Excerpt:

Lyme disease is a zoonotic, vector-borne disease affecting humans, dogs,
horses and other species. It is caused by infection with spirochetes of the
Borrelia burgdorferi sensu lato group which are transmitted to the mammalian
host by infected ticks (Ixodes). Exposure to B. burgdorferi is commonly
diagnosed by serological testing. The gold standard for the detection of
antibodies to B.
burgdorferi is a two-step procedure of an ELISA followed by confirmatory
Western blotting (WB). Here, we developed and validated a new bead-based
multiplex assay for the detection of antibodies to B. burgdorferi in canine
serum which combined the testing by ELISA and WB in a single quantitative
test. B. burgdorferi outer surface protein A (OspA), OspC and OspF were
expressed in E. coli. The recombinant proteins were coupled to fluorescent
beads providing the matrix of the assay. Two sets of canine sera were used
for validation of the multiplex assay. First, sera from 79 dogs with known
ELISA and WB results were used to establish the conditions of the assay.
These samples were selected to provide similar numbers of pre-tested sera
ranging from negative to high positive results and included sera from
vaccinated and/or naturally infected dogs. A high correlation was observed
for detection of antibodies to B. burgdorferi in the single and multiplex
assays (n=79). Spearman’s rank correlations were 0.93, 0.88 and 0.96 for
OspA, OspC and OspF, respectively. Second, a total of 188 canine serum
samples that were not tested previously were used for further multiplex
assay validation. All samples were also blindly analyzed for antibodies to
B.
burgdorferi antigens by WB. The WB results provided a ‘relative gold
standard’
for each antigen and were used to perform a receiver operating curve
analysis.
The areas under the curves were 0.93 for OspA, 0.82 for OspC, and 0.89 for
OspF.
Multiplex assay interpretation ranges for antibodies to all three B.
burgdorferi antigens in canine serum were established by likelihood
analysis. The diagnostic sensitivities of the individual OspA, OspC and OspF
bead-based assays were 83%, 62% and 82%, respectively, and the diagnostic
specificities were 90%, 89% and 86%, respectively. The new multiplex assay
provides a sensitive and fully quantitative platform for the simultaneous
evaluation of antibodies to B.
burgdorferi OspA, OspC and OspF antigens and distinguishes between
antibodies that originated from vaccination or natural exposure to B.
burgdorferi.
Copyright A(c) 2010. Published by Elsevier B.V.

Excerpt:

Dogs and people are exposed to and susceptible to infection by
many of the same tick-borne bacterial pathogens in the order
Rickettsiales, including Anaplasma phagocytophilum, Ehrlichia
canis, E. chaffeensis, E. ewingii, Rickettsia rickettsii, R.
conorii, and other spotted fever group rickettsiae. Recent
findings include descriptions of novel Ehrlichia and Rickettsia
species, recognition of the occurrence and clinical significance
of co-infection, and increasing awareness of Rhipicephalus
sanguineus-associated diseases. Newer molecular assays are
available, although renewed efforts to encourage their use are
needed. This review highlights the ecology and epidemiology of
these diseases, and proposes avenues for future investigation.
Published by Elsevier Ltd.

Excerpt:

To determine the role of Bartonella species as causes of acute
febrile illness in humans from Thailand, we used a novel strategy
of co-cultivation of blood with eukaryotic cells and subsequent
phylogenetic analysis of Bartonella-specific DNA products.
Bartonella species were identified in 14 blood clots from febrile
patients. Sequence analysis showed that more than one-half of the
genotypes identified in human patients were similar or identical
to homologous sequences identified in rodents from Asia and were
closely related to B. elizabethae, B. rattimassiliensis, and B.
tribocorum. The remaining genotypes belonged to B. henselae, B.
vinsonii, and B. tamiae. Among the positive febrile patients,
animal exposure was common: 36% reported owning either dogs or
cats and 71% reported rat exposure during the 2 weeks before
illness onset. The findings suggest that rodents are likely
reservoirs for a substantial portion of cases of human Bartonella
infections in Thailand.

Excerpt:

As experts from around the world met in New York this week they discussed the need for greater understanding of the threat posed by ticks, fleas and sand flies. Leading scientists called on veterinarians and dog-owners around the world to take action to protect dogs and humans from potentially lethal diseases.

Ticks, mosquitoes, fleas and, in some countries, sand flies are critical in the transmission of diseases to both dogs and humans, including life-threatening conditions such as Lyme Disease, Leishmaniasis and other important diseases such as Ehrlichiosis.

