The currently circulating influenza viruses that cause human disease are divided into two groups: A and B. Influenza A has 2 subtypes which are important for humans: A(H3N2) and A(H1N1), of which the former is currently associated with most deaths. Influenza viruses are defined by 2 different protein components, known as antigens, on the surface of the virus. They are spike-like features called haemagglutinin (H) and neuraminidase (N) components.
The virus is easily passed from person to person through the air by droplets and small particles excreted when infected individuals cough or sneeze. The influenza virus enters the body through the nose or throat. It then takes between one and four days for the person to develop symptoms. Someone suffering from influenza can be infectious from the day before they develop symptoms until seven days afterwards.
Upper respiratory tract illnesses have been associated with an increased risk of ischemic heart disease and stroke. During two influenza seasons, we assessed the influence of vaccination against influenza on the risk of hospitalization for heart disease and stroke, hospitalization for pneumonia and influenza, and death from all causes.
Disease spreads very quickly among the population especially in crowded circumstances. Cold and dry weather enables the virus to survive longer outside the body than in other conditions and, as a consequence, seasonal epidemics in temperate areas appear in winter.
A cold often starts with feeling tired, sneezing, coughing and having a runny nose. You may not have a fever or you may run a low fever--just 1 or 2 degrees higher than usual. You may also have muscle aches, a scratchy or sore throat, watery eyes and a headache.
The flu starts suddenly and hits hard. You'll probably feel weak and tired, and have a fever, dry cough, a runny nose, chills, muscle aches, severe headache, eye pain and a sore throat. It usually takes longer to get over the flu than a cold.
Overall, influenza is responsible for 36,000 deaths and 225,000 hospitalizations in the United States each year. People with cardiovascular disease are particularly vulnerable, because the flu can exacerbate heart disease symptoms directly, and can also lead to conditions like viral or bacterial pneumonia that cause flare-ups of cardiovascular disease.
Influenza, commonly known as flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses). In humans, common symptoms of influenza infection are fever, sore throat, muscle pains, severe headache, coughing, and weakness and fatigue.In more serious cases, influenza causes pneumonia, which can be fatal, particularly in young children and the elderly.
If you have heart disease, you should get an annual flu shot. That's the message put out by the American Heart Association and the American College of Cardiology. Studies have shown that death from the flu (influenza) is more common among people with cardiovascular disease than among people with any other chronic condition. Doctors have long recommended that older adults and other high-risk groups get flu shots, but are now placing more emphasis on the importance of flu shots for those with heart disease. The flu shot could prevent thousands of flu-related complications and deaths every year in people who have heart disease.
Influenza virus remains among the most important pathogens infecting elderly people. Vaccination is the most cost-effective strategy to reduce morbidity and mortality due to influenza.The demand for influenza vaccine is driven by recognition of its health and economic benefits. Vaccine reduces all cause mortality in the elderly by 30 to 50% and prevents > or =30% of hospital admissions for influenza-related respiratory disease, heart disease and stroke.
Patients with cardiovascular disease are more likely to die from influenza than patients with any other chronic condition, according to the new AHA/ACC scientific advisory.Studies have found that annual flu vaccinations can prevent death in adults and children with chronic conditions of the cardiovascular system.
A new way to get the flu vaccine is a nasal spray called Flu-Mist. It is a live virus vaccine and can only be used for healthy people ages 5-49.The flu shot only stimulates immunity in the blood, not in the nose and throat as FluMist does. "That's the theoretical advantage over the shot -- FluMist gives you a broader immunity. So it's a very good way of protecting against the flu," said King, who is also a professor of pediatrics at the University of Maryland School of Medicine. King says that FluMist is just as effective as the flu shot. "It's been shown to be over 90 percent effective in children against culture-proven flu so it's a very good vaccine.
Recent studies have suggested that paediatric influenza is a greater medical problem than usually thought because it can cause excess hospitalisations, medical visits, and antibiotic prescriptions even in healthy children, especially those under 2 years. Furthermore, influenza in otherwise healthy children may have substantial socioeconomic consequences for the children and their household contacts. These findings have led many experts to encourage the more widespread use of influenza vaccine in childhood.
nfluenza can trigger deadly heart attacks, researchers said on Wednesday in a study that supports what experts have long believed -- flu can kill people even if they do not die directly from the flu.
Their report shows that the seasonal virus can worsen heart disease and that deaths from heart attacks and heart disease are far more common during flu season.
This can add up to 90,000 extra deaths a year in the United States alone, said Dr. Mohammad Madjid of the University of Texas-Houston, who led the study.
Writing in the European Heart Journal, the researchers said their findings add to a growing list of reasons why people should get annual flu shots. They also said people with heart disease should stick to their medications religiously.
"Our research has shown that influenza epidemics are associated with a rise in coronary deaths," Madjid said in a statement. "This calls for more intensive efforts to increase the vaccination rate in people at risk of coronary heart disease.
"This may be especially important in an influenza pandemic when we would expect to see high mortality among the elderly and those suffering from heart problems or who have multiple coronary risk factors," he said.
Flu viruses change every year and several are usually circulating in any given season, making the risk of flu high for most people.
"Between 10 and 20 percent of people catch flu every year and I have estimated that we can prevent up to 90,000 coronary deaths a year in the (United States) if every high-risk patient received an annual flu vaccination," Madjid said.
Madjid and colleagues at the Influenza Research Institute in St. Petersburg, Russia, studied autopsy reports on people who died from heart disease in that city from between 1993 and 2000.
"This was a population where only a small minority was receiving flu vaccines or statin drugs, so this enabled us to see what happened naturally in the absence of these medicines," Madjid said.
They found that 11,892 people died from heart attacks and 23,000 died from chronic heart disease.
Deaths from heart attacks increased by a third in flu epidemic weeks compared to non-epidemic weeks and the chances of dying from chronic heart disease increased by a tenth.
"This study shows that flu is an important trigger of heart attacks because flu is a severe infection, with high incidence rates and is readily preventable." Madjid said.
"If people can recognize that the flu vaccine has specific cardioprotective effects, then high-risk people will be more likely to make sure that they receive the influenza vaccine every year."
|
| 126 : vote(s) so far
| Cast your vote: