INFLUENZA

Evening Post, Volume CXXIII, Issue 19, 23 January 1937, Page 7

INFLUENZA

ATTACK ON DISEASE A FORWARD STEP ? In 1932 Dr. Thomas M. Rivers, of the Rockefeller Institute, a well-known authority on viruses, had this to say before the American Society of Clini- ; cal Medicine in his presidential address (writes the science editor of the "New ; York Times"): "Many viruses obtain entrance into their hosts by way of the upper, respiratory tract. Our inability to control disorders arising in this manner is not due to the fact that we have not used . some special kind of medium for the cultivation of the viruses but because it is essential that we breathe, and as yet no one has suggested a practical method of obtaining uninfected air for human beings living amongst their fellows." It may be that this opinion, now four years old, may have to be revised in t.he light of some experiments which have been conducted by Drs. H. W. ! Brown and W. F. Wells, of the Harvard School of Public Health. They have shown that the virus of influenza can live in air, and that it can be killed by rays from ultra-violet lamps. But whether ultra-violet rays are indeed practical in Dr. Rivers's sense, meaning efficient and inexpensive, only further research can reveal, i A FILTERABLE VIRUS. Bacteriologists are agreed that influenza is caused by what is called a filterable virus, which is merely a name for something about which very little is known. Whether a filterable virus is a collection of germs too small to be seen in any microscope or whether it is a mysterious chemical that becomes virulent when it touches living tissue is still a matter of dispute. It is called "filterable" because it can pass through a porcelain strainer so fine that it holds back microscopic bacteria. Medieval medicos thought that the diseases we call contagious were borne by the air. It was so good a hypothesis that their successors of the twentieth century still cherish it. But is it true of influenza? If so, how long does influenza virus live in the air? There are other supposedly ultramicroscopic organisms besides the filterable viruses. Bacteriophage is one—a name for an invisible something that preys on visible germs. About five years ago Dr. Merl G. Colvin, of the Yale University Medical School, showed that bacteriophage can travel through air a distance of thirty-five feet in five minutes, also that it floated about in the dust of his laboratory for at least eighteen days. The more thoroughly he swept and mopped the more did he find. There is a difference between a filterable virus and bacteriophage. Still ; Dr. Colvin's work shows that others had been wondering whether invisible miscroscopic organisms were wafted , about in the air. , i BROWN-WELLS EXPERIMENTS. Drs. Brown and Wells have gone a ' step further. Can a filterable virus— i to wit, the influenza virus—live when : it is thus floating about? They made a series of experiments which covered five years, it is said. ! One of the most virulent strains of ; influenza virus is known as Porto Rico : 8. Brown and Wells sprayed it into a sealed tank. Next they drew off ; some of the contaminated tank air and whirled it about in a centrifugal sep- : arator devised by Dr. Wells. Thus ; they recovered heavier material which they inoculated into ferrets. Down came the ferrets with the disease. Who could doubt that influenza is carried by the air after that? Can the virus be killed in the air? Another batch of contaminated air ' was passed through deadly rays from a cold quartz mercury lamp. More centrifuging of the collected air. More inoculations. But the ferrets did not succumb. ; Whether a forward step lias been taken in the conquest of influenza it is too early to decide. But the question naturally arises: If the water of : swimming pools can be effectively treated with ultra-violet rays to kill micro-organisms, why not the air we breathe? Mercury lamps are cheap to operate. But is the cost so low that it is posible tcf» irradiate a whole mo-tion-picture theatre with ultra-violet light? It is to be inferred from the account of their work which Drs. Brown and Wells publish in "Science" that the stuff which they collected after whirling contaminated air in a centrifugal separator was inoculated directly into ferrets. Should not some bacteriologist put ferrets in a tankful of contaminated air and see whether they catch influenza merely by breathing as we do? THE TWO STAGES, In the study of influenza there have been two stages. The first was concerned with the life and effect of the bacillus that Peiffer thought he had discovered. By 1918 bacteriologists ceased to believe in it—could not verify his microscopic studies in fact. The second stage was entered with the conviction that influenza is caused by an invisible organism or some chemical called a filterable virus. The method of transmitting influenza is of crucial importance. But there is no evidence as yet that the disease spreads naturally from infected animals to others living in contact with them. At least that is the verdict expressed in the British Medical Council's report for 1933-34. Studies made during the epidemic of influenza of 1918 are still being quoted. Volunteers were then inocu- ' lated with filtrates that came from sufferers. But experiments in which volunteers were exposed to sneezing and coughing influenza victims came to nothing. This does not mean that the influenza virus is not air-borne —merely that it was impossible to exercise the necessary scientific control. For one thing, there was no way of checking or knowing the personal immunity of volunteers.