La influenza es una enfermedad infecciosa que se caracteriza por cuadros de fiebre alta y malestar general. Desde la pandemia originada en México en 2009 por el virus de influenza A(H1N1)pdm09, este virus ha estado circulando hasta la actualidad, afectando a miles de personas en todo el país cada temporada. Durante la pandemia de COVID-19, y debido al aumento de las medidas de prevención, los casos reportados por influenza en las temporadas anteriores a 2023 fueron menores, sin embargo, hasta enero de 2024, la influenza había tenido un aumento en los casos a nivel internacional, siendo el subtipo predominante el A(H1N1). Debido al potencial pandémico de este virus, se mantiene bajo vigilancia de las autoridades sanitarias, quienes monitorean su comportamiento entre temporadas, sin embargo, está en nuestras manos promover su prevención mediante la vacunación.

Human interaction with natural ecosystems, such as deforestation and animal markets, increases the risk of the emergence of new zoonotic viruses. Added to this is the constant mutation of already existing viruses, such as influenza, which can trigger new epidemics. Additionally, climate change alters animal migration patterns, thus facilitating the spread of infectious diseases. Among the recent outbreaks of viral respiratory diseases, the most notable are COVID-19 (SARS-CoV-2), which emerged in 2019 in Wuhan, China; the H1N1 swine influenza pandemic, which appeared in 2009 in Mexico; and avian flu, caused by the AH5N1 and AH7N9 influenza viruses, recorded since 1997 with limited transmission from birds to humans. Other outbreaks include AH3N2 and AH5N6, which have emerged since 2016, causing isolated cases with symptoms like seasonal influenza. Furthermore, within the other coronavirus family, notable mentions include MERS, which appeared in 2012 in Saudi Arabia, and SARS, which emerged in 2002 in China. In general, these respiratory diseases share similar symptoms, ranging from fever and cough to severe pneumonia, making their diagnosis and epidemiological monitoring challenging. For this reason, this chapter will thoroughly address the molecular diagnosis of respiratory diseases as a key tool for the identification and clinical management of these infections.

Aging is commonly accompanied by increased cardiovascular risk and diet plays a crucial role in health condition. The aim of this study was to determine cardiovascular risk factors as predictors of nutritional risk in Mexican older adults. A cross-sectional study on Mexican patients aged ≥60 years with cardiovascular risk factors affiliated with a medical unit in Northeast Mexico was performed from July to December 2021. The nutritional risk evaluations were performed using the Mini Nutritional Assessment (MNA) questionnaire. After a multivariate analysis, the cardiovascular risk factors identified as independent predictors of risk of malnutrition were hypertriglyceridemia (adjusted OR (AOR): 1.8; 95% CI: 1.03–3.14; p = 0.04) and systolic hypertension I (AOR: 2.28; 95% CI: 1.04–5.02; p = 0.041); age over 80 years (AOR: 5.17; 95% CI: 1.83–14.65, p = 0.002) and elementary school education (AOR: 2.34; 95% CI: 1.20–4.55; p = 0.013) were also related. The cross-sectional design and single-center approach of this study limits the generalizability of the results; however, conducting timely evaluations of blood pressure, triglyceride levels, and risk of malnutrition using the MNA tool for patients aged ≥60 years could prevent illness and reduce mortality within this population group.

The Mexican Social Security Institute registered a significant number of suspected Zika virus (ZIKV) cases during the 2016–2018 outbreak. This study aims to describe the distribution of confirmed ZIKV cases, their correlation with rainfall and temperature, and associated factors with infection or hospitalization, considering pregnancy. A retrospective analysis was performed on 13,259 suspected ZIKV cases. Binary logistic regression was performed to determine potentially associated factors with infection or hospitalization. Correlations between positive cases and environmental factors were analyzed using the Pearson correlation and an autoregressive integrated moving average (ARIMA) test. Female sex and age > 30 were associated with ZIKV infection when excluding pregnant women. In pregnant women, a higher infection rate in the first and second trimesters compared to third trimester was observed. In Veracruz, rainfall correlated with positive cases in 2016 (n = 5; r = 0.9977, p < 0.001) and 2017 (n = 12; r = 0.7467, p = 0.005) correlated with rainfall only in 2017 (r = 0.7975, p = 0.002); this was not significant with the ARIMA analysis. Further research is suggested to elucidate factors involved in the transmission, pathogenicity and epidemiology of this and other vector-borne disease viruse.