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.

RESUMEN Los estudios taxonómicos sobre mosquitos se basan en la descripción morfológica de larvas y adultos. Sin embargo, son pocos los estudios enfocados en la descripción morfológica de los huevos a pesar de su valor taxonómico. La descripción de los huevos de mosquitos mediante microscopía electrónica de barrido (MEB) permite obtener imágenes más detalladas de la ornamentación del huevo, los cuales pueden proporcionar caracteres diagnósticos de la especie. El objetivo del trabajo fue describir los huevos de Psorophora cyanescens por MEB y proporcionar datos de fecundidad de la especie. En general, los huevos de Ps. cyanescens son de forma elíptica y muy anchos. El exocorión se caracteriza por un patrón de polígono, donde cada polígono consta de crestas longitudinales unidas por crestas cruzadas que definen áreas "hexagonales" regulares. Cada cresta longitudinal consiste en un pequeño tubérculo. Los pequeños tubérculos son irregulares, rectangulares, redondeados o tubulares. La ornamentación del exocorión también presenta largos tubérculos cónicos en toda la región del huevo. El aparato micropilar ubicado en la región anterior del huevo tiene un collar prominente, continuo y grueso. Psorophora cyanescens puso huevos maduros a los 2.5 días después de la alimentación sanguínea. El número promedio de huevos por hembra fue de 82.20 (± 13.31). Este es el primer estudio que describe la ultraestructura de la morfología de los huevos de Ps. cyanescens mediante MEB. Con el aporte del presente trabajo, son cinco las especies del género Psorophora que cuentan con la descripción de la morfología de los huevos mediante MEB: Ps. albigenu, Ps. albipes, Ps. columbiae, Ps. cyanescens, and Ps. ferox.

ABSTRACT Taxonomic studies on mosquitoes are based on the morphological description of larvae and adults. However, few studies have focused on the morphological description of eggs despite their taxonomic value. The description of mosquito eggs by scanning electron microscopy (SEM) allows more detailed descriptions of the ornamentation of the egg, which can provide diagnostic characters of the species. The objective of the work was to describe the eggs of Psorophora cyanescens by SEM and provide fecundity data for the species. In general, Ps. cyanescens eggs are elliptical and very wide. The exochorion is characterized by polygon pattern, where each polygon consists of longitudinal ridges joined by cross-ridges defining regular "hexagonal" areas. Each longitudinal ridge consisting by a small tubercle. The small tubercles are irregular, rectangular, rounded, or tubular. The ornamentation of the exochorion also has long and conical tubercles throughout the egg region. The micropylar apparatus located in the anterior region of the egg has a prominent, continuous and thickness collar. Psorophora cyanescens laid mature eggs at 2.5 days post-feeding. The mean number of eggs per female was 82.20 (± 13.31). This is the first study that describes the ultrastructure of the morphology of the eggs of Ps. cyanescens by SEM. With the contribution of the present work, there are five species of the genus Psorophora whose eggs morphology is described by SEM: Ps. albigenu, Ps. albipes, Ps. columbiae, Ps. cyanescens, and Ps. ferox.

ABSTRACT This study was designed to assess whether churches in endemic dengue districts in Merida, Mexico provide suitable breeding habitats for mosquitoes and are potential sites for dengue virus (DENV) transmission. Churches were inspected for immature and adult mosquitoes once every week from November 2015 to October 2016. A total of 10,997 immatures of five species were collected. The most abundant species were Aedes aegypti (6,051) and Culex quinquefasciatus (3,018). The most common source of immature Ae. aegypti were buckets followed by disposable containers. Adult collections yielded 21,226 mosquitoes of nine species. The most common species were Cx. quinquefasciatus (15,215) and Ae. aegypti (3,902). Aedes aegypti were found all year long. Female Ae. aegypti (1,380) were sorted into pools (166) and assayed for flavivirus RNA by RT-PCR and Sanger sequencing. Two pools were positive for DENV (DENV-1 and 2). In conclusion, we demonstrated that some churches in Merida are infested with mosquitoes all year long and they potentially serve as sites for DENV transmission and should therefore be considered for inclusion in mosquito and arboviruses control and surveillance efforts.

ABSTRACT Aedes aegypti is the vector of the arboviruses causing dengue, chikungunya and zika infections in Mexico. However, its presence in public places has not been fully evaluated. In a cemetery from Merida, Yucatan, Mexico, the productivity of Ae. aegypti, the gonotrophic cycle, and the presence of Ae. aegypti females infected with arboviruses were evaluated. Immature and adult mosquitoes were inspected every two months between April 2016 to June 2017. For the gonotrophic cycle length, the daily pattern of total and parous female ratio was registered and was analyzed using time series analysis. Ae. aegypti females were sorted into pools and assayed for flavivirus RNA by RT-PCR and Sanger sequencing. Aedes aegypti immatures represented 82.86% (8,627/10,411) of the collection. In total, 1,648 Ae. aegypti females were sorted into 166 pools. Two pools were positive; one for dengue virus (DENV-1) and the other for zika virus (ZIKV). The phylogenetic analysis revealed that the DENV-1 is more closely related to isolates from Brazil. While ZIKV is more closely related to the Asian lineage, which were isolates from Guatemala and Mexico. We report some evidence of vertical transmission of DENV-1 in nulliparous females of Ae. aegypti. The gonotrophic cycle was four and three days in the rainy and dry season, respectively. The cemetery of Merida is an important focus of Ae. aegypti proliferation, and these environments may play a role in arboviruses transmission; probably limiting the efficacy of attempts to suppress the presence of mosquitoes in domestic environments.