Impacto indirecto de COVID-19 en las tasas de incidencia de enfermedades transmitidas por vector en México / Indirect impact of COVID-19 on the incidence rates of vector-borne diseases in Mexico

Resumen Introducción: La distribución espacial y temporal de la infección por SARS-CoV-2 sobrepasa las áreas endémicas de enfermedades transmitidas por vector (ETV), cuya vigilancia en México ha cambiado sustancialmente a partir del primer caso confirmado de COVID-19. Objetivos: Estimar y comparar las tasas de incidencia de las ETV antes y después de la introducción del SARS-CoV-2 en México. Métodos: Estudio retrospectivo de casos de ETV de 2014 a 2021. Las tasas de incidencia de cada ETV en el periodo previo (2014-2019) y posterior (2020-2021) a la introducción del SARS-CoV-2 en México fueron calculadas y comparadas. Resultados: Antes de la introducción del SARS-CoV-2, las tasas de incidencia de las ETV fueron altas y posterior a la introducción del coronavirus hubo un descenso en los índices epidemiológicos; sin embargo, solo se identificó diferencia estadística significativa en la tasa de incidencia de la malaria (p ≤ 0.05) y otras rickettsias (p ≤ 0.05). Conclusiones: Algunas medidas para reducir los casos de COVID-19, como el distanciamiento social, el confinamiento domiciliario, la reducción en el aforo en el transporte público y el trabajo en casa, probablemente contribuyeron a disminuir temporalmente el número de casos de las ETV; sin embargo, puede haber rebrote de las ETV en el futuro cercano.

Abstract Introduction: SARS-CoV-2 infection spatial and temporal distribution overlaps with endemic areas of vector-borne diseases (VBD), whose surveillance in Mexico has substantially changed since the first COVID-19 confirmed case. Objectives: To estimate and compare the incidence rates of VBDs before and after the introduction of SARS-CoV-2 in Mexico. Methods: Retrospective study of VBD cases from 2014 to 2021. The incidence rates of each VBD in the period before (2014-2019) and after (2020-2021) the introduction of SARS-CoV-2 in Mexico were calculated and compared. Results: Before the introduction of SARS-CoV-2, the incidence rates of VBDs were high and after the introduction of coronavirus there was a decrease in epidemiological indices; however, there was only statistically significant difference in the incidence rate of malaria (p ≤ 0.05) and other rickettsiae (p ≤ 0.05). Conclusions: Some measures to reduce COVID-19 cases, such as social distancing, home confinement, reductions in public transport and working at home (home office), probably temporarily decreased the number of VBD cases; however, there may be a resurgence of VBDs in the near future.

Toxoplasmosis i Mexico: epidemiological situation in humans and animals / Toxoplasmosis en México: situación epidemiológica en humanos y animales

Toxoplasmosis is a parasitic disease widely distributed throughout the world, infecting a wide variety of animal species including humans. In Mexico, this parasite has been detected in different parts of the country, particularly in the tropical areas where the parasite can remain infective for long periods of time due to the environmental conditions (i.e. high temperature and humidity over the whole year). Several epidemiological studies have been conducted in both human and animal populations, but despite the wide distribution of the agent in the country, there is a significant lack of knowledge on the parasite transmission, treatment alternatives and control measures. The lack of feral cat populations and control measures in sites of meat production for human consumption are playing a role that has led to the wide spread of the disease in the country, particularly in tropical areas of Southeastern Mexico. For these reasons, this manuscript aims to review the published information on relevant epidemiological aspects of infection with T. gondii in humans and animals from Mexico.

