.38–235.1).ConclusionIn this study setting, approximately one-seventh (13.6 %) of the acute undifferentiated febrile illness were due to scrub typhus. Systemic complications were common (33.3 %). Serum creatinine >1.5 mg/dl was a predictor of MODS and mortality.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0186-x) contains supplementary material, which is available to authorized users.

Endemic Scrub Typhus in South America

Scrub typhus is a life-threatening zoonosis caused by Orientia tsutsugamushi organisms that are transmitted by the larvae of trombiculid mites. Endemic scrub typhus was originally thought to be confined to the so called “tsutsugamushi triangle” within the Asia–Pacific region. In 2006, however, two individual cases were detected in the Middle East and South America, which suggested that the pathogen was present farther afield. Here, we report three autochthonous cases of scrub typhus caused by O. tsutsugamushi acquired on Chiloé Island in southern Chile, which suggests the existence of an endemic focus in South America. (Funded by the Chilean Comisión Nacional de Investigación Científica y Tecnológica and the Wellcome Trust.)

Scrub typhus associated with hemophagocytic lymphohistiocytosis: A report of six pediatric patients.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune disorder that may be inherited or secondary to infection, malignancy or rheumatological disease. The aim of the present study was to highlight the clinical features of scrub typhus-associated HLH in children. A retrospective study was performed on 6 pediatric patients with scrub typhus-associated HLH. For each patient, medical records were reviewed and analyzed, and demographic, clinical and laboratory data and outcomes were collected. The duration of fever prior to admission ranged between 4 and 12 days. All patients exhibited persistent or intermittent fever, eschar, hepatosplenomegaly and lymphadenopathy at the time of diagnosis. Five patients experienced acute respiratory distress syndrome and disseminated intravascular coagulation (DIC) during hospitalization. Thrombocytopenia was detected in all patients with cytopenia involving two or three cell types, simultaneously. Coagulopathy with prolonged prothrombin time and/or activated partial thromboplastin time were noted in all patients. Markedly elevated serum ferritin levels (>1,500 µg/ml) were identified in all patients. Elevated lactate dehydrogenase (>1,000 U/l) was detected in 4 (66.7%) patients and elevated alanine aminotransferase was exhibited by 5 (83/3%) patients. Lung infiltrates and consolidation were the most common imaging findings. Only 1 patient succumbed, with DIC and multi-organ failure. Of the survivors, 1 patient was lost to follow-up, and the remaining patients are in remission with excellent general health, to date. In conclusion, HLH should be considered in severe pediatric cases of scrub typhus. Upon the early recognition of this syndrome, prompt and supportive treatment in the pediatric intensive care unit are vital.

Study on the epidemiological characteristics and influencing factors of scrub typhus in the autumn-winter natural foci, from 2006 to 2013

To investigate the spatiotemporal expansion and risk factors of scrub typhus (ST) in Shandong, Jiangsu and Anhui provinces. Based on the reported cases in Shandong and Jiangsu from 2006 to 2013, and Anhui from 2008 to 2013 epidemiological characteristics of ST and associated environmental factors were analyzed, using the panel negative binomial regression model. A total of 2 968, 2 331 and 3 447 ST cases were respectively reported in Shandong, Jiangsu and Anhui during 2006-2013, with the average annual incidence rates as 0.39, 0.38 and 0.94 per 100 000 population. Uptrend in Shandong and Jiangsu, but a slight rollback seen in Anhui were observed. Expansion of natural foci was found in the 3 provinces, with affected counties accounted for 38.0%, 48.2% and 46.5% in Shandong, Jiangsu and Anhui, respectively in 2013. Cases were clustered in autumn but with a peak of single epidemic appeared in October or November, in all the 3 provinces. More female and elderly patients were seen, than in the other age groups, in all the 3 provinces. Majority of the cases were farmers, with an increasing trend in incidence, in all these provinces, followed by housekeepers in Shandong and preschool children in Anhui. The risk factors of transmission in all the 3 provinces were negatively associated with the monthly precipitation, and showing an " inverted-U" pattern in association with monthly temperature. A positive relationship between the risk of transmission and monthly relative humidity was found in Shandong and Jiangsu provinces. However, an " inverted-U" pattern between the risk of transmission and the monthly sunshine hour, appeared in Shandong and Anhui provinces. The incidence of Scrub typhus in Shandong was also positively related to the coverage of forest. Surveillance programs and health education measures should focus on the warm and moist areas in all the 3 provinces, and also on forestry areas in Shandong. Health education and prevention on mite-bite should be targeted, especially on high-risk populations as the elderly and farmers, in the 3 provinces. Housekeepers in Shandong and children in Anhui should also be under special concern.

Spatiotemporal Dynamics of Scrub Typhus Transmission in Mainland China, 2006-2014.

