Fever and Rash

Infectious causes of fever and rash pose a diagnostic challenge for the emergency provider. It is often difficult to discern rashes associated with rapidly progressive and life-threatening infections from benign exanthems, which comprise the majority of rashes seen in the emergency department. Physicians must also consider serious noninfectious causes of fever and rash. A correct diagnosis depends on an exhaustive history and head-to-toe skin examination as most emergent causes of fever and rash remain clinical diagnoses. A provisional diagnosis and immediate treatment with antimicrobials and supportive care are usually required prior to the return of confirmatory laboratory testing.

Neurological manifestation of Brazilian spotted fever in childhood

Rocky Mountain Spotted Fever is a rickettsial disease caused by the bacteria Rickettsia rickettsii. In Brazil, the disease is known as Brazilian spotted fever (BSF), being the most significant tick-borne disease in the country. Among the affected patients, only 5% of cases occur in children aged one to nine years. Typical symptoms of the disease are fever, rash, headache and digestive symptoms. Neurological manifestations such as seizures, aphasia and hemiparesis have been described in few patients. This study aimed to describe the case of an infant diagnosed with BSF who presented severe signs of neurological manifestation.

Case Report: Fatal Rickettsiosis in Pregnancy

Rocky Mountain spotted fever (RMSF) is a tick-borne infection caused by Rickettsia rickettsii. We present a series of two cases of pregnant patients who showed up at the emergency room of a hospital in Nuevo León, Mexico. Both patients lived in environments where R. rickettsii is endemic and they presented with several days of symptoms, including fever. Both patients developed a rash and had stillbirths during their hospital stay. Treatment with doxycycline was delayed, with fatal results in both patients. Diagnosis of RMSF was confirmed via polymerase chain reaction assay postmortem. The need to link epidemiological clues with clinical data is critical in the diagnosis and early treatment of RMSF to prevent maternal deaths.

An impedimetric immunosensor for diagnosis of Brazilian spotted fever in blood plasma

Brazilian spotted fever (BSF) is a serious disease of medical importance due to its rapid evolution and high lethality. The effectiveness of the treatment mainly depends on the rapid diagnosis, which is currently performed by indirect immunofluorescence and PCR tests, which require high costs and laboratory structure. In order to propose an alternative methodology, we sought to develop an impedimetric immunosensor (IM) based on the immobilization of specific IgY antibodies for IgG anti Rickettsia rickettsii, using blood plasma from capybara (Hydrochoerus hydrochaeris), for characterization, validation and applications of the ready IM. IM selectivity was observed when comparing capybara reagent IgG (IgGcr) readings with non-reagent IgG (IgGnr). A reagent IgG calibration curve was obtained, from which the limits of detection (LOD) and quantification (LOQ) of 1.3 ng mL-1 and 4.4 ng mL-1 were calculated, respectively. The accuracy tests showed that different concentrations of IgGcr showed a maximum deviation of 20.0%, with CI between 90.00% and 95.00%. Intermediate precision tests showed a relative standard deviation of 2.09% for researcher 1 and 2.61% for researcher 2, and the F test showed no significant difference between the recovery values found between the two analysts, since Fcal 1.56 < 5.05 and P-value 0.48 > 0, 05. Therefore, an impedimetric immunosensor was developed to detect anti BSF IgG in capybara blood plasma, which greatly contributes to the improvement of diagnostic tests, cost reduction and ease of execution.

Serologic Testing for Rocky Mountain Spotted Fever in a Low-Incidence Region

BACKGROUND

Tick-borne diseases have grown in incidence over recent decades. As a result, diagnostic testing has become more common, often performed as broad antibody-based panels for multiple tick-transmitted pathogens. Rocky Mountain spotted fever (RMSF) is rare in our region yet may cause severe morbidity, leading to diagnostic screening in low-risk patients. We sought to describe trends in RMSF diagnostic testing, rate of IgG seropositivity, and clinical features of those tested.

METHODS

We performed a retrospective chart review of patients ≤21 years old undergoing testing for RMSF and/or with an ICD-9/10 code for RMSF. Patients were categorized by infection likelihood based on clinical and laboratory criteria adapted from Centers for Disease Control and Prevention's (CDC) case definition of spotted fever rickettsioses. Clinical data were collected and analyzed with descriptive statistics.

