Swine flu pandemic: More than 20 percent of the population infected
The swine flu pandemic initially caused a real state of emergency in the healthcare sector worldwide in 2009 before it turned out to be significantly less dangerous than originally feared. An international team of researchers led by Maria van Kerkhove and Siddhivinayak Hirve from the "Global Influenza Program" of the World Health Organization (WHO) has now presented a meta-study on the infection rates with H1N1 viruses in the specialist magazine "Influenza and Other Respiratory Viruses". Accordingly, more than 20 percent of the population worldwide have now become infected with the pathogen. Fortunately, the mortality rate was extremely low.
According to the results of the researchers, significantly more people have been infected with the swine flu virus than originally thought. In addition, "the global impact of the influenza A (H1N1) pandemic is not well understood," the scientists write. They see their current work as a contribution to a better understanding of the swine flu pandemic 2009/2010. The evaluation of existing epidemiological studies enables a realistic estimate of the actual infection numbers. The swine flu pandemic originated in Mexico in early 2009, from where the pathogens spread all over the world. There was great fear among the population of a potentially fatal threat. A vaccine to protect against the pathogens was hastily presented. However, there was soon suspicion that this could be associated with considerable side effects, and millions of vaccine doses remained until they were destroyed in late 2011. In August 2010, the WHO declared the pandemic over.
Children and adolescents with the highest swine flu infection rate The international research team around Kerkhove and Hirve analyzed as part of his meta-study "the data from 27 published / unpublished studies from 19 countries / administrative regions" worldwide. The data came from Australia, Canada, China, Finland, France, Germany, India, Italy, Japan and the Netherlands, among others. Based on the detection of specific antibodies against the H1N1 viruses in more than 90,000 blood samples, the scientists determined how many people in the respective regions had already been infected with the swine flu pathogens. An age-specific evaluation of the data was also carried out. A total of around 24 percent of people had antibodies to swine flu in their blood, the WHO experts report. Children between the ages of five and 19 are 47 percent and children between the ages of zero and four are 36 percent, according to the scientists. Comparable infection rates can also be assumed in the countries not examined.
Low mortality due to swine flu infections The scientists confirm with their current meta study from the previous year studies that also came to the conclusion that significantly more people than the WHO estimated among one million worldwide until the end of the pandemic with the pathogen infected and the number of deaths was significantly higher than the assumed 18,500. However, whether the H1N1 virus may have caused 280,000 deaths as determined in the study from last year remains open. Because the high infection rate in the population of more than 20 percent is offset by a relatively low mortality. The researchers led by Maria van Kerkhove and Siddhivinayak Hirve came to the conclusion that only 0.02 percent of the patients died as a result of the swine flu infection. "Our results offer unique insights into the global impact of the H1N1 pandemic and underline the need to standardize seroepidemiological studies and include them in pandemic plans," the researchers concluded. (fp)
Read also about swine flu:
Was the swine flu causing more deaths?
Sleeping sickness due to the swine flu vaccine
Flu increases the risk of narcolepsy
Narcolepsy risk from swine flu vaccine
Swine flu is no reason to panic
Photo credit: Gerd Altmann / pixelio.de