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Background: Rickettsia spp. are vector-borne zoonotic pathogens that cause febrile illness in humans. Rickettsioses is not included in the Colombian national surveillance system and is subsequently expected to be underreported. This cross-sectional study aimed to determine the seroprevalence of Rickettsia spp. and the closely related Orientia tsutsugamushi in two indigenous populations residing in the Sierra Nevada de Santa Marta, Colombia. Materials and Methods: Serum samples (n = 539) were collected from the Wiwa and Koguis people between 2021 and 2022. Serum samples were screened for spotted fever group (SFG) and typhus group (TG) Rickettsia spp. using the Fuller laboratories Rickettsia IgG IFA kit and for O. tsutsugamushi with the Scrub Typhus Detect™ IgG ELISA. Results: We observed an overall seroprevalence of 26.2% (95% confidence interval [CI] 22.5-30.1] for Rickettsia spp. of the SFG, 5.4% (95% CI 3.6-7.6) for Rickettsia spp. of the TG and 4.3% (95% CI 2.7-6.3) for O. tsutsugamushi. Common risk factors for zoonotic disease infections were assessed for 147 of the Wiwa participants. Increased odds of seropositivity for SFG Rickettsia spp. were observed for Wiwa participants who cared for livestock, including assisting with the birth of cattle (odds ratio [OR] = 8.85; 95% CI 1.54-50.90; p = 0.015) and goats (OR = 7.60; 95% CI 1.70-33.90; p = 0.008). Conclusions: These results highlight a notable exposure to Rickettsia spp., especially the SFG, in rural Colombia. Together with recent reports of high mortality for Rocky Mountain Spotted Fever in nearby regions of South America, more detailed investigations focusing on improving knowledge and awareness as well as "One Health" and "causes-of-fever" studies are needed. The characterization of Rickettsia spp. infections in humans, livestock, and tick vectors with their potential transmission routes could make a high impact on these easily treatable diseases.
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Orientia tsutsugamushi , Infecções por Rickettsia , Rickettsia , Tifo por Ácaros , Colômbia/epidemiologia , Estudos Soroepidemiológicos , Humanos , Rickettsia/isolamento & purificação , Rickettsia/imunologia , Orientia tsutsugamushi/isolamento & purificação , Orientia tsutsugamushi/imunologia , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/microbiologia , Adulto , Masculino , Pessoa de Meia-Idade , Feminino , Adolescente , Tifo por Ácaros/epidemiologia , Estudos Transversais , Adulto Jovem , Criança , Animais , Idoso , Anticorpos Antibacterianos/sangue , Pré-Escolar , Povos IndígenasRESUMO
INTRODUCCIÓN: La rickettsiosis, enfermedad potencialmente mortal, es trasmitida por vectores como Rhipicephalus sanguineus, Dermacentor variabilis y D. andersonii, reservorios de Rickettsia rickettsii. En Baja California, México, es endémica, multifactorial, tiene alta letalidad, sus manifestaciones clínicas inespecíficas y ataque multisistémico dificultan el diagnóstico y tratamiento oportuno. OBJETIVO: Identificar los factores de riesgo asociados a la letalidad por rickettsiosis trasmitida por garrapatas en Mexicali, Baja California. PACIENTES Y MÉTODOS : Estudio observacional, analítico, transversal, retrospectivo, de 40 registros de pacientes con diagnóstico confirmado de rickettsiosis, periodo 2014 a 2018. Variables analizadas: sociodemográficas, clínicas, laboratorio clínico, evolución y desenlace. Se reportan frecuencias y medidas de asociación. RESULTADOS: 24 defunciones y 16 vivos. Más de 90% tuvo contacto conocido con garrapatas. Afectó en su mayoría a < 45 años en ambos grupos. La evolución antes del ingreso fue similar y la estancia hospitalaria fue mayor en los pacientes vivos (3,2 ± 4.7 vs 10,62 ± 7,6 p = 0,0002). Fiebre, cefalea, mialgias fueron predominantes. Datos asociados con letalidad: disfunción respiratoria (OR 38,33 IC95% 4,06-361,3 p < 0,0001), creatinina elevada (OR 15,4 IC95% 3,08-76,77 p < 0,0003), retardo del llenado capilar (OR 13,0 IC95% 2,73-61,78 p = 0,0005), dolor abdominal (OR 8,33, IC95% 1,90-36,44 p = 0,0029), AST (OR 7,5, IC95% 1,69-33,27 p = 0,005). CONCLUSIÓN: Esta enfermedad requiere de identificación temprana de factores que se asocian con letalidad para un tratamiento oportuno y adecuado.