RESULTS

One hundred and seventy patients were included. 5.8% met CDC criteria for rickettsial infection, 6.5% had an elevated IgG titer but lacked suggestive symptoms, and 87.6% had a negative IgG titer. Many patients tested were unlikely to have RMSF, including 50% lacking fever, 20% lacking any RMSF "classic triad" symptoms, 13% without acute illness, and 22% tested during months with low tick activity. Convalescent serology was performed in 7.6% of patients and none underwent Rickettsia rickettsii polymerase chain reaction (PCR) testing.

CONCLUSIONS

Diagnostic testing was frequently performed in patients unlikely to have RMSF. We identified many opportunities for improving test utilization. Reserving testing for those with higher pretest probability, performing convalescent serology, and utilizing PCR may improve the accuracy of RMSF diagnosis and reduce clinical challenges stemming from inappropriate testing.

Typhus Group Rickettsiosis, Brazilian Amazon

Rickettsia rickettsii infection is the only rickettsiosis included in the list of reportable diseases in Brazil, where typhus group rickettsioses, mainly murine typhus, have been underreported. We report a case of typhus group rickettsiosis with unique ecologic particularities in a patient from the Brazilian Amazon, where, to our knowledge, rickettsioses have not been reported.

Needlestick-Associated Rocky Mountain Spotted Fever, Brazil

We report a fatal case of Rocky Mountain spotted fever (RMSF) in a man in Brazil without recent history of tick bites or environmental exposure. He received an accidental needlestick while working as a nurse. The nurse and his patient died. Both cases were confirmed as RMSF by molecular methods.

Fatal Brazilian Spotted Fever Associated with Dogs and Amblyomma aureolatum Ticks, Brazil, 2013

In São Paulo metropolitan area, Brazil, Amblyomma aureolatum ticks are the main vector of Rickettsia rickettsii, which causes Brazilian spotted fever. In 2013, a boy in São Paulo died of Brazilian spotted fever associated with household dogs and A. aureolatum ticks. Prompt recognition and treatment of this illness might prevent deaths.

A Cluster of Cases of Rocky Mountain Spotted Fever in an Area Of Colombia Not Known to be Endemic for This Disease

Rocky Mountain spotted fever (RMSF) has been reported in Colombia since 1937. Most recent outbreaks were in 2006-2008, followed by the absence of recognized cases. This report describes new clinical cases of RMSF and epidemiologic investigations. Medical records were reviewed, and fieldwork, serological and molecular diagnostic testing, and bacterial isolation were performed. Fever, hypotension, abdominal discomfort, and rash accompanied by thrombocytopenia and leukopenia were the most characteristic manifestations. Two convalescent sera from the index case and sera from two dogs revealed high anti-spotted fever group Rickettsia antibody titers. Rickettsia rickettsii was isolated from case 4. Cases 2 and 3 were identified by epidemiological connection with the index case. Thus, a new cluster of cases of RMSF was identified in Antioquia, Colombia, with the occurrence of fatal cases, which indicates the active circulation of the bacteria and a potential risk for the population.

[Fatal case of co-infected of rickettiosis and dengue virus in Mexico]

BACKGROUND

Rocky Mountain spotted fever (RMSF) is a disease spread by an infected tick and it is lethal if patient is not treated on time. Symptom similarities with other exanthematous diseases may delay the diagnosis, which leads to its mortality.

CLINICAL CASE

We show the lethal case of a patient with medical record of high blood pressure and no history of travel, who lived in Sonora, Mexico. At the beginning, it was suspected that the patient had a dengue virus infection, which was confirmed positive by an ELISA test. Patient’s rapid deterioration, multi-organic failure and the characteristics of her exanthema led to the suspicion of the presence of RMSF. We started doxycycline treatment; however, patient died after seven days of evolution. It was confirmed a co-infection of Rickettssia spp. and dengue virus.

CONCLUSION

In rickettsial endemic zones, treatment with doxycycline should be employed in patients with similar symptoms, even though there is evidence of the presence of other etiologic agents.

