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.

Detección de Rickettsia typhi en Rhipicephalus sanguineus s.l. y Amblyomma mixtum en el sur de México / Detection of Rickettsia typhi in Rhipicephalus sanguineus s.l. and Amblyomma mixtum in South Mexico

Resumen: Objetivo: Determinar la presencia de Rickettsia typhi en Rhipicephalus sanguineus s.l. y Amblyomma mixtum, en el sur de México. Material y métodos: Las garrapatas fueron colectadas en humanos y animales domésticos. Se determinó la presencia de Rickettsia por reacción en cadena de la polimerasa (PCR, por sus siglas en inglés) y secuenciación. Resultados: 10/39 viales de trabajo amplificaron fragmentos de los genes gltA, htrA y ompB, en 7/10 proveniente de Rh. sanguineus s.l. colectadas de perros y en 3/10 de A. mixtum colectadas de caballo y humano. La secuenciación indicó R. typhi en Rh. sanguineus y A. mixtum con homología de 100% (LS992663.1), para una región del gen de htrA, y de 99% (LS992663.1), con las regiones de los genes de gltA y OmpB. La tasa mínima de infección (TMI) para R. typhi fue de 3.88. Conclusiones: Las garrapatas Rhipicephalus sanguineus s.l. y Amblyomma mixtum están infectadas naturalmente con R. typhi en el sur de México.

Abstract: Objective: To determine the presence of Rickettsia typhi in Rhipicephalus sanguineuss.l. and Amblyomma mixtum in southern Mexico. Materials and methods: Ticks were collected in humans and domestic animals. The presence of Rickettsia was determined by PCR and sequencing. Results: 10/39 work vials amplified fragments of the gltA,htrA and ompB genes. On 7/10 from Rh. sanguineus s.l collected from dogs and in 3/10 of A. mixtum collected from horse and human. Sequencing indicated R. typhi in Rh. Sanguineus and A. mixtum with 100% homology (LS992663.1) for a region of the htrA gene and 99% (LS992663.1) with the regions of the gltA and OmpB genes. The minimum infection rate (TMI) for R. typhi was 3.88. Conclusions: Rhipicephalus sanguineuss.l. and Amblyomma mixtum are naturally infected with R. typhi in Southern Mexico.

First description of a clinical case of murine typhus in Campeche, Mexico

Abstract Murine typhus is a flea-borne disease caused by Rickettsia typhi, which was first detected in Mexico in 1927. It was not until 1996 that the first systematized study involving this pathogen was conducted in two coastal states of Mexico. We now report the first confirmed case of murine typhus in the state of Campeche, which occurred in a male patient who exhibited fever, thrombocytopenia, hyperbilirubinemia, and a rash. Furthermore, the patient reported having had previous contact with Rickettsia reservoirs.

Caso probable de tifus murino con falla ventilatoria en una adolescente del área urbana de Cali, Colombia / Probable case of murine typhus with respiratory failure in an adolescent from the urban area of Cali, Colombia

El tifus murino es una enfermedad infecciosa de carácter zoonótico causada por Rickettsia typhi . Se presenta el caso de una paciente femenina de 13 años edad, procedente del área urbana de la ciudad de Cali, quien presentó un cuadro febril asociado a taquipnea y exantema maculopapular generalizado en tronco y extremidades. Durante las primeras 48 h en la UCI pediátrica desarrolló rápido deterioro clínico, fiebre persistente, aumento de reactantes de fase aguda, presencia de infiltrados pulmonares intersticiales bilaterales y derrame pleural, requiriendo ventilación mecánica no invasiva. Se inició tratamiento con doxiciclina frente a la sospecha de una posible infección por agentes rickettsiales. Veinticuatro horas más tarde la paciente presentó mejoría clínica, resolución del exantema y retiro de la ventilación no invasiva. Por medio de la prueba de inmunofluorescencia indirecta se evidenciaron títulos de 1:512 frente al grupo del tifus, constatando el diagnóstico probable de tifus murino.

Murine typhus is a zoonotic infectious disease caused by Rickettsia typhi . We report a case of a 13-year old female patient from the urban area of the city of Cali, who presented with fever, associated with tachypnoea and generalised maculopapular exanthema on the trunk and limbs. During the first 48 h in the paediatric ICU, she rapidly deteriorated, with persistent fever, increased acute phase reactants, bilateral interstitial pulmonary infiltrates and pleural effusion requiring noninvasive ventilation. Treatment with doxycycline was initiated due to a suspected infection by rickettsial agents. Twenty-four hours later the patient presented clinical improvement and resolution of the exanthema, thus the non-invasive ventilation was withdrawn. By means of a indirect immunofluorescence test, titres of 1:512 were shown against the typhus group, leading to the probable diagnosis of murine typhus.