BACKGROUND: Rickettsiosis, a potentially fatal disease, is transmitted by vectors such as Rhipicephalus sanguineus, Dermacentor variabilis and D. andersonii, reservoirs of Rickettsia rickettsii. In Baja California, Mexico, it is endemic, multifactorial, has high lethality, its nonspecific clinical manifestations and multisystem attack make diagnosis and timely treatment difficult. AIM: Identify the risk factors associated with lethality due to tick-transmitted rickettsiosis in Mexicali, Baja California. METHODS: Observational, analytical, cross-sectional, retrospective study of 40 records of patients with a confirmed diagnosis of rickettsiosis, period 2014 to 2018. Analyzed variables: sociodemographic, clinical, clinical laboratory, evolution and outcome. Frequencies and association measures are reported. RESULTS: 24 patients died and 16 survived. More than 90% had reported contact with ticks. It mostly affected ≤ 45 years in both groups. The evolution before admission was similar, and the hospital stay was longer in patients who lived (3.2 ± 4.7 vs 10.62 ± 7.6 p = 0.0002). Fever, headache, and myalgia are predominant. Data associated with lethality: respiratory dysfunction (OR 38.33 95% CI 4.06-361.3 p < 0.0001), elevated creatinine (OR 15.4 95% CI 3.08-76.77 p < 0.0003), delayed capillary refill (OR 13.0, 95% CI 2.73-61.78 p = 0.0005), abdominal pain (OR 8.33, 95% CI 1.90-36.44 p = 0.0029), AST (OR 7.5, 95% CI 1.69-33.27 p = 0.005). CONCLUSION: This disease requires early identification of factors that are associated with lethality for timely and adequate treatment.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Infecções por Rickettsia/mortalidade , Doenças Transmitidas por Carrapatos/mortalidade , Rickettsia , Infecções por Rickettsia/tratamento farmacológico , Estudos Transversais , Fatores de Risco , Doenças Transmitidas por Carrapatos/tratamento farmacológico , Rickettsiose do Grupo da Febre Maculosa , México/epidemiologia , Antibacterianos/uso terapêuticoRESUMO
Spotted fever group Rickettsia spp. (SFGR) are a large group of tick-borne bacteria causing important emerging and re-emerging diseases that affect animals and humans. While SFGR are found worldwide, a lack of surveillance and misdiagnosis particularly affect South American countries. Colombia is a high burdened country in South America, yet rickettsioses are not deemed a nationally reportable condition limiting disease-specific public health resources. As mortality rates are high for one Rickettsia pathogen species, there is a great need to better understand the epidemiological and ecological factors that increase SFGR transmission risk regionally. This literature review provides an overview of Colombia-based SFGR studies connecting knowledge about both vectors and hosts.
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Multisystem Inflammatory Syndrome in Children (MIS-C) presents with fever, fatigue, elevated inflammatory markers (acute phase reactants), and a history of exposure to SARS-CoV-2 or positive antibodies to SARS-CoV-2. As the COVID-19 pandemic unfolded, the risk of MIS-C in the pediatric population increased. However, exposure to other viruses and the presence of SARS-CoV-2 positive antibodies in children hospitalized for various pathogen-associated illnesses will also remain common and may complicate differential diagnoses with diseases endemic to the region such as rickettsial diseases. The objective was to highlight the desirability of medical personnel systematically incorporating rickettsiosis as a differential diagnosis for MIS-C when studying a child with fever, non-specific symptoms, and elevated inflammatory markers. In conclusion MIS-C should be considered in children with elevated inflammatory markers when there is a history of COVID-19 and they also meet criteria that have already been established by international agencies, such as CDC and WHO.