Exposure to Ticks and their Pathogens in Northeast Missouri

While the prevalence of human pathogens has been quantified in ticks in Adair County, Missouri, the prevalence of residents acquiring tick-borne diseases and seeking medical treatment has not. A public survey (n=109) revealed that 96% of respondents reported finding attached ticks on their person; of these, 38% developed symptoms post tick bite; of these, 55% reported consultation with a health care provider. Overall, 89% of practitioners surveyed had treated at least one patient for tick-borne disease. Rocky Mountain spotted fever and Lyme disease were the most common illnesses diagnosed, however, the only confirmed cases reported by Missouri Department of Health and Senior Services from 2013-2017 were ehrlichiosis. Results from these surveys indicate that exposure to ticks is common and ehrlichiosis infections are likely underdiagnosed while Rocky Mountain spotted fever and Lyme disease are likely overdiagnosed.

Fatal Rocky Mountain Spotted Fever along the United States-Mexico Border, 2013-2016

Although these cases are uncommon, early recognition and prompt initiation of appropriate treatment are vital for averting severe illness and death.

Rocky Mountain spotted fever (RMSF) is an emerging public health concern near the US–Mexico border, where it has resulted in thousands of cases and hundreds of deaths in the past decade. We identified 4 patients who had acquired RMSF in northern Mexico and subsequently died at US healthcare facilities. Two patients sought care in Mexico before being admitted to US-based hospitals. All patients initially had several nonspecific signs and symptoms, including fever, headache, nausea, vomiting, or myalgia, but deteriorated rapidly without receipt of a tetracycline-class antimicrobial drug. Each patient experienced respiratory failure late in illness. Although transborder cases are not common, early recognition and prompt initiation of appropriate treatment are vital for averting severe illness and death. Clinicians on both sides of the US–Mexico border should consider a diagnosis of RMSF for patients with rapidly progressing febrile illness and recent exposure in northern Mexico.

[Complications and cause of death in mexican children with rocky mountain spotted fever]

BACKGROUND

Rocky Mountain spotted fever is a life threatening disease caused by Rickettsia rickettsia, characterized by multisystem involvement.

METHODS

We studied 19 dead children with Rocky Mountain spotted fever. All children who were suspected of having rickettsial infections were defined as having Rocky Mountain spotted fever by serology test and clinical features. Through the analysis of each case, we identified the clinical profile and complications associated to the death of a patient.

RESULTS

In nine (69.2%) of 13 cases that died in the first three days of admission, the associated condition was septic shock. Others complications included respiratory distress causes by non-cardiogenic pulmonary edema, renal impairment, and multiple organ damage.

CONCLUSIONS

The main cause of death in this study was septic shock. The fatality rate from Rocky Mountain spotted fever can be related to the severity of the infection, delay in diagnosis, and delay in initiation of antibiotic therapy. Pulmonary edema and cerebral edema can be usually precipitated by administration of excess intravenous fluids.

Treatment of Tick-Borne Diseases

OBJECTIVE:

To review the data regarding the pharmacotherapy of Lyme disease, Rocky Mountain spotted fever (RMSF), and the human ehrlichioses.

DATA SOURCES:

English-language literature was identified via MEDLINE (1966–January 2002) using the keywords Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis. Textbooks and other pertinent resources were also reviewed.

STUDY SELECTION AND DATA EXTRACTION:

All articles identified through the data sources above were evaluated and reviewed if pertinent to the objective.

DATA SYNTHESIS:

Tick-borne diseases are the most common vector-transmitted diseases in North America. Each disease causes significant morbidity and, in the case of RMSF, mortality if patients go untreated. If the disease syndromes are recognized early and treatment is initiated, complications are greatly reduced. Doxycycline is active against each of the causative organisms, simplifying empiric treatment.

CONCLUSIONS:

Effective pharmacotherapy exists to treat each of these diseases, assuming diagnosis is made quickly. The β-lactam and tetracycline antibiotics appear to be the most effective therapy for Lyme disease. The tetracyclines, but not the β-lactams, are effective for RMSF and the human ehrlichioses. Since Borrelia burgdorferi and the human granulocytic ehrlichiosis agent are becoming more common coinfecting pathogens, tetracycline or doxycycline should be considered the drugs of choice for patients from endemic areas where exposure to both pathogens may have occurred. Doxycycline is the preferred agent because of decreased frequency of administration and adverse effects.

