Etiological characterization of acute undifferentiated febrile illness in Apartadó and Villeta municipalities, Colombia, during COVID-19 pandemic.

Background: Acute undifferentiated febrile illness (AUFI) is one of the leading causes of illness in tropical regions. Although malaria is the most important cause, other pathogens such as Dengue (DENV), Leptospira and recently, Coronavirus Disease 2019 (COVID-19) have gained importance. In Colombia, few studies aimed to identify the etiology of AUFI. Most of them performed in Apartadó and Villeta municipalities, identifying the active circulation of several pathogens. Thus, we conducted a cross-sectional study in these municipalities to characterize the etiologies of AUFI during COVID-19 pandemic. Methods: An active surveillance was conducted between September and December 2021 in local hospitals of Apartadó and Villeta municipalities. Febrile patients were enrolled after voluntarily agreeing to participate in the study. Ten different etiologies were evaluated through direct, serological, molecular and rapid diagnostic methods. Results: In Apartadó a confirmed etiology was found in 60% of subjects, DENV (25%) being the most frequent, followed by leptospirosis (16.7%), malaria (10%), COVID-19 (8.3%), spotted fever group (SFG) rickettsiosis (6.7%) and Chikungunya (1.7%). In Villeta, a specific etiology was confirmed in 55.4% of patients, of which SFG rickettsiosis (39.3%) was the most frequent, followed by leptospirosis (21.4%), DENV (3.6%) and malaria (1.8%). No cases due to Mayaro, Yellow Fever, Oropouche and Venezuelan Equine Encephalitis viruses were detected. Conclusion: We confirm the relevance of dengue fever, leptospirosis, SFG rickettsiosis, COVID-19 and malaria as causes of AUFI in the municipality of Apartadó, and highlight the great importance of SFG rickettsiosis as the main cause of AUFI in the municipality of Villeta.

Natural SARS-CoV- 2 infection in domestic cats and dogs of humans diagnosed with COVID-19 in Valle de Aburrá, Antioquia / Infección natural por SARS-CoV-2 en gatos y perros domésticos de personas con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia

Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARSCoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. OBJETIVO: Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. RESULTADOS: De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. CONCLUSIONES: Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión  zoonótica o entre especie.

Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARSCoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. Objetivo. Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. Resultados. De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. Conclusiones. Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión zoonótica o entre especie.

Infección natural por SARS-CoV-2 en gatos y perros domésticos de personas con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia / Natural SARS-CoV- 2 infection in domestic cats and dogs of humans diagnosed with COVID-19 in Valle de Aburrá, Antioquia

Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARS-CoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. Objetivo. Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. Resultados. De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. Conclusiones. Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión zoonótica o entre especie.

Introduction: The severe acute respiratory syndrome caused by the new coronavirus SARS-CoV-2 is the cause of the health emergency due to the COVID-19 pandemic. Although humans are the main susceptible host, experimental studies and reported cases of natural infection have evidenced scenarios of SARS-CoV-2 reverse zoonosis in animals. Objective: To evaluate the natural infection of SARS-CoV-2 in cats and dogs with owners diagnosed with COVID-19 in the Valle de Aburrá subregion in Antioquia, Colombia. Materials and methods. The circulation of SARS-CoV-2 was evaluated by RT-qPCR and RT-PCR in samples of nasopharyngeal and oropharyngeal smears from cats and dogs whose owners presented latent COVID-19 infection. Positive cases were verified through amplification of N, E and RdRp gene fragments; with the latter being sequenced and the phylogenetically analyzed. Results. From 80 tested animals, 6 cats and 3 dogs resulted positive for natural SARS-CoV-2 infection. These animals did not show any clinical signs; and their infected owners only reported mild signs of COVID-19, without clinical complications. Regarding analysis of one of the sequences, a single nucleotide polymorphism (SNP) was found, with a substitution in position 647, resulting in the change of the amino acid serine (S) for isoleucine (I). The cases occurred in the municipalities of Caldas, Medellín and Envigado. Conclusions. It is inferred that natural infection in cats and dogs is associated with direct contact with a positive COVID-19 patient.

