sources of replacements for breeding flocks (2) the use of separate hatching facilities for eggs from such flocks (3) the frequent use of diagnostic laboratories, to discover new outbreaks which may endanger future replacement sources (4) the recognition of numerous animal reservoirs of these diseases which must be controlled to prevent transmission (5) fly control, and (6) cooperation of growers, hatcheries, veterinarians and State agencies in securing replacements from salmonellosis free sources. PARACOLON INFECTIONS The signifiance of the etiological relationship between paracolon organisms and enteric infections in man is difficult to determine due to the frequent recovery of some of these strains from the feces of apparently healthy persons and the lack of adequate methods of classification of different types. However, there have been numerous reports (8, 9, 30, 31) indicating pathogenicity of some types. Many of the paracolon organisms contain antigens common to the Salmonella and Shigella groups. This is particularly true of the Arizona group of paracolons which are closely related to the Salmonella. The excellent work of Edwards and his coworkers (32, 33, 34, 35) in establishing a satisfactory serologic classification for the Arizona group and presentation of epidemiological data leaves no doubt that these paracolon organisms are pathogenic for animals. The majority of cultures of this group that have been studied were isolated from fowls, egg powder, and reptiles. Many cultures were obtained by Hinshaw and McNeil (36,37) during studies of infections among reptiles and turkeys. The symptoms and pathology in birds infected with these paracolon bacilli are comparable to those which occur in salmonellosis in fowls. The organisms have been isolated from heart blood, and all organs indicating a definite septicemia; young fowls, particularly poults, appear more susceptible. Mortality in flocks was comparable to that found in Salmonella infections. The spread of the infections by hatcheries and through eggs has been clearly established (35, 36). There have been scattered reports of the isolation of Arizona paracolon bacilli from man. Of 456 cultures studied by Edwards, West and Bruner (35) 5 were from human sources. All were from cases of enteric infection in which no other pathogenic organisms were recognized. Verder et al (38) isolated a paracolon identified by Edwards as Ar. 1, 2: 1, 2,5 from 70 percent of patients cultured during an outbreak of gastro-enteritis involving 51 student nurses. The organism was not obtained from 16 normal students cultured. Buttiaux and Kesteloot (39) reported the isolation of paracolon bacilli similar to the Arizona group from 6 patients, 3 with acute enteric disease, 2 with chronic colitis, and 1 with a typhoidlike fever. In 1950, Murphy and Morris (40) described 2 small outbreaks of gastroenteritis, both of which were associated with a member of the Arizona paracolon group. In both episodes, evidence relating to source of infection, incubation period and symptoms of individuals involved resembled the pattern observed in food infections due to Salmonella. Bacteriological findings indicated the paracolon bacillus was the etiologic agent. Thus, the necessity for the prevention and control of this infection in fowl is obvious. ERYSIPELAS The occurrence of a septicemia associated with Erysipelothrix rhusiopathiae the causative agent of swine erysipelas and erysipeloid infection in man, has been reported in many species of birds. Fish though not susceptible carry the organism on the slime. The disease is relatively common in turkeys and ducks (41, 42, 43). It is characterized in acute cases by febrile symptoms and occasionally diarrhea; death may occur in 1 to 2 days; in chronic cases by loss of appetite, diarrhea and gradual emaciation (44). Diagnosis depends upon bacteriological examination as lesions are indefinite and not usually considered pathognomonic. The infection in man, first recognized by Rosenbach, in 1884, may occur as a mild, localized cutaneous lesion, sometime accompanied by mild arthritic symptoms; as a diffuse or generalized cutaneous eruption, with arthritic symptoms and negative blood culture or as a septicemic form with endocarditis (45). Chronic cases of long duration have also been reported (46). Ersipeloid has long been recognized as an occupational disease of abattoir employees, veterinarians, butchers, kitchen workers and those handling poultry and fish (47). In a review of 100 cases Klauder (48) was able to obtain a history of contact with animals, animal products or fish. Stiles (41) reported cutaneous lesions and symptoms of erysipeloid in the owners of an infected turkey flock. Successful treatment of the disease in man with penicillin has been reported frequently (46, 49, 50). Stiles considered the public health significance of marketing possible infected turkeys and outlined the procedure followed in an outbreak in one flock. Apparently healthy fowls were marketed to a processing plant where they were subjected to Federal inspection. Questionable birds were rejected and the slaughtered birds were boned and sterilized by canning. According to Klauder (48), the virulence of E. rhustopathiae varies in different species and in the same species. The organism has the capacity to change suddenly from a harmless saprophyte to a