Detección molecular de Rickettsia typhi en perros de una comunidad rural de Yucatán, México / Molecular evidence of Rickettsia typhi infection in dogs from a rural community in Yucatán, México

Introducción. Rickettsia typhi es la bacteria causante del tifus múrido o endémico, el cual es transmitido al ser humano principalmente por medio de las heces infectadas de pulgas y en cuyo ciclo de infección se encuentran involucrados distintos animales sinantrópicos y domésticos. En la comunidad rural de Bolmay, Yucatán, México, se reportaron casos de tifus múrido en seres humanos durante el periodo 2007-2010. Objetivo. Identificar la presencia de R . typhi y estimar la frecuencia de infección en perros de Bolmay, México. Materiales y métodos. Se tomaron muestras de sangre completa de 128 perros, se les extrajo el ADN total y se analizaron mediante reacción en cadena de la polimerasa (PCR) para amplificar los fragmentos del gen de 17 kDa y omp B , y confirmar la presencia de Rickettsia spp. Los productos de las reacciones se enviaron a secuenciación y se les hizo un análisis de alineamiento con Basic Local Alignment Search Tool (BLAST). Resultados. Se encontró una frecuencia de infección de 5,5 % (7/128). El alineamiento demostró 99 % de homologación para el gen de 17 kDa y 100 % para el gen omp B en R . typhi . Conclusión. Se detectó la presencia de R . typhi pero una baja frecuencia de infección en perros de la comunidad de estudio; sin embargo, la especie podría representar un riesgo de transmisión para los seres humanos.

Introduction: Rickettsia typhi causes murine or endemic typhus, which is transmitted to humans primarily through flea bites contaminated with feces. Synanthropic and domestic animals also contribute to the infection cycle of R. typhi . Cases of murine typhus in humans were reported in the rural community of Bolmay, Yucatán, México, between 2007 and 2010. Objective: To identify the presence of R . typhi and estimate the frequency of infection in dogs from Bolmay, México, a locality with previous reports of murine typhus in humans. Materials and methods: Whole blood samples were taken from 128 dogs. Total DNA was extracted for use in the polymerase chain reaction (PCR) to amplify fragments of the 17 kDa and omp B genes and confirms the presence of Rickettsia spp. The reaction products were sequenced, and alignment analysis was performed using the BLAST tool. Results: The frequency of R. typhi infection in dogs was 5.5 % (7/128). The alignment identified 99% and 100% homology to the R . typhi 17 kDa and omp B genes, respectively. Conclusion: We confirmed the presence of R . typhi in dogs in the studied community but at a low frequency. However, there is potential risk of transmission to humans.

Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES / Rickettsia typhi y R. felis en roedores y sus pulgas en Yucatán como posible agente causal de casos febriles indefinidos

Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

Rickettsia typhi es el agente causal del tifo murino; una enfermedad zoonótica transmitida por vector mundialmente distribuida, comúnmente asociada con la presencia de roedores domésticos y silvestres. Los casos humanos de tifo murino en el Estado de Yucatán son frecuentes. Sin embargo, no existe evidencia de la presencia de Rickettsia typhi en mamíferos o vectores en Yucatán. En la búsqueda de vectores y reservorios de Rickettsia typhi, evaluamos la presencia de bacterias del género Rickettsia en roedores y sus ectoparásitos de un pequeño municipio del estado de Yucatán por medio de técnicas de PCR convencional y secuenciación de ADN. Se identificó la presencia de Rickettsia typhi en muestras de sangre obtenidas de Rattus rattus y reportamos por primera vez la presencia de Rickettsia felis en la pulga Polygenis odiosus colectado de Ototylomys phyllotis. Complementariamente, Rickettsia felis fue detectado en la pulga Ctenocephalides felis parasitando al roedor Peromyscus yucatanicus. No se identificó especie de Rickettsia en las muestras de sangre de O. phyllotis y P. yucatanicus analizados. Nuestros resultados contribuyen también en el conocimiento de ciclo de vida biológico del género Rickettsia.