Prevalence of Ehrlichia canis and Hepatozoon canis in sheltered dogs in southern Aburrá Valley, Colombia

Background: Bacteria of the Anaplasmataceae family and canine hemoparasitic protozoans transmitted by ticks are common in Colombia due to circulation and biological adaptation of vector Rhipicephalus sanguineus sensu lato (s.l.). Objective: To detect the circulation of Ehrlichia canis and Hepatozoon canis in sheltered dogs in three municipalities in southern Aburrá Valley, province of Antioquia, Colombia. Methods: Primers were used to amplify the 16S rRNA associated with the Anaplasmataceae family, dsb for Ehrlichia sp. and 18S rRNA for Hepatozoon sp. Results: Of the 357 samples of venous blood obtained, representing all the sheltered dogs in the study zone, Ehrlichia canis DNA was detected in 2.2% of individuals, showing identity of 100% with previous sequences from the GenBank. Hepatozoon canis showed 8.7% (31/357) prevalence of infection, with 100% identity to genotypes from Japan, Brazil, and Spain. Only one sequence of H. canis exhibited a phylogenic divergence concerning H. canis previously reported in Brazil and the Old World. Conclusions: This study confirms the circulation of E. canis and H. canis in asymptomatic shelter dogs in the south-central zone of the Aburrá Valley, province of Antioquia, Colombia. The present study is the first molecular detection of H. canis in the Province of Antioquia and the third report of canine hepatozoonosis from Colombia, highlighting the importance of considering this agent in veterinary clinic.

Antecedentes: Los agentes patógenos transmitidos por garrapatas, tales como las bacterias de la familia Anaplasmataceae y los protozoos hemoparasitarios caninos, son comunes en Colombia debido a la circulación y la adaptación biológica del vector Rhipicephalus sanguineus sensu lato (s.l.). Objetivo: Detectar la circulación de Ehrlichia canis y Hepatozoon canis en perros protegidos en tres municipios del sur del Valle de Aburrá, departamento de Antioquia, Colombia. Métodos: Se usaron cebadores para amplificar el gen 16S rRNA asociado con la familia Anaplasmataceae y el gen dsb para Ehrlichia sp. y el 18S rRNA para Hepatozoon sp. Resultados: De las 357 muestras de sangre venosa obtenidas, que representan a todos los perros de albergues en la zona de estudio, 2,2% fueron positivas para Ehrlichia canis, con 100% de identidad con secuencias anteriores publicadas en todo el mundo. Hepatozoon canis mostró una prevalencia de infección del 8,7% (31/357), con una identidad del 100% con genotipos de Japón, Brasil y España. Solo una secuencia de H. canis exhibió divergencia filogénica en relación con H. canis previamente reportada en Brasil y el Viejo Mundo. Conclusiones: Este estudio confirma la circulación de E. canis y H. canis en perros asintomáticos de albergues en la zona centro-sur del Valle de Aburrá, departamento de Antioquia, Colombia. El presente estudio es la primera detección molecular en el Departamento de Antioquia y el tercer reporte de hepatozoonosis canina de Colombia destacando la importancia de considerar este agente en la clínica veterinaria.

Antecedentes: Agentes patogênicos transmitidos por carrapatos, como bactérias da família Anaplasmataceae e protozoários hemoparasitários caninos, são comuns na Colômbia devido à circulação e adaptação biológica do vetor Rhipicephalus sanguineus sensu lato (s.l.). Objetivo: Detectar Ehrlichia canis e Hepatozoon canis em cães abrigados em três municípios do sul do vale de Aburrá, departamento de Antioquia, Colômbia. Métodos: Os primers foram utilizados para amplificar o rRNA 16S associado à família Anaplasmataceae, o dsb para Ehrlichia sp. e o rRNA 18S para Hepatozoon sp. Resultados: Das 357 amostras de sangue venoso obtidas, representando todos os cães abrigados na zona de estudo, 2,2% foram positivas para Ehrlichia canis, com 100% de identidade com sequências anteriores publicadas em todo o mundo. Hepatozoon canis mostrou uma prevalência de infecção de 8,7% (31/357), com 100% de identidade com genótipos do Japão, Brasil e Espanha. Apenas uma sequência de H. canis apresentou divergência filogênica em relação a H. canis previamente relatados no Brasil e no Velho Mundo. Conclusões: Este estudo confirma a circulação de E. canis e H. canis em cães de abrigo assintomáticos na zona centro-sul do vale de Aburrá, departamento de Antioquia, Colômbia. O presente estudo é a primeira detecção molecular no Departamento de Antioquia e o terceiro relato de hepatozoonose canina na Colômbia, destacando a importância de considerar este agente na clínica veterinária.