pathogenic parasite. Although man is relatively immune when the organism enters the gastro intestinal tract, cutaneous infections appear rather commonly. Skalova (51) in Yugoslavia has reported one fatal case of infection with E. rhusiopathiae. STAPHYLOCOCCOSIS Staphylococci are widely distributed in nature but they may cause a variety of disease entities in man, domestic animals and fowl. Avian staphylococcosis has been reported in turkeys by Jungherr (52) Hinshaw and McNeil (53) and Hinshaw (54), in geese by Lucet (55), in ducks by Van Heelsbergen (56), and less frequently in chickens (57, 58). In fowl the infection occurs as an acute septicemia or chronic arthritis also known as bursitis, hock disease, ostitis or synovitis. In man, the most frequent manifestation is food poisoning, produced by an enterotoxin liberated by the growth of some staphylococcus strains in food prior to ingestion. Septicemia occurs occasionally in man. Although, no reports have been found concerning the transmission of fowl staphylococcosis to humans McNeil (59) states that they have isolated Micrococcus pyrogenes from boils on the hands of workers in poultry killing plants. This potential source of infection in man warrants further study. STREPTOCOCCOSIS Streptococcus infections occur in both man and birds. Ingalls (1) is of the opinion that the infection in poultry does not play a prominent part in human disease, however, he has observed that the handling, dressing or eating of infected birds may serve as a source of infection in man. Acute streptococcic septicemia in fowls was first observed in this country by Norgaard and Mohler, 1902 (60) and later by Hudson (61). The disease is highly fatal. A chronic infection of hens due to hemolytic streptococci (group C) was reported by Edwards and Hull (62). Buxton (63) in England reports an acute infection of poultry due to streptococcus zooepidemicus which became chronic after 4 weeks. Edwards (64) states that all streptococcal infections of poultry that he has encountered have been due to the so-called animal group C types. A search of the literature reveals no reports of infection of fowls due to group A streptococcus strains. TUBERCULOSIS Avian tuberculosis is widely distributed in poultry throughout the central and north central sections of the United States. It frequently also infects swine, occasionally cattle and rarely man. It is most common in chickens and pigeons, although it does infect other species of fowl. Chickens are susceptible only to the avian type of the tubercle bacillus. The question of the pathogenicity of avian tubercle bacilli for man has received much speculation. Feldman (65) has reviewed the literature up to 1938 and concluded that although human infection does occur, it is very rare. He further observed that many of the reported cases were inadequately or incompletely studied resulting in a questionable diagnosis of avian tuberculosis. Rich (66) reviewed the data available up to 1944 and noted "that if progressive tuberculosis is ever produced in the human being by the avian tubercle bacillus it must be only rarely." There have been a few confirmed cases, however, in which the organisms were identified. Bradbury and Younger (67) reported a case of pulmonary tuberculosis in a man from whom organisms were identified as the avian type on three occa sources of replacements for breeding flocks (2) the use of separate hatching facilities for eggs from such flocks (3) the frequent use of diagnostic laboratories, to discover new outbreaks which may endanger future replacement sources (4) the recognition of numerous animal reservoirs of these diseases which must be controlled to prevent transmission (5) fly control, and (6) cooperation of growers, hatcheries, veterinarians and State agencies in securing replacements from salmonellosis free sources. The signifiance of the etiological relationship between paracolon organisms and enteric infections in man is difficult to determine due to the frequent recovery of some of these strains from the feces of apparently healthy persons and the lack of adequate methods of classification of different types. However, there have been numerous reports (8, 9, 30, 31) indicating pathogenicity of some types. Many of the paracolon organisms contain antigens common to the Salmonella and Shigella groups. This is particularly true of the Arizona group of paracolons which are closely related to the Salmonella. The excellent work of Edwards and his coworkers (32, 33, 34, 35) in establishing a satisfactory serologic classification for the Arizona group and presentation of epidemiological data leaves no doubt that these paracolon organisms are pathogenic for animals. The majority of cultures of this group that have been studied were isolated from fowls, egg powder, and reptiles. Many cultures were obtained by Hinshaw and McNeil (36,37) during studies of infections among reptiles and turkeys. The symptoms and pathology in birds infected with these paracolon bacilli are comparable to those which occur in salmonellosis in fowls. The organisms have been isolated from heart blood, and all organs indicating a definite septicemia; young fowls, particularly poults, appear more susceptible. Mortality in flocks was comparable to that found in Salmonella infections. The spread of the infections by hatcheries and through eggs