CHICAGO, Dec. 2 (UPI) -- Aside from the dearth of treatments to battle avian-flu virus H5N1, the bug is also proving elusive for physicians to diagnose from a standard X-ray, researchers said Friday.
Radiologists reviewing the X-ray of a patient with the deadly viral disease would see a white haze that won't immediately signal bird flu, they stressed. Thus, in the face of the looming pandemic threat, doctors should be prepared to delve further into the patient's environmental risk factors, researchers warned.
For example, if the patient has had contact with sick birds or has been on a farm where birds are raised, the bird-flu alarm bell should sound, they said.
"You can't tell that the patient has influenza A subtype H5N1 just by looking at an X-ray," said Nagmi Qureshi, a fellow in thoracic radiology at Churchill Hospital of the University of Oxford, United Kingdom.
Qureshi said it is unclear at first blush from reviewing the X-ray of a patient with the infection whether the culprit is viral or bacterial.
Bird flu has already struck 130 people in Europe and Asia and killed 67 of them.
Qureshi said that in the 14 cases from Vietnam that she was able to study in detail, all the patients had influenza A subtype H5N1. Nine of those patients, including two out of three children, died, she said at the annual meeting of the Radiological Society of North America, where she discussed the disease patterns seen in the patients.
"The X-ray features have some characteristics of both viral and bacterial infection," she told United Press International, "but we cultured no bacteria from any of these patients' sputum or from their blood."
The patients were treated with both broad spectrum antibiotics and anti-virals because of the possibility that either type of infection was involved.
She noted that primary viral pneumonia -- the disease that is killing people who contract avian flu -- is a relatively rare type of disease. Most forms of pneumonia are caused by bacterial infections.
"Characteristically," she said, "the patients who died came in very sick, got even sicker and died -- within nine days." The survivors, however, who were hospitalized for as long as 42 days, developed other complications -- liquid in the lungs and areas of deep infections in the lungs, Qureshi said.
The investigators studied 98 X-rays of the 14 patients, all of whom were under age 35. "We and others have noted that the pattern of infection among young, healthy individuals -- none of these patients were elderly -- is similar to what has been described as the pattern of the 1918 influenza epidemic also called the Spanish flu," Qureshi said.
Judith Amorosa, clinical professor of radiology at the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, told UPI: "There is nothing very specific about the chest X-rays that would lead doctors to think of avian flu. There really is nothing very special about it on the X-rays. The possibility of an avian-flu epidemic is very worrying because we have few treatments that are useful against viral pneumonias. We do not have a lot of experience with this disease."