La toxoplasmosis es una enfermedad parasitaria ampliamente distribuida en todo el mundo y puede infectar a una gran diversidad de especies animales y a los humanos. En México, esta parasitosis ha sido detectada en diferentes partes del país, en particular en las zonas tropicales en donde debido a las condiciones ambientales (ej. alta temperatura y humedad a lo largo todo el año), el parásito puede mantenerse infectante por largos períodos de tiempo en el medio ambiente. Se han realizado diversos estudios epidemiológicos tanto en poblaciones humanas como en animales y se observa que a pesar de la amplia distribución y buen establecimiento del agente en el país, existe un importante desconocimiento desde la epidemiologia, tratamientos alternativos o las medidas de control. La falta de control de las poblaciones ferales de felinos así como el establecimiento de medidas de control en unidades de producción de carne de diferentes especies para consumo humano están jugando un papel primordial que ha favorecido la amplia diseminación de la enfermedad en el país, principalmente en las zonas tropicales del sureste mexicano. Por lo que este manuscrito tiene como objetivo revisar la información publicada hasta ahora que nos describe aspectos epidemiológicos relevantes de la infección por T. gondii en humanos y animales de México.

American trypanosomiasis and associated risk factors in owned dogs from the major city of Yucatan, Mexico

Background The American trypanosomiasis is a zoonosis caused by the protozoaTrypanosoma cruzi (T. cruzi). The disease is widely distributed throughout the American continent, affecting a wide range of hosts, including dogs. It is present in the canine population in the State of Yucatan, Mexico. However, no significant studies in owned dogs have been performed in the metropolitan area of Merida. A transversal study was conducted in 370 owned dogs from Merida, Yucatan, Mexico.Methods A cross-sectional study including 370 dogs was performed in a major city of Yucatan, Mexico, to detect IgG antibodies against T. cruzi. A commercial ELISA test kit was used and a chi-square test used to evaluate associated risk factors; odds ratio (OR) and 95 % confidence interval (CI) were also estimated.Results The indirect ELISA and western blot (WB) tests were used to detect specific immunoglobulin G antibodies against T. cruzi in serum samples. A prevalence of 12.2 % was found; age and area of residence were statistically associated with seropositivity in dogs (p<0.05).Conclusions Results from the present study suggests the presence and abundance of the vector in urban conditions where a high number of seropositive cases ofT. cruzi cases were found.(AU)

American trypanosomiasis and associated risk factors in owned dogs from the major city of Yucatan, Mexico

Background The American trypanosomiasis is a zoonosis caused by the protozoaTrypanosoma cruzi (T. cruzi). The disease is widely distributed throughout the American continent, affecting a wide range of hosts, including dogs. It is present in the canine population in the State of Yucatan, Mexico. However, no significant studies in owned dogs have been performed in the metropolitan area of Merida. A transversal study was conducted in 370 owned dogs from Merida, Yucatan, Mexico.Methods A cross-sectional study including 370 dogs was performed in a major city of Yucatan, Mexico, to detect IgG antibodies against T. cruzi. A commercial ELISA test kit was used and a chi-square test used to evaluate associated risk factors; odds ratio (OR) and 95 % confidence interval (CI) were also estimated.Results The indirect ELISA and western blot (WB) tests were used to detect specific immunoglobulin G antibodies against T. cruzi in serum samples. A prevalence of 12.2 % was found; age and area of residence were statistically associated with seropositivity in dogs (p 0.05).Conclusions Results from the present study suggests the presence and abundance of the vector in urban conditions where a high number of seropositive cases ofT. cruzi cases were found.

Importancia de la caracterización de cepas de Trypanosoma cruzi / The importance of the characterisation of Trypanosoma cruzi strains

El trypanosoma cruzi (T. cruzi) es un protozoario hemoflagelado, considerado el agente causal de la enfermedad de Chagas y es transmitido a los hospederos mamíferos por medio de insectos vectores del género Triatoma. El T. cruzi presenta un pleomorfismo natural, al cual se ha atribuido a la diferencia de severidad con que se presenta la enfermedad en el hospedero humano y otros mamíferos. Considerando este aspecto han sido varios los trabajos sobre caracterización de cepas de T. cruzi, abarcando aspectos biológicos, bioquímicos y moleculares para poder establecer un método de clasificación de las diferentes cepas de dicho parásito, de manera que las cepas que pertenezcan a un mismo grupo compartan estos aspectos y así una cepa pudiera ser representativa de ese grupo, simplificando los estudios a realizar. Esta revisión pretende dar un panorama de los diferentes métodos de caracterización de la cepas T. cruzi, para tratar de agruparlas para su mejor estudio y control