Showing papers in "American Journal of Public Health in 1939"

Development of Tuberculosis in Infected Children.

Abstract: IN laboratory animals where time of infection and dose of bacilli can be controlled there is substantial agreement that primary infection with tuberculosis, if not overwhelming, results in a measurably increased resistance to subsequent inoculations with tubercle bacilli.1' 2, 3 In man the picture is less clear. Although the typical parenchymal infiltration of primary infection, followed by resolution, fibrosis and calcification, is not infrequently observed roentgenologically, the exact date of reinfection and the duration of exposure are rarely known, and the dosage of bacilli is wholly problematical. Furthermore, it has not been demonstrated how far the results of inoculation experiments with tuberculosis in laboratory animals can be applied to natural infection in man. From a public health standpoint the relationship between primary infection with tuberculosis and the development of subsequent progressive disease has become a problem of major importance. Is a primary infection acquired during childhood a relative safeguard against subsequent exposure? or does the sensitization acquired through such infection result in increased susceptibility to destructive lesions? Much evidence might be cited to

Epidemiology of Leptospirosis.

Abstract: DURINVG the past 2 years the Epidemiological Intelligence Services of the \West have repeatedlv requested cooperation in the solution of the etiologic factors responsible for outbreaks or sporadic cases of jaundice. Epidemics involving small rural schools have occurred in AMay and June and affected as many as 42 children at one time. In another, the cases of catarrhal jaundice were seen in familial distribution shortly before or during the rainy season which was followed by floods. Invariably, the serological examination, inoculations of guinea pigs, and the examination of rodents collected within the epidemic area yielded no evidence which would stigmatize the Leptospira icterohaemnorrhagiae as the cauisative factor. In fact, a careful analysis of the clinical cases, the incubation time of from 3 to 4 weeks, and the obvious contagious character lead to the conclusion that these outbreaks were indistinguishable from the well known epidemic catarrhal or infective hepatic jaundice previously described by Blumer1 and others for this country and well known in Great Britain through the publications by Pickles,2

Experimental Infection of Dermacentor Andersoni Stiles with the Virus of Lymphocytic Choriomeningitis.

Abstract: ALTHOUGH only 4 years have elapsed since Armstrong and Lillie 1 showed that lymphocytic choriomeningitis is an infectious disease caused by a virus, the evidence indicates that the etiologic agent can be transmitted in several ways. Traub 2 has shown that the virus is discharged in the urine and nasal secretions of infected mice: Findlay and Stern 3 SUCceeded in infecting 3 of 20 mice by nasal instillation of the virus. Finally Wooley, Armstrong, and Onstott 4 have been able to transmit infection occasionally by instilling the virus into the urethra or vagina of monkeys. They have also demonstrated the virus in the seminal fluid and testicular tissue of infected animals. On the basis of these findings, together with the fact that antibodies against the virus were found by them more commonly in adults and especially in criminal and merchant seamen classes, these investi-

Immunization Against Tetanus with Alum-Precipitated Tetanus Toxoid.

Abstract: IN the earlier papers by Bergey and Etris in 1933 1, 2 on the immunizing value of tetanus toxoid it was shown that the plain toxoid or anatoxin of Ramon 3 was much too irritating for human use. Therefore they refined the plain toxoid by precipitating it with aluminum potassium sulphate and washing, a method similar to that of Wells, Graham, and Havens 4 for diphtheria toxoid. They found that the resulting alum-precipitated toxoid stimulated the formation of tetanus antitoxin when injected into guinea pigs. The alum-precipitated toxoid used throughout these experiments was prepared from a toxin which contained 10,000 m.l.d. per cc. before detoxification. Preliminary work was done by injecting guinea pigs at various intervals with 1 cc. doses of alum-precipitated toxoid. It was found that the serum of such guinea pigs receiving two injections given 90 days apart contained as much as 20 units of tetanus antitoxin per cc. Comparative tests made at the same time demonstrated the superior antigenic value of the alum-precipitated toxoid over the plain toxoid. The results of these experiments led to the following studies made on two groups of humans, youths and adults.

Analysis of the Subsequent Course of Diagnosed Cases of Tuberculosis.

Abstract: THE use of life table procedure in studying morbidity and mortality of those in familial contact with tuberculosis 1 was discussed before the Epidemiology Section of the American Public Health Association by Frost in 1932 Since that time the method has been applied to material in the field of tuberculosis by many of his students Dr Frost was also especially interested in the extension of the life table procedure to the study of the course of the disease, which necessitated the development of a method of handling the information regarding the cases as to death (from all causes) retrogression, or improvement of the patients His intense interest in this analysis was in large part responsible for the development of the method presented here The death and survival rates of cases of tuberculosis were summarized by Brieger 2 in 1937, and the expectation of survival in pulmonary tuberculosis has been shown for cases at the Brompton Hospital3 In many of these studies the status of cases (living or dead) at certain time intervals after admission to, or discharge from sanatoria was known For cases found in