Human Babesiosis, Yucatán State, Mexico, 2015.

In 2015, we detected clinical cases of babesiosis caused by Babesia microti in Yucatán State, Mexico. Cases occurred in 4 children from a small town who became ill during the same month. Diagnosis was confirmed using conventional PCR followed by sequencing of the DNA fragment obtained.

Presence of Rickettsia Species in a Marginalized Area of Yucatan, Mexico.

In the state of Yucatan, Mexico, rickettsiosis has become a common vector-borne disease in the general population. Ectoparasite species such as Rhipicephalus sanguineus and Amblyomma mixtum have been identified as Rickettsia vectors in Yucatan by studies focused on the wild animal population in rural areas. There have been studies that have tried to determine the presence of Rickettsia species in ectoparasites collected in Yucatan, but these studies did not include marginalized areas, where living in close contact with domestic and peridomestic animals that carry ectoparasites is a high-risk factor for acquiring rickettsial infection or many other vector-borne diseases. We evaluated the vector diversity and the presence of Rickettsia species presence in the ectoparasite population that parasitizes domestic animals in a marginalized rural town of Yucatan, Mexico; we also evaluated the seroprevalence of rickettsial antibodies in the human population of this town in order to determine the prevalence of rickettsial infection. A total of 437 ectoparasites were collected from the study area. The tick specimens collected belonged to the species Rhipicephalus sanguineus (n=380, 49 positive), Amblyomma mixtum (n=3, 0 positive), Ixodes affinis (n=4, 0 positive), Ctenocephalides felis (n=33, 0 positive), and Trichodectes canis (n=17, 0 positive). Conventional polymerase chain reaction and sequencing were used to identify the DNA of Rickettsia. Six out of 354 (1.8%) serum samples were positive for antibody to R. typhi. The combination of low antibody titers and the presence of Rickettsia species infecting ectoparasite species found in the study area requires eco-epidemiological studies and the identification of potentially protective practices or habits.

Serological survey of Leptospira interrogans, Toxoplasma gondii and Trypanosoma cruzi in free roaming domestic dogs and cats from a marginated rural area of Yucatan Mexico.

To evaluate the serological status for Trypanosoma cruzi, Toxoplasma gondii and Leptospira interrogans antibodies in free roaming dogs and cats from a marginated rural community in Yucatan Mexico, 100 households were visited and animals sampled. From the 106 samples, 93 were from dogs and 13 were from cats. Frequency of positive results for T. gondii, T. cruzi and Leptospira spp was 97.8%, 9.7% and 45.2% for dogs and 92.3%, 0.0% and 15.2% for cats, respectively. No associations with age, sex and body condition was found for T. gondii and Leptospira spp neither for the place where pets sleep, fumigation or presence of triatomes in the household in the case of T. cruzi. For leptospirosis the most common serovars found were Canicola, Autralis and Bratislava in dogs and cats with titres of 100 or 200 with exception of one dog with a titre of 400. The high frequency of seropositive dogs suggests a high circulation of the agents in the population of free roaming owned dogs and cats probably due to the lack of control of the reservoirs and vectors involved. Domestic animals in those rural communities can be sentinels to assess the risk of human exposure in the rural communities.

A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico.

INTRODUCTION: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. OBJECTIVE: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. METHODS: A cross sectional study on women with spontaneous abortion was conducted. Serum samples were tested for Leptospirosis by the microaglutination test, to estimate the frequency of the infecting serovar. The indirect ELISA IgM was used to detect recent infection by L. interrogans. DNA was extracted from paraffin-embedded tissue of placenta for PCR detection of L. interrogans. RESULTS: Overall frequency of infection with L. interrogans in the 81 women with abortion was 13.6%. Five of the 12 serovars evaluated were found and included. Two of the 11 women with abortion and positive to microaglutination test were also positive to the ELISA IgM test. None samples were positive for PCR Leptospira diagnosis. CONCLUSION: two women could be associated with spontaneous abortion due to leptospirosis, because they showed antibodies against L. interrogans in the microaglutination test and ELISA IgM assays. Differences between regions were found with respect to the prevalences of lesptospirosis.

INTRODUCCIÓN: Leptospirosis es una enfermedad zoonótica que afecta principalmente la población humana de bajos recursos. Infección aguda por leptospirosis durante el embarazo se ha asociado con aborto espontáneo y muerte fetal durante el primer trimestre del embarazo. OBJETIVO: Estimar la frecuencia de infección por Leptospira interrogans en mujeres con aborto espontáneo en el estado de Yucatán, México. MÉTODOS: Se efectuó un estudio transversal en 81 mujeres con aborto espontáneo. La prueba de referencia para Leptospirosis, prueba de microaglutinación, se utilizó para estimar la frecuencia de la serovar infectante. El ELISA IgM indirecto se utilizó para detectar infección reciente por L. interrogans. Se extrajo ADN a partir de tejido embebido en parafina de placenta para la detección de L. interrogans por PCR. RESULTADOS: La frecuencia global de la infección con L. interrogans en 81 mujeres con aborto, fue del 13.6%. Se encontró cinco de 12 serovares de Leptospira. Dos de las 11 mujeres con aborto espontáneo y positivo a microaglutinación también fueron positivas a la prueba ELISA IgM. Ninguna muestra fue positiva hacia el diagnóstico PCR de Leptospira. CONCLUSION: Dos mujeres podrían estar asociados con el aborto espontáneo debido a la leptospirosis, porque mostraron anticuerpos contra L. interrogans en la microaglutinación y ensayos de ELISA IgM. Diferencias entre regiones fueron encontradas con respecto a las prevalencias de leptospirosis.

