Associations between seasonal influenza and meteorological parameters in Costa Rica, Honduras and Nicaragua

Abstract

Seasonal influenza affects a considerable proportion of the global population each year. We assessed the association between subnational influenza activity and temperature, specific humidity and rainfall in three Central America countries, i.e. Costa Rica, Honduras and Nicaragua. Using virologic data from each country's national influenza centre, rainfall from the Tropical Rainfall Measuring Mission and air temperature and specific humidity data from the Global Land Data Assimilation System, we applied logistic regression methods for each of the five sub-national locations studied. Influenza activity was represented by the weekly proportion of respiratory specimens that tested positive for influenza. The models were adjusted for the potentially confounding co-circulating respiratory viruses, seasonality and previous weeks' influenza activity. We found that influenza activity was proportionally associated (P<0.05) with specific humidity in all locations [odds ratio (OR) 1.21-1.56 per g/kg], while associations with temperature (OR 0.69-0.81 per °C) and rainfall (OR 1.01-1.06 per mm/day) were location-dependent. Among the meteorological parameters, specific humidity had the highest contribution (~3-15%) to the model in all but one location. As model validation, we estimated influenza activity for periods, in which the data was not used in training the models. The correlation coefficients between the estimates and the observed were ≤0.1 in 2 locations and between 0.6-0.86 in three others. In conclusion, our study revealed a proportional association between influenza activity and specific humidity in selected areas from the three Central America countries.

Space-time epidemiology and effect of meteorological parameters on influenza-like illness in Phitsanulok, a northern province in Thailand

“…Pearson's correlation coefficient between meteorological parameters and number of ILI cases showed different significance levels (Table 3). We are in agreement that higher humidity has positive relation (directly proportional) to the number of ILI cases (Soebiyanto et al, 2015;Tang et al, 2010). Additionally, humidity had a highly significant correlation with the number of ILI 1 month later, possibly due to increasing humidity decreases immunity to the disease and thus increasing virus survival (Tamerius et al, 2013).…”

“…As often observed in temperate regions (Viboud et al, 2006;Soebiyanto et al, 2015), respiratory viruses have an inverse association with lower temperatures. Besides higher humidity, lower temperatures may also facilitate survival and transmission of respiratory pathogens as showed by Lowen et al (2007).…”

“…Recent epidemiological modelling has greatly improved our knowledge of viral evolution and the related complex antigenic evolution, but there is also a need to understand the spatio-temporal aspects of the vectorborne respiratory diseases (Nelson and Holmes, 2007;Soebiyanto et al, 2015). Furthermore, in a series of monitored influenza studies with special reference to ILI viruses, it is stressed that ILI spatio-temporal dynamics must be clarified within the broader aspect of respiratory infections (Bollaerts et al, 2013).…”

Influence of meteorological parameters in the seasonality of influenza viruses circulating in Northern Cameroon

“…Previous reports from tropical regions particularly in Bangladesh, Guatemala, El Salvador, and Panama also revealed a proportional association between influenza and humidity [ 2,9,20 ]. Since airborne transmission is unlikely in these circumstances, transmission of influenza probably occurs through contact and droplet modes . On the other hand, none of the variables could explain influenza B activity.…”

Spatial and Temporal Spread of Acute Viral Respiratory Infections in Young Children Living in High-altitude Rural Communities

“…Previous studies have described temperature, rainfall, and humidity with respect to ARI and recognize the importance of meteorological and environmental parameters 21,22 . To assess the influence of temperature and rainfall, we compared average temperatures and rainfall among the corresponding viral respiratory seasons included in our study.…”