Ten years after the
discovery of spirochaetes as agents of Lyme disease in 1982 in the USA,
three genomic species had diverged from the phenotypically heterogeneous
strains of Borrelia burgdorferi isolated in North America and Europe:
Borrelia afzelii, B. burgdorferi sensu stricto (further B. burgdorferi),
and Borrelia garinii.
Abstract The presence of antibodies toOccurrence of Spotted Fever Rickettsiosessera of 129 forest
workers from northeastern and southern Poland was assayed by indirect
immunofluorescence. Previous environmental studies revealed presence of
spotted fever group (SFG) rickettsiae in ticks collected from these areas.
Additionally, the workers were examinated for the presence of antibodies
specific to other tick-borne bacteria: Anaplasma phagocytophilum, Bartonella
spp., and B.
burgdorferi.
The results of the studies have shown the presence of specific SFG
rickettsiae antibodies in 14.7% of tested forest workers, among them 78.9%
had species-specific antibodies to R. massiliae. Contrary to previous
detection R.
helvetica and R. slovaca in ticks collected in the environment of the
examined area, no species-specific antibodies to these species were detected
in studied workers. Antibodies to B. burgdorferi (44%) were found in forest
workers more often than antibodies to other tested pathogens. B. burgdorferi
was also the main component of coinfections. The most frequent confirmed
serologically coinfections were simultaneous infections with B. burgdorferi
and Bartonella spp. found in 10% of tested individuals. So far, SFG
rickettsiae infections have not been diagnosed in Poland; however, the
presence of the bacteria in ticks and presence of specific antibodies in
humans exposed to arthropods show the need for monitoring the situation. The
list of tick-borne pathogens is increasing, but knowledge about the
possibility of humans acquiring multipathogens infections after tick bite
still needs evaluation.
In the far-western United States, the nymphal stage of the
western black-legged tick, Ixodes pacificus, has been implicated
as the primary vector to humans of Borrelia burgdorferi sensu
stricto (hereinafter referred to as B. burgdorferi), the
causative agent of Lyme borreliosis in North America. In the
present study, we sought to determine if infection prevalence
with B. burgdorferi in I.
pacificus nymphs and the density of infected nymphs differ
between dense-woodland types within Mendocino County, California,
and to develop and evaluate a spatially-explicit model for
density of infected nymphs in dense woodlands within this
high-incidence area for Lyme borreliosis. In total, 4.9%
(264) of 5431 I. pacificus nymphs tested for the presence of B.
burgdorferi were infected. Among the 78 sampling sites, infection
prevalence ranged from 0 to 22% and density of infected nymphs
from 0 to 2.04 per 100 m(2). Infection prevalence was highest in
woodlands dominated by hardwoods (6.2%) and lowest for redwood
(1.9%) and coastal pine (0%). Density of infected nymphs also was
higher in hardwood-dominated woodlands than in conifer-dominated
ones that included redwood or pine. Our spatial risk model, which
yielded an overall accuracy of 85%, indicated that warmer areas
with less variation between maximum and minimum monthly water
vapor in the air were more likely to include woodlands with
elevated acarological risk of exposure to infected nymphs. We
found that 37% of dense woodlands in the county were predicted to
pose an elevated risk of exposure to infected nymphs, and that
94% of the dense-woodland areas that were predicted to harbor
elevated densities of infected nymphs were located on
privately-owned land.
Borrelia burgdorferi sensu lato, carried by Ixodes ticks, is one of the
most significant human pathogens responsible for Lyme disease. As there
is no standardized method of polymerase chain reaction (PCR) for
detection and identification of spirochetes’ DNA, we carried out a
comparative analysis using a set of complementary primers for three
regions in the genomic DNA of these bacteria (genes fla, rrs and
non-coding rrs-rrlA region). DNA extracted from 579 Ixodes ricinus ticks
was subjected to nested PCR. DNA of the examined spirochetes was
detected in 43 (7.4 %) lysates when we used fla gene as molecular
marker, in 7 (1.2 %), using primers complementary to the rrs gene, and
in 12 (2.1 %) lysates complementary to the non-coding rrs-rrlA sequence.
Restriction fragment length polymorphism (RFLP) analysis, based on fla
gene, helped identify species from the B. burgdorferi sensu lato (B.
burgdorferi sensu stricto, B. afzelii, B. garinii, B. valaisiana),
detect co-infections, and also identify B. miyamotoi. Therefore the fla
gene is the most sensitive and specific molecular marker for the
detection and identification of Borrelia spirochetes in I. ricinus.
Abstract: The life transmission cycle of B. burgdorferi requires migration of spirochetes from tick’s gut to its salivary glands during vertebrate’s blood sucking, penetrating to the vertebrate’s tissues and their colonization. A special feature of these bacteria, despite
its relatively small genome, is the ability to adapt in different host environments. Continued
Clinical practice guidelines are increasing in number. Unfortunately,
when scientific evidence is uncertain, limited, or evolving, as is often
the case, conflict often arises between guideline committees and
practicing physicians, who bear the direct responsibility for the care of
individual patients. The 2006 Infectious Diseases Society of America
guidelines for Lyme disease, which have limited scientific support,
could, if implemented, limit the clinical discretion of treating physicians
and the treatment options available to patients
Introduction
Clinical practice guidelines are now ubiquitous throughout the
United States. The National Guidelines Clearing House, under the
category “diseases,” currently lists 2,126 separate guidelines on its
web site. Clinical guidelines are intended to assist physicians in
patient care by clearly communicating the results of the guideline
committees’ evaluation of available therapeutic options. However,
the processes by which individual guidelines are constructed may be
less clear, leading to disagreements between the issuing committee
and the physicians who treat patients-physicians who may well be
as experienced and knowledgeable as the guideline committee. Continued
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Borrelia burgdorferi sensu lato, carried by Ixodes ticks, is one of the