Murine typhus in Xishuangbanna Prefecture, Yunnan Province,China / 中国人兽共患病学报

ABSTRACT:In recent years ,there has been high prevalence of murine typhus in Yunnan Province ,People's Republic of China .A large outbreak of murine typhus occurred in Xishuangbanna Prefecture ,Yunnan Province in 2010 .However ,not all cases were confirmed by laboratory assays ;therefore ,field epidemiologic and laboratory investigations of murine typhus in Xishuangbanna Prefecture were conducted in 2011 .Blood samples were collected from clinical diagnostic cases at the acute and convalescence stages of murine typhus in Xishuangbanna Prefecture ,Yunnan Province ,from June to September of 2011 ,and blood and spleen samples were collected from mice sharing the same habitats as the patients .Immunofluorescence assays were used to test for the presence of IgM and IgG antibodies against Rickettsia typhi in sera from patients and mice .Real‐time PCR was used to detect the groEL gene of R .typhi in blood clots from patients at the acute stage and in spleen tissue from mice .A total of 1 157 clinically diagnosed murine typhus cases occurred in Xishuangbanna Prefecture ,Yunnan Province in 2011 ,with an incidence of 102 .10/100 000 .Of these cases ,80 were investigated by laboratory assays and 74 of 80 patients were confirmed to have murine typhus .The coincidence rate between the clinical diagnosis and laboratory detection was 92 .50% .The positivi‐ty rate for IgG antibodies against R .typhi was 14 .0% (14/100) for Rattus f lavipectus ,while the rate by PCR was 9 .0%(9/100) .That laboratory diagnoses confirmed that the severity of the murine typhus outbreak in Xishuangbanna cannot be ig‐nored .The distribution of host animals transmitting R .typhi underscores this conclusion .

Delayed-Onset Complete Atrioventricular Block in a Patient with Murine Typhus Myocarditis / 대한내과학회지

Murine typhus is a flea-borne infectious disease caused by Rickettsia typhi, of which myocarditis is a rare complication in the acute disseminating phase. A 62-year-old female presented with a fever and was diagnosed with murine typhus. She was treated with doxycycline and discharged after complete resolution of the fever. However, recurrent presyncope and exertional dyspnea developed 6-8 weeks later. Complete atrioventricular (AV) block with a wide QRS escape rhythm and a left bundle branch block configuration was documented. Subacute myocarditis was diagnosed based on persistent cardiac troponin-I elevation and typical cardiac magnetic resonance imaging findings. A permanent pacemaker was implanted for symptomatic complete AV block. Few reports of myocarditis in murine typhus have been published. We report a case of murine typhus myocarditis complicated by complete AV block in the late convalescence phase.

Murine Typhus: Clinical and epidemiological aspects / Tifo Murino: Aspectos clínicos y epidemiológicos

Rickettsia typhi is an intracellular bacteria who causes murine typhus. His importance is reflected in the high frequency founding specific antibodies against R. typhi in several worldwide seroepidemiological studies, the seroprevalence ranging between 3-36%. Natural reservoirs of Rickettsia typhi are rats (some species belonging the Rattus Genus) and fleas (Xenopsylla cheopis) are his vector. This infection is associated with overcrowding, pollution and poor hygiene. Typically presents fever, headache, rash on trunk and extremities, in some cases may occur organspecific complications, affecting liver, kidney, lung or brain. Initially the disease is very similar to other diseases, is very common to confuse the murine typhus with Dengue fever, therefore, ignorance of the disease is a factor related to complications or non-specific treatments for the resolution of this infection. This paper presents the most relevant information to consider about the rickettsiosis caused by Rickettsia typhi

Sero-epidemiological investigation on Rickettsia typhi,Bartonella henselae and Orientia tsutsugamushi in farmers from rural areas of Tianjin,2007-2009 / 中华流行病学杂志

Objective To study the sero-epidemiological starus regarding Rickettsia (R.) typhi,Bartonella (B.) henselae and Orientia (O.) tsutsugamushi in farmers from rural areas of Tianjin.Methods Field epidemiological surveys were performed in 8 districts (county) of Tianjin city from 2007 to 2009.886 farmers were randomly recruited and their serum samples collected to detect the specific antibodies of R.typhi,B.henselae and O.tsutsugamushi by micro-indirect immunoflorescence (IFA).Results The total antibody positive rates of R.typhi increased from 5.0% to 58.2% while B.heaselae had an increase from 2.6% to 14.5% and O.tsutsugamushi increased from 1.8% to 39.8%.Geographic distribution showed that farmers living in the central and southeast areas were higher than that in other areas.Conclusion Infections of both R.typhi,B.henselae and O.tsutsugamushi in farmers from Tianjin areas were popular and the antibody positive rates ofR.typhi,B.henselae and O.tsutsugamushi had an annual increase.