Subcorneal pustular dermatosis associated with Coccidioides immitis

Coccidioidomycosis (AKA "Valley fever") is a primary pulmonary infection via airborne spores released from coccidioides immitis in the soil. Reactive cutaneous eruptions resulting from the pulmonary infection are difficult to diagnose because skin biopsies do not contain the organism. We present an adolescent male with primary pulmonary C.immitis infection manifesting with biopsy proven subcorneal pustular dermatosis. Serological studies revealed increasingly positive titers for coccidioidomycosis and symptoms resolved promptly following initiation of systemic antifungal therapy. Our unique case presentation illustrates subcorneal pustular dermatosis as a reactive eruption owing to primary pulmonary coccidioidomycosis. An association between the two conditions warrants further investigation.

[Seroprevalence of risk factors associated with rickettsiosis (Rickettsia rickettsii) in humans in Baja California, Mexico]

INTRODUCTION

Rickettsiosis caused by Rickettsia rickettsii is capable of infecting vertebrates, including humans. The symptoms are high fever, headache, myalgia, nausea, vomiting, abdominal pain, and cough. Mortality can be up to 30% in untreated patients.

AIMS

To prove the existence of rickettsiosis in Ensenada, Baja California, Mexico, because no human cases have been reported.

MATERIAL AND METHODS

This observational, cross-sectional, descriptive study included 384 samples of humans in Ensenada, Baja California. Antibodies against R. rickettsii were measured with the kit R. rickettsii ELISA(®) Helica Biosystems, Inc., adapted for use in humans using human IgG conjugate antibodies. To determine the sensitivity and specificity, 32 human samples were submitted to IFA. Specific primers were used for the molecular diagnosis of R. rickettsii in dogs and ticks.

RESULTS

The seroprevalence adjusted rickettsiosis in humans was 2.9% (95% CI: 0.8-5.3), seropositivity was not associated with sex, age, occupation, household, dogs, pet deworming program against ticks, the type of yard, and mobility of the dog between home and the street.

CONCLUSIONS

With substantial agreement of k between ELISA and IFA, it follows that the results of seroprevalence of this work are reliable.

Case records of the Massachusetts General Hospital: Case 5-2014: 2014: A 59-year-old man with fever, confusion, thrombocytopenia, rash, and renal failure

A 59-year-old man was admitted to this hospital because of fever, confusion, rash, thrombocytopenia, and renal failure, 10 days after a hunting trip in the Nevada valley. Diagnostic procedures were performed, and diagnostic test results were received from another hospital.

Rocky Mountain Spotted Fever in a patient treated with anti-TNF-alpha inhibitors

Rocky Mountain Spotted Fever (RMSF) is a tick-bourne illness, which can be fatal if unrecognized. We discuss the case of a patient treated with an anti-TNF-alpha inhibitor for rheumatoid arthritis who later developed a generalized erythematous macular eruption accompanied by fever. The clinical findings were suggestive of RMSF, which was later confirmed with serology. Prompt treatment with doxyclycine is recommended for all patients with clinical suspicion of RMSF.

Dermatologic emergencies

Life-threatening dermatologic conditions include Rocky Mountain spotted fever; necrotizing fasciitis; toxic epidermal necrolysis; and Stevens-Johnson syndrome. Rocky Mountain spotted fever is the most common rickettsial disease in the United States, with an overall mortality rate of 5 to 10 percent. Classic symptoms include fever, headache, and rash in a patient with a history of tick bite or exposure. Doxycycline is the first-line treatment. Necrotizing fasciitis is a rapidly progressive infection of the deep fascia, with necrosis of the subcutaneous tissues. It usually occurs after surgery or trauma. Patients have erythema and pain out of proportion to the physical findings. Immediate surgical debridement and antibiotic therapy should be initiated. Stevens-Johnson syndrome and toxic epidermal necrolysis are acute hypersensitivity cutaneous reactions. Stevens-Johnson syndrome is characterized by target lesions with central dusky purpura or a central bulla. Toxic epidermal necrolysis is a more severe reaction with full-thickness epidermal necrosis and exfoliation. Most cases of Stevens-Johnson syndrome and toxic epidermal necrolysis are drug induced. The causative drug should be discontinued immediately, and the patient should be hospitalized for supportive care.

