Three rickettsioses, Darnley Island, Australia

We report 3 rickettsioses on Darnley Island, Australia, in the Torres Strait. In addition to previously described cases of Flinders Island spotted fever (Rickettsia honei strain "marmionii"), we describe 1 case of Queensland tick typhus (R. australis) and 2 cases of scrub typhus caused by a unique strain (Orientia tsutsugamushi).     

Rickettsia felis in Xenopsylla cheopis, Java, Indonesia

Rickettsia typhi and R. felis, etiologic agents of murine typhus and fleaborne spotted fever, respectively, were detected in Oriental rat fleas (Xenopsylla cheopis) collected from rodents and shrews in Java, Indonesia. We describe the first evidence of R. felis in Indonesia and naturally occurring R. felis in Oriental rat fleas.     

Spotted Fever Group Rickettsioses in Israel, 2010–2019

In a multicenter, nationwide, retrospective study of patients hospitalized with spotted fever group rickettsiosis in Israel during 2010–2019, we identified 42 cases, of which 36 were autochthonous. The most prevalent species was the Rickettsia conorii Israeli tick typhus strain (n = 33, 79%); infection with this species necessitated intensive care for 52% of patients and was associated with a 30% fatality rate. A history of tick bite was rare, found for only 5% of patients; eschar was found in 12%; and leukocytosis was more common than leukopenia. Most (72%) patients resided along the Mediterranean shoreline. For 3 patients, a new Rickettsia variant was identified and had been acquired in eastern, mountainous parts of Israel. One patient had prolonged fever before admission and clinical signs resembling tickborne lymphadenopathy. Our findings suggest that a broad range of Rickettsia species cause spotted fever group rickettsiosis in Israel.     

Antigenic relationships between the typhus and spotted fever groups of rickettsiae.

Paired sera from cases of epidemic typhus in Ethiopia and from probable cases of Rocky Mountain spotted fever (RMSF) in the United States were examined by microagglutination (MA) and microimmunofluorescence (micro-IF) tests for antibodies against Rickettsia prowazekii, Rickettsia typhi, Rickettsia canada, Rickettsia rickettsii, Rickettsia conorii and Ricksettsia akari. IgG and IgM antibodies against the various rickettsiae were titrated with specific fluorescein-conjugated anti-IgG and anti-IgM sera. Purified, particulate rickettsial antigens were employed in all tests. A majority of patients acutely ill with epidemic typhus produced both IgG and IgM antibodies against R. prowazekii, R. typhi and R. canada. Concurrently they produced IgG (but seldom IgM) antibodies against members of the spotted fever group. In contrast, patients ill with probably spotted fever, while producing IgG and IgM antibodies against R. rickettsii, R. conorii and R. akari, also produced both IgG and IgM antibodies with about equal frequency against members of the typhus group. It was concluded that a relatively broad antigenic relationship exists between rickettsiae of the typhus and spotted fever groups.     

Emerging rickettsioses of the Thai-Myanmar border

To investigate the presence of rickettsioses in rural residents of the central Thai-Myanmar border, we tested the blood of 46 patients with fever. Four patients had murine typhus, three patients had scrub typhus, and eight patients had spotted fever group rickettsioses, including the first case of Rickettsia felis infection reported in Asia.     

云南省保山市一起地方性斑疹伤寒暴发的调查

目的 了解云南省保山市一起地方性斑疹伤寒暴发的流行病学特征.方法 收集患者的流行病学资料.应用外斐反应和间接免疫荧光方法同时检测患者血清中莫氏立克次体、恙虫病东方体IgG抗体.用PCR检测鼠类脾脏标本中莫氏立克次体、普氏立克次体gltA基因,恙虫病东方体56kDa蛋白基因,斑点热群立克次体ompA基因,埃立克体16S rRNA基因和无形体16SrRNA基因.结果 2009年7-8月保山市隆阳区该起地方性斑疹伤寒累计发病58例,其中48例为临床诊断病例,10例为实验室诊断病例.3例地方性斑疹伤寒实验室诊断病例存在Karp型恙虫病东方体感染.PCR检测黄胸鼠脾脏85份,其中莫氏立克次体gltA片段阳性3份(阳性率为3.5%),其序列与莫氏立克次体Wilmington株(GenBank U59714.1)同源性为100%;普氏立克次体、恙虫病东方体、斑点热群立克次体、无形体和埃立克体均为阴性.结论 经流行病学、临床资料和实验室检测证实,保山市隆阳区该起疫情为地方性斑疹伤寒.从当地优势鼠种黄胸鼠中检测到莫氏立克次体核酸及序列,表明当地存在地方性斑疹伤寒疫源地.

