There were few radical changes in incidence of reportable diseases in 1956 as compared with 1955.

After a temporary rise in incidence of diphtheria which began in the latter half of 1955 and extended into the first half of 1956, the number of reported cases began to decline. The 1956 total is slightly more than 20 percent below the total for 1955, and the total for the last half of 1956 is about 40 percent under that for the same period of the previous year. However, several States reported more cases in 1956 than in 1955, and some localized outbreaks continued to occur. In the most recent one, it was clearly evident that the level of immunity in the involved population was far below that needed to prevent this infection.

The number of reported cases of infectious encephalitis in 1956 was about 50 percent in excess of that for 1955. This disease category includes postinfectious as well as arthropodborne (mosquito) types of infection. Localized outbreaks and sporadic cases of the latter occurred in various parts of the country. Human cases of eastern equine encephalomyelitis, principally in children, were reported in Massachusetts and Maryland. Virus was isolated from brain tissue of fatal cases. Confirmed cases in horses were also reported in these States and in New Jersey, Delaware, and Alabama. Outbreaks of this disease in birds on pheasant farms located in Connecticut, Massachusetts, and New Jersey were confirmed by virus isolation. Pools of mosquitoes captured in New Jersey and Georgia also yielded virus. Western equine encephalomyelitis infections in man were not common in 1956. Laboratory confirmed cases were reported in Texas and California, and scattered cases in 5 other western States. A large number of cases of the St. Louis type of infection, mostly in adults, occurred in localized epidemics in 2 areas each in Kentucky and Colorado, and single areas of Kansas and Texas. In Indiana, no outbreak was defined, but a number of cases have been confirmed by serologic tests.

The provisional number of psittacosis cases reported in 1956 is about 90 percent in excess of the number for 1955. One or more cases occurred in 38 different States. The 6 States reporting the largest numbers were North Carolina with 76, Minnesota 62, California 44, Oregon 43, Illinois 38, and Texas 33. A great majority of the cases for which epidemiological reports were received had contact with parakeets. Contact with ducks, chickens, and pigeons was also reported as probable sources of infection. Laboratory infection was indicated in 2 cases. A large proportion of the cases reported in Oregon followed contact with turkeys on farms, in poultry processing plants and rendering plants situated in the northwestern part of the State. Texas also reported cases in which contact with turkeys was established as the probable source of infection.

There was an increase in incidence of typhoid fever in 1956. Thirty States reported more cases than in 1955. Early in the year, numerous cases were reported in several midwestern States from which the same phage-type of organism was recovered. Although some widely distributed food product was suspected as the vehicle of infection, definite proof of such a source could not be found. During the summer, another group of cases, also reported from a number of States, was traced to a church camp meeting attended by several hundred people. Epidemiological evidence indicated that the water sup

ply of the camp was the likely medium of spread of the infection. A known carrier who harbored the same phage-type of organism as that recovered from the majority of the cases had attended the camp meeting and may have been the original source of infection.

The number of cases of infectious hepatitis reported in 1956 was about 40 percent below the total for 1955, and 60 percent below that for 1954. Meningococcal infections and typhus fever cases were also reported in smaller numbers in 1956. There were no confirmed cases of smallpox but several suspect cases were investigated. A review of poliomyelitis incidence in 1956 appeared in last week's "Morbidity and Mortality Weekly Report."

SUMMARY OF MORTALITY

During the 52-week period January 1 through December 29, 1956, a total of 534,103 deaths was reported by the 108 major cities listed in table 4. This was 1.5 percent more than the number of deaths (526,008) reported by these cities during the 52-week period January 2 through December 31, 1955.

The chart on page 6 shows the number of deaths reported in the major cities of the United States by week during 1956. The outstanding feature in the mortality picture is the high level of deaths beginning in March and continuing through June. Excess deaths during the early months of the year have often resulted from influenza outbreaks, however, the increase in deaths for March through June of 1956 compared with the same period of preceding years was not associated with a widespread occurrence of influenza.

Again in the last 4 months of the year, the level of deaths reported weekly in 1946 was close to or above the maximum for the corresponding weeks of the previous 5 years.

The cities in the West South Central Division reported in 1956 the largest percentage increase in deaths over 1955. Each week, with only 6 exceptions, the number of deaths reported in 1956 was above the 3-year median (1953-55) for that week. A satisfactory explanation for this excess has not been made.

Malaria

EPIDEMIOLOGICAL REPORTS

Dr. J. D. Martin, Louisiana State Department of Health, has reported a case of malaria in a 31-year-old woman who spent the month of August in Mexico. During the last week of her stay she became ill with diarrhea which continued until she returned home. Other symptoms were chills and a high fever. Plasmodium vivax was demonstrated by blood smear.

Psittacosis

Dr. Dean Fisher, Maine State Department of Health and Welfare, has reported a case of psittacosis in a 56-year-old man. This man became ill with sweats, chills, fever, and a severe cough. The family owned a parakeet purchased in Florida 3 years ago. The bird was apparently in good health until about the time VIBRARY. Home treatment was ad

JAN 1 4 1957

ministered but the bird died and was buried. Several months later the diagnosis of psittacosis was made when a laboratory report on paired sera showed that the patient had in the past been infected with psittacosis.

Tularemia

Dr. James R. Amos, Missouri Department of Public Health and Welfare, has reported a case of tularemia in a 62-yearold woman. She was bitten on the finger by a sick cat which had been confined in a small building. It is known that the cat frequently killed and ate wild rabbits. The woman denied having handled any of the rabbits killed by the cat or any other rabbit or squirrel in years. A blood specimen from the cat was serologically positive for Pasteurella tularensis in a dilution of 1:40 and a specimen from the patient was positive in a titer of 1:640.

Diphtheria

An outbreak of diphtheria, in which cases were very mild or had no clinical illness, has been reported by the Highlands County (Florida) Health Department. During a 2-month period 6 cases were reported in a town of 5,000 inhabitants. Four

were in a third grade class in school but the other two had no apparent association with the school. Only 1 of the 6 had any prior diphtheria immunization. All persons had positive cultures, typed as mitis virulent, without typical clinical symptoms.

Salmonellosis

Information has been received of the occurrence of an outbreak of salmonellosis in a school in Maryland. Of 664 persons served turkey dinners in the cafeteria, an estimated 150 became ill. This estimate was based on the number absent from school and the normal absenteeism, in addition to the number who became ill at school. The pupils developed moderate to severe abdominal cramps with sudden onset, and violent diarrhea from 10 to 26 hours after the meal.

The turkeys, Government frozen surplus, were issued under the school lunch program. Ten turkeys were placed in a 36-degree refrigerator to thaw over the weekend. On Monday some of the birds were not completely thawed. At least 2 of them were tightly stuffed and the turkeys placed in an oven. After cooking, the turkeys were left at room temperature until Continued on page 8