A confirmed case of macrophage activation syndrome secondary to spotted fever rickettsiosis: Response to immunomodulation in a pediatric patient in northeastern, Mexico

An 8-year-old girl with a rash and high-grade fever for 6 days arrived at the emergency room. She had an erythematous macular rash on the face, trunk, arms, and legs. Further interrogation called attention to the presence of close contact with stray dogs. Her town had been recognized as a site of a rickettsiosis outbreak in the past year. Spotted fever rickettsiosis was suspected, and doxycycline treatment was initiated. Macrophage activation syndrome (MAS) secondary to Rickettsia rickettsii infection was diagnosed according to the Hemophagocytic lymphohistiocytosis and EULAR/PRINTO/PRES 2016 criteria. As there are no clear guidelines on the treatment of MAS secondary to R. rickettsii. the course of action taken by the pediatric intensive care unit team was to avoid disseminated intravascular coagulopathy and treat MAS, both life-threatening conditions. Directed therapy with high doses of methylprednisolone and intravenous immunoglobulin therapy was initiated. The patient recovered, regaining her functional state before the illness. Few articles have described the association between MAS and rickettsiosis, an illness with high mortality, which makes it paramount to detect and treat promptly.

Rickettsia conorii infection with fatal complication

ABSTRACT Rickettsial diseases (RD) are a group of endotheliotropic infectious diseases caused by different species of genera Rickettsia. RD are not an uncommon disease and may be misdiagnosed during the evaluation of acute febrile illness due to a lack of reliable serological marker and diagnostic culture methods. Clinical manifestation of RD varies from febrile illness with rashes and myalgia to fatal complications such as shock and respiratory failure. We describe a case of a young male who presented initially with acute febrile illness, followed by shock and respiratory failure, and unfortunately succumbed to death. A post-mortem examination showed histological features of endotheliotropic infection, such as interstitial / perivascular edema in various organs and noncardiogenic pulmonary edema (suggesting increased vascular permeability) and evidence of vasculitis in the lung, liver, and intestines. Molecular studies performed from lung, liver, and kidney tissue confirm the diagnosis of spotted fever group rickettsial disease due to Rickettsia conorii.

Frecuencia de anticuerpos y seroconversión frente a Rickettsia spp. en pacientes atendidos en instituciones de salud del departamento de Caldas, Colombia, 2016-2019 / Frequency of antibodies and seroconversion against Rickettsia spp in patients consulting health institutions in the department of Caldas, Colombia, 2016-2019

Resumen | Introducción. Las rickettsiosis son enfermedades zoonóticas transmitidas por artrópodos que cumplen el papel de vectores y reservorios, y cuyos síntomas son inespecíficos, por lo que su diagnóstico clínico es difícil. La inmunofluorescencia indirecta (IFI) es el método de referencia para el diagnóstico. En Colombia, ha resurgido el interés por su estudio por los casos de rickettsiosis detectados en el norte del departamento de Caldas a partir del 2001. Objetivo. Establecer la frecuencia de anticuerpos y la seroconversión contra Rickettsia spp. en pacientes atendidos en instituciones de salud del departamento de Caldas, Colombia, entre 2016 y 2019. Materiales y métodos. Se hizo un estudio de diseño cuantitativo, observacional y descriptivo, con una muestra no probabilística de 175 pacientes atendidos en diferentes municipios de Caldas, a quienes se les realizó IFI para la detección de anticuerpos en fase aguda y convaleciente contra Rickettsia rickettsii, R. typhi y R. felis. Resultados. El promedio de edad de los pacientes fue de 31 años. Los municipios con mayor proporción de seropositivos fueron Belalcázar, Chinchiná, Filadelfia, La Dorada, La Merced y Manizales. El 66 % tenía mascotas y el 12 % reportó picaduras por artrópodos. Los signos y síntomas más frecuentes fueron cefalea (69,7 %), artromialgia (60 %), y fiebre (58,2 %). La seroprevalencia por IgG fue de 60 % para R. rickettsii, 47,9 % para R. typhi y 24 % para R. felis. Ocho pacientes presentaron seroconversión. Conclusión. Se encontró evidencia de la circulación de rickettsias del grupo de las fiebres manchadas y del grupo del tifus asociada con casos humanos en el departamento de Caldas.