An updated review and current challenges of Guanarito virus infection, Venezuelan hemorrhagic fever.

Guanarito virus (GTOV) is a member of the family Arenaviridae and has been designated a category A bioterrorism agent by the US Centers for Disease Control and Prevention. It is endemic to Venezuela's western region, and it is the etiological agent of "Venezuelan hemorrhagic fever" (VHF). Similar to other arenaviral hemorrhagic fevers, VHF is characterized by fever, mild hemorrhagic signs, nonspecific symptoms, thrombocytopenia, and leukopenia. Patients with severe disease usually develop signs of internal bleeding. Due to the absence of reference laboratories that can handle GTOV in endemic areas, diagnosis is primarily clinical and epidemiological. No antiviral therapies are available; thus, treatment includes only supportive analgesia and fluids. GTOV is transmitted by contact with the excreta of its rodent reservoir, Zygodontomys brevicauda. The main reasons for the emergence of the disease may be the increase in the human population, migration, and changes in land use patterns in rural areas. Social and environmental changes could make VHF an important cause of underdiagnosed acute febrile illnesses in regions near the endemic areas. Although there is evidence that GTOV circulates among rodents in different Venezuelan states, VHF cases have only been reported in the states of Portuguesa and Barinas. However, due to the increased frequency of invasions by humans into wildlife habitats, it is probable that VHF could become a public health problem in the nearby regions of Colombia and Brazil. The current Venezuelan political crisis is causing an increase in the migration of people and livestock, representing a risk for the redistribution and re-emergence of infectious diseases.

Seroepidemiology of Sarcocystis neurona and Neospora spp. in horses, donkeys, and mules from Colombia.

Sarcocystis neurona and Neospora spp. are related protozoa that can cause equine protozoal myeloencephalitis (EPM). The present study aimed to determine the frequency of antibodies to these parasites in 649 equids (351 horses, 267 donkeys, and 31 mules) from six departments in the North and Northwest of Colombia. For this purpose, the indirect fluorescent antibody test (IFAT) was used for detecting antibodies against S. neurona and Neospora spp. with a cut-off point of 1:20 and 1:50, respectively. A binomial logistic regression model was selected to predict variables associated with exposure. The frequency of anti-S. neurona antibodies was 14.24% (95% CI: 10.84-18.44) for horses, 2.99% (95% CI: 1.39-6.04) for donkeys, and 16.13% (95% CI: 6.09-34.47) for mules. The risk for S. neurona infection was significantly lower in donkeys (OR: 0.18 [0.08-0.38]; p<0.001) than horses and mules, and higher in animals with a poor body condition (OR: 2.82 [1.45-6.05]; p<0.05). Additionally, older animals (>12y) had a higher risk of seropositivity (OR: 5.26 [1.88-19.1]; p<0.05), as well as animals that inhabit climatic conditions associated with tropical very dry forest (OR: 1.85 [1.01-3.51]; p<0.05). Córdoba and Antioquia departments presented the highest seropositivity to S. neurona with 13.01 and 8.3%, respectively. The frequency of anti-Neospora spp. antibodies was 1.42% (95% CI: 0.52-3.48) for horses, 1.12% (95% CI:0.29-3.52) for donkeys and 0% (95%, CI: 0-0) for mules. Atlántico was the state with the highest seropositivity to Neospora spp. (10%). No risks associated with Neospora spp. infection were found. These findings allow us to conclude that equids from these regions of Colombia are exposed to S. neurona, but antibodies to Neospora spp. are uncommon. Further studies are necessary to explore the presence of these two agents in other areas of the country. In addition, we need to prove the importance of the above-mentioned risk factors over the susceptibility of horses to these protozoal agents and the epidemiological impact of these underdiagnosed coccidia.