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COVID-19/complicações , Rickettsia rickettsii , Rickettsia typhi , Síndrome de Resposta Inflamatória Sistêmica , Criança , Humanos , Criança Hospitalizada , México , Pandemias , FebreRESUMO
Abstract Multisystem Inflammatory Syndrome in Children (MIS-C) presents with fever, fatigue, elevated inflammatory markers (acute phase reactants), and a history of exposure to SARS-CoV-2 or positive antibodies to SARS-CoV-2. As the COVID-19 pandemic unfolded, the risk of MIS-C in the pediatric population increased. However, exposure to other viruses and the presence of SARS-CoV-2 positive antibodies in children hospitalized for various pathogen-associated illnesses will also remain common and may complicate differential diagnoses with diseases endemic to the region such as rickettsial diseases. The objective was to highlight the desirability of medical personnel systematically incorporating rickettsiosis as a differential diagnosis for MIS-C when studying a child with fever, non-specific symptoms, and elevated inflammatory markers. In conclusion MIS-C should be considered in children with elevated inflammatory markers when there is a history of COVID-19 and they also meet criteria that have already been established by international agencies, such as CDC and WHO
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Rickettsia parkeri belongs to the spotted fever group (SFG) of the Rickettsia genus. This bacterium causes mild rickettsiosis in humans and is mainly transmitted by Amblyomma ticks. Its medical importance is emerging in the Americas, including Mexico. Synanthropic rodents and domiciled dogs participate as accidental hosts in epidemiological cycles of Rickettsia of the SFG. The aim is to report the presence of R. parkeri in synanthropic rodents and domiciled dogs from a rural community of Yucatán, Mexico. Rodents were captured, and plasma samples were taken from dogs in 48 households from Ucú, Yucatán, Mexico. A spleen sample (rodents) and plasma (dogs) were used in the propagation of Rickettsia on Vero cells. These infected cells were used in the extraction of genomic DNA. Rickettsia DNA was identified using a semi-nested PCR (snPCR); some products were sent for sequencing. The recovered sequences were analysed with bioinformatics programs, and a phylogenetic tree was built to determine the Rickettsia species. One hundred animals were sampled: 36 synanthropic rodents and 64 dogs. The snPCR evidenced the presence of Rickettsia DNA in 10 rodents (10/36, 27.8%) and 18 dogs (18/64, 28.1%), which represents a global frequency of 28% (28/100) in this study. The bioinformatics analysis yielded homology to R. parkeri and was demonstrated in the phylogenetic tree. The first evidence of the presence of R. parkeri in synanthropic rodents (Mus musculus) from Mexico is presented; likewise, the participation of domestic dogs in the transmission cycle of this bacterium with potential importance in public health is confirmed.
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Ticks are vectors for several pathogens, including bacteria belonging to the Rickettsia genus, such as Rickettsia rickettsii and Rickettsia parkeri, the causative agents of spotted fever. The aim of the present study was to investigate the tick species richness and rickettsial agents associated with wild birds captured in the Humaita Forest Reserve, Acre, in the Western Amazon region. Wild birds were captured with ornithological nets for visual inspection with the purpose of collecting ticks, which were identified through morphological analyses and molecular tests for several genes (12S rDNA, 16S rDNA, gltA, ompA, and sca4). A total of 607 wild birds were captured, 12% of which were parasitized by 268 ticks of the Amblyomma genus, with new host-parasite associations reported for Amblyomma calcaratum, Amblyomma geayi, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, and Amblyomma varium. Of the total ticks collected, 113 were tested for the presence of rickettsial DNA fragments, with 19 testing positive for R. parkeri in A. geayi, Rickettsia tamurae-like in Amblyomma sp., and Rickettsia amblyommatis in A. geayi, A. longirostre, and Amblyomma sp. We detected R. tamurae-like in Amblyomma larvae for the first time in the Western Brazilian Amazon biome, and registered spotted fever group rickettsiae, although the relevance of the detected species in a public health context should be further explored in South America, as well as new host-parasite interactions in this underexplored region.