Tick-borne febrile illnesses lacking specific symptoms

We report here one case of tularemia, one case of human monocytic ehrlichiosis, and one case of febrile illness most consistent with tularemia with titers suggestive of Rocky Mountain spotted fever in residents of three south-central Missouri counties. All three cases had with nonspecific symptoms of a febrile illness. All three patients had a history of a tick bite, common in south-central Missouri, but only two patients reported the tick bite when first seen. In these three cases, the severity of the illness provided a clue that led to a diagnosis of tick-borne febrile illnesses by confirmatory serology in two cases. It is very important that physicians be aware of these diseases in the spring and summer months.

Rickettsial and other tick-borne infections

Tick bites are best prevented by people avoiding tick-infested areas. When this is not possible, tick bites may be prevented by the wearing of long trousers that are tucked into boots. The best method to avoid tick bites is twofold: application of a topical deet (N,N-diethyl-m-toluamide) repellent to exposed skin, and treatment of clothing with permethrin. This system is currently used by the US Army to protect soldiers. Ticks can crawl underneath clothing and bite untreated portions of the body; therefore, treating clothing is imperative. Permethrin is nontoxic to humans, and can be used in any age group. Permethrin is commercially available. Checking clothing regularly while in tick-infested areas is highly recommended to back up the few hours of protection provided by the insect repellents. It is also recommended that the entire body be carefully screened for ticks and other parasites by campers and hunters while they are staying in and after leaving infested areas. Any tick found should be removed immediately. Removing ticks may not be easy. It is best to use blunt, rounded forceps, and a magnifying glass to remove ticks, especially when immature ticks are found. The forceps are used to grasp the mouthparts of the tick as close as possible to the skin, and then the tick is pulled upward, perpendicular to the skin, with a continuous and steady action. Usually any mouth parts of the tick retained in the skin are eliminated uneventfully by the body. Other methods of removing ticks, such as using fingers, lighted cigarettes, petroleum jelly, or suntan oil, should be avoided. Killing the tick in situ may increase the risk of regurgitation by the tick and the transmission of infectious agents. Most stick bites are uncomplicated, and result only in benign cutaneous inflammatory reactions that may be pruritic for a few days. As a result of mouthparts being retained at the feeding site, a granuloma may rarely develop. There are no data to indicate that antimicrobial prophylaxsis is beneficial to the tick-bitten patient to prevent disease. It must be kept in mind that the risk of transmission of disease increases with the duration of attachment and generally requires greater than 24 to 48 hours. The degree of tick engorgement or the time since tick exposure and discovery of the tick may be used to establish the likely duration of attachment and the risk of disease transmission. Reducing and controlling tick populations is difficult. Habitat modifications, including vegetation management by cutting, burning, and herbicide treatment, and drainage of wet areas are one strategy for tick control, but their effects are often short-lived, and they can cause severe ecologic damage. Chemicals used to control ticks may cause environmental contamination, and therefore, toxicity for humans and animals. Biologic control methods for ticks include the promotion of natural predators. Natural predators of ticks are beetles, spiders, and ants, and parasites such as insects, mites and nematodes. Tick control is best based on the concept of integrated pest management, in which different control methods are adapted to one area or against one tick species with due consideration to their environmental effects. Tick-borne diseases are increasing in prevalence. Perhaps it is because people are undertaking more outdoor activities, which result in contact with ticks and their pathogens. Clinicians should be aware of the clinical sign of tick-transmitted diseases, because morbidity and mortality as a result of these diseases increases substantially if there are delays in diagnosis and treatment. Tick-borne illness occur in distinctive geographic areas. The reporting of these illnesses and diseases to the health department enables the gathering of information and statistics. The public should be informed about the risks of disease in tick-infested areas and the means of preventing infections. The most common diseases are caused by Rickettsia, Borrelia, and Ehrichia, but with continued study, new pathogens and diseases will continue to emerge.

A case of Rocky Mountain spotted fever

Rocky Mountain spotted fever is a serious, generalized infection that is spread to humans through the bite of infected ticks. It can be lethal but it is curable. The disease gets its name from the Rocky Mountain region where it was first identified in 1896. The fever is caused by the bacterium Rickettsia rickettsii and is maintained in nature in a complex life cycle involving ticks and mammals. Humans are considered to be accidental hosts and are not involved in the natural transmission cycle of this pathogen. The author examined a 47-year-old woman during a periodic recall appointment. The patient had no dental problems other than the need for routine prophylaxis but mentioned a recent problem with swelling of her extremities with an accompanying rash and general malaise and soreness in her neck region. Tests were conducted and a diagnosis of Rocky Mountain spotted fever was made.

