Decreasing prevalence of Q fever in Illinois.

There were 858 (37.7 percent) Q fever-infected dairy herds among the 2,277 tested in Illinois in 1963. The percentage decreased to 19.2 percent (380 of 1,975) in 1967. Reaction rates (complement-fixation test titer of 1:8 or greater) in serum samples from veterinarians decreased from 13.3 percent in 1956 to 3.9 percent in 1964 and from 3.6 percent in 1966 to 0 percent in 1968, 1970, 1972. There were 14 (2.7 percent) reactive serum samples among 526 abattoir workers tested in 1966; reaction rates were higher among workers having contact with swine (8.2 percent) than among workers having contact with cattle (1.8 percent). Two (0.1 percent) of 1,432 serum samples collected from 1967 to 1971 during preemployment examinations at another abattoir were reactive. Only two clinical cases of Q fever were reported to the Illinois Department of Public Health in the period 1963-80. All evidence evidence points to a decreasing prevalence of Q fever in Illinois.

Malignant catarrhal fever III. Experimental infection of sheep, domestic rabbits and laboratory animals with malignant catarrhal fever virus.

Five of 19 sheep became infected when inoculated with a virulent strain of malignant catarrhal fever virus isolated in Kenya One of the infected animals was killed in extremis; its blood and lymph node suspension reproduced the classical disease in three steers. Calves exposed to these sheep did not become infected during 89 days of close contact. The Kenya strain of malignant catarrhal fever virus infected rabbits, guinea pigs and hamsters, producing occular and nasal discharges, paralysis and death. The virus recovered from these animals in cell cultures produced disease in rabbits and steers. Neutralizing antibodies were found in the rabbit sera. Infant mice, chicken and duck embryos were refractory to infection with malignant catarrhal fever virus.

Un metodo simplificado para la deteccion de anticuerpos contra la fiebre porcina africana, mediante la inmunoelectroosmoforesis. / A simplified method for the detection of african swine fever antibodies by immunoelectroosmophoresis

Se han elaborado equipos con nuevo diseno y procedimientos que permiten detectar con mayor rapidez las precipitinas contra el virus de la fiebre porcina africana. La metodologia se puede aplicar tambien en el diagnostico de la hepatitis y en otros procedimientos electroforeticos. La gran reduccion de los costos hace estos metodos accesibles a los laboratorios pequenos

Comparison of African and American forms of malignant catarrhal fever: transmission and clinical signs.

African and American forms of malignant catarrhal fever (MCF) infections were produced by inoculating blood from affected cattle into susceptible cattle. Ease of disease transmission, incubation period, volume of blood required for infection, and clinical signs were compared in 30 cattle with African MCF and in 19 with American MCF. American MCF was more difficult to transmit than was African MCF and required eight to ten times more blood as inoculum. American MCF incubation period was more than twice as long as that of the African MCF, but the disease course was three times shorter. Clinical signs were similar for the two forms; however, in the American form, the disease was more acute and a larger percentage of animals had severe diarrhea.

A progress report on the status of a new disease of American cats: cytauxzoonosis.

A protozoon disease of domestic cats in the U.S.A. which resembled diseases of African ungulates caused by blood parasites of the family Theileridae and the genus Cytauxzoon was first described by scientists of the University of Missouri in 1976. The Plum Island Animal Disease Center of the U.S. Department of Agriculture (USDA) became involved in an effort to discover the relationship of the parasite to those of African species and to ascertain if the disease posed a threat to American livestock. More than 500 cats were infected and the disease studied experimentally by scientists of both institutions. Passage of the parasite was accomplished by parenteral administration of fresh or deep frozen blood or tissues from infected cats. With the exception of a single cat, immunized at PIADC, the experimental disease has terminated fatally about 20 days following exposure. Most cats died within 9-15 days after infection. Diagnosis of the disease is accomplished by study of blood smears, stained with Giemsa and by examination of sections from major visceral organs. Piroplasms are not always found in blood smears, but large masses of schizonts are always found in at least one of the following organs: lungs, spleen, liver or lymph nodes. Since the disease almost invariably has a fatal termination in cats, it is believed that the reservoir is in another species of animal. The new disease has now been reported from Missouri, Arkansas, Texas and Georgia, with new isolations of the parasite having been made in recent months.

An indirect fluorescent antibody test for the detection of Cytauxzoon-like organisms in experimentally infected cats.

Antiserum to feline Cytauxzoon-like parasites was used in conjunction with labeled rabbit antisera to feline globulins to detect the presence of Cytauxzoon-like parasites in spleens of experimentally infected cats. Frozen spleen sections from 21 infected cats showed positively fluorescing masses within splenic veins and a diffuse scattering of discretely fluorescing cells in the red and white pulp. The distribution of fluorescence corresponded with the appearance of parasitized reticuloendothelial cells in histological preparations of spleen tissue. This indirect fluorescent antibody test consistently detected the presence of Cytauxzoon-like parasites in frozen spleen sections from experimentally infected cats.

Experimental infection of white-tailed deer with rinderpest virus.

White-tailed deer (Odocoileus virginianus) succumbed to experimental infection with virulent rinderpest (RP) virus that was also lethal to cattle and goats. The deer developed clinical signs typical of RP and died 5 and 6 days post-inoculation. Infection was confirmed by recovery of virus from blood before death, from lymph node tissue after necropsy, and demonstration of specific complement fixing antigen in those tissues. Electron micrographs of infected Vero cell cultures revealed extracellular virions and intracytoplasmic and intranuclear inclusions made of randomly distributed fibrillar strands.