Detection of tick-borne rickettsial pathogens in naturally infected dogs and dog-associated ticks in Medellin, Colombia.

Tick-borne rickettsial pathogens (TBRP) are important causes of infections in both dogs and humans. Dogs play an important role as a biological host for several tick species and can serve as sentinels for rickettsial infections. Our aim was to determine the presence of TBRP in dogs and in dog-associated ticks and their potential risk to human diseases in Medellin, Colombia. DNA for E. canis (16S rRNA and dsb) and A. platys (groEl) was detected in 17.6% (53/300) and 2.6% (8/300) of dogs, respectively. Antibodies against Ehrlichia spp. 82 (27.3%) and Anaplasma spp. 8 (2.6%) were detected in dogs. Antibody reactivity against both agents were found in 16 dogs (5.3%). Eight dogs showed antibody for Rickettsia spp. with titers that suggest 3 of them had a probable exposure to R. parkeri. Rhipicephalus sanguineus s.l. (178/193) was the main tick in dogs, followed by R. microplus (15/193). The minimum infection rates (MIR) in R. sanguineus were 11.8% for E. canis and 3.4% for A. platys. E. canis and A. platys are the main TBRP infecting dogs and ticks and R. sanguineus s.l. is likely involved in the transmission of both agents. Interestingly, we found serological evidence of exposure in dogs for spotted fever group rickettsiae.

Hard ticks (Acari: Ixodidae) from Colombia, a review to its knowledge in the country / Garrapatas duras (acari: ixodidae) de colombia, una revisión a su conocimiento en el país

RESUMEN Las garrapatas son artrópodos de gran impacto sobre la economía pecuaria y la salud humana debido a las pérdidas generadas en la producción, y a su capacidad de transmitir microorganismos. Pese a la evidencia de circulación de una gran diversidad de garrapatas en Colombia, no se cuenta con compilaciones actualizadas de la variedad de especies presentes, por lo cual los autores presentan una revisión de literatura sobre las garrapatas de la familia Ixodidae reportadas en Colombia incluyendo su distribución geográfica, sus hospederos y los microorganismos reportados en aquellas especies registradas en este país. En la recopilación se evidenció la presencia en Colombia de diferentes especies de garrapatas de los géneros Amblyomma, Ixodes, Haemaphysalis, Rhipicephalus y Dermacentor. El género con mayor variedad fue Amblyomma con 29 especies, seguido de Ixodes con 11 especies, y de los géneros Dermacentor, Haemaphysalis y Rhipicephalus se reportaron dos especies para cada uno. Las especies se distribuyeron en la mayoría de los departamentos de Colombia y en una amplia diversidad de hospederos entre los cuales se incluyen animales domésticos, sinantrópicos y silvestres. Adicionalmente se encontró que algunas garrapatas reportadas podrían jugar un papel como vectores potenciales de diversos microorganismos que pueden afectar a la salud publica y veterinaria. Esperamos que este trabajo sea un aporte para apoyar la investigación en garrapatas y el estudio de los agentes transmitidos por estas en Colombia.

ABSTRACT Ticks are arthropods with significant impact on the economy of livestock and public health, due to losses generated in production, and their ability to transmit microorganisms. Despite the evidence of circulation of different tick species in the country, there are no updates concerning the variety of existing species, therefore, the authors of this manuscript offer a literature review on ticks from the Ixodidae family reported in Colombia including their geographical distribution, their hosts and the microorganisms they carry and might transmit in Colombia. In this manuscript, we described the presence in the country of different species of ticks of the genera Amblyomma, Ixodes, Haemaphysalis, Rhipicephalus, and Dermacentor. The genus with the greatest variety was Amblyomma with 29 species, followed by Ixodes with 11 species, and of the genus Dermacentor, Haemaphysalis and Rhipicephalus two species were reported for each. These species are distributed in most departments and a wide variety of hosts, including domestic, synanthropic and wild animals. Additionally, it was found that some reported ticks could play a role as potential vectors of various microorganisms that could affect public and veterinary health. We expect that this work will be a contribution to support tick research and the study of tick-borne agents in Colombia.