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Ixodidae , Rickettsia , Rickettsiose do Grupo da Febre Maculosa , Infestações por Carrapato , Carrapatos , Animais , Carrapatos/microbiologia , Ixodidae/microbiologia , Brasil/epidemiologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Infestações por Carrapato/parasitologia , Rickettsia/genética , Animais Selvagens , Rickettsiose do Grupo da Febre Maculosa/veterinária , Amblyomma/genética , Aves , DNA RibossômicoRESUMO
Fleas and ticks represent the two main groups of ectoparasites that infest companion animals. In particular, the flea Ctenocephalides felis felis and several members of the Rhipicephalus sanguineus complex are the main vectors of a wide range of pathogens on the American continent. They are competent vectors for several members of the genus Rickettsia, which encompass at least 15 pathogenic obligate intracellular bacteria that colonize the endothelial cells of vertebrates. In Mexico, 10 species of Rickettsia belonging to three groups have been detected in six species of ectoparasites from dogs in 9 of the 32 states of the country. However, in some larger regions of the country, active epidemiological surveillance has not been carried out. For this reason, the aim of this study was to identify the presence of members of the genus Rickettsia in fleas and ticks of dogs and cats in the state of Puebla, Mexico. A cross-sectional study was carried out to collect ectoparasites of dogs and cats during August to November 2019. Samples were fixed in 70% ethanol and examined to identify the presence of Rickettsia DNA by the amplification and sequencing of specific fragments of the gltA and ompB genes using conventional PCR. The recovered sequences were compared with those deposited in GenBank, and phylogenetic analyses were carried out to identify the position of the pathogens detected with respect to the valid species previously reported worldwide. Additionally, ecological parameters of the ectoparasite infestations were also calculated. We recovered 196 ectoparasites belonging to two species, 33 C. felis felis and 163 R. sanguineus s.l. (Rhipicephalus linnaei), parasitizing 46 hosts (42 dogs and 4 cats) in 11 localities of the state of Puebla. We detected the presence of Rickettsia felis in three pools of C. felis felis, and five from R. sanguineus s.l. Our work provides the first record of R. felis in hard ticks of Mexico and Central America, with new collection localities for this pathogen in central Mexico.
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Doenças do Gato , Doenças do Cão , Felis , Infestações por Pulgas , Rhipicephalus sanguineus , Rickettsia felis , Rickettsia , Sifonápteros , Animais , Gatos , Cães , Sifonápteros/microbiologia , Rickettsia felis/genética , Doenças do Gato/parasitologia , Filogenia , Estudos Transversais , Células Endoteliais , México/epidemiologia , Doenças do Cão/microbiologia , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/veterinária , Rickettsia/genéticaRESUMO
BACKGROUND & OBJECTIVES: Coexistence of tick-borne diseases in some regions in Latin America makes the diagnosis difficult due to shared initial signs and symptoms. Rickettsiosis, Lyme disease and recently, scrub typhus are gaining more importance. The objective of this study is to develop a multiplex-PCR assay for a differential diagnosis of rickettsiosis, Lyme disease and scrub typhus. METHODS: By using bibliographic and bioinformatic analysis, we identify candidate regions to perform the multiplex- PCR assay for Rickettsia sp., Borrelia burgdorferi and Orientia tsutsugamushi as well as identify optimal melting temperature and sensibility analysis. RESULTS: We identified specific primer pairs for Rickettsia sp, Borrelia burgdorferi and Orientia tsutsugamushi with different PCR fragment length but a common melting temperature, 58°C. INTERPRETATION & CONCLUSION: We successfully developed a Multiplex PCR assay for differential diagnosis of rickettsiosis, Lyme disease and scrub typhus that could be a rapid and easy option in clinical and epidemiological practice.
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Doença de Lyme , Orientia tsutsugamushi , Infecções por Rickettsia , Tifo por Ácaros , Humanos , Doença de Lyme/diagnóstico , Reação em Cadeia da Polimerase Multiplex , Orientia tsutsugamushi/genética , Tifo por Ácaros/diagnóstico , Tifo por Ácaros/microbiologiaRESUMO
Background and objectives: we investigated the existence of a historical geographic overlap between the location of spotted fever group rickettsiosis human cases, a disease caused by the gram-negative bacterium Rickettsia sp., and that of mammalian reservoirs, specifically domestic horses and capybaras, in the urban perimeter of the city of Juiz de Fora, Minas Gerais, Brazil. Methods: cases of human rickettsiosis that occurred during a period of 17 years (2003-2020) were geolocated and the distribution of cases in time and geographic space was assessed using 1st and 2nd order geospatial association indicators. We also analyzed the overlap between the locations of human rickettsiosis cases and the area of occurrence of domestic horses and capybaras. Results: men were diagnosed more often than women, but a large proportion of affected women died. The results indicate an aggregation of human rickettsiosis cases in time (cases tend to occur close to each other at each epidemic event) and in geographic space (cases are concentrated in a specific geographic region of the urban perimeter). Human cases seem to be more associated with city regions with: i) higher local frequency of domestic horses and not capybaras; ii) lower rates of family development. Conclusion: it is suggested that, in the local epidemiological scenario, domestic horses appear to be the main sources of the rickettsia infecting humans, not capybaras.(AU)
