Nathan J. Schneider

Enteric bacteriological studies in a large colony of primates.

Diarrheal diseases consistently have been the major disease problem at the monkey-conditioning farm operated by the National Foundation for Infantile Paralysis a t Okatie Farms, S.C. In 1953 A. V. Hardy, of the Comniission on Enteric Infections of the Armed Forces Epidemiological Board, was called in for consultation to determine what could be done to reduce the high mortality experienced in the monkey colony at Okatie Farms. A preliminary report1 of his findings was presented a t the Animal Care Panel in 1954 in Chicago, Ill. His studies indicated that Shigella and Salmonella were widely present in these primates and that the sulfonamide drug therapy used a t that time was not proving effective in reducing enteric infections or mortality. On the basis of these early findings and in order to determine more fully the nature and extent of enteric infections as they are related to diarrheal disease and mortality, intensive laboratory studies were initiated. Okatie Farms was established to receive shipments of rhesus (Macaca mulatta) and cynomolgus (Macaca cynomolgus) monkeys from India and the Philippines, respectively, and to hold them for a period of conditioning before shipment to laboratories throughout the United States. There has been in recent years an urgent need for large numbers of monkeys for use in tissue culture procedures, for diagnostic studies, and for research in virology, particularly in poliomyelitis. During 1955 more than 60,000 monkeys were received a t Okatie Farms. The physical facilities a t the farm originally were divided into four areas: (1) well area; ( 2 ) ready-for-shipment area; (3) hospital; and (4) recuperation area. Upon arrival, the 80 to 100 animals contained in 6 to 8 small shipping crates were transferred to a large group cage in the well area to be held for 1 to 4 weeks, unless illness ensued. These “gang cages” were checked twice daily, and all apparently ill animals were removed to the hospital for specific therapy. Following clinical recovery from the illness, the animals were transferred to the recuperation area and later to the well area. Clinically healthy animals were placed in the readyfor-shipment area to await distribution. The maintenance in large gang cages and the repeated transfers provided ample opportunity for the spread of enteric infections. Later, the above plan was modified by instituting intramuscular injection of all animals with broad-spectrum antibiotics on their arrival. This was done to ensure mass prophylactic therapy on an individual basis with a minimum handling of animals. Also, in so far as practicable, animals received in one shipment were kept together a t least until most of the animals were distributed. Rhesus and cynomolgus monkeys were always caged separately and in different areas if possible. Each shipment included about 1500 to 1800 animals.

EXPERIMENTAL RABIES INFECTION IN WILD RODENTS

The potential for wild rodents to serve as inapparent rabies reservoirs in nature has not been well evaluated. In this study five species of rodents were inoculated intramuscularly with rabies virus derived from naturally infected wild animals. Inoculated rodents were observed for behavioral changes, and those which died were tested for rabies. Differences in species susceptibility and salivary gland virus tropism were noted and discussed as these factors might affect the epidemiological potential of rabies in wild rodents.

Fox rabies in Florida.

Fox rabies has always been recognized as a substantial part of the rabies problem in Florida. The purpose of this paper is to present our data on rabies in the gray fox (Urocyon cinereoargenteus floridanus Rhoads), the only native species which supports epizootic rabies in Florida. Red foxes (Vulpes fulva), which are increasing in number in parts of the western counties, have not been implicated as rabies vectors. The data presented here were gathered from records of the state and county health organizations, from citizens and public servants who were involved in rabies control work, and from field observations made during control operations in the last four years of an epizootic. Much of the information about rabid fox behavior came from

The First Isolation of St. Louis Encephalitis Virus from Mosquitoes in Florida

Summary A summary of data relating to the initial isolation and identification of St. Louis encephalitis (SLE) virus from Culex mosquitoes in Florida has been presented. The agent PI5 was isolated from mosquitoes collected in November 1961 and was used to prepare HA and CF antigens for serological studies of the 1962 epidemic in Florida.