Influenza‐like illness sentinel surveillance in one hospital in Medellin, Colombia. 2007–2012

Abstract

BackgroundThe city of Medellin in Colombia has almost no documentation of the causes of acute respiratory infections (ARIs). As part of an ongoing collaboration, we conducted an epidemiologic surveillance for influenza and other respiratory viruses. It described the influenza strains that were circulating in the region along with their distribution over time, and performing molecular characterization to some of those strains. This will contribute to the knowledge of local and national epidemiology.ObjectivesTo analyze viral etiologic agents associated with influenza like illness (ILI) in participants reporting to one General hospital in Medelllin, Colombia.ResultsFrom January 2007 to December 2012, a total of 2039 participants were enrolled. Among them, 1120 (54·9%) were male and 1364 (69%) were under the age of five. Only 124 (6%) were older than the age of 15. From all 2039 participants, 1040 samples were diagnosed by either isolation or RT-PCR. One or more respiratory viruses were found in 737 (36%) participants. Of those, 426 (57·8%) got influenza A or B. Adenoviral and parainfluenza infections represented 19·1% and 14·9% of viral infections, respectively. Influenza A was detected almost throughout the whole year except for the first quarter of 2010, right after the 2009 influenza A pandemic. Influenza B was detected in 2008, 2010, and 2012 with no pattern detected. During 2008 and 2010, both types circulated in about the same proportion. Unusually, in many months of 2012, the proportion of influenza B infections was higher than influenza A (ranging between 30% and 42%). The higher proportion of adenovirus was mainly detected in the last quarter of years 2007 and 2010. Adenoviral cases are more frequent in participants under the age of four.ConclusionsThe phylogenetic analysis of influenza viruses shows that only in the case of influenza A/H1N1, the circulating strains totally coincide with the vaccine strains each year.

Epidemiology of respiratory infections among adults in Qatar (2012-2017)

“…For instance, 43% positivity rate was reported from 2,031 ILI cases in Philippines (ASIA) [15], 41.7% from a total of 580 cases in Italy (EUROPE) [16], and 42.6% out of 6,835 cases in Peru (SOUTH AMERICA) [17]. Relatively lower rates were reported in Colombia (36% in 2039 individuals) [9] and in China (34.6% of 5805 subjects) [18]. Conversely, few other reports showed higher frequencies reaching to 61% in Cameron [3], 61.8% in Brazil [10], and 75.1% in Madagascar [8].…”

“…Importantly, accurate data on the incidence and epidemiological distribution of respiratory viruses is significant to the general public health, and have important implication on disease prevention and control. Thus, national surveillance systems for influenza and ILIs have been implemented in several countries [8][9][10].…”

Epidemiological and Virological Characteristics of Influenza in Chongqing, China, 2011-2015

“…However, ILI cases were highest among children aged < 5 years old. This phenomenon could be explained by the fact that besides influenza virus, other pathogens, such as rhinoviruses, respiratory syncytial viruses (RSV), and enteroviruses, might be more likely to infect small children aged < 5 years [9, 20–22]. Thus, more respiratory viral etiologies should be tested in the surveillance system in future, especially among children < 5 years.…”

Viral etiologies of influenza‐like illness and severe acute respiratory infections in Thailand

“…been limited before avian influenza reemerged in the late 1990s. 3 However, generally only 6%-21% of respiratory infections are associated with influenza viruses in the tropics, [4][5][6][7] leaving a significant number of infections for which the etiology is unknown.…”