Excerpt:

The number of known Bartonella species is rapidly growing. Some of them are responsible for distinct infectious diseases and show different prevalence and antibiotic susceptibility profiles. Not only have some vectors of Bartonella not been fully characterized, but also intermediate hosts are actually much more numerous and diverse than previously thought. Among these, dogs differ from cats because they tend to suffer an overt disease similar to humans, thus providing the base for a useful animal indicator and research model. Among the debilitating conditions with an unclear impact on the course of these infections, specific conditions (e.g., homelessness, alcoholism) have been linked to a much higher prevalence and to high risk of unfavorable outcome. Due to the limited arsenal of antibiotics effective in vivo on this peculiar intracellular pathogen, the risk/benefit balance of antibiotic therapy is sometimes difficult to draw. In this evolving picture, the recent discoveries of new species highlights the importance of basic molecular biology resources that would bring major public health benefits if available in endemic areas, and specifically in many areas of Peru and Bolivia.

Excerpt:

We conducted a prospective study to determine causes of acute febrile illness in 4 community hospitals, 2 in Chiang Rai (northern Thailand) and 2 in Khon Kaen (northeastern Thailand). We enrolled patients >7 years of age with a temperature >38°C who were brought to study hospitals for treatment from February 4, 2002, through March 28, 2003. Patients were excluded if they had a history of fever for >2 weeks or an infection that could be diagnosed clinically. Acute-phase serum samples were collected at the time of enrollment and convalescent-phase serum samples 3–5 weeks later. We enrolled nonfebrile control patients >14 years of age who had noninfectious conditions; acute-phase serum samples were collected. Clinical information was abstracted from patient charts. Nurses conducted physical examinations and personal interviews to collect information on patients’ demographic characteristics, exposures to animals, and outdoor activities.

Serum samples were tested for immunoglobulin (Ig) G antibodies to Bartonella spp. by immunofluorescent antibody assay at the Bartonella Laboratory of the Centers for Disease Control and Prevention, Fort Collins, CO, USA. Strains used for antigen production were: B. elizabethae (F9251), B. henselae (Houston-1), B. quintana (Fuller), and B. vinsonii subsp. vinsonii (Baker). Homologous hyperimmune serum specimens were produced in BALB/c mice as previously described (8). Bartonella infection was considered confirmed in febrile patients who had a >4-fold rise in IgG antibody titers and a convalescent-phase titer >64. Probable infection was defined as 1) a 4-fold antibody titer rise but convalescent-phase titers of 64, or 2) high and stable titers (>512 in acute-phase and convalescent-phase serum samples), or 3) acute-phase titer >512 with a >4-fold titer fall. Paired serum samples from febrile patients were also tested for serologic evidence of other common causes of febrile illness in Southeast Asia.

Febrile patients with acute-phase and convalescent-phase IgG antibody titers <128 were considered not to have Bartonella infection; we compared demographic and clinical characteristics of these patients to Bartonella-infected patients. To evaluate potential risk factors, we compared Bartonella-infected case-patients >14 years of age without serologic evidence of other infections (n = 20) to nonfebrile controls with IgG to Bartonella <128 (n = 70). Age adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were calculated.

J Vet Emerg Crit Care (San Antonio). 2010 Feb 1;20(1):8-30.

Bartonellosis: an emerging infectious disease of zoonotic
importance to animals and human beings.

Breitschwerdt EB, Maggi RG, Chomel BB, Lappin MR.

Department of Clinical Sciences, Center for Comparative Medicine
and Translational Research, College of Veterinary Medicine, North
Carolina State University, Raleigh, NC 27606.

Objective- To provide a review of clinically relevant
observations related to Bartonella species as emerging pathogens
in veterinary and human medicine. Data
Sources- Literature as cited in PubMed and as generated by each
of the authors who have contributed to various aspects of the
clinical understanding of bartonellosis. Human Data Synthesis-
Important historical and recent publications illustrating the
evolving role of animal reservoirs as a source of human
infection. Veterinary Data Synthesis- Comprehensive review of the
veterinary literature.

Conclusions- In addition to inducing life-threatening illnesses,
such as endocarditis, myocarditis, and meningoencephalitis and
contributing to chronic debilitating disease, such as arthritis,
osteomyelitis, and granulomatous inflammation in cats, dogs, and
potentially other animal species; pets and wildlife species can
serve as persistently infected reservoir hosts for the
transmission of Bartonella spp. infection to veterinary
professionals and others with direct animal contact.

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PMID: 20230432  [PubMed – in process]