BackgroundScrub typhus is endemic in the Asia-Pacific region including China, and the number of reported cases has increased dramatically in the past decade. However, the spatial-temporal dynamics and the potential risk factors in transmission of scrub typhus in mainland China have yet to be characterized.ObjectiveThis study aims to explore the spatiotemporal dynamics of reported scrub typhus cases in mainland China between January 2006 and December 2014, to detect the location of high risk spatiotemporal clusters of scrub typhus cases, and identify the potential risk factors affecting the re-emergence of the disease.MethodMonthly cases of scrub typhus reported at the county level between 2006 and 2014 were obtained from the Chinese Center for Diseases Control and Prevention. Time-series analyses, spatiotemporal cluster analyses, and spatial scan statistics were used to explore the characteristics of the scrub typhus incidence. To explore the association between scrub typhus incidence and environmental variables panel Poisson regression analysis was conducted.ResultsDuring the time period between 2006 and 2014 a total of 54,558 scrub typhus cases were reported in mainland China, which grew exponentially. The majority of cases were reported each year between July and November, with peak incidence during October every year. The spatiotemporal dynamics of scrub typhus varied over the study period with high-risk clusters identified in southwest, southern, and middle-eastern part of China. Scrub typhus incidence was positively correlated with the percentage of shrub and meteorological variables including temperature and precipitation.ConclusionsThe results of this study demonstrate areas in China that could be targeted with public health interventions to mitigate the growing threat of scrub typhus in the country.

The role of neutrophils during Orientia infection.

Abstract Scrub typhus is a seriously neglected disease with approximately one-third of the world’s population at risk of being infected with Orientia tsutsugamushi, and the occurrence of over one million scrub typhus cases annually illustrate its importance in global health. All scrub typhus case studies that report blood cell counts, describe neutrophilia during the course of infection. Patients with confirmed scrub typhus have significant increases in activated neutrophil proteins in serum, and the increase of neutrophil recruiting cytokines. We also observed neutrophilia as well as neutrophil recruitment to infected tissues in intravenously infected mice, suggesting key role for neutrophils in scrub typhus disease progression. To determine the role of neutrophils in this infection, female C57BL/6 mice were lethally challenged, and neutrophils were depleted one day prior to infection (D−1) or six (D+6) days post infection. The effects of neutrophil depletion were observed to be dependent on the time post infection. Animals depleted early (D-1) exhibited more severe pathology at an earlier time point and had disease progression similar to non-depleted animals but had greater survival. Animals depleted 6 dpi recovered weight, and signs of illness had resolved by 12 dpi. Histopathology demonstrated decreased cellular infiltrates when compared to infected, non-depleted animals. Depletion of neutrophils decreased mortality independent of when depleted, but only depletion 6 dpi resulted in amelioration of signs. These data suggest an important role of neutrophils in tissue pathology and disease progression during scrub typhus infection.

Spatial analysis of autumn-winter type scrub typhus in Shandong province, 2006-2014

To discuss the spatial-temporal distribution and epidemic trends of autumn-winter type scrub typhus in Shandong province, and provide scientific evidence for further study for the prevention and control of the disease. The scrub typhus surveillance data during 2006-2014 were collected from Shandong Disease Reporting Information System. The data was analyzed by using software ArcGIS 9.3(ESRI Inc., Redlands, CA, USA), GeoDa 0.9.5-i and SatScan 9.1.1. The Moran' s I, log-likelihood ratio(LLR), relative risk(RR)were calculated and the incidence choropleth maps, local indicators of spatial autocorrelation cluster maps and space scaning cluster maps were drawn. A total of 4 453 scrub typhus cases were reported during 2006-2014, and the annual incidence increased with year. Among the 17 prefectures(municipality)in Shandong, 13 were affected by scrub typhus. The global Moran's I index was 0.501 5(P<0.01). The differences in local Moran' s I index among 16 prefectures were significant(P<0.01). The " high-high" clustering areas were mainly Wulian county, Lanshan district and Juxian county of Rizhao, Xintai county of Tai' an, Gangcheng and Laicheng districts of Laiwu, Yiyuan county of Zibo and Mengyin county of Linyi. Spatial scan analysis showed that an eastward moving trend of high-risk clusters and two new high-risk clusters were found in Zaozhuang in 2014. The centers of the most likely clusters were in the south central mountainous areas during 2006-2010 and in 2012, eastern hilly areas in 2011, 2013 and 2014, and the size of the clusters expanded in 2008, 2011, 2013 and 2014. One spatial-temporal cluster was detected from October 1, 2014 to November 30, 2014, the center of the cluster was in Rizhao and the radius was 222.34 kilometers. A positive spatial correlation and spatial agglomerations were found in the distribution of autumn-winter type scrub typhus in Shandong. Since 2006, the epidemic area of the disease has expanded and the number of high-risk areas has increased. Moreover, the eastward moving and periodically expanding trends of high-risk clusters were detected.