[Rocky Mountain spotted fever in children: clinical and epidemiological features]

OBJECTIVE

To report the clinical features of the Rocky Mountain spotted fever (RMSF) in children of southern Sonora, Mexico.

MATERIAL AND METHODS

Nine cases were studied at the Sonora State Children's Hospital. One case was defined by clinical features and positive serological tests (indirect immunofluorescence assay or reaction to Proteus OX 19). Demographic and clinical characteristics of the patients were registered.

RESULTS

The study subjects were children from two to twelve years ofage. All patients have had contact with tick-infested dogs and had fever, as well as petechial rash. Laboratory findings included high levels of hepatic aminotransferase, hyponatremia and thrombocytopenia. Therapy with chloramphenicol and doxyciclyne was administered after the first seven days of the onset of illness. The mortality rate was 22%.

CONCLUSIONS

This study supports the presence of RMSF in the state of Sonora, Mexico, which should be considered as a public health hazard, requiring immediate actions for prevention and control.

Clinical and laboratory features, hospital course, and outcome of Rocky Mountain spotted fever in children

OBJECTIVES

To describe the clinical characteristics and course of children with laboratory-diagnosed Rocky Mountain spotted fever (RMSF) and to identify clinical findings independently associated with adverse outcomes of death or discharge with neurologic deficits.

STUDY DESIGN

Retrospective chart review of 92 patients at six institutions in the southeastern and southcentral United States from 1990 to 2002. Statistical analyses used descriptive statistics and multiple logistic regression.

RESULTS

Children with RMSF presented to study institutions after a median of 6 days of symptoms, which most commonly included fever (98%), rash (97%), nausea and/or vomiting (73%), and headache (61%); no other symptom or sign was present in >50% of children. Only 49% reported antecedent tick bites. Platelet counts were <150,000/mm3 in 59% of children, and serum sodium concentrations were <135 mEq/dL in 52%. Although 86% sought medical care before admission, only 4 patients received anti-rickettsial therapy during this time. Three patients died, and 13 survivors had neurologic deficits at discharge. Coma and need for inotropic support and intravenous fluid boluses were independently associated with adverse outcomes.

CONCLUSIONS

Children with RMSF generally present with fever and rash. Delays in diagnosis and initiation of appropriate therapy are unacceptably common. Prognosis is guarded in those with hemodynamic instability or neurologic compromise at initiation of therapy.

A rickettsial mixed infection in a Dermacentor variabilis tick from Ohio

We present the first report of superinfection in a Dermacentor variabilis tick from nature. The single tick, collected in Ohio, was found infected with Rickettsia belli, R. nontanensis, and R. rickettsii.

Dermatologic emergencies

Primary care physicians are the gatekeepers of the medical community. They are the physicians to whom patients first present, and they are often the physicians with whom patients have the longest lasting relationships. Primary care physicians, as a result of these long-term relationships, have been endowed with a unique responsibility to the health of their patients. By the very nature of their practice, primary care physicians do not have the resources to treat emergent life-threatening conditions. They must, however, be able to diagnose these potentially life-threatening conditions and be able to stabilize and appropriately refer a patient for urgent evaluation by specialists or emergency physicians. There are many types of emergencies encountered in the outpatient setting, ranging from cardiac to toxicologic. As important as recognizing signs and symptoms of cardiac ischemia is the ability to recognize potentially life-threatening dermatologic disorders or dermatologic manifestations of life-threatening systemic diseases.

Fever and rash in a child: when to worry?

The differential diagnosis of a fever and rash presenting in a pediatric patient is quite extensive. This article is not all-inclusive but is meant to aid in the diagnosis to differentiate serious, life-threatening eruptions from more benign common rashes.

[Rickettsial spotted fever in the Paraná Delta. An emerging disease]

We describe a case of rickettsial spotted fever in the Paraná Delta region of Buenos Aires province in Argentina. The patient developed an acute febrile syndrome characterized by myalgias, headache, asthenia and moderate odynophagia, followed by a diffuse macular, papular, and purpuric exanthema. The patient had been bitten recently by a tick on the left preauricular region and an erosive papular lesion was evident at the bite site. An indirect immunofluorescence antibody assay identified antibodies reactive with spotted fever group rickettsiae in the patient's serum. The patient improved rapidly with doxycycline. Several considerations relating to the identity of the rickettsial species and tick vector are discussed, including the possibility that this patient's illness may have been caused by Rickettsia parkeri.