has been clearly established (35, 36). There have been scattered reports of the isolation of Arizona paracolon bacilli from man. Of 456 cultures studied by Edwards, West and Bruner (35) 5 were from human sources. All were from cases of enteric infection in which no other pathogenic organisms were recognized. Verder et al (38) isolated a paracolon identified by Edwards as Ar. 1, 2: 1, 2,5 from 70 percent of patients cultured during an outbreak of gastro-enteritis involving 51 student nurses. The organism was not obtained from 16 normal students cultured. Buttiaux and Kesteloot (39) reported the isolation of paracolon bacilli similar to the Arizona group from 6 patients, 3 with acute enteric disease, 2 with chronic colitis, and 1 with a typhoidlike fever. In 1950, Murphy and Morris (40) described 2 small outbreaks of gastroenteritis, both of which were associated with a member of the Arizona paracolon group. In both episodes, evidence relating to source of infection, incubation period and symptoms of individuals involved resembled the pattern observed in food infections due to Salmonella. Bacteriological findings indicated the paracolon bacillus was the etiologic agent. Thus, the necessity for the prevention and control of this infection in fowl is obvious. ERYSIPELAS The occurrence of a septicemia associated with Erysipelothrix rhusiopathiae the causative agent of swine erysipelas and erysipeloid infection in man, has been reported in many species of birds. Fish though not susceptible carry the organism on the slime. The disease is relatively common in turkeys and ducks (41, 42, 43). It is characterized in acute cases by febrile symptoms and occasionally diarrhea; death may occur in 1 to 2 days; in chronic cases by loss of appetite, diarrhea and gradual emaciation (44). Diagnosis depends upon bacteriological examination as lesions are indefinite and not usually considered pathognomonic. The infection in man, first recognized by Rosenbach, in 1884, may occur as a mild, localized cutaneous lesion, sometime accompanied by mild arthritic symptoms; as a diffuse or generalized cutaneous eruption, with arthritic symptoms and negative blood culture or as a septicemic form with endocarditis (45). Chronic cases of long duration have also been reported (46). Ersipeloid has long been recognized as an occupational disease of abattoir employees, veterinarians, butchers, kitchen workers and those handling poultry and Distribution of the infection in man and animals appears to be worldwide (78, 79); in chickens outbreaks have been reported in many parts of the United States and England (80, 81, 82). Although no reports have been found to indicate direct transmission of Listeria infection from poultry to man the fact that both are susceptible warrants consideration of the situation from a public-health standpoint. PASTEURELLA According to Burroughs (83) grouse, sage hen, quail, and horned owl have been found naturally infected with tularemia. At least two cases of tularemia (84, 85) have occurred in man where the source of infection was attributed to pheasants dressed by the individuals. Apparently the disease does not exist or is very rare in poultry since it is not referred to in Disease of Poultry edited by Biester and Schwarte in 1948. Pseudotuberculosis Pseudotuberculosis caused by Pasteurelia pseudotuberculosis rodentium, is a disease occurring in birds, animals, and man (86, 87). It is characterized by an acute septicemia of short duration followed by a chronic focal infection which gives rise to tubercular lesions in various organs. In fowl, outbreaks have been reported chiefly in turkeys and rarely in ducks, pigeons, and chickens causing considerable losses in the former. In man it appears to be rare but highly fatal. Meyer (88) refers to reports of 14 human cases, 11 of which terminated fatally. According to Meyer the mode of transmission is not definitely known, but it is believed that P. pseudotuberculosis, widely distributed in nature and disseminated through infectious excretions of affected birds or rodents, attacks susceptible animals through the digestive tract. Usually the abdominal viscera are primarily diseased. Injuries of the skin may also serve as portals of entry. Direct or indirect contact may introduce the infection into a flock of birds. Hygenic conditions and prevention of exposure to infection are the usual prophylactic procedures. Pasteurella multocida, as the name indicates has more than one host. The many strains of this group change continuously in physiologic functions, antigenic structure, and pathogenic ability. The total range of susceptible animal species is wide including man, rodents, herbivores, fowls and possibly carnivores but each host has its characteristic limitations beyond which it rarely goes in spontanteous disease. The first bacteriologically proved human case was reported by Brugnatelli (88) in 1913. Since that time human infections with P. multocida are being recognized more frequently. A review of the literature since 1930 by Schipper (90) revealed 21 bacteriologically proven cases from reports on 39 cases. Further evidence to support the occurrence of more frequent infection in man was presented by Needham (91). He isolated P. multocida from 11 patients of the Mayo Clinic during 1947. Later Olsen and Needham (92) reported the isolation of this