Abstract | Introduction: Rickettsioses are zoonotic diseases transmitted by arthropods acting as vectors and reservoirs. Disease symptoms are nonspecific and, therefore, their clinical diagnosis is difficult. Indirect immunofluorescence (IFA) is the gold standard assay for diagnosis. The interest for conducting studies on these pathologies has resurfaced in Colombia since 2001; besides, previous studies have evidenced cases of rickettsiosis in the north of the department of Caldas. Objective: To establish the frequency of antibodies and seroconversion against Rickettsia spp. In patients consulting health institutions in Caldas, Colombia, from 2016 to 2019. Materials and methods: We conducted a quantitative, observational, and descriptive study on a non-probabilistic sample of 175 patients with symptoms compatible with rickettsiosis who consulted in different municipalities of Caldas, Colombia; IFA was performed to detect antibodies in the acute and convalescent phases against Rickettsia rickettsii, Rickettsia typhi, and Rickettsia felis. Results: The average age of the patients was 31 years. The municipalities with the highest proportion of seropositive cases were Belalcázar, Chinchiná, Filadelfia, La Dorada, La Merced, and Manizales; 66% of patients owned pets and 12% reported arthropod bites. The most frequent signs and symptoms were headache (69.7%), arthromyalgia (60%), and fever (58.2%). IgG seroprevalence was 60% for R. rickettsii, 47.9% for R. typhi, and, and 24% for R. felis. Eight patients presented seroconversion. Conclusion: We found evidence of the circulation of Rickettsia species from the spotted fever group and the typhus group associated with human cases in Caldas.

Investigation and research on ticks carrying spotted fever group rickettsia in the border area of Tumen River Basin / 中华预防医学杂志

Objective@#To understand the situation and genotype distribution of spotted fever group rickettsia (SFGR) in the border area of Tumen River Basin in free ticks in Yanbian Korean Autonomous Prefecture (Yanbian Prefecture), Jilin Province. @*Methods@#From April to September, 2017, ticks were collected using flagging method from Hunchun, Tumen, Helong and Longjing cities in the Tumen River basin of Yanbian Prefecture. Outer membrane protein A (ompA) was detected by Polymerase Chain Reaction (PCR), then, the species were identified by gene sequencing and analyzed systematically. The positive rate of pools and MIR(minimum infection rate per 100 ticks,MIR) of SFGR were calculated, and the difference of positive rate of pools among ticks with different characteristics was compared by Chi-square test. @*Results@#A total of 3 079 ticks were collected and divided into 536 pools. The positive rate of pools of SFGR nucleic acid was 39.7% (213 pools). The MIR of SFGR was 6.9%.The positive rate of pools of SFGR in Dermacentor silvarum, Haemaphysalis concinna, Haemaphysalis japonica, Haemaphysalis longicornis and Ixodes persulcatus were 80.4% (41/51), 14.0% (25/179), 20.2% (18/89), 78.9% (101/128) and 25.9% (21/81), and the difference was statistically significant (P<0.001). There was statistical difference in the positive rate of pools of SFGR in developmental stages of ticks (P<0.001); the positive rate of pools of female adults, male adults, nymph and larvae were 36.4% (95/261), 34.2% (67/196), 56.3% (40/71) and 7/8, and the MIR was 7.9%, 7.7%, 4.9% and 3.5%. The five genotype was detected which was Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis, Candidatus Rickettsia tarasevichiae,Rickettsia monacensis and have 98%-100% homology with known gene sequences. Candidatus Rickettsia longicornii, Rickettsia raoultii, Rickettsia heilongjiangensis and Candidatus Rickettsia tarasevichiae showed close evolutionary relationship with known specie (have 98%-100% homology with known gene sequences); Rickettsia monacensis showed Far from evolutionary relationship with known species (have 98% homology with known gene sequences). @*Conclusion@#SFGR infection of ticks is common in the border areas of the Tumen River Basin. There was high diversity in SFGR species and tick species in the areas surveyed.

Caso autóctono de fiebre manchada por Rickettsia parkeri en Ensenada, Buenos Aires / Autochthonous case of spotted fever caused by Rickettsia parkeri in Ensenada, Buenos Aires

Se comunica un caso autóctono de fiebre manchada por Rickettsia parkeri en un adulto residente en Ensenada, Provincia de Buenos Aires ocurrido en el verano de 2016. El cuadro, secundario a una mordedura de garrapata en la pierna izquierda, se presentó como un síndrome febril agudo con deterioro del estado general, cefalea, mialgias, artralgias y exantema maculopapular. El sitio de la mordedura presentaba una úlcera con escara necrótica. El diagnóstico se confirmó por conversión serológica IgG anti-antígenos del género Rikettsia. La secuencia de un fragmento del gen gltA amplificado a partir de la lesión de piel presentó 100% identidad nucleotídica con las secuencias de cepas de R. parkeri aisladas en Argentina y en varios países de América. El paciente evolucionó favorablemente al tratamiento con doxiciclina.