Murine Typhus Presenting as Hemorrhagic Vesicles and Dyspnea: A case report

Murine (endemic) typhus is a zoonotic infection caused by Rickettsia typhi (formerly known as Rickettsia mooseri). Rickettsia typhi is an obligate intracellular organism that multiplies within the cytoplasm of mainly endothelial cells. It is transmitted from rats by injection of contaminated flea feces into the skin of the host. The disease manifests itself with the gradual onset of fever, myalgia, and headache appearing 7-14 days after infection. A maculopapular rash is found in some patients (proportions ranging from 20 to 80% in different series). We report a rare case of murine typhus with presentation of hemorrhagic vesicles and dyspnea which was treated at our emergency department, and we give a brief review of the literature.

Murine Typhus as a Cause of Acute Respiratory Distress Syndrome in Endemic Area / 결핵

BACKGROUND: Murine typhus is a fea-borne, worldwide Rickettsial disease caused by Rickettsia typhi. Its symptoms are typically mild byt sometimes can be fatal. The major clinical features include fever, rash, and headache. Recently, we experienced 6 cases of ARDS associated with a Rickettsia typhi infection. This study was aimed to analyze the attributing factors for fatal murine typhus and to review the characteristics of the pateints who showed acute respiratory distress syndrome as the initial presentation. METHODS: The medical records of 15 patients diagnosed as murine typhus were reviewed. The diagnosis was made by single titers of 1:512 or higher, or a 4-fold rise with compatible clinical features. Acute Respiratory Distress syndrome (ARDS) was define according to the American-European Consensus Conference. The characteristics between the ARDS group and the non-ARDS group of murine typhus were compared. RESULTS: Six patients developed ARDS as their initial presentation. Two of them were women and three of them had lived urban area. None of them a showed skin rash. One of them expired during treatment. The time lapse until the commencement of the specific treatment, the lower serum albumin level, the higher serum total bilirubin level, the higher APACHE III score and the higher MOD score were significantly associated with the ARDS group compared to the non-ARDS group. CONCLUSIONS: Murine typhus should be considered as one of the etiologies for the ARDS of unknown cause, particularly in an endemic regions. ARDS caused by Murine typhus generally has a good prognosis.

Characterization of a Species-specific Antigen in Rickettsia typhi

Murine typhus is an acute febrile illness caused by Rickettsia typhi. It is one of the four major acute febrile illnesses in Korea during autumn. To study a species-specific antigen of R. typhi, two clinical isolates (87-91 and 87-100) and two reference strains (VR-144 and VR-738) were analyzed by mouse antisera and monoclonal antibodies (MAbs). On SDS- polyacrylamide gel electrophoresis (PAGE), R. typhi showed major antigen bands of 135, 80, 75, 64, 47, 22, and 19 kDa and these bands differed with those of other species. On Western blot analysis, the MAbs reacting only with R. typhi could only detect 135 kDa protein. The 135 kDa protein appeared to be the species-specific antigen. Other MAbs showing cross-reactivity with R. prowazekii reacted with 135 kDa protein in fresh culture supernatant of R. typhi infected host cell. However, the cross-reacting antibody did also react with smaller protein bands, most of which seem to be degradation products of the 135 kDa protein since they increase in old protein stocks purified from R. typhi harvested from infected host cell. These suggest that 135 kDa protein is unstable and the R. typhi specific epitopes are located at the regions of 135 kDa protein that are removed when the protein is degraded. The 135 kDa protein or its specific and stable recombinant protein would serve an important target for the development of vaccine and specific diagnostic antigen.

A Case of Murine Typhus Acquired in a Laboratory / 감염

Rickettia typhi is an obligate intracellular organism and usually seen microscopically as gram-negative pleomorphic coccobacilli. Murine typhus is an acute febrile illness caused by R. typhi and transmitted to human by fleas. Fever, skin rash, headache, and myalgia characterize the clinical illness. The risk for laboratory personnel is from exposure to infectious aerosols, accidental inoculation, or exposure to bites by infected ectoparasites. A 27-year old man was admitted to the hospital because of fever and myalgia. He had worked with R. typhi in a laboratory and was exposed to R. typhi 10 days ago. The present illness began seven days before admission, when he developed high fever and conjunctival injection. One day before admission, he developed generalized erythematous skin rash and generalized edema. Immunofluorescence test with rickettsial antigen was positive at 1:4,096 on admission. He received 200 mg of doxycycline for 7 days and became afebrile on the third day after treatment.