Justificativa e objetivos: foi investigada a existência de uma sobreposição geográfica histórica entre a localização dos casos de riquetsiose humana do grupo da febre maculosa, um grupo de doenças causadas pela bactéria Gram-negativa Rickettsia sp., e dos reservatórios mamíferos, especificamente cavalos domésticos e capivaras, no perímetro urbano do município de Juiz de Fora, Minas Gerais, Brasil. Métodos: foram geolocalizados os casos de riquetsiose humana ocorridos durante um período de 17 anos (2003-2020), sendo avaliada a distribuição dos casos no tempo e espaço geográfico através de indicadores de associação geoespacial de 1a e 2a ordem. Também analisamos a superposição dos locais dos casos de riquetsiose humana com a área de ocorrência de cavalos domésticos e capivaras. Resultados: homens foram diagnosticados mais frequentemente que as mulheres, mas grande proporção das mulheres acometidas faleceu. Os resultados indicam uma agregação dos casos de riquetsiose humana no tempo (os casos tendem a ocorrer próximos entre si a cada evento epidêmico) e no espaço geográfico (os casos se concentram em uma região geográfica específica do perímetro urbano). Os casos humanos aparentam ser mais associados às regiões da cidade com: i) maior frequência local de cavalos domésticos e não das capivaras; ii) menores índices de desenvolvimento familiar. Conclusão: sugere-se que, no cenário epidemiológico local, são os cavalos domésticos que aparentam ser as principais fontes da riquétsia infectando os humanos, não as capivaras.(AU)
Justificación y objetivos: investigamos la existencia de una superposición geográfica histórica entre la localización de casos de rickettsiosis exantemáticas humana, enfermedad causada por la bacteria gramnegativa Rickettsia sp., y la de mamíferos reservorios, específicamente caballos domésticos y capibaras, en el perímetro urbano de la ciudad de Juiz de Fora, Minas Gerais, Brasil. Métodos: se geolocalizaron los casos de rickettsiosis humana ocurridos durante un período de 17 años (2003-2020), y se evaluó la distribución de casos en el tiempo y espacio geográfico utilizando indicadores de asociación geoespacial de 1er y 2do orden. También analizamos la superposición entre las ubicaciones de los casos de rickettsiosis humana y el área de ocurrencia de los caballos domésticos y capibaras. Resultados: los hombres fueron diagnosticados con más frecuencia que las mujeres, pero una gran proporción de mujeres afectadas fallecieron. Los resultados indican una agregación de casos de rickettsiosis humana en el tiempo (los casos tienden a ocurrir cerca uno del otro en cada evento epidémico) y en el espacio geográfico (los casos se concentran en una región geográfica específica del perímetro urbano). Los casos humanos parecen estar más asociados con regiones urbanas con: i) mayor frecuencia local de caballos domésticos y no de capibaras; ii) menores tasas de desarrollo familiar. Conclusión: se sugiere que, en el escenario epidemiológico local, los caballos domésticos parecen ser las principales fuentes de la rickettsia que infecta a los humanos, no los capibaras.(AU)
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Infecções por Rickettsia , Febre Maculosa das Montanhas Rochosas , Rickettsiose do Grupo da Febre Maculosa , Localização Geográfica de RiscoRESUMO
Of the documented tick-borne diseases infecting humans in México, Rocky Mountain spotted fever (RMSF), caused by the Gram-negative bacterium Rickettsia rickettsii, is responsible for most fatalities. Given recent evidence of brown dog tick, Rhipicephalus sanguineus s.l., as an emerging vector of human RMSF, we aimed to evaluate dogs and their ticks for rickettsiae infections as an initial step in assessing the establishment of this pathosystem in a poorly studied region of northeastern México while evaluating the use of dogs as sentinels for transmission/human disease risk. We sampled owned dogs living in six disadvantaged neighborhoods of Reynosa, northeastern México to collect whole blood and ticks. Of 168 dogs assessed, tick infestation prevalence was 53%, composed of exclusively Rh. sanguineus s. l. (n = 2170 ticks). Using PCR and sequencing, we identified an overall rickettsiae infection prevalence of 4.1% (n = 12/292) in ticks, in which eight dogs harbored at least one infected tick. Rickettsiae infections included Rickettsia amblyommatis and Rickettsia parkeri, both of which are emerging human pathogens, as well as Candidatus Rickettsia andeanae. This is the first documentation of pathogenic Rickettsia species in Rh. sanguineus s.l. collected from dogs from northeastern México. Domestic dog infestation with Rickettsia-infected ticks indicates ongoing transmission; thus, humans are at risk for exposure, and this underscores the importance of public and veterinary health surveillance for these pathogens.