We present a case of spotted fever occurred in an adult residing in Ensenada, Buenos Aires province in February 2016. The patient presented with an acute febrile syndrome associated with a skin necrotic lesion on the left leg secondary to a tick bite. The general symptoms were a maculopapular rash, headache, myalgia, and arthralgias. Seroconversion of anti-Rickettsia specific IgG antibodies confirmed recent infection. The nucleotidic and aminoacidic sequences of a gltA gen fragment matched 100% the sequences of R. parkeri strains from Argentina and other countries of America. The patient responded well to treatment with doxycycline.

Caso fulminante de rickettsiosis (Rickettsia rickettsii) en una lactante del sureste de México / Fatal case of rickettsiosis in a toddler from southeastern Mexico

La fiebre manchada de las Montañas Rocosas es una enfermedad ocasionada por Rickettsia rickettsii, una bacteria transmitida por garrapatas infectadas, y que se caracteriza por fiebre, exantema, artralgias y mialgias, aunque, ocasionalmente, su presentación es inespecífica. Debido a que su evolución asemeja otras enfermedades exantemáticas, como dengue o chikungunya, su diagnóstico no es de primera intención, a pesar de que países como México tienen las características ecológicas y socioeconómicas propicias para su transmisión, con índices de mortalidad hasta de 30% en pacientes pediátricos. Esta elevada mortalidad se asocia a diagnósticos y terapia retrasados debido al desconocimiento médico acerca de la enfermedad, lo que propicia la aparición de formas atípicas y fulminantes de fiebre manchada de las Montañas Rocosas. El objetivo del presente trabajo es describir un caso clínico fulminante de fiebre manchada de las Montañas Rocosas para que sea considerada en el diagnóstico diferencial, lo cual impactaría directamente en los índices de mortalidad.

Rocky Mountain spotted fever is a disease caused by Rickettsia rickettsii, a bacteria transmitted by infected ticks. It is characterized by fever, exanthema, arthralgias and myalgias; but sometimes its clinical presentation is non specific. Due to its similarities with other exanthematic diseases like dengue or chikungunya, Rocky Mountain spotted fever is not a first line diagnosis, even though countries like Mexico show the ecologic and socioeconomic characteristics that favor its transmission, with a 30% mortality rate among pediatric patients. This mortality rate has been associated to a delayed diagnosis and therapy, due to a poor knowledge among physicians regarding this disease; this favors the occurrence of atypical and fulminant cases. The objective of this work is to describe a fulminant case of Rocky Mountain spotted fever, expecting that this disease could be later considered among the differential diagnosis which could directly impact its mortality rate.

Present state and future of tick-borne infectious diseases in Korea

The incidence of vector-borne infectious diseases is increasing due to developments in diagnostic techniques, as well as due to economic, environmental, and ecological factors such as global warming, increased rainfall, globalization, and urbanization. Tick-borne infectious diseases occurring in Korea include severe fever with thrombocytopenia syndrome, Lyme disease, anaplasmosis, and Japanese spotted fever. Various skin lesions, such as erythema migrans, tick bite sites, rash, and eschar, are associated with tick-borne infectious diseases. It is necessary to remove ticks immediately to prevent transmission of these tick-borne infectious diseases. Especially for conditions such as Lyme disease, at least 24 to 48 hours of tick attachment to the host is required for transmission of the causative pathogens to the host. Tick-borne diseases are acquired after outdoor activities and have nonspecific symptoms such as fever, headache, and chills, which make them difficult to identify without a diagnostic test. Rapid diagnosis and early treatment can reduce the otherwise significant morbidity and mortality associated with these conditions; therefore, therapy should not be delayed until laboratory confirmation is received.

Enfoque clínico del síndrome febril agudo en Colombia / Clinical approach to acute febrile syndome in Colombia

El síndrome febril agudo se refiere a un conjunto de enfermedades que cursan con fiebre en el contexto de exposición en áreas tropicales y que constituyen un motivo de consulta frecuente en el servicio de urgencias. Este artículo revisa el enfoque clínico del síndrome febril agudo en Colombia y de las enfermedades más prevalentes o graves que lo causan. Se presenta el enfoque sindromático y se establece una revisión sucinta de los síntomas principales, signos de alarma, tratamiento, prevención y notificación en el sistema de vigilancia en salud pública.

Acute febrile syndrome refers to a group of diseases with fever as a main symptom, in a context of living in or having been exposed to tropical climates. It is a frequent cause for consultation in the emergency room. This paper reviews the clinical approach to acute febrile syndrome and the most prevalent or severe causes. We present the syndromatic approach to the patient and a short review of the main symptoms, alarm signs, treatment, prevention and notification to the public health surveillance system of the most frequent causes.

