Risk for rabies transmission from encounters with bats, Colorado, 1977-1996.
(9/1576)
To assess the risk for rabies transmission to humans by bats, we analyzed the prevalence of rabies in bats that encountered humans from 1977 to 1996 and characterized the bat-human encounters. Rabies was diagnosed in 685 (15%) of 4,470 bats tested. The prevalence of rabies in bats that bit humans was 2.1 times higher than in bats that did not bite humans. At least a third of the encounters were preventable. (+info)
Australian bat lyssavirus infection in a captive juvenile black flying fox.
(10/1576)
The newly emerging Australian bat lyssavirus causes rabieslike disease in bats and humans. A captive juvenile black flying fox exhibited progressive neurologic signs, including sudden aggression, vocalization, dysphagia, and paresis over 9 days and then died. At necropsy, lyssavirus infection was diagnosed by fluorescent antibody test, immunoperoxidase staining, polymerase chain reaction, and virus isolation. Eight human contacts received postexposure vaccination. (+info)
Identification of Mycobacterium bovis in bovine clinical samples by PCR species-specific primers.
(11/1576)
Tuberculosis, caused by Mycobacterium bovis is emerging as the most important disease affecting cattle. Furthermore, it results in a major public health problem when transmitted to humans. Due to its difficult and non-specific diagnosis, M. bovis has been declared to be one of the etiologic agents causing significant economic loss in the cattle industry. Our group evaluated a more rapid and specific method, based on a new polymerase chain reaction species-specific primers, which amplifies a 470-base pair fragment of the M. bovis genome. A total of 275 milk-producing cows were studied by intradermal tuberculin test (ITT) which gave 184 positive and 91 negative cases. From them, 50 animals were taken from a cattle ranch free of tuberculosis. Three different samples were collected from each animal (blood, nasal mucus, and milk). Positive results were obtained from 26 animals by PCR (11.4%), 1 by bacteriological culturing (0.4%) and 1 by bacilloscopy (0.4%). This finding suggests, as in previous reports, that ITT, normally used for bovine tuberculosis detection, has the inconvenience of having a broad range of specificity and sensitivity, and the PCR technique is a more specific and sensitive test to detect infection associated with M. bovis. Therefore, we propose this PCR assay as a useful tool in the epidemiological characterization of infected animals in areas considered to be at high risk of transmission. (+info)
Hyperendemic focus of Q fever related to sheep and wind.
(12/1576)
Q fever is a worldwide zoonosis which is caused by Coxiella burnetii and presents as both acute or chronic cases. The disease can be transmitted from animal reservoirs to humans by the inhalation of infected aerosols. The authors investigated the epidemiology of Q fever in the Bouches-du-Rhone district of southern France. The study area was centered around the small town of Martigues near the cities of Marseille and Aix-en-Provence, where the incidence of the disease seemed higher than in neighboring areas. Epidemiologic data included sheep breeding and wind. Between 1990 and 1995, Q fever was diagnosed in 289 patients, leading to an incidence rate of 35.4 per 100,000 in the study area (range: 6-132), compared with 6.6 in the area of Marseille, and 11.4 in the area of Aix-en-Provence. There was a graphical and statistical relation between the sheep densities, the incidence of the disease, and the strong, local wind known as the Mistral, which blows from the northwest. Although Coxiella burnetii transmission is multifactorial, we may speculate that the high endemicity in the study area is related to a contamination by aerosols because the Mistral blows through the local steppe where 70,000 sheep are bred. This public health problem requires further studies in order to confirm this hypothesis, and to identify more individual and preventable risk factors. (+info)
Hantavirus pulmonary syndrome (HPS) is a rodentborne viral disease characterized by severe pulmonary illness and a case-fatality ratio of 43%. Sin Nombre virus is the primary hantavirus that causes HPS in the United States, and the deer mouse (Peromyscus maniculatus) is its predominant carrier. CDC-sponsored studies of rodent populations since 1994 have yielded data that suggest an increased risk for infection for humans in some areas of the southwestern United States during the summer of 1999. This report describes increases in human cases during January-May 1999, current hantavirus prevalence in rodent populations, the need for renewed attention to reduce the risk for hantavirus exposure, and the importance of physician awareness and early detection in the treatment of HPS. (+info)
Search for cross-species transmission of porcine endogenous retrovirus in patients treated with living pig tissue. The XEN 111 Study Group.
(14/1576)
Pig organs may offer a solution to the shortage of human donor organs for transplantation, but concerns remain about possible cross-species transmission of porcine endogenous retrovirus (PERV). Samples were collected from 160 patients who had been treated with various living pig tissues up to 12 years earlier. Reverse transcription-polymerase chain reaction (RT-PCR) and protein immunoblot analyses were performed on serum from all 160 patients. No viremia was detected in any patient. Peripheral blood mononuclear cells from 159 of the patients were analyzed by PCR using PERV-specific primers. No PERV infection was detected in any of the patients from whom sufficient DNA was extracted to allow complete PCR analysis (97 percent of the patients). Persistent microchimerism (presence of donor cells in the recipient) was observed in 23 patients for up to 8.5 years. (+info)
Cowpox: reservoir hosts and geographic range.
(15/1576)
It is generally accepted that the reservoir hosts of cowpox virus are wild rodents, although direct evidence for this is lacking for much of the virus's geographic range. Here, through a combination of serology and PCR, we demonstrate conclusively that the main hosts in Great Britain are bank voles, wood mice and short-tailed field voles. However, we also suggest that wood mice may not be able to maintain infection alone, explaining the absence of cowpox from Ireland where voles are generally not found. Infection in wild rodents varies seasonally, and this variation probably underlies the marked seasonal incidence of infection in accidental hosts such as humans and domestic cats. (+info)
A comparison of wildlife control and cattle vaccination as methods for the control of bovine tuberculosis.
(16/1576)
The Australian brushtail possum is the major source of infection for new cases of bovine tuberculosis in cattle in New Zealand. Using hypothetical values for the cost of putative cattle and possum Tb vaccines, the relative efforts required to eradicate Tb in cattle using possum culling, possum vaccination or cattle vaccination are compared. For realistic assumed costs for 1080 poison bait, possum culling is found to be a cost-effective strategy compared to cattle vaccination if the required control area is below 13 ha per cattle herd, while possum vaccination is cost-effective for control areas of less than 3 ha per herd. Examination of other considerations such as the possible roles of possum migration and heterogeneities in possum population density suggest that each control strategy may be superior under different field conditions. Finally, the roles of the possum in New Zealand, and the Eurasian badger in Great Britain and Ireland in the transmission of bovine tuberculosis to cattle are compared. (+info)