Seroprevalence of arenavirus and hantavirus in indigenous populations from the Caribbean, Colombia

Abstract INTRODUCTION: In Colombia, there is insufficient epidemiological surveillance of zoonotic hemorrhagic viruses. METHODS: We performed a sero-epidemiological study in indigenous populations of Wayuü, Kankuamos, and Tuchin communities using Maciel hantavirus and Junin arenavirus antigens for IgG detection by ELISA. RESULTS IgG antibodies to hantavirus and arenavirus were found in 5/506 (1%) and 2/506 (0.4%) serum samples, respectively. CONCLUSIONS: Arenavirus and hantavirus circulate in indigenous populations from the Colombian Caribbean region, and the results indicate that the indigenous populations are exposed to these zoonotic agents, with unknown consequences on their health, despite low seroprevalence.

Detection of tick-borne rickettsial pathogens in naturally infected dogs and dog-associated ticks in Medellin, Colombia / Detecção de patógenos rickettsiais transmitidos por carrapatos em cães naturalmente infectados e carrapatos associados a cães em Medellin, Colômbia

Abstract Tick-borne rickettsial pathogens (TBRP) are important causes of infections in both dogs and humans. Dogs play an important role as a biological host for several tick species and can serve as sentinels for rickettsial infections. Our aim was to determine the presence of TBRP in dogs and in dog-associated ticks and their potential risk to human diseases in Medellin, Colombia. DNA for E. canis (16S rRNA and dsb) and A. platys (groEl) was detected in 17.6% (53/300) and 2.6% (8/300) of dogs, respectively. Antibodies against Ehrlichia spp. 82 (27.3%) and Anaplasma spp. 8 (2.6%) were detected in dogs. Antibody reactivity against both agents were found in 16 dogs (5.3%). Eight dogs showed antibody for Rickettsia spp. with titers that suggest 3 of them had a probable exposure to R. parkeri. Rhipicephalus sanguineus s.l. (178/193) was the main tick in dogs, followed by R. microplus (15/193). The minimum infection rates (MIR) in R. sanguineus were 11.8% for E. canis and 3.4% for A. platys. E. canis and A. platys are the main TBRP infecting dogs and ticks and R. sanguineus s.l. is likely involved in the transmission of both agents. Interestingly, we found serological evidence of exposure in dogs for spotted fever group rickettsiae.

Resumo As riquétsias transmitidas por carrapatos (RTC) são causas importantes de infecção em cães e humanos. Os cães exercem um papel essencial como hospedeiros biológicos para diversas espécies de carrapatos, assim como podem ser úteis como sentinelas de infecções por riquétsias. O intuito deste estudo foi determinar a presença de RTC em cães, assim como em seus carrapatos, para determinar o risco potencial de doença humana em Medellín, Colômbia. DNA de Ehrlichia canis (16S rRNA e dsb) e Anaplasma platys (groEl) foi detectado em 17,6% (53/300) e 2,6% (8/300) dos cães, respectivamente. Anticorpos contra Ehrlichia spp. (82; 27,3%) e Anaplasma spp. (8; 2,6%) foram detectados nos cães. Reatividade de anticorpos contra ambos patógenos (Ehrlichia e Anaplasma) foi detectada em 16 cães (5,3%). Oito animais apresentaram anticorpos contra Rickettsia spp., e 3 deles sugerem uma provável exposição a Rickettsia parkeri. Rhipicephalus sanguineus s.l. (178/193) foi a principal espécie de carrapatos, seguida de R. microplus (15/193). A taxa de infecção mínima em R. sanguineus foi 11,8% para E. canis e 3,4% para A. platys. E. canis e A. platys são as principais RTC que infectam cãese R. sanguineus s.l. provavelmente está envolvido na transmissão de ambos os agentes. É evidente, porém, a exposição sorológica dos cães a riquétsias do grupo da febre maculosa.

Seroprevalence of arenavirus and hantavirus in indigenous populations from the Caribbean, Colombia.

