INFLUENZA VIRUS

Waikato Times, Volume 121, Issue 20126, 23 February 1937, Page 9

INFLUENZA VIRUS

KILLED BY VIOLET RAY. HARVARD RESEARCH. Influenza, one of the unwliipped plagues of civilisation, was declared by two Harvard scientists recently to be a step nearer the fate of smallpox, yellow fever, diptheria, and typhoid fever, says the New York Times. They reported on the results of experiments on the transmission of influenza virus by the air we breathe, and how they killed it by contact with ultra-violet rays. Their success caps a series of patient studies over the last five years, opening up a vast field in preventive medicine whereby, they said, the air In hospitals, operating theatres, schools, and auditoriums may be freed from dangerous germs.

W. F. Wells, instructor in sanitary science at the Harvard School of Public Health, who with LI. W. Brown, fellow, General Education ■Board, Harvard School of Public Health, made the discovery, explained the method and the tests. Virus in Suspension. “Dr 'Brown’s splendid technique lias fortunately made it possible to carry on the experiments with influenza virus,” Dr. Wells said. When a person sneezes, he explained, droplets are expelled into the air. These droplets evaporate instantaneously, but they leave a residue “in suspension.” The residue is like tobacco smoke. It practically will not settle, but drifts on air currents. If a person has influenza and sneezes, this residue contains the virus.

The scientists said that their experiments proved that this' virus can drift alive for least 30 minutes—long enough to go from person to person breathing the air in a room. In their experiments, Dr. Wells said, a liquid suspension of the virus, obtained from the lungs of a ferret suffering a typical attack of influenza, was atomised into a large, sealed, glasslined steel tank. The air was then drawn out through two tubes for sampling and the material recovered given to ferrets. One sample was drawn through a glass ohamber with an ultra-violet light in it. Ferrets inoculated with material directly from the tank developed influenza. Ferrets inoculated with material after passing over the ultraviolet lamp remained well. Both experimenters reported that the virus In the air passing over the lamp must have been killed because it was impossible to transmit llie influenza to the ferrets. They emphasised that It w r as the same air as that drawn directly from the tank, the only difference being the Irradiation. Every precaution was used to prevent the escape of the virus-laden air into the building to avoid any possibility of spreading influenza. Asked whether there was any practical application ahead, Dr. Wells said: “In view of the proved possibility of infected matter being carried by air, reasonable efforts to free air supplies from living micro-organisms are justified in the light of general sanitary principles. The effectiveness of ultraviolet light for such purposes- would also seem to he demonstrated by our experiments.”

Grounds for Hope.

He emphasised that no scientist could go beyond his experiments, but added: “The great reduction of intestinal disease through water purification since the' turn of the century might prompt us to hope that some of the diseases which are transmitted through the respiratory tract may be checked by methods for purifying air supplies. Perhaps air-borne infection is not yet so generally accepted as water-borne typhoid.” “This acceptance,” he said, "could only develop with the general recognition of the possibility of infection being carried through air and the firther possibility of controlling this infection by artificial means. “ This is the purpose of the experimental work carried on at Harvard during the past five years.” The experiments with influenza virus by two Harvard scientists present the first definite proof that the virus is carried in the air, in the opinion of Dr. lago Galdston, director of the medical Information bureau of the New York Academy of Medicine Other scientists have bolfev°l that the virus was air borne, he said, but have not definitely proved their theories. Dr. Galdston pointed out that the experiments at Harvard apparently had not identified the virus. The success of the scientists in killing the virus with ultra-violet rays may have some practical application, If an effective means of irradiation could be developed, lie said. He explained, however, that there are several methods of killing the virus. Several scientists in New York have been working on experiments to combat the influenza virus, and also I lie virus that causes the common cold The Harvard scientists, Dr. Galdston said, appeared to have readied a definite basis for further experiments leading to identification and control of the disease.