Brazilian Spotted Fever: the importance of dermatological signs for early diagnosis

Brazilian spotted fever is an acute febrile infectious disease caused by Rickettsia rickettsii, transmitted by tick bite. As this disease is rare and has high mortality rates in Brazil, the clinical aspects and epidemiological data may help the diagnosis. We report a case of Brazilian spotted fever in a 19-year-old patient who presented maculopapular exanthema in the palmar region and upper limbs, lymphadenopathy, fever, chills, headache, conjunctival hyperemia, nausea, vomiting, dyspnea, myalgia, developing neurological signs and abdominal pain. He was treated with doxycycline with clinical improvement. We emphasize the importance of the recognition of this disease by dermatologists as cutaneous manifestations are the key findings to establish early diagnosis and prevent complications.

Caso probable de fiebre manchada ( Rickettsia felis) transmitida por pulgas / Probable case of flea-borne spotted fever ( Rickettsia felis )

Rickettsia felis es el agente etiológico de la fiebre manchada transmitida por pulgas, cuyo principal vector y reservorio es Ctenocephalides felis . Típicamente, la enfermedad se presenta como fiebre aguda asociada a cefalea, astenia, exantema máculo-papular generalizado y, en algunos casos, con escara de inoculación. En los últimos años, R. felis ha venido adquiriendo un papel importante en la etiología del síndrome febril agudo, calificándola como una enfermedad emergente y subdiagnosticada. La inmunofluorescencia indirecta es actualmente el método diagnóstico de referencia. Sin embargo, esta técnica presenta limitaciones relacionadas con la reacción cruzada que existe entre las diferentes especies del género Rickettsia . En el presente reporte se describe el caso de un paciente de 16 años con síndrome febril agudo secundario a infección probable por R. felis .

Rickettsia felis is the etiologic agent of flea-borne spotted fever, with Ctenocephalides felis as its main vector and reservoir. Typically, the disease presents as acute fever associated with headache, asthenia, generalized maculo-papular rash, and in some cases, an inoculation eschar. In recent years, R. felis has acquired an important role in the etiology of the acute febrile syndrome; it is indeed an emerging infectious disease, albeit underdiagnosed. Indirect immunofluorescence assay (IFA) is currently the reference diagnostic method. However, this technique has limitations related to the cross reactivity among different species of rickettsiae. Herein, we describe a case of a 16 year-old patient with an acute febrile syndrome secondary to probable infection with R. felis.

Rickettsiosis transmitidas por garrapatas en las Américas: avances clínicos y epidemiológicos, y retos en el diagnóstico / Tick-borne rickettsioses in the Americas: clinical and epidemiological advances, and diagnostic challenges

Las rickettsiosis son entidades clínicas de tipo zoonótico, causadas por bacterias intracelulares estrictas de los géneros Rickettsia y Orientia, pertenecientes a la familia Rickettsiaceae. Su ecología está determinada por factores ambientales y la presencia de vectores específicos que condicionan el establecimiento y la epidemiología en diferentes regiones del mundo. En las Américas, durante el siglo XX, únicamente eran reconocidas tres de estas enfermedades: la fiebre manchada de las Montañas Rocosas, el tifus epidémico y el tifus endémico, Sin embargo, a partir del año 2000 se han descrito mas de 10 especies diferentes previamente desconocidas en este continente, tanto en artrópodos como en casos clínicos, hecho que permite clasificarlas como entidades clínicas emergentes y reemergentes. Dadas las manifestaciones clínicas de las enfermedades causadas por rickettsias, siendo la gran mayoría inespecíficas y, por lo mismo, compartidas con otras enfermedades infecciosas, especialmente virales y bacterianas, han sido enmarcadas entre los diagnósticos diferenciales del síndrome febril agudo, tanto en áreas urbanas como tropicales. En la actualidad, se cuenta con métodos diagnósticos directos e indirectos, que son útiles en la identificación del agente infeccioso, en este caso, causante de rickettsiosis.

Rickettsioses are a group of zoonotic diseases caused by strict intracellular bacteria of the genus Rickettsia and Orientia which belong to the Rickettsiaceae family. Their ecology is influenced by environmental factors and the presence of specific vectors that determine the establishment and epidemiology in different world regions. In America, during the 20 th century, only three of these diseases were recognized: Rocky Mountain spotted fever, epidemic typhus and endemic typhus. However, since 2000, more than 10 different species that had previously been unknown in this continent have been described, both in arthropods and in clinical cases, fact that classifies them as emerging and re-emerging diseases. Given the clinical manifestations of the diseases caused by rickettsias, being the majority unspecific and, therefore, shared with other infectious diseases, especially viral and bacterial, they have been framed within the differential diagnoses of acute febrile syndrome in urban and tropical areas. Nowadays, there are direct and indirect diagnostic methods, which are useful in the definition of the infectious agent, in this case, the cause of rickettsioses.