INTRODUCTION: In Colombia, there is insufficient epidemiological surveillance of zoonotic hemorrhagic viruses. METHODS: We performed a sero-epidemiological study in indigenous populations of Wayuü, Kankuamos, and Tuchin communities using Maciel hantavirus and Junin arenavirus antigens for IgG detection by ELISA. RESULTS: IgG antibodies to hantavirus and arenavirus were found in 5/506 (1%) and 2/506 (0.4%) serum samples, respectively. CONCLUSIONS: Arenavirus and hantavirus circulate in indigenous populations from the Colombian Caribbean region, and the results indicate that the indigenous populations are exposed to these zoonotic agents, with unknown consequences on their health, despite low seroprevalence.

Epidemiological characterization of incident cases of Rickettsia infection in rural areas of Urabá region, Colombia.

INTRODUCTION: Most of the studies related to rickettsial infection in Colombia are cross-sectional because of the challenge in conducting prospective studies on infectious disease that may have a difficult diagnosis. Although cross-sectional studies are essential to detect people exposed to rickettsiae, they are not suited to demonstrate the recent circulation of this pathogen in areas at risk of transmission. OBJECTIVE: To characterize the epidemiology of incident cases of Spotted fever group (SFG) rickettsial infection in humans and equines from rural areas of Urabá region in Colombia where outbreaks of rickettsiae previously occurred. MATERIALS AND METHODS: A prospective study was conducted in the Alto de Mulatos and Las Changas in the Urabá region. Serum samples and socio-ecological information were collected from 597 people enrolled in 2015, and a second sample was collected from 273 people a year later. Indirect immune-fluorescence assays for detection of IgG antibody against rickettsiae were done using slides with Rickettsia rickettsii antigens. A titer ≥128 was considered positive. Incident cases were defined as (i) serological conversion of IgG titers from seronegative to seropositive or (ii) at least a four-fold increase in IgG end point titers in the second sample. RESULTS: The cumulative incidence of rickettsial infection was 6.23% (95%CI 3.67-9.78) in humans and 32.31% (21/65) of incident cases in equines. Incident cases were mostly females (82.35%), the median age of cases was 41.02 years (IQR 18.62-54.1), and 29.41% reported tick bites during the study period. Results from multivariate analysis showed that removal of ticks after working outdoors is a protective factor for rickettsial infection (RR 0.26, 95%CI 0.08-0.84) and that a higher incidence of infection occurred in people who reported fever in the last year (RR 4.26, 95%CI 1.15-9.31). CONCLUSIONS: These results showed recent circulation of SFG rickettsiae in areas where previous lethal outbreaks have been reported, supporting the implementation of preventive measures to halt rickettsial transmission in the studied communities.

Development of a serosurveillance assay for detection of Necoclí virus exposure.

Hantavirus cardiopulmonary syndrome (HPS) has gained importance in Latin America as an emerging disease, with reports of about 4000 HPS cases; however, this is probably an underestimate because of limited surveillance programs and diagnostic tools to confirm HPS. In order to address this issue and develop better serosurveillance capability, we evaluated three recombinant peptides from the Necoclí virus (NECV) nucleocapsid in antibody-capture ELISA. We cloned and expressed antigens representing the whole NECV nucleocapsid protein (NECV-rN), the immunodominant domain (NECV-rN100), and a serospecific domain (NECV-rN428), and then we compared these antigens in ELISA to detect IgG antibodies to NECV in human sera. We evaluated human sera collected during two epidemiological studies from the area where NECV was discovered. The first group included 609 sera from healthy individuals, and the second one included 89 samples from patients with undifferentiated febrile illness. In these two groups, hantavirus infection had previously been determined by the presence of IgG to Maciel virus (MCLV), a hantavirus closely related to NECV. The number of IgG-positive sera was higher using the Necoclí ELISA with the rN100 protein, which detected antibodies in a higher percentage of healthy individuals, 129/609 (21.2%), as well as in febrile patients, 11/89 (12.3%). In contrast, using MCLV ELISA, 8 of 609 (1.3%) and 4 of 89 (4.5%) samples from healthy and febrile patients, respectively, were seropositive. The agreement between the NECV and MCLV ELISA assays was ≥ 82.3%; however, the kappa indices were weak but statistically significant for rN (0.251 CI; 0.138-0.365) and rN100rN (0.153 CI; 0.084-0.223). The weak kappa indices were attributed to decreased MCLV ELISA assay sensitivity. These results suggest that NECV rN and rN100 have increased specificity and could be further validated for improved diagnosis of hantavirus infections.