A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico / Estudio transversal de leptospirosis y muerte fetal en Yucatán, México

Introduction: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. Objective: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. Methods: A cross sectional study on women with spontaneous abortion was conducted. Serum samples were tested for Leptospirosis by the microaglutination test, to estimate the frequency of the infecting serovar. The indirect ELISA IgM was used to detect recent infection by L. interrogans. DNA was extracted from paraffin-embedded tissue of placenta for PCR detection of L. interrogans. Results: Overall frequency of infection with L. interrogans in the 81 women with abortion was 13.6%. Five of the 12 serovars evaluated were found and included. Two of the 11 women with abortion and positive to microaglutination test were also positive to the ELISA IgM test. None samples were positive for PCR Leptospira diagnosis. Conclusion: two women could be associated with spontaneous abortion due to leptospirosis, because they showed antibodies against L. interrogans in the microaglutination test and ELISA IgM assays. Differences between regions were found with respect to the prevalences of lesptospirosis.

Introducción: Leptospirosis es una enfermedad zoonótica que afecta principalmente la población humana de bajos recursos. Infección aguda por leptospirosis durante el embarazo se ha asociado con aborto espontáneo y muerte fetal durante el primer trimestre del embarazo. Objetivo: Estimar la frecuencia de infección por Leptospira interrogans en mujeres con aborto espontáneo en el estado de Yucatán, México. Métodos: Se efectuó un estudio trasversal en 81 mujeres con aborto espontáneo. La prueba de referencia para Leptospirosis, prueba de microaglutinación, se utilizó para estimar la frecuencia de la serovar infectante. El ELISA IgM indirecto se utilizó para detectar infección reciente por L. interrogans. Se extrajo ADN a partir de tejido embebido en parafina de placenta para la detección de L. interrogans por PCR. Resultados: La frecuencia global de la infección con L. interrogans en 81 mujeres con aborto, fue del 13.6%. Se encontró cinco de 12 serovares de Leptospira. Dos de las 11 mujeres con aborto espontáneo y positivo a microaglutinación también fueron positivas a la prueba ELISA IgM. Ninguna muestra fue positiva hacia el diagnóstico PCR de Leptospira. Conclusion: Dos mujeres podrían estar asociados con el aborto espontáneo debido a la leptospirosis, porque mostraron anticuerpos contra L. interrogans en la microaglutinación y ensayos de ELISA IgM. Diferencias entre regiones fueron encontradas con respecto a las prevalencias de leptospirosis.

Associated Factors to Seroprevalence of Ehrlichia spp. in Dogs of Quintana Roo, Mexico.

The objective of this study was to determine the seroprevalence to Ehrlichia spp. in dogs from Xcalak, Quintana Roo, Mexico, and the associated factors. Serum samples were obtained from 118 dogs and used in an indirect immunofluorescent assay test for the detection of antibodies against Ehrlichia spp. A questionnaire was used to obtain information about possible variables associated with seroprevalence. These variables were analyzed through Chi2 test and logistic regression. Dog seroprevalence of antibodies against Ehrlichia spp. was 64% (75/118). Fifty-two percent (61/118) of dogs had tick infestation which was identified as Rhipicephalus sanguineus sensu lato. Anemia was observed in 36% of dogs. Leucopenia (2.5%), thrombocytopenia (70%), and hemorrhage (14%) were also observed. Thirty-one percent (23/75) of dogs with anemia, 4% (3/75) of dogs with leucopenia, 80% (60/75) of dogs with thrombocytopenia, 17% (13/75) of dogs with hemorrhages, and 59% (44/75) of dogs with ticks were positive for Ehrlichia spp. antibodies. The factors associated with seroprevalence were age (1-3 and >3 years old, OR = 7.77 and OR = 15.39, resp.), tick infestation (OR = 3.13), and thrombocytopenia (OR = 3.36). In conclusion, seroprevalence of Ehrlichia spp. was high in the community of Xcalak and its associated factors were age, tick infestation, and thrombocytopenia.

Rickettsia typhi in rodents and R. felis in fleas in Yucatán as a possible causal agent of undefined febrile cases.

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 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.

Rickettsia felis as emergent global threat for humans.

Rickettsia felis is an emergent pathogen belonging to transitional group rickettsiae. First described in 1990, R. felis infections have been reported to occur worldwide in fleas, mammals, and humans. Because clinical signs of the illness are similar to those of murine typhus and other febrile illnesses such as dengue, the infection in humans is likely underestimated. R. felis has been found throughout the world in several types of ectoparasites; cat fleas appear to be the most common vectors. R. felis infection should be considered an emergent threat to human health.

Rickettsia felis, the agent of an emerging infectious disease: Report of a new case in Mexico.

The fourth case of human infection with Rickettsia felis in Yucatán, Mexico was documented by serologic testing and polymerase chain reaction (PCR). The role of R. felis in human disease has been demonstrated by molecular methods in a few patients from the U.S., Yucatán, Brazil and Germany. Apparently, there is a wide spectrum in the clinical presentation of the worldwide reported cases.