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Doenças do Cão , Rhipicephalus sanguineus , Rickettsia , Infestações por Carrapato , Animais , Doenças do Cão/epidemiologia , Cães , Humanos , México/epidemiologia , Rhipicephalus sanguineus/microbiologia , Rickettsia/genética , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterináriaRESUMO
La rickettsia es una bacteria transmitida por vectores como la garrapata, piojos, ácaros entre otros. El ser humano es un hospedero accidental, la rickettsia se transmite al ser humano por medio de la saliva de la garrapata infectada inoculando la bacteria a la piel. Existen diferentes especies de rickettsia, la especie más importante en América es la Rickettsia rickettsii, reportándose casos en diferentes partes del mundo. Esta enfermedad se caracteriza por un daño al endotelio de los vasos sanguíneos de pequeño calibre, ocasionando lesiones en piel, a nivel pulmonar, cerebral y renal principalmente. Sus manifestaciones clínicas iniciales son inespecíficas y se pueden confundir con otras enfermedades por lo cual una historia clínica detallada es lo que nos puede llevar a una sospecha diagnóstica temprana. Esta patología se considera una enfermedad reemergente, debido a que en muchos lugares existe un subregistro de la misma, esto como resultado de una falta de sospecha clínica y aplicación de medidas de prevención. En Panamá desde los años 1950 se diagnosticaron los primeros casos. En este año en curso (2021), se diagnosticaron dos casos pediátricos en el Hospital del Niño Dr. José Renan Esquivel, los cuales serán objetos de revisión en este artículo.
Rickettsia are bacteria transmitted by vectors such as ticks, lice, mites. The human being is an accidental host, the rickettsia is transmitted to the human being through the saliva of the infected tick inoculating the bacteria to the skin. There are different species of Rickettsia, the most important species in America is Rickettsia rickettsii. This disease is characterized by damage to the endothelium of small caliber blood vessels, causing lesions mainly in the skin, lung, brain, and kidney. Its initial clinical manifestations are nonspecific and can be confused with other diseases, which is why a detailed clinical history is what can lead us to an early diagnostic. This disease is considered a reemerging disease in spite of having a wide distribution and knowledge of the disease due to lack of suspicion and prevention. In Panama, the first cases were diagnosed in the 1950s and this year 2021 two cases were diagnosed in children at the Hospital del Niño Dr. José Renán Esquivel.
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Human tick-borne rickettsioses are caused by Rickettsia africae, Rickettsia massiliae, Rickettsia parkeri, Rickettsia philipi and Rickettsia rickettsii in the American continent. Rickettsia parkeri represents the second most important agent of eschar-associated spotted fever throughout the American continent. In Mexico, the presence of three strains of this bacterium (Black Gap, Maculatum and Atlantic Rainforest) has recently been reported in four species of ticks from five states (Baja California, Campeche, Sonora, Tabasco and Veracruz) and rickettsaemia was demonstrated in a dog from the state of Yucatán. We report two human cases of R. parkeri-rickettsiosis from Yucatan, Mexico. These findings have increased the interest in R. parkeri surveillance in the human population, due to the fluctuating regional Spotted Fever morbidity and mortality in the country.
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Doenças do Cão , Ixodidae , Infecções por Rickettsia , Rickettsia , Rickettsiose do Grupo da Febre Maculosa , Animais , Cães , Humanos , México/epidemiologia , Rickettsia/genética , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/microbiologia , Infecções por Rickettsia/veterinária , Rickettsiose do Grupo da Febre Maculosa/epidemiologia , Rickettsiose do Grupo da Febre Maculosa/veterinária , Estados UnidosRESUMO
We report a human case of rickettsiosis caused by Rickettsia parkeri strain Atlantic Rainforest in Mexico in an adult woman from a small town in the north of Yucatan, Mexico. We confirmed diagnosis using conventional PCR and sequence analysis. Health providers should be aware of clinical manifestations of rickettsioses in this region.
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Ixodidae , Infecções por Rickettsia , Rickettsia , Adulto , Animais , Feminino , Humanos , Ixodidae/microbiologia , México , Reação em Cadeia da Polimerase , Rickettsia/genética , Infecções por Rickettsia/diagnóstico , Infecções por Rickettsia/microbiologiaRESUMO
There is a lack of studies regarding tick-associated Rickettsia in the Amazon biome. Aiming to contribute to this knowledge, our research group collected ticks in the Western Amazon to better understand the tick fauna and their associated Rickettsia. In this study, we detected Rickettsia parkeri strain Atlantic rainforest DNA in the tick Amblyomma ovale Koch, 1844 in Rio Branco municipality, Acre state, northern Brazil. This is the first time that the R. parkeri strain Atlantic rainforest has been reported in the Amazon biome and is the first evidence of the circulation of a pathogenic spotted fever group (SFG) Rickettsia in this biome. This finding provides substantial information to help public health authorities understand which species of Rickettsia may be related to Amazon spotted fever cases.