Enfermedades virales transmitidas por garrapatas / Tick-borne viruses and their diseases

RESUMEN Los virus transmitidos por garrapatas (VTG) pertenecen a las familias Flaviviridae, Bunyaviridae, Reoviridae, Asfarviridae y Orthomyxoviridae y son agentes causales de diferentes enfermedades en humanos y animales. Debido a la creciente importancia epidemiológica que están teniendo los VTG, esta revisión pretende englobar el conocimiento actual de estos agentes y las enfermedades que producen, así como exponer las estrategias abordadas en prevención y tratamiento que se han implementado hasta el momento en diferentes países. Es evidente que para la región Neotropical hacen falta estudios sobre los VTG presentes en la región, ya que la gran mayoría de los artículos, tanto revisiones de tema como trabajos originales, presentan datos de las regiones Neártica y Paleártica. Considerando el panorama actual de los estudios de VTG en la región Neotropical y las particularidades de la misma, es muy probable que existan otros VTG aún no identificados que podrían tener algún impacto en salud pública.

SUMMARY Tick-borne viruses (TBVs) belong to the Flaviviridae, Bunyaviridae, Reoviridae, Asfarviridae and Orthomyxoviridae families and cause different diseases in humans and animals. Due to the epidemiologic relevance of TBVs, this review highlights the actual knowledge of these agents and the diseases they cause, besides of the prevention and treatment strategies implemented so far. It is evident that studies that address the TBVs present in the Neotropical region are missing, since most of the studies, both reviews and original articles, present data from the Nearctic and Palearctic regions. Considering the current picture of the TBVs studies in the Neotropical area and its peculiarities, is probable that other not yet identified TBVs exist in this zone and have an impact in public health.

An Approach to the Identification and Phylogenetic Analysis of Emerging and Hemorrhagic Fever Viruses.

An important aspect of virological surveillance is the identification of the detected viruses. Broad surveillance, that typically employs deep sequencing of collected tissue samples, provides the investigator with many sequence files constructed from overlapping stretches of DNA sequences. Directed surveillance for viruses of a specific taxonomic group provides the investigator with sequence files from cDNA amplified using specific primers to conserved viral regions. Here we will describe general approaches to identify hemorrhagic viral agents through phylogenetic analysis of cDNA sequences obtained during surveillance activities.

Epidemiological Surveillance of Viral Hemorrhagic Fevers With Emphasis on Clinical Virology.

This article will outline surveillance approaches for viral hemorrhagic fevers. Specific methods for surveillance of clinical samples will be emphasized. Separate articles will describe methods for surveillance of rodent-borne viruses (roboviruses) and arthropod-borne viruses (arboviruses). Since the appearance of hantaviruses and arenaviruses in the Americas, more than 30 different species in each group have been established, and therefore they have become the most frequently emerging viruses. Flaviviruses such as yellow fever and dengue viruses, although easier to recognize, are also more widely spread and therefore considered a very important public health issue, particularly for under-developed countries. On the other hand, marburgviruses and ebolaviruses, previously thought to be restricted to the African continent, have recently been shown to be more global. For many of these agents virus isolation has been a challenging task: trapping the specific vectors (mosquitoes and ticks), and reservoirs (rodents and bats), or obtaining the samples from suspected clinical human cases demands special protective gear, uncommon devices (respirators), special facilities (BSL-3 and 4), and particular skills to recognize the slow and inapparent cytopathic effects in cell culture. Alternatively, serological and molecular approaches have been very helpful in discovering and describing newly emerging viruses in many areas where the previous resources are unavailable. Unfortunately, in many cases, detailed studies have been performed only after outbreaks occur, and then active surveillance is needed to prevent viral dissemination in human populations.

Sampling Design and Mosquito Trapping for Surveillance of Arboviral Activity.

