Swine Flu Packs Bigger Jolt for Asthmatics, Diabetics

Swine flu sufferers who have asthma, diabetes or other conditions that may worsen their illness should seek medical care as soon as the infection is suspected, the World Health Organization said.
Pneumonia and other complications from the pandemic virus may develop within 24 hours, and any patient with difficulty breathing, who is drowsy or dehydrated, or who has had a fever for more than three days should be seen urgently by a doctor, according to the Geneva-based WHO. Severely ill patients should be given Roche Holding AG’s Tamiflu straight away and may need a double dose, WHO said yesterday in a 15-page report. 
The WHO’s latest guidance follows a meeting in Washington last month of doctors, scientists and public health officials to review studies and unpublished data as colder weather spurs epidemics across the Northern Hemisphere. 
“The guidelines are broadly similar to the strategies used in Australia and New Zealand during our recent outbreak,” said Steven Webb, an intensive-care specialist at the Royal Perth Hospital, who participated in the meeting. “They are sensible and pragmatic. They should be widely disseminated and represent a highly useful starting point for clinicians.” 
‘Rapidly Progressive Pneumonia’ 
More than 6,000 people have died after catching the new H1N1 strain since it was discovered in Mexico in April and spread to 195 countries. While the majority of those infected develop “mild-to-moderate disease,” the virus is capable of causing fatal complications, including “rapidly progressive pneumonia especially in children and young to middle-aged adults,” WHO said. 
As most people have little or no immunity to H1N1, the pandemic is striking down people in a wider age range than seasonal flu, which kills predominantly the frail elderly, WHO said. It’s also capable of infecting the lower respiratory tract, heightening the risk of lung disease and respiratory failure. 
Diagnosing H1N1 may be more difficult in patients with lower respiratory illness because initial laboratory tests sometimes fail to pick up the infection in specimens from the nose and throat, according to the report. Samples from the trachea and bronchi, which are harder to collect, may provide a more accurate result, it said. 
False Negative Tests 
Researchers in Australia and New Zealand are investigating the proportion of critically ill H1N1 patients whose infection wasn’t diagnosed by so-called polymerase chain reaction tests, Webb said in an e-mail today. A small proportion of patients in both countries who failed repeated PCR tests were later found to have been infected with H1N1 based on antibody studies, he said. 
The spectrum of symptoms ranges from headache and sore throat with or without fever to rapidly progressive, life- threatening pneumonia, the United Nations health agency said. Gastrointestinal symptoms, such as nausea, vomiting and diarrhea, have also been reported. 
Children younger than two years, pregnant women, people with lung diseases, metabolic disorders, weakened immune systems and certain neurological conditions are among groups at higher risk of developing a severe disease, WHO said. H1N1 also poses greater risk of complications in obese individuals and disadvantaged and indigenous populations, it said. 
On average, about half of hospitalized patients have had at least one or more underlying medical conditions, according to the report. About a third of patients with very severe illness admitted to intensive care units were previously healthy. 
Pregnancy Risk 
People over the age of 65 typically represent the bulk of adult admissions for respiratory ailments during the winter flu season, said Justin Denholm, an infectious diseases research fellow at the Royal Melbourne Hospital. “The difference here is seeing younger people, previously well people and pregnant women.” 
Risk factors in previously healthy persons that predict increased risk of progressive disease or severe complications “are incompletely understood,” according to the WHO. 
Pregnant women, especially those with preexisting medical conditions, are at increased risk for complications from influenza, which can cause spontaneous abortion, preterm birth, and fetal distress, WHO said. 
According to a study last week, about one in eight H1N1 patients hospitalized during the first two months of the epidemic in Melbourne were pregnant, compared with nationwide prevalence of 1.1 percent. Pregnant women with suspected or confirmed H1N1 infection “warrant closer observation and early antiviral treatment,” WHO said. 
‘Real Difference’ 
“Young, pregnant women with bilateral pneumonia -- we don’t see that every flu season,” Denholm said in a telephone interview today. “That’s a real difference related to the virus.” 
The WHO estimates more than 482,300 people worldwide have been sickened by H1N1. Commercially available diagnostic tests aimed at producing a rapid result in doctors’ offices may miss many infections and shouldn’t be relied on to determine whether to treat or lift infection-control measures, the agency said. 
“Under no circumstances should influenza diagnostic testing delay initiation of infection control practices or antiviral treatment, if pandemic (H1N1) 2009 disease is suspected,” WHO said.