Rocky mountain spotted fever hospitalizations among American Indians

To describe the epidemiology of Rocky Mountain spotted fever (RMSF) among American Indians/Alaska Natives (AI/ANs), we conducted a retrospective analysis of hospitalization records with an RMSF diagnosis using Indian Health Service (IHS) hospital discharge data for calendar years 1980-2003. A total of 261 RMSF hospitalizations were reported among AIs, for an average annual hospitalization rate of 1.21 per 100,000 persons; two deaths were reported (0.8%). Most hospitalizations (88.5%) occurred in the Southern Plains region, where the rate was 4.23 per 100,000 persons. Children 1-4 years of age had the highest age-specific hospitalization rate of 2.50 per 100,000 persons. The overall annual RMSF hospitalization rate declined during the study period. Understanding the epidemiology of RMSF among AI/ANs and educating IHS/tribal physicians on the diagnosis of tick-borne diseases remain important for the prompt treatment of RMSF and the reduction of the disease occurrence among AI/ANs, particularly in high-risk areas.

Fatal human infection with Rickettsia rickettsii, Yucatán, Mexico

The first fatal Rickettsia rickettsii infection was diagnosed in the southwest of Mexico. The patient had fever, erythematous rash, abdominal pain, and severe central nervous system involvement with convulsive crisis. The diagnosis of R. rickettsii infection was established by immunohistochemistry and specific polymerase chain reaction.

[Study on the development of a real-time quantitative polymerase chain reaction assay to detect Rickettsia]

OBJECTIVE

To develop a real-time quantitative polymerase chain reaction(PCR) assay for detecting Rickettsia rickettsii.

METHODS

The primers and TaqMan-MGB probe were designed according to the ompB gene of R. rickettsii. A DNA fragment of ompB gene amplified from R. rickettsii by PCR was used as a standard template for the development of the method.

RESULTS

5 copies of ompB fragments of R. rickettsii were detected. The genomic DNA of R. rickettsii was detected by the developed quantitative PCR assay. However, the genomic DNA from another rickettsial or bacterial agent was not determined. Through this developed method, the positive results were obtained from the animals and cells, artificially infected with R. rickettsii.

CONCLUSION

The real-time quantitative PCR assay seemed to be highly sensitive and specific which might be used to rapidly detect R. rickettsia DNA in various samples and to early diagnose patients infected by R. rickettsii.

Rocky Mountain spotted fever

Rocky Mountain spotted fever (RMSF) is an unusual but important dermatological condition to identify without hesitation. The classic triad of headache, fever, and a rash that begins on the extremities and travels proximally to involve the trunk is found in a majority of patients. The cutaneous centripetal pattern is a result of cell to cell migration by the causative organism Rickettsia rickettsii. Such individuals should receive prompt antimicrobial therapy and supportive care to avoid serious and potentially fatal complications.

Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichioses, and anaplasmosis--United States: a practical guide for physicians and other health-care and public health professionals

Tickborne rickettsial diseases (TBRD) continue to cause severe illness and death in otherwise healthy adults and children, despite the availability of low cost, effective antimicrobial therapy. The greatest challenge to clinicians is the difficult diagnostic dilemma posed by these infections early in their clinical course, when antibiotic therapy is most effective. Early signs and symptoms of these illnesses are notoriously nonspecific or mimic benign viral illnesses, making diagnosis difficult. In October 2004, CDC's Viral and Rickettsial Zoonoses Branch, in consultation with 11 clinical and academic specialists of Rocky Mountain spotted fever, human granulocytotropic anaplasmosis, and human monocytotropic ehrlichiosis, developed guidelines to address the need for a consolidated source for the diagnosis and management of TBRD. The preparers focused on the practical aspects of epidemiology, clinical assessment, treatment, and laboratory diagnosis of TBRD. This report will assist clinicians and other health-care and public health professionals to 1) recognize epidemiologic features and clinical manifestations of TBRD, 2) develop a differential diagnosis that includes and ranks TBRD, 3) understand that the recommendations for doxycycline are the treatment of choice for both adults and children, 4) understand that early empiric antibiotic therapy can prevent severe morbidity and death, and 5) report suspect or confirmed cases of TBRD to local public health authorities to assist them with control measures and public health education efforts.

