Burden of influenza in Latin America and the Caribbean: a systematic review and meta‐analysis

Abstract

Please cite this paper as: Savy et al. (2012) Burden of influenza in Latin America and the Caribbean: a systematic review and meta‐analysis. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12036. Objective Influenza causes severe morbidity and mortality. This systematic review aimed to assess the incidence, etiology, and resource usage for influenza in Latin America and the Caribbean. Design Meta‐analytic systematic review. Arcsine transformations and DerSimonian Laird random effects model were used for meta‐analyses. Setting A literature search from 1980 to 2008 in MEDLINE, Cochrane Library, EMBASE, LILACS, Ministries of Health, PAHO, proceedings, reference lists, and consulting experts. Sample We identified 1092 references, of which 31 were finally included, in addition to influenza surveillance reports. We also used information from the 10 reports from the collaborative group for epidemiological surveillance of influenza and other respiratory virus (GROG), and information retrieved from the WHO global flu database FLUNET. Main outcome measures Incidence, percentage of influenza specimens out of the total received by influenza centers and resource‐use outcomes. Results A total of 483 130 specimens of patients with influenza were analyzed. Meta‐analysis showed an annual rate of 36 080 (95%CI 28 550 43 610) influenza‐like illness per 100 000 persons‐years. The percentage of influenza out of total specimens received by influenza centers ranged between 4.66% and 15.42%, with type A the most prevalent, and A subtype H3 predominating. The mean length of stay at hospital due to influenza ranged between 5.8 12.9 days, total workdays lost due to influenza‐like illnesses were 17 150 days, and the mean direct cost of hospitalization was US$575 per laboratory‐confirmed influenza case. Conclusions Our data show that seasonal influenza imposes a high morbidity and economic burden to the region. However, the vaccine‐uptake rate has been low in this region. Population‐based cohort studies are required to improve the knowledge about incidence and resource utilization, which would inform healthcare authorities for decision making.

Estimation of influenza and severe acute respiratory illness incidence (burden) in three provinces of the Islamic Republic of Iran, 2012 and 2013

“…The selected provinces, Western Azerbaijan, Alborz and Hamedan, are all located in north-western and western mountainous parts of the country, with mainly cold weather during at least 7-8 months of the year All three provinces have comparable altitude and weather conditions (Table 1), both of which affect influenza virus activity and seasonality. According to the WHO manual, the data collected were of appropriate quality (influenza case finding was expected to be around 10-20% of SARI cases during the cold seasons) (5,(8)(9)(10) and the definitions of ILI and SARI cases had been followed.…”

Patterns of influenza B circulation in Brazil and its relevance to seasonal vaccine composition

“…In the Latin America and Caribbean region, seasonal influenza causes high morbidity placing a substantial economic burden on healthcare systems and society. 12 Data on the burden of influenza disease for Brazil are limited, most likely due to underreporting. 12 Between 2000 and 2008, data from the influenza surveillance system in Brazil revealed that influenza-like illness (ILI) led to a total of 4.39-16.92% of hospital consultations, and in 2008, of all positive reported influenza cases, 43.29% (95% CI: 37.59-49.13) were influenza B.…”

Hacia un mejor control de la influenza mediante la vacunación

“…Un meta-análisis de 31 artículos publicados en el período 1980-2008 reveló que la influenza B fue identificada en solamente 14% de los casos de ETI y en 21% de los casos de hospitalizaciones 35 . Hubo una variación grande en la circulación de la influenza A y B entre países vecinos y, en algunos años, la cepa B fue encontrada en más de 50% de los casos 36 .…”

“…Los datos de Brasil y Argentina indicaron que, en América Latina, no hubo concordancia entre las cepas B en circulación y aquellas incluidas en la vacuna recomendada para el Hemisferio Sur, siendo similar a aquellas observadas en los E.U.A., Europa y Australia 39,40,[42][43][44] . La influenza B en América Latina es frecuente (hasta 70% en algunos países y años) 35 , imprevisible, varía de un país a otro, de un año para el siguiente y de una región para otra, aun en el mismo país [39][40][41][42] . Las cepas de influenza B causaron brotes entre personas en condiciones de aglomeración, Fuerzas Armadas y turistas 45,46 .…”