organism from an additional 26 cases bringing the total to 37 cases observed at the Mayo Clinic during the period from October 1946 to July 1951. Twenty-seven of the 37 patients were either farmers or members of a farmer's family. The source of material for bacteriologic study included bronchial secretion 17, sputum 15, empyema fluid 2, abscess of frontal sinus 1, appendiceal abscess 1, and purulent drainage from joint 1. All strains from these cases were found to be sensitive to low concentrations of penicillin. Although most of the patients had bronchiectasis, the authors consider P. multocida a probable "secondary invader." They emphasize, however, that the isolation of animal Pasteurella in cases of human disease has a definite significances. In view of the relative prevalence of human infection they recommend a more thorough search be made for this organism in infected material. Neter and associates (93, 94) have observed P. multocida wound infections in four children following bites by or contact with animals. These investigators (95) found aureomycin superior to terramycin treatment of P. multocida infection in mice. Numerous outbreaks of Pasturella infection (fowl cholera) in poultry have caused considerable losses. Murray (96) states that "while man may generally consume without harm fowls that are suffering from the disease, it is advised that their meat should under no circumstances be used as human food." DIPHTHERIA Although there appears to be no evidence indicating that diphtheria in poultry is of public health significance, at least one human case has been reported in which evidence pointed to chickens as the source of infection. In a study of 256 cases of human diphtheria where contact with chickens was established, Litterer (97) reported 2 instances in which fowl harbored the virulent organisms. Identical organisms were isolated from a child in the family who owned the fowls. He was able to infect chickens with cultures obtained from infected children and chickens and concluded that fowl can transmit virulent diphtheria to man. According to Huyyra and Marek (44) the "so called" fowl diphtheria or "roup" is caused by a virus and the disease is now known as the muco-membranous form of fowl pox. VIRUS DISEASES Eastern equine encephalitis Eastern equine encephalitis, primarily a summer disease of equine and avian animals, is transmissible to man, in whom it is usually characterized by extensive inflammation and destruction of the central nervous system. It was first recovered from human CNS tissue by Fothergill et al (98), 1938; in the same year the first natural outbreak in birds was reported by Tyzzer, Sellers, and Bennett (99) who encountered fatal infection in ringnecked pheasants in Connecticut. Also in 1938 Fothergill et al (100) observed natural infection in pigeons in Massachusetts. Beaudette and Black (101) have reported the appearance of natural outbreaks of pheasants in New Jersey from 1938 through 1946 except in 1940 and 1941. Davis (102) found that 6 species of Aedes mosquitoes were capable of transmitting the virus from infected birds to normal animals after a 9-day incubation period. Mosquitoes fed on infected birds transmitted virus to mice and birds; those fed on mice transmitted it to birds, mice and guinea pigs. The symptoms reported in pheasants include paralysis, staggering, head drawn over back, and anorexia. Death occurred 1 or 2 days or the birds recovered slowly. The infection has been produced experimentally in chickens and turkeys. After experimental inoculation, Ten Broeck (103) and Tyzzer (104), working independently, showed that chickens may develop a viremia without visible signs of infection. In man, children appear more susceptible. A mortality rate of 65-70 percent has been reported in the age group under 10 years. Western and St. Louis encephalitis The western and St. Louis types of encepholamyelitis are similar in many respects and although they are quite distinct from the eastern type, they also infect a wide range of hosts including equine animals and fowl. The extensive studies of Hammon have shown the important role that birds play in the epidemiology of these diseases. During the summer of 1941 Hammon et al. (105, 106) in the Yakima Valley, Wash., found that Culex tarsalis mosquitoes were infected with the viruses of Western and St. Louis equine encephalitis, and that approximately 50 percent of the chickens of the area had specific antibodies for these viruses, but no chicken epizootic had been observed. Experimental infection with both viruses produced a viremia but no signs of illness. Evidence indicates that viremia of man and horses is of short duration. Virus isolations from blood are rare. These authors also observed that Culex tarsalis fet predominantly on birds. Recently (107, 108) the chicken mite Dermanyssus gallinae has been found infected with the St. Louis and western type viruses. These findings have focused even more attention on the chicken as an important source of mosquito infection. In further studies in the Yakima Valley, Hammon (109) examined 576 sera from mammals and wild and domestic birds by the neutralization test for antibodies against both viruses. Each of the viruses were positive in approximately 50 percent of sera from domestic fowl; 17-22 percent in wild birds, and only 8 percent from wild mammals. |