In the last weeks we have seen an increase of the impact of influenza activity:
At 28th January, this year it was published by the European Center for Disease Prevention and Control the ECDC annual risk assessment on influenza for the remainder of the season. The main highlights were that medium or high rates of influenza intensity are likely to be observed in Europe.
The figure 1 show us the intensity in week 4. As we can see, Belgium, Italy and Portugal had the highest intensity in Europe. Portugal is the only country that as reported a majority of virus Influenza type B.
The number of consultation rates for influenza-like illness in primary care (data from Portugal) as registered an overall increase and at a higher level, when compared with 2013 (data from ECDC):
As we seen the intensity is high for Portugal and the number of people going to the primary care for consultation as also increase. And what about mortality rate? Is linked with the influenza intensity?
The EURO MOMO, that publish a weekly bulletin of the all-cause mortality levels in 19 European countries or regions of countries, as reported that excess all-cause mortality has been observed among the elderly (65+), on higher levels compared to the previous four winter seasons, during the recent weeks in seven of 15 reporting countries (Portugal, England, Scotland, Wales, the Netherlands, France and Spain). They do not attribute to a specific cause, but they suggested some clues:
- the start of the influenza season
- the extreme cold
- the increase in acute respiratory illness
In 2012, Portugal had also in this season a excess all-cause mortality levels among the elderly, as observed in the EXCESS MORTALITY AMONG THE ELDERLY IN 12 EUROPEAN COUNTRIES, FEBRUARY AND MARCH 2012, from Eurosurveillance, available here. The authors said that the:
“…preliminary data indicate that the impact of influenza in Europe differs from the recent pandemic and post pandemic seasons. The current excess mortality among the elderly may be related to the return of influenza A (H3N2) virus, potentially with added effects of a cold snap.”
Both report had pointed the weather (cold) and Influenza effect for this overall excess all-cause mortality rate.
Other report, from World Health Organization, that made an analysis about the environmental health inequalities in Europe (read here), has reported that about 40% and 33% of the excess winter deaths are attributable to cardiovascular and respiratory diseases respectively, and the risk is 3x times higher the houses with coldest indoor temperatures. The same report as shown that Portugal has one of the highest prevalences of inability to keep the home warm, especially in houses with at least one adult older than 65 years:
In last October was published in the International Journal of COPD an interesting article about the causes and consequences of seasonal variation in COPD exacerbations, they had suggested that the seasonality of exacerbations is greater in more temperate climates, like Portugal, with less protection from outdoor and indoor cold exposure.
I will end and summarize this post saying that, yes, the environment appears to be key factor in overall excess rate mortality among some risk population (elderly and chronic patients), especially related to the capacity to warm our house. Countries like Portugal should look for this when preparing the winter season because it appears that not only the flu vaccination will be enough in some cases.
References:
- Influenza Activity Map, available where: http://www.ecdc.europa.eu/en/healthtopics/seasonal_influenza/epidemiological_data/Pages/influenza_activity_EU_EEA_activity_maps.aspx, European Centre for Disease Prevention and Control, retrieved from web at 04-02-2015.
- European Centre for Disease Prevention and Control. Seasonal influenza in the EU/EEA countries, 2014–2015. Stockholm: ECDC; 2015.
- Mazick A, Gergonne B, Nielsen J, Wuillaume F, Virtanen MJ, Fouillet A, Uphoff H, Sideroglou T, Paldy A, Oza A, Nunes B, Flores-Segovia VM, Junker C, McDonald SA, Green HK, Pebody R, Mølbak K. Excess mortality among the elderly in 12 European countries, February and March 2012. Euro Surveill. 2012;17(14):pii=20138. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20138
- WHO Regional Office for Europe: Environmental health inequalities in Europe. Bonn: WHO European Centre for Environment and Health. WHO Regional Office For Europe, 2012.
- Donaldson GC, Wedzicha JA. The causes and consequences of seasonal variation in COPD exacerbations. Int J Chron Obstruct Pulmon Dis. 2014 Oct 6;9:1101-10.