Abstract：

Objective To understand the epidemiologic characteristics of endemic typhus in Baoshan city. Methods Epidemiological data were collected and characteristics were analyzed. IgG antibody(Ab) of Rickettsia mooseri and Orientia tsutsuganushi in serum of patients were tested using both Weil-Felix and IFA method. The Rickettsia mooseri gltA gene, Rickettsia prowazekii gltA gene,Orientia tsutsugamushi 56 kDa protein gene, SFGR ompA gene, Ehrlichia sp. 16S rRNA gene and Anaplasma sp. 16S rRNA gene in spleen of mice were examined by PCR. Results Fifty- eight endemic typhus cases were found in Longyang district of Baoshan city, during July to August, 2009.Among them, 48 cases were confirmed by clinical diagnosis and 10 cases by laboratory tests. The Ab of Orientia tsutsugamushi Karp serotype was detected in 3 cases from laboratory diagnosis. The spleen samples from 85 Rattns flavipectus were tested using PCR. Of them, 3 samples for Rickettsia mooseri gltA gene showed positive (positive rate was 3.5% ), and the homology of 3 Rickettsia mooseri and Rickettsia mooseri Wilmington strain (GenBank U59714.1) was 100% through comparing gene sequence. The results of PCR for detecting Rickettsia prowazekii, Orientia tsutsugamushi, SFGR,Anaplasma sp. and Ehrlichia. sp were all negative. Conclusion The outbreak of endemic typhus was confirmed in Longyang district of Baoshan city through epidemiological data, clinical diagnosis and laboratory tests. Rickettsia mooseri DNA was detected in the dominant Raw flavipectus, suggesting that endemic typhus did exist in the local areas.     

Rickettsia prowazekii and real-time polymerase chain reaction

Rickettsia prowazekii is the causative agent of epidemic typhus and a potential bioterrorism agent. Sensitive and specific rapid assays are needed to complement existing methods of detecting this organism. We developed a real-time quantitative polymerase chain reaction assay by using a species-specific probe targeting the gltA gene. This assay, which was rapid, specific for R. prowazekii only, and sensitive (cutoff detection of 1 to 5 copies per sample), detected and directly identified R. prowazekii in blood of 12 experimentally infected mice sampled at day 3 and 6 postinfection or in naturally or experimentally infected lice. Because our assay is highly standardized and easily adaptable, it could improve epidemic typhus surveillance in public health programs, especially for countries with underdiagnosed or unrecognized human cases.     

Flinders Island spotted fever rickettsioses caused by "marmionii" strain of Rickettsia honei, Eastern Australia

Australia has 4 rickettsial diseases: murine typhus, Queensland tick typhus, Flinders Island spotted fever, and scrub typhus. We describe 7 cases of a rickettsiosis with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). Cases were most prevalent in autumn and from eastern Australia, including Queensland, Tasmania, and South Australia. One patient had a history of tick bite (Haemaphysalis novaeguineae). An isolate shared 99.2%, 99.8%, 99.8%, 99.9%, and 100% homology with the 17 kDa, ompA, gltA, 16S rRNA, and Sca4 genes, respectively, of Rickettsia honei. This Australian rickettsiosis has similar symptoms to Flinders Island spotted fever, and the strain is genetically related to R. honei. It has been designated the "marmionii" strain of R. honei, in honor of Australian physician and scientist Barrie Marmion.     

Murine typhus and febrile illness, Nepal

Murine typhus was diagnosed by PCR in 50 (7%) of 756 adults with febrile illness seeking treatment at Patan Hospital in Kathmandu, Nepal. Of patients with murine typhus, 64% were women, 86% were residents of Kathmandu, and 90% were unwell during the winter. No characteristics clearly distinguished typhus patients from those with blood culture-positive enteric fever.     

Rickettsia parkeri in Amblyomma maculatum ticks, North Carolina, USA, 2009-2010

We detected Rickettsia parkeri in 20%-33% of Amblyomma maculatum ticks sampled in North Carolina. Results highlight the high frequencies of R. parkeri-infected ticks in the state with the highest annual incidence of Rocky Mountain spotted fever. Epidemiologic studies are needed to definitively link R. parkeri to cases of spotted fever rickettsiosis.     

High Seroprevalence of Antibodies against Spotted Fever and Scrub Typhus Bacteria in Patients with Febrile Illness,Kenya

Serum samples from patients in Kenya with febrile illnesses were screened for antibodies against bacteria that cause spotted fever, typhus, and scrub typhus. Seroprevalence was 10% for spotted fever group, <1% for typhus group, and 5% for scrub typhus group. Results should help clinicians expand their list of differential diagnoses for undifferentiated fevers.     

Murine Typhus in Child, Yucatan, Mexico

A case of murine typhus in Yucatan was diagnosed in a child with nonspecific signs and symptoms. The finding of Rickettsia typhi increases the number of Rickettsia species identified in Yucatan and shows that studies are needed to determine the prevalence and incidence of rickettsioses in Mexico.     

Murine Typhus and Leptospirosis as Causes of Acute Undifferentiated Fever, Indonesia

To investigate rickettsioses and leptospirosis among urban residents of Semarang, Indonesia, we tested the blood of 137 patients with fever. Evidence of Rickettsia typhi, the agent of murine typhus, was found in 9 patients. Another 9 patients showed inconclusive serologic results. Thirteen patients received a diagnosis of leptospirosis. No dual infections were detected.     