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Ixodidae , Rickettsia , Amblyomma , Animais , Brasil/epidemiologia , Ecossistema , Ixodidae/microbiologia , Floresta Úmida , Rickettsia/genéticaRESUMO
ABSTRACT Spotted fever (SF) is a tick-borne zoonosis caused by bacteria of the genus Rickettsia . The disease varies in severity from mild clinical forms to severe cases. In Brazil, Rickettsia rickettsii SF is the most serious rickettsiosis and can result in death if not diagnosed and treated at the onset of symptoms. The SF mild form is caused by Rickettsia parkeri strain Atlantic Rainforest, and this etiological agent has been reported in the South, Southeast and Northeast regions of the country, in areas of preserved or little antropized Atlantic Rainforest. Amblyomma ovale is the proven vector and dogs are the hosts associated with the bioagent cycle. During a SF case investigation in Paraty municipality, Rio de Janeiro State, an Atlantic Rainforest biome area in Southeastern Brazil, the human pathogen R. parkeri strain Atlantic Rainforest was detected by PCR in a sample of human skin inoculation eschar and in a female A. ovale tick collected from a dog. These results expand the known area of occurrence of this mild form rickettsiosis in Brazil. In addition, the results of the present study indicate the importance of implementing programs to control canine ectoparasites and to raise awareness of the risks of infection, signs and symptoms of SF caused by R. parkeri strain Atlantic Rainforest.
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Regional differences in tick-borne disease epidemiology may be related to biological variations between vector populations. Amblyomma aureolatum (Ixodida: Ixodidae), a neotropical tick, is known from several regions in Brazil. However, only in the metropolitan area of São Paulo (SP) state are there studies that establish its role as a vector of a pathogenic rickettsia (Rickettsia rickettsii). The aim of the study was to analyze the genetic diversity, population dynamics, and rickettsia infection in A. aureolatum populations from different spotted fever scenarios in Brazil. Samples were subjected to DNA extraction, amplification and sequencing of 12S rDNA, cytochrome oxidase subunit II and D-loop mitochondrial markers for tick population analyses, and gltA, htrA, ompA, and ompB genes for rickettsia researches. Of the 7-17 tick haplotypes identified, 5-13 were exclusive to each population and 2-12 for each epidemiological scenario, as well as three haplotypes shared by all populations. Amblyomma aureolatum populations are expanding, and do not appear to be genetically structured vis-a-vis the different epidemiological scenarios studied. Rickettsia bellii (in SP) and Rickettsia felis (in Santa Catarina) were identified as infecting A. aureolatum. No relationship between tick haplotypes and rickettsia types were observed.
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Rickettsioses are distributed among a variety of hematophagous arthropods, and represent an emergent threat. The presence of rickettsial bacteria in ectoparasites collected from pigs from Argentina is still unknown. This study investigated the presence and identity of Rickettsia spp. in fleas, Pulex irritans, and sucking lice, Haematopinus suis, of domestic and feral pigs, Sus scrofa, from Central-Northern Argentina, through the genes gltA and ompB. Rickettsial bacteria were detected in 50% of fleas and 24% of lice. The BLASTn analysis of the ompB gene fragments in P. irritans samples showed identities 99% and 100% with R. felis. Positive samples of H. suis were 99% similar with species from the spotted fever group, future amplifications of a more polymorphic fragment of the ompB gene will allow to corroborate the identity of the Rickettsia species present in these lice samples. The Rickettsia spp. reported in the present study are having eventually been associated with cases of human diseases, and the circulation of these agents in arthropods has already been reported in several countries. Therefore, the identification of circulating pathogenic agents, such as reported in this study, is crucial for development of preventive measures for the control of ectoparasite-borne rickettsiosis diseases. Further studies, using serology techniques, will be allow to explore the ability of pigs as a possible Rickettsia reservoir and its role as part of transmission cycle of Rickettsia spp. in the studied scenarios.
