Salmonellosis in wild birds feeding at sewage treatment works.

Between June 1976 and August 1977 faeces were collected from 599 wild British birds caught during ringing operations at two sewage treatment works in south-east England. Samples were incubated with selenite-F broth to detect the presence of Salmonella. Salm. anatum was isolated from one bird, a Dunnock Prunella modularis an incidence of 0.17% of the total birds examined and 3.23% of the Dunnocks. Comparisons are drawn with previously reported studies and it is suggested that sewage treatment works play little part in the transmission of Salmonella infections to wild birds feeding there.     

Mayaro virus in wild mammals, French Guiana

A serologic survey for Mayaro virus (Alphavirus, Togaviridae) in 28 wild nonflying forest mammal species in French Guiana showed a prevalence ranging from 0% to 52% and increasing with age. Species active during the day and those who spent time in trees were significantly more infected, results consistent with transmission implicating diurnal mosquitoes and continuous infectious pressure.The Mayaro virus is a zoonotic Alphavirus (family Togaviridae) responsible for epidemics of febrile exanthematous illness in Latin America and Amazonia (1). Although the death rate is low, Mayaro fever is a major arboviral infection relevant to public health in rural populations, with an increasing incidence of human cases in the Amazonian basin following ecosystem disturbances (2). The activity of the Mayaro virus can be described as a constantly moving wave, transmitted among susceptible vertebrates by sylvatic Culicidae mosquitoes (3). Haemagogus mosquitoes are the main vectors; they are diurnal canopy dwellers common in high pristine rainforests (4). Several vertebrate hosts, mainly primates, rodents, and birds, are considered to be reservoirs, although their exact role in maintaining the virus is insufficiently understood (2). Previous serologic surveys have shown high prevalence rates in primates, but the virus has been isolated only from lizards and one marmoset (5,6); experimental inoculation of marmosets resulted in a short period of viremia, although the titer was nevertheless probably high enough to infect vectors (4). Human disease outbreaks could occur when birds or vectors introduce the virus into rural areas with high densities of both Haemagogus and potential reservoirs.This emerging disease has recently been reported in French Guiana, a French administrative unit on the northern coast of South America (6). To investigate the diversity of the reservoir species, a serologic survey for Mayaro virus was conducted on 28 nonflying mammalian rainforest species, in a total of 579 animals; no previous surveys in wild vertebrate species has included so many samples. Investigations on antibody responses in potential hosts are important first steps for understanding viral dynamics (7). Since the infectious process plays a major role in wildlife ecology (8), we used Mayaro infection as a case study to investigate the correlation between ecologic and biologic patterns of potential hosts and their susceptibility to infection.     

A review of metal accumulation and toxicity in wild mammals. I. Mercury

Release of Hg compounds into the environment from point sources has largely been curtailed due to the known impacts of Hg on biological systems. Mercury continues to be released into the environment, however, from nonpoint sources such as combustion of fossil fuels and smelting operations. While the accumulation and toxicity of Hg in aquatic biota, domestic animals, and humans is well documented, relatively little is understood about these processes in wild terrestrial mammals. The purpose of this paper is to review the available literature on Hg levels and toxicity in wild mammals (excluding marine mammals). It is clear that Hg levels are biomagnified within terrestrial food chains, where carnivores greater than omnivores greater than herbivores. Among carnivorous species, Hg levels are generally highest in fish-eating animals. There is usually a high degree of correlation of Hg levels between different animal tissues. The age and sex of an animal appear to influence observed Hg levels, but field data are conflicting for both factors. Tissue Hg levels are affected by location, with significant differences attributable to both local contamination and natural background variability. Experimental studies have shown many mammal species to sensitive to Hg intoxication, but documented incidents of Hg poisoning in wild mammals are rare. Such rarity may be more a function of our inability to observe and demonstrate Hg poisoning in wild populations, rather than an absence of the disease.     

Excretion of vancomycin-resistant enterococci by wild mammals

A survey of fecal samples found enterococcal excretion in 82% of 388 bank voles (Clethrionomys glareolus), 92% of 131 woodmice (Apodemus sylvaticus), and 75% of 165 badgers (Meles meles). Vancomycin-resistant enterococci, all Enterococcus faecium of vanA genotype, were excreted by 4.6% of the woodmice and 1.2% of the badgers, but by none of the bank voles.     