云南省玉溪市红塔区鼠型斑疹伤寒病原及血清流行病学调查

目的明确玉溪市红塔区是否为鼠型斑疹伤寒疫源地。方法采用微量室温补体结合法，对红塔区人群和鼠类进行鼠型斑疹伤寒（莫氏）立克次体血清抗体检测，用鼠、鼠体外寄生节肢动物标本接种豚鼠进行病原体分离，并调查鼠密度和鼠蚤指数。结果调查的7镇14个调查点人群血清抗体均检出阳性，总阳性率28．92％（96／332），几何平均滴度（GMT）为10．83，其中发热患者和健康人群抗体阳性率分别为31．86％（72／226）和22．64％（24／106）；男女阳性率分别为26．71％（43／161）、30．99％（53／171），性别间差异无统计学意义（P〉0，05）；年龄组阳性率分别为0-6岁29．63％（8／27）、7-18岁18．06％（13／72）、19-39岁39．62％（42／106）、40-59岁27．50％（22／80）、60岁以上23．40％（11／47），各年龄组差异有统计学意义（P〈0．05）；10个调查点捕获的鼠类均检出抗体，阳性率为44．95％（89／198），GMT为30．30；从11组鼠类标本中分离到5株莫氏立克次体，从6组蚤类标本中分离到3株莫氏立克次体，病原体分离率为44．44％（8／18），其中鼠类为45．45％（5／11）、蚤类为50．00％（3／6）；1组螨类标本接种豚鼠未引起豚鼠发病；确诊1例鼠型斑疹伤寒病例；褐家鼠和黄胸鼠占捕鼠总数的99．49％（197／198）、印鼠客蚤占捡蚤总数的74．26％（303／408），鼠蚤指数为2．06，鼠密度为11．13％。结论红塔区人群和鼠类中存在鼠型斑疹伤寒，且处在较高感染水平，可认定该区为鼠型斑疹伤寒疫源地。     

Spotted fever group rickettsiae in ticks, Germany

To explore increased risk for human Rickettsia spp. infection in Germany, we investigated recreational areas and renatured brown coal surface-mining sites (also used for recreation) for the presence of spotted fever group rickettsiae in ticks. R. raoultii (56.7%), R. slovaca (13.3%), and R. helvetica (>13.4%) were detected in the respective tick species.     

Prevalence of antibodies to Rickettsia conorii Coxiella burnetii and Rickettsia typhi in Salamanca province (Spain). Serosurvey in the human population

The Salamanca Province of Spain is an endemic zone for Mediterranean spotted fever. In this area, only one case of Q fever has been reported and typhus group rickettsial diseases have never been diagnosed. To obtain a panoramic view of the presence of antibodies to the most ubiquitous rickettsial agents, 400 sera specimens from a statistically representative sample of the human population of Salamanca City and its surrounding province were subjected to indirect microimmunofluorescent test for antibodies against Rickettsia conorii, Coxiella burnetii, phase II, and Rickettsia typhi antigens. Titers 1:40 to R. conorii were found in 73.5% of the sera. Positivity was more common in subjects who reported closer contact with the natural environment and/or with domestic animals. Seropositivity to C. burnetii, phase II, was detected in 50.2% of sera. These positive cases were related to rural environmental factors and to prevoius contact with animals. The frequency of antibodies increased with age showing a progressive exposure to the rickettsial antigen. The prevalence of antibodies to R. conorii and C. burnetii in the human population of Salamanca Province is higher than that reported from any other geographic zone. The study of antibodies to R. typhi showed that 12.5% of the sera had titers 1:40. According to our results, seropositivity to this rickettsial antigen cannot be related to any particular group of population nor interpreted totally as cross reactivity with R. conorii. Our data show a wide distribution of R. conorii and C. burnetii antigens in Salamanca Province, and also indicate the presence of R. typhi antigens in this area.     

用多聚酶链反应技术检测实验感染恙虫病立克次体的恙螨

作者首次采用多聚酶链反应技术检测感染恙虫病立克次体的媒介恙螨，包括成虫的幼虫。证实ＰＣＲ是一可用于恙虫病流行病学调查的新的敏感方法。     

Severe spotted fever group rickettsiosis, Australia

We report 3 cases of spotted fever group rickettsial infection (presumed Queensland tick typhus) in residents of northern Queensland, Australia, who had unusually severe clinical manifestations. Complications included renal failure, purpura fulminans, and severe pneumonia. Clinical illness caused by Rickettsia australis may not be as benign as previously described.     

Rickettsia raoultii-like Bacteria in Dermacentor spp. Ticks, Tibet, China

TO THE EDITOR: Rickettsia raoultii is an obligate intracellular gram-negative bacterium belonging to the spotted fever group (SFG) of the genus Rickettsia. Genotypes RpA4, DnS14, and DnS28, originally isolated from ticks from Russia in 1999 (1), were designated as Rickettsia raoultii sp. nov. on the basis of phylogenetic analysis (2). R. raoultii has been found mainly in Dermacentor spp. ticks in several countries in Europe (3). It was detected in a Dermacentor marginatus tick from the scalp of a patient with tick-borne lymphadenitis in France (2), which suggests that it might be a zoonotic pathogen. We determined the prevalence of R. raoultii-like bacteria in Dermacentor spp. in highland regions in Tibet.