Assuntos
Anoplura , Rickettsia , Sifonápteros , Animais , Anoplura/microbiologia , Argentina , Rickettsia/genética , Sifonápteros/microbiologia , Sus scrofa , SuínosRESUMO
INTRODUCCIÓN: Las rickettsiosis son enfermedades emergentes transmitidas por vectores artrópodos cuyos agentes etiológicos corresponden a bacterias patógenas del género Rickettsia y Orientia . Bacterias de este género han sido descritas en el norte y sur de Chile. OBJETIVO: Determinar presencia de Rickettsia spp. en garrapatas colectadas a partir de perros domésticos en Rapa Nui-Isla de Pascua, Región de Valparaíso. MÉTODOS: Fueron muestreados 20 perros callejeros durante octubre del año 2018. Se colectaron ocho garrapatas adultas desde siete animales (prevalencia: 35%); luego de su identificación taxonómica fueron sometidas a amplificación y secuenciación del gen ADNm 16S para garrapata y gltA (citrato sintetasa) para Rickettsia . RESULTADOS: Todos los ejemplares de garrapatas adultas correspondieron genéticamente a Rhipicephalus sanguineus sensu stricto lo cual fue confirmado mediante un análisis filogenético. En dos garrapatas (25%) se encontraron secuencias idénticas de gltA compatibles con " Candidatus Rickettsia andeanae", que formaron un clado monofilético con aislados obtenidos en Brasil, Chile y Perú. CONCLUSIÓN: Se documenta la presencia de " Ca. R. andeanae" s. s. en Rapa Nui-Isla de Pascua, asociado por primera vez a garrapatas del complejo R. sanguineus en Chile.
BACKGROUND: Rickettsioses are vector-borne emerging diseases caused by pathogenic bacteria of the genera Rickettsia and Orientia . Bacteria of these genera have been described in northern and southern Chile, respectively. AIM: To determine the presence of Rickettsia spp. in ticks collected from domestic dog in Rapa Nui-Easter Island, Valparaíso Region. METHODS: 20 stray dogs were sampled during October 2018. Overall, eight adult ticks were collected from seven animals (prevalence: 35%); after morphological identification, were submitted to DNA extraction and amplification and sequencing of the tick mitochondrial 16S DNA gene. The screening for Rickettsia was performed targeting the gltA (citrate synthetase) gene. RESULTS: A phylogenetic analysis confirmed the identity of the ticks as Rhipicephalus sanguineus sensu stricto. In two ticks (25%), we retrieved identical sequences of gltA compatible with " Candidatus Rickettsia andeanae", which formed a monophyletic group with conspecific isolates obtained in Brazil, Chile and Peru. CONCLUSION: This study proves the presence of " Ca . R. andeanae" in R. sanguineus s. s. at Rapa Nui-Easter Island, which also corresponds to the first report of this Rickettsia spp. in R. sanguineus complex for Chile.
Assuntos
Animais , Cães , Rickettsia/genética , Infecções por Rickettsia/veterinária , Rhipicephalus sanguineus/microbiologia , Doenças do Cão , FilogeniaRESUMO
Rickettsia parkeri rickettsiosis is recognized as the second most prevalent tick-borne disease caused by spotted fever group rickettsiae in the Americas, where two pathogenic strains (R. parkeri sensu stricto and R. parkeri strain Atlantic rainforest) have been related to human infections and transmitted by Amblyomma spp. ticks. We developed a systematic review that evaluated all available evidence in the literature regarding clinical, epidemiological, and laboratory features of R. parkeri rickettsiosis, including confirmed and probable cases. We followed the recommendations made by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guide. We excluded papers that contained missing information of some variables and publications in which it was not possible to separate data for confirmed and probable cases. A total of 77 clinical cases (32 confirmed cases and 45 probable cases) were considered for this review. Overall, our results show that R. parkeri rickettsiosis is more frequent in males in the age group of 18-64 years and that a history of tick exposure was frequent (>90%). Cases were described in the United States, Argentina, Brazil, Uruguay and Colombia. Clinically, more than 60% of the cases had fever (mean of 93%), eschar (mean of 87%), and rash (mean of 68%). Headache and myalgia were predominant nonspecific symptoms (mean of 67% and 61%, respectively). Our results show that at least 60% of R. parkeri cases had altered laboratory parameters, most often showing an increase in transaminases and leukopenia. Tetracyclines-class antibiotics were used in most (>85%) of the patients. Overall, only 9% of cases required hospitalization and there was a 100% rate of clinical recovery in all of cases.