Word: infectivity
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Dates: during 1940-1949
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Undulant fever may smolder for years, suddenly flare up into a complex disease resembling typhoid, malaria or tuberculosis. It is caused by any of three germs of the group Brucella (named after Sir David Bruce, who discovered the strain in 1886). Brucellae infect cattle, sheep, goats and pigs, cause a disease known as contagious abortion. Between 11 and 20% of all U.S. cattle are infected, causing a yearly loss to farmers of some $80,000,000. The disease is transmitted to man through milk, butter, cheese, and through handling of infected carcasses; it is not passed from one person...
...Strains of bacteriophage are found in the human intestinal tract, in urine, pus, blood and sewage. About 25 years ago, bacteriophage was first isolated by a British scientist from a dead germ colony. The mysterious substance that killed the bacteria was able to pass through a fine filter and infect other colonies. Some doctors soon dreamed of it as a universal panacea. (Sinclair Lewis dramatized this hope in his novel Arrowsmith.) Compared to the early days, the claims last week seemed conservative...
...artificial propagation the Department of Agriculture now hopes to spread it ten times as fast. At the U.S. Beetle Control Station at Moorestown, N.J., technicians infect healthy grubs with it, pampering them until the bacteria multiply profusely. Then they grind up the diseased grubs and mix them with talc so the hardy bacteria spores can be conveniently handled and sprinkled in fields...
...most intensive disease-spreading was under way last week in Maryland, where it is subsidized with State funds and helped by the U.S. Department of Agriculture. This week a similar campaign begins in New Jersey, where the first few spores were sown in 1939. The method is to heavily infect two half-acre plots of turf (where grubs thrive best) in each square mile. Birds, breezes and flying beetles then complete spreading the disease. Purpose of spore-sowing is not, as in spraying, to kill beetles on a specific plot but to establish the beetle enemy widely. Spore powder...
Scientists who have been experimenting with poliomyelitis (infantile paralysis) virus have been considerably hampered because the only animal they could infect was the expensive rhesus monkey. Last year Dr. Charles Armstrong of the U. S. Public Health Service finally succeeded in giving polio to ordinary cotton rats. That hurdle passed, he was able to pass the infection from cotton rats to mice...