Progress In War On Infectious Disease

Press, Volume CVII, Issue 31542, 2 December 1967, Page 5

Progress In War On Infectious Disease

(By

WALTER FROEHLICH)

Infectious diseases—ailments generated by transmissible agents such as bacteria or viruses—remain by far the most widespread causes of illness and death in the world today. Ample proof exists that many of these diseases are preventable and curable. More of them will almost certainly become so soon. There is even speculation that many infectious diseases could gradually be made to disappear from the earth.

Perhaps that utopia is too much to hope for, but there is a definite trend in that direction.

For example, in the United States, Europe and several other regions, infectious diseases are no longer the major cause of death. Chronic, non-infectious illnesses, especially the degenerative diseases of middle age and advanced, age—particularly heart and blood vessel diseases, and certain types of cancer—and even accidents, take heavier tolls. Thus in these, areas, nontransmissible diseases now outrank as a cause of death the traditional bacterial and viral illnesses which once spread fekr and havoc there, and continue ,to■ do so in varying degrees in other parts of the world. In the United States and Europe and several other regions, smallpox and yellow fever have become almost extinct 1 Typhoid,, typhus, cholera and plague and childhood diseases such as diphtheria and whooping cough have become so extremely rare that few young doctors have ever seen a case.

Effective Vaccines Mainly responsible for this happy situation has been the development and widespread use of vaccines which prevent these diseases. Massive vaccination campaigns have been accompanied and fol'lowed by continuous vigilance by public health officials to isolate and institute prompt treatment for any suspected cases and for all contacts to. whom the patient might have spread the disease agents before his isolation. Also, many of the bacteria and viruses which were once responsible for widespread epidemics have been engineered out of existence in some areas. This has been accomplished by modern water supply and sewage and waste disposal systems, and by improved food handling and preservation and other public hygiene techniques. Meanwhile, in the last 25 years drugs, especially antibiotics such as penicillin, have emerged for effective treatment of most of the ’serious infectious diseases. The combination of all

these efforts and techniques, with the subsequent reduction in deaths from infectious diseases, is largely responsible for the rises in average life expectancy in almost every region on earth.

How discovery of new ways to combat even a single Infectious disease can leave a trail of better health and greater happiness throughout the world was perhaps most dramatically demonstrated by development in the 1950 s in the United States of the Sa)k and Sabin . poliomyelitis vaccines.

Poliomyelitis The Salk vaccine, developed by Dr Jonas E. Salk, then of Pittsburgh, Pennsylvania, became available for public use on April 12, 1955. It is in.jected into the body. The Sabin vaccine, in contrast, is a fluid that is easily taken by mouth. -

The two vaccines have been distributed through much of the world and have vastly reduced outbreaks of poliomyelitis which formerly paralysed and permanently maimed millions of persons. In the United States, poliomyelitis is no longer considered a major health problem, with only a few dozen cases each year compared with tens of thousands in the years before use of the vaccines.

When a poliomyelitis epidemic broke out in Nicaragua in the spring of 1967 in an area where many persons remained unvaccinated, United States experts immediately dispatched vaccination teams and other help to stem the outbreak.

With effective controls now available for most serious infectious diseases, U nited States researchers have recently focused increasing attention on the less serious ones. Though not life-threaten-ing in themselves, these diseases often are followed by permanently disabling complications.

Thus,, the vaccine against measles (the disease is known among doctors as rubeola), developed In the United States in the early 19605, is now protecting millions of children throughout the world. In the United States the occurrence of measles has diminished to such an extent that public health officials have set the incredible goal of eradicating within one year this disease of which it was once said that “every child gets it." The theory is that massive vaccination campaigns will deprive the measles virus of its needed dwelling place inside the human body and that the virus will then die out.

Mumps And Measles

Experimental vaccines now undergoing trials in the United States will, hopefully, become available within a few years for protection against mumps and German measles (known as rubella). The latter disease can injure an unborn child if the mother gets the disease in the early months of pregnancy.

United States researchers also report they are coming closer to developing a vaccine against “strep” infections (which can cause heart and kidney damage) and against strains of influenza virus not controlled by present influenza vaccines. There are even optimistic reports about prospects for a

long-sought vaccine against the common cold, the world's most widespread single disease, which is not serious by itself but which causes much discomfort and huge economic losses by time lost from work.

More efficient tools for administering new vaccines are helping in the battle against infectious diseases. A new jet spray gun shoots smallpox vaccine by air pressure between layers of skin in a split second, replacing the tedious task of pricking the skin with a needle. A doctor can now inoculate up to 1500 persons an hour as opposed to 100 an hour when a needle is used. The jet-gun method also causes much less discomfort to the patient. Meanwhile, some researchers are aiming for what would be considered a medical dream come true—a one-shot vaccine that would provide protection against many, if not all, infectious diseases simultaneously. Vaccines covering three or four such diseases are already in use in the United States. The attainment of a multiple vaccine was brought closer recently by the development by the United States Atomic Energy Commission of a new centrifuge, a device that spins fluids at very high speeds. The spinning causes heavier components to drift nearer the outside of the circle, and lighter portions to remain proportionately closer to the Circle’s centre. This “layering” of components for selective removal of some is necessary in the manufacture of vaccines.

Long-range Weapon

Still another long-range and rather unconventional weapon against infectious diseases is being devised by a team of researchers in the United States working under Dr Maurice R. Hilleman at the Merck Institute for Therapeutic Research at West Point, Pennsylvania. Dr Hilleman, already famed for his work on the mumps and measles vaccines, has, together with several colleagues. discovered a way to promote the production of a mysterious substance called interferon that fights virtually all kinds of disease-causing viruses.

The body normally produces the substance in small amounts when challenged by an invading virus, but Dr Hilleman has devised an injection that will speed up that production to prevent viruses from becoming sufficiently established in the body to cause infection.

However, to translate his system—so far tried only on laboratory animals—into routine use for humans will almost certainly require several years of additional research. Bacteria on the average measure only about l/50,000in (1/20,000 centimetre) in diameter, and viruses are many times smaller than that. In spite of—or perhaps because of—their almost infinitesimal size, they constitute one of man’s oldest and most stubborn enemies.

Continued research is gradually increasing the understanding of the almost incredibly small world of these microbes. That understanding may, in turn, lead to man's eventual mastery over these tiny antagonists.— United States Information Service.