[Rickettsia helvetica: an emerging tick-borne pathogen in Hungary and Europe]

Rickettsia helvetica belonging to spotted fever group rickettsiae was recently detected by polymerase chain reaction followed by sequencing in European sheep ticks (Ixodes ricinus) from Hungary. Current knowledge on these rickettsiae and the clinical and diagnostic aspects of R. helvetica infection is summarized. In acute cases, R. helvetica is generally responsible for flu-like symptoms. Nevertheless, recent data indicate that in chronic cases, these rickettsiae can be responsible for perimyocarditis resulting sudden cardiac death and might play a role in the pathogenesis of aortic valve disease. The diagnosis can be based on serological, molecular and histological methods. A summary of the information available from Hungary and neighbouring countries on the prevalence of tick-borne encephalitis virus, Anaplasma, Borrelia, Francisella, Rickettsia and Babesia infections in I. ricinus is also presented.

A highly sensitive and specific real-time PCR assay for the detection of spotted fever and typhus group Rickettsiae

A highly specific real-time polymerase chain reaction (PCR) assay was developed to detect spotted fever and typhus group rickettsiae using the citrate synthase gene as the target. The assay amplified rickettsial members of the spotted fever and typhus group including Rickettsia akari, R. australis, R. conorii, R. honei, "R. marmionii," R. sibirica, R. rickettsii, R. typhi, and R. prowazekii. The ancestral group rickettsia, R. bellii, did not produce a positive reaction, nor did other members of the order Rickettsiales or any non-rickettsial bacteria. The assay had a sensitivity of one target copy number per reaction as determined by serial dilutions of a plasmid containing a spotted fever group target sequence. This quantitative assay is useful for the enumeration of rickettsiae in clinical specimens and the diagnosis of rickettsial illnesses, when rickettsial numbers are very low.

[Souvenirs from vacation. Rocky Mountain spotted fever]

Eine 37-jährige Patientin stellt sich nach der Rückkehr von einer Rundreise durch Nordamerika mit einem Status febrilis seit zehn Tagen und einem makulösem extremitätenbetontem Exanthem seit einem Tag vor. Bei suggestiver Klinik und Besuch der Rocky Mountains wird ein Rocky Mountain spotted fever diagnostiziert. Die Serologie für Rickettsia conorii, die mit Rickettsia rickettsii kreuzreagiert, war positiv und bestätigte die klinische Diagnose. Allerdings konnte der beweisende vierfache Titeranstieg, möglicherweise wegen spät abgenommener ersten Serologie, nicht nachgewiesen werden. Nach zweiwöchiger antibiotischer Therapie mit Doxycycline waren Status febrilis und Exanthem regredient.

Tick-borne infections in children: epidemiology, clinical manifestations, and optimal management strategies

Ticks can transmit bacterial, protozoal, and viral infections to humans. Specific therapy is available for several of these infections. Doxycycline is the antimicrobial treatment of choice for all patients, regardless of age, with Rocky Mountain spotted fever, human monocytic ehrlichiosis, or human granulocytic ehrlichiosis. Chloramphenicol has been used to treat these infections in children but is demonstrably inferior to doxycycline. In patients with Mediterranean spotted fever, doxycycline, chloramphenicol, and newer macrolides all appear to be effective therapies. Therapy of Lyme disease depends on the age of the child and stage of the disease. For early localized disease, amoxicillin (for those aged <8 years) or doxycycline (for those aged >/=8 years) is effective. Doxycycline, penicillin V (phenoxymethylpenicillin) or penicillin G (benzylpenicillin) preparations, and erythromycin are all effective treatments for tick-borne relapsing fever. Hospitalized patients with tularemia should receive gentamicin or streptomycin. Doxycycline and ciprofloxacin have each been investigated for the treatment of tularemia in outpatients; however, these agents do not yet have established roles in the treatment of this disease in children. Combination therapy with clindamycin and quinine is preferred for children with babesiosis; the combination of azithromycin and atovaquone also appears promising. Ribavirin has been recently shown to markedly improve survival in patients with Crimean-Congo hemorrhagic fever. The role of antiviral therapy in the treatment of other tick-borne viral infections, including other hemorrhagic fevers and tick-borne encephalitis, is not yet defined.