Mosquitoes are the most important vectors for arboviral human diseases across the world. Diseases such as Dengue Fever (DF), West Nile Virus (WNV), Yellow Fever (YF), Japanese Encephalitis (JE), Venezuelan Equine Encephalitis (VEE), and St. Louis Encephalitis (SLE), among others, have a deep impact in public health. Usually mosquitoes acquire the arboviral infection when they feed on viremic animals (birds or mammals), so their infection can be detected along the year or in short periods of time (seasons). All of this depends on the frequency and seasonality of the encounters between viremic animals and vectors.With the convergence of several phenomena like the increasing traveling of human populations, globalization of economy and more recently the global warming, the introduction of nonendemic arbovirus into new areas has become the current scenario. As examples of this new social and environmental frame we can mention the outbreak of West Nile Virus in North America in the late 1990s and more recently the outbreaks of chikungunya and Zika virus in the Americas. The present chapter deals with one of the first steps in the development of research studies and diagnosis programs, the surveillance of arboviruses in their vectors, the sampling design and mosquito trapping methods. The chapter also includes some important considerations and tips to be taken into account during the mosquito fieldwork.

Epidemiological Surveillance of Rodent-Borne Viruses (Roboviruses).

This article will outline surveillance approaches for rodent-borne viruses (roboviruses). We present a synopsis of the main categories of trapping methods with some notes about their use in fieldwork. We also describe the types of laboratory analysis commonly used in Robovirus surveillance.

A Primate Model for Viral Hemorrhagic Fever.

Lymphocytic choriomeningitis virus strain WE (LCMV-WE), a Risk Group 3 virus, causes a disease in rhesus monkeys that closely resembles human infection with Lassa fever virus, a Risk Group 4 agent. Three stages of disease progression have been defined and profiled in this model: pre-viremic, viremic, and terminal. The earliest or pre-viremic stage reveals changes in the blood profile predictive of the later stages of disease. In order to identify whether specific changes are pathognomonic, it was necessary to perform a parallel infection with an attenuated virus (LCMV-Armstrong). Here we review the use of nonhuman primates to model viral hemorrhagic fever and offer a step-by-step guide to using a rhesus macaque model for Lassa fever.

Comprehensive Genome Scale Phylogenetic Study Provides New Insights on the Global Expansion of Chikungunya Virus.

Since the India and Indian Ocean outbreaks of 2005 and 2006, the global distribution of chikungunya virus (CHIKV) and the locations of epidemics have dramatically shifted. First, the Indian Ocean lineage (IOL) caused sustained epidemics in India and has radiated to many other countries. Second, the Asian lineage has caused frequent outbreaks in the Pacific islands and in 2013 was introduced into the Caribbean, followed by rapid spread to nearly all of the neotropics. Further, CHIKV epidemics, as well as exported cases, have been reported in central Africa after a long period of perceived silence. To understand these changes and to anticipate the future of the virus, the exact distribution, genetic diversity, transmission routes, and future epidemic potential of CHIKV require further assessment. To do so, we conducted the most comprehensive phylogenetic analysis to date, examined CHIKV evolution and transmission, and explored distinct genetic factors associated with the emergence of the East/Central/South African (ECSA) lineage, the IOL, and the Asian lineage. Our results reveal contrasting evolutionary patterns among the lineages, with growing genetic diversities observed in each, and suggest that CHIKV will continue to be a major public health threat with the potential for further emergence and spread. IMPORTANCE: Chikungunya fever is a reemerging infectious disease that is transmitted by Aedes mosquitoes and causes severe health and economic burdens in affected populations. Since the unprecedented Indian Ocean and Indian subcontinent outbreaks of 2005 and 2006, CHIKV has further expanded its geographic range, including to the Americas in 2013. Its evolution and transmission during and following these epidemics, as well as the recent evolution and spread of other lineages, require optimal assessment. Using newly obtained genome sequences, we provide a comprehensive update of the global distribution of CHIKV genetic diversity and analyze factors associated with recent outbreaks. These results provide a solid foundation for future evolutionary studies of CHIKV that can elucidate emergence mechanisms and also may help to predict future epidemics.