Isolation of Leishmania species from wild mammals in French Guiana

Between 1981 and 1987, 486 wild mammals collected from 13 sites in French Guiana were examined for Leishmania. Eleven of 31 two-toed sloths, Choloepus didactylus, were infected, 4 of the isolates being identified as L. braziliensis guyanensis. This species was also found in 2 Didelphis marsupialis and 2 Proechimys sp. L. mexicana amazonensis was isolated from 3 Proechimys sp., 2 of which were P. cuvieri. The role of these mammals in the life cycles of the 2 anthropotropic species of Leishmania encountered in French Guiana is discussed.     

Land use and west nile virus seroprevalence in wild mammals

We examined West Nile virus (WNV) seroprevalence in wild mammals along a forest-to-urban gradient in the US mid-Atlantic region. WNV antibody prevalence increased with age, urbanization, and date of capture for juveniles and varied significantly between species. These findings suggest several requirements for using mammals as indicators of transmission.     

Bovine tuberculosis in domestic and wild mammals in an area of Dorset. III. The prevalence of tuberculosis in mammals other than badgers and cattle.

A large sample of the wild mammals found on a farm in South Dorset were trapped and examined for the presence of Mycobacterium bovis following the discovery of widespread infection in cattle and badgers. M. bovis was isolated from the lymph nodes of two out of 90 rats (rattus norvegicus) and one out of seven foxes (Vulpes vulpes) but no lesions of tuberculosis were observed. It was concluded that the badger was the only species of wild mammal which was a reservoir of M. bovis in this area.     

Bovine tuberculosis in domestic and wild mammals in an area of Dorset. I. Tuberculosis in cattle.

A major outbreak of tuberculosis occurred in cattle on a farm in Dorset between 1970 and 1976. Six hundred and twenty-six cattle were slaughtered either because they reacted to the tuberculin test or had been exposed to infection. No source of infection was found until 1974 when badgers infected with Mycobacterium bovis were first discovered. An analysis of the tuberculin test records of this herd and the six surrounding herds indicated that tuberculosis had been a sporadic problem since the early 1960''s. Two peaks of infection occurred in the most severely affected herd in 1970 and 1974 when 20.8% and 27.3% of animals, respectively, reacted to the tuberculin test. These figures are exceptionally high. During the last 20 years there have been two periods when all the herds in the area had synchronous outbreaks consistent with a common source. Analysis indicated that cattle were at greatest risk in April and May and suggest that there was re-exposure to infection at this time each year. In addition the cattle were apparently exposed to M bovis, at sufficiently high levels for transmission to occur, for only a relatively short period of time.     

First detection of tularaemia in domestic and wild mammals in Iran

During a study on the ecology of small-mammal-borne infections in Iran, over 4 600 wild mammals were collected at 47 localities. Attempts were made to isolate Francisella tularensis from the spleens of 3 548 of these animals. All were found to be negative. In addition, sera from 200 sheep and cattle and from 39 wild mammals were tested: 8 sheep, 3 oxen, and 1 hedgehog showed evidence of recent infection. This is the first report of tularaemia in Iran. The relationship of these findings to the potential distribution of natural foci in Iran and adjacent countries indicates that the infection in Asia may be more widespread than was previously thought.     

Bovine tuberculosis in domestic and wild mammals in an area of Dorset. I. Tuberculosis in cattle

A major outbreak of tuberculosis occurred in cattle on a farm in Dorset between 1970 and 1976. Six hundred and twenty-six cattle were slaughtered either because they reacted to the tuberculin test or had been exposed to infection. No source of infection was found until 1974 when badgers infected with Mycobacterium bovis were first discovered. An analysis of the tuberculin test records of this herd and the six surrounding herds indicated that tuberculosis had been a sporadic problem since the early 1960's. Two peaks of infection occurred in the most severely affected herd in 1970 and 1974 when 20.8% and 27.3% of animals, respectively, reacted to the tuberculin test. These figures are exceptionally high. During the last 20 years there have been two periods when all the herds in the area had synchronous outbreaks consistent with a common source. Analysis indicated that cattle were at greatest risk in April and May and suggest that there was re-exposure to infection at this time each year. In addition the cattle were apparently exposed to M bovis, at sufficiently high levels for transmission to occur, for only a relatively short period of time.     

Bovine tuberculosis in domestic and wild mammals in an area of Dorset. III. The prevalence of tuberculosis in mammals other than badgers and cattle

A large sample of the wild mammals found on a farm in South Dorset were trapped and examined for the presence of Mycobacterium bovis following the discovery of widespread infection in cattle and badgers. M. bovis was isolated from the lymph nodes of two out of 90 rats (rattus norvegicus) and one out of seven foxes (Vulpes vulpes) but no lesions of tuberculosis were observed. It was concluded that the badger was the only species of wild mammal which was a reservoir of M. bovis in this area.