Abstract. The maintenance of Borrelia burgdorferi in a population of Peromyscus leucopus was investigated from 202 mark and recapture mice and 61 mice that were removed from a site in Baltimore County, Maryland. Borrelia burgdorferi infection was detected by culture and polymerase chain reaction (PCR) of ear tissue, and exposure to the spirochete was quantified by serology. Overall prevalence of B. burgdorferi, as determined by culture and PCR of ear tissue at first capture, was 25% in the longitudinal sample and 42% in the cross-sectional sample. Significantly more juvenile mice were captured in the longitudinal sample (18%) than in the cross-sectional sample (0%). Among 36 captured juvenile mice, only one was infected with B. burgdorferi; this contributed to a significant trend for infection with B. burgdorferi with age. Recovery from infection with B. burgdorferi was not detected among 77 mice followed for an average of 160 days. The incidence rate of infection with B. burgdorferi was 10 times greater in mice captured during two periods of high risk of exposure to nymphal Ixodes scapularis ticks compared with a period of low risk. Maintenance of B. burgdorferi in this population was dependent on indirect transmission of the organism from infected ticks to susceptible mice and development of chronic infection with the spirochete, which had no measurable effect on the survival of infected mice.Since Lyme disease was first described in 1977, 1 it has become the most commonly reported vector-borne disease in the United States. 2 The disease, which is caused by the spirochete Borrelia burgdorferi, 3,4 is transmitted to humans by the bite of an Ixodid tick: Ixodes scapularis in the eastern and northcentral parts of the United States (I. dammini 5 as synonymized by Oliver and others 6 ) and I. pacificus 7,8 in the western United States. An enzootic cycle involving vertebrate hosts and ticks is critical for the maintenance of the spirochete in Lyme disease enzootic areas in the eastern and mid-central parts of the United States because the rate of transovarial transmission of the spirochete in I. scapularis is extremely low. 9 Transovarial transmission of B. burgdorferi in I. pacificus has been demonstrated; 10 however, on the west coast of the United States the relative importance of ticks and vertebrate animals in the maintenance of B. burgdorferi remains unclear.Although B. burgdorferi has been isolated from a wide variety of mammalian and avian hosts in the eastern and northcentral parts of the United States, 11,12 only white-footed mice (Peromyscus leucopus), 13,14 chipmunks (Tamias striatus) and meadow voles (Microtus pennsylvanicus), 15 skunks (Mephitis mephitis) and raccoons (Procyon lotor), 16 and Norway rats (Rattus norvegicus) 17 have been shown to be competent reservoir hosts of B. burgdorferi in enzootic cycles of the organism in those areas. White-footed mice, in comparison with meadow voles and chipmunks 15 and skunks and raccoons, 16 are generally recognized in these areas as the most important reserv...

During surveillance for various tickborne pathogens in the upper Midwest during the summer and early fall of 1995, a Bartonella-like agent was detected in the blood of mice that were concurrently infected with Borrelia burgdorferi or Babesia microti (or both). The organism was isolated in pure culture after inoculation of blood from wild-caught mice into C.B-17 scid/scid mice. Phylogenetic analysis of the 16S rRNA and the citrate synthase genes showed that the novel Bartonella species and a Bartonella isolate from a mouse captured on Martha's Vineyard, Massachusetts, were closely related to each other and secondarily related to Bartonella grahamii and Bartonella vinsonii. [11] has been reported granulocytic ehrlichiosis (HGE), has also been described [1, 2]. All three pathogens are transmitted by the deer tick; acquisiand could account for the occurrence of some coinfected vector ticks. However, coinfection of mice with B. burgdorferi and tion of infection in ticks probably occurs via feeding of immature stages of the tick on the white-footed mouse (Peromyscus Ehrlichia species has not been described. The original intention of this study was to describe the prevaleucopus), which appears to be an important reservoir of infection with all of these agents. Consistent with their overlapping lence of infection with B. burgdorferi, B. microti, and Ehrlichia species in P. leucopus mice, wild-caught in Minnesota and transmission cycles, coinfection with these agents in some human cases has been described, with possible effect on disease Wisconsin. Unexpectedly, instead of detecting Ehrlichia species in the blood of P. leucopus, we detected a novel Bartonella duration and severity [3]. Indeed, coinfection with other tickborne pathogens may be a confounding variable in investigaspecies. Herein we describe the outcome of these surveillance studies and the isolation and initial characterization of the ortions of the biologic variation of Lyme disease [4]. Animal experiments were conducted using a protocol approved by the Mayo delein, IL), identified to species, weighed, sexed, and examined for and 1000 mg of fosfomycin/mL as previously described [14]. The were placed in 10 mM HCl and were dipped in 95% ethanol and

In December 2019, a novel coronavirus of likely zoonotic origin, SARS-CoV-2, was discovered following detection of an outbreak of acute respiratory disease in people from Wuhan, China (Zhou et al., 2020). The virus has since spread across the world and in early March 2020 the WHO declared COVID-19, the disease caused by the virus, a pandemic (https://www.who.int/dg/speec hes/detai l/who-direc tor-gener al-s-openi ng-remar ks-at-the-media -brief ing-on-covid -19---11-march -2020). As of November 2020, worldwide mortality from COVID-19 was over 1,360,000 deaths (https://coron avirus.jhu.edu/map.html; Accessed November 20, 2020).Coronaviruses have large (~30 kb), positive-sense, RNA genomes and are known to infect a variety of mammals and birds. Their genomes are also known to have a high propensity for recombination with other coronaviruses. Coronaviruses are classified as alpha-, beta-, gamma-or deltacoronaviruses. Both alpha-and betacoronaviruses infect mammals, and while worldwide bats are known to be infected by both types of viruses (Decaro & Larusso, 2020; Falcon et al., 2011), only alphacoronaviruses have been found to date in North American bats (Olival et al., 2020).

ABSTRACT:We determined the antibody prevalence