Scrub typhus in rural Rajasthan and a review of other Indian studies

Background:Scrub typhus is an acute febrile illness which has been reported from various parts of India with Rajasthan recently joining the list of affected states. Aim:To report a series of paediatric scrub typhus cases from rural Rajasthan. Study design:Retrospective review of children with scrub typhus admitted to the wards and paediatric intensive care unit (PICU) of a tertiary-care hospital. Methods:The study was undertaken over an 8-month period from May to December 2013. All patients with a clinical presentation and/or serological confirmation of scrub typhus who tested negative for malaria, enteric fever, dengue, leptospirosis and urinary tract infection (UTI) were included. A range of investigations were undertaken including IgM-ELISA for scrub typhus, followed by appropriate medical management. Results:Thirty patients satisfied the inclusion criteria. The mean (SD, range) age of the patients was 8·56 (3·43, 3–16) years. The most common clinical features were fever (n = 30, 100%), headache (n = 20, 66%), myalgia (n = 15, 50%), hepatosplenomegaly (n = 18, 60%) and pallor (n = 5, 16%). Typical features such as eschar and rash were observed in only one (3·3%) and three (10%) patients, respectively; none had generalised lymphadenopathy or conjunctival congestion. IgM-ELISA for scrub typhus was positive in 28 patients (93·3%) and 27 responded to doxycycline within 24–72 hours. One of the three patients who required PICU support responded to intravenous chloramphenicol and, of the other two (6·6%), one died of acute respiratory distress syndrome and the other owing to acute renal failure. Conclusion:A high index of suspicion is essential for early diagnosis and prevention of complications in scrub typhus together with prompt referral from rural areas to a higher centre. Awareness of the disease manifestations may further help to prevent excessive investigations in patients presenting with non-specific febrile illness and reduce the economic burden to the family and society in resource-constrained settings.

전북지역 쯔쯔가무시증 발생과 기후요소의 상호 관련성

Objectives: Scrub typhus is one of the most prevalent vector-borne diseases. It is caused by Orientia tsutsugamushi, which is transmitted when people are bitten by infected chigger mites. This study aims at quantifying the association between the incidence of scrub typhus and meteorological factors in Jeollabuk-do Province over the period 2001-2015. Methods: Reported cases of scrub typhus were collected from the website of the Disease Web Statistical System supported by the Korea Centers for Disease Control and Prevention (KCDC). Simultaneous meteorological data, including temperature, rainfall, relative humidity, and sunshine duration were collected from the website of the National Climate Data Service System by the Korea Meteorological Administration. Correlation and regression analyses were applied to identify the association between the incidence of scrub typhus and meteorological factors. Results: The general epidemiological characteristics of scrub typhus in Jeollabuk-do Province were similar to those nationwide for sex, age, and geographical distribution. However, the annual incidence rate (i.e., cases per 100,000) of scrub typhus in Jeollabuk-do Province was approximately four times higher than all Korea`s 0.9. The number of total cases was the highest proportion at 13.3% in Jeonbuk compared to other regions in Korea. The results of correlation analysis showed that there were significant correlations between annual cases of scrub typhus and monthly data for meteorological factors such as temperature and relative humidity in late spring and summer, especially in the case of temperature in May and June. The results of regression analysis showed that determining factors in the regression equation explaining the incidence of scrub typhus reached 46.2% and 43.5% in May and June. Using the regression equation, each 1oC rise in the monthly mean temperature in May or June may lead to an increase of 38 patients with scrub typhus compared to the annual mean of incidence cases in Jeollabuk-do Province. Conclusion: The result of our novel attempts provided rational evidence that meteorological factors are associated with the occurrence of scrub typhus in Jeollabuk-do. It should therefore be necessary to observe the trends and predict patterns of scrub typhus transmission in relation to global-scale climate change. Also, action is urgently needed in all areas, especially critical regions, toward taking steps to come up with preventive measures against scrub typhus transmission.

Scrub typhus in rural Rajasthan and a review of other Indian studies

Background: Scrub typhus is an acute febrile illness which has been reported from various parts of India with Rajasthan recently joining the list of affected states.Aim: To report a series of paediatric scrub typhus cases from rural Rajasthan. Study design: Retrospective review of children with scrub typhus admitted to the wards and paediatric intensive care unit (PICU) of a tertiary-care hospital. Methods: The study was undertaken over an 8-month period from May to December 2013. All patients with a clinical presentation and/or serological confirmation of scrub typhus who tested negative for malaria, enteric fever, dengue, leptospirosis and urinary tract infection (UTI) were included. A range of investigations were undertaken including IgM-ELISA for scrub typhus, followed by appropriate medical management. Results: Thirty patients satisfied the inclusion criteria. The mean (SD, range) age of the patients was 8·56 (3·43, 3–16) years. The most common clinical features were fever (n = 30, 100%), headache (n = 20, 66%), myalgia (n = 15, 50%), hepatosplenomegaly (n = 18, 60%) and pallor (n = 5, 16%). Typical features such as eschar and rash were observed in only one (3·3%) and three (10%) patients, respectively; none had generalised lymphadenopathy or conjunctival congestion. IgM-ELISA for scrub typhus was positive in 28 patients (93·3%) and 27 responded to doxycycline within 24–72 hours. One of the three patients who required PICU support responded to intravenous chloramphenicol and, of the other two (6·6%), one died of acute respiratory distress syndrome and the other owing to acute renal failure. Conclusion: A high index of suspicion is essential for early diagnosis and prevention of complications in scrub typhus together with prompt referral from rural areas to a higher centre. Awareness of the disease manifestations may further help to prevent excessive investigations in patients presenting with non-specific febrile illness and reduce the economic burden to the family and society in resource-constrained settings.