By Linda on Dec 30, 2009 in Infections | comments(0)
Background: Morphea, granuloma annulare (GA) and lichen sclerosus et atrophicans (LSA) have also been suggested to be linked to Borrelia infection. Previous studies based on serologic data or detection of Borrelia by immunohistochemistry and polymerase chain reaction (PCR) reported contradictory results. Thus, we examined skin biopsies of morphea, GA and LSA by PCR to assess the prevalence of Borrelia DNA in an endemic area and to compare our results with data in the literature.
Methods: Amplification of DNA sequences of Borrelia burgdorferi sensu lato by nested PCR from formalin-fixed and paraffin-embedded skin biopsies of morphea, GA and LSA, followed by automated sequencing of amplification products. PCR-based studies on Borrelia species in these disorders published until July 2009 were retrieved by a literature search. Continued
By Linda on Dec 19, 2009 in Infections | comments(0)
Rates of infection of Amblyomma americanum (L.) by Ehrlichia chaffeensis were
compared in 100 ticks collected from sites in each of four states: Indiana,
North Carolina, Kentucky, and Mississippi. The overall infection rates were
similar among sites, ranging from 1 to 4%. Because pathogenic differences may
exist between E. chaffeensis strains, nested polymerase chain reaction (PCR)
amplification of the variable-length PCR target (VLPT), and sequencing of the
amplicons were performed to differentiate between strains. The most common
infecting strains at all sites exhibited a repeat profile of 1,2,3,4
(corresponding to the Arkansas/Jax/Osceola and Liberty strains). To determine
whether the minimum infection rates (MIRs) or the most common infecting strain
were changing over time in southern Indiana sites, 2765 ticks from six counties
in 2000 and 837 ticks from seven counties in 2004 also were examined in pools of
five ticks per pool. The MIRs for 2000 and 2004 were 3.5 and 4.2% respectively,
suggesting that the overall MIRs remained low. At two sites, in Pike and
Harrison counties, however, infection rates more than doubled from 2000 to 2004
(7 to 16% and 0.3 to 2.7% respectively). Across all sites, the most common
infecting strains (Arkansas/Jax/Osceola and Liberty) did not significantly
change (68% in 2000; 79% in 2004). Continued
By Linda on Dec 19, 2009 in Infections | comments(0)
Among the various species of hard ticks, Ixodes ricinus is the most frequently
found tick throughout Europe. As with other ixodid ticks, the developmental
cycle runs through three stages. In each stage a blood meal is required in order
to develop to the next stage. Ixodes ricinus has been found to feed on more than
300 different vertebrate species. Usually, larval ticks feed on small mammals
such as mice and become infected with various microorganisms and viruses, of
which some are substantial pathogens to humans. The pathogens remain in the tick
during molting and are thus transstadially transmitted to the next developmental
stage. Pathogens transmitted to humans are the agents of Lyme borreliosis, the
tick-borne encephalitis virus, Rickettsia species, Anaplasma phagocytophilum,
occasionally Francisella tularensis, and protozoal Babesia species. Within the
scope of an EU project Ixodes ricinus ticks from all federal states of Austria
were searched by means of PCR methods for bacterial pathogens such as Anaplasma
phagocytophilum, Borrelia burgdorferi sensu lato, Coxiella burnetii, Ehrlichia
spp., Francisella tularensis, Rickettsia spp., and protozoal Babesia.
Additionally, the prevalence of Bartonella spp. in this tick species was also
determined. Besides the singular detection of Coxiella burnetii and Francisella
tularensis in one tick collection site the overall prevalence of Anaplasma
phagocytophilum, borreliae, rickettsae and babesiae in Ixodes ricinus amounted
to 15%, 14%, 6% and surprising 36% and 51%, respectively. Bartonellae were
detected in about 7%.
By Linda on Dec 14, 2009 in Infections | comments(0)
A total of 559 fleas representing four species (Pulex irritans, Ctenocephalides felis, Ctenocephalides canis and Spilopsyllus cuniculi) collected on carnivores (five Iberian lynx Lynx pardinus, six European wildcat Felis silvestris, 10 common genet Genetta genetta, three Eurasian badger Meles meles, 22 red fox Vulpes vulpes, 87 dogs and 23 cats) in Andalusia, southern Spain, were distributed in 156 pools of monospecific flea from each carnivore, and tested for Bartonella infection in an assay based on polymerase chain reaction (PCR) amplification of the 16 S-23 S rRNA intergenic spacer region. Continued
By Linda on Dec 7, 2009 in Infections | comments(0)
HLA-DR alleles determine responsiveness to Borrelia burgdorferi antigens in a
mouse model of self-perpetuating arthritis.
Iliopoulou BP, Guerau-De-Arellano M, Huber BT.
Tufts University, Boston, Massachusetts.
OBJECTIVE: Arthritis is a prominent manifestation of Lyme disease, which is
caused by infection with Borrelia burgdorferi (Bb). Chronic Lyme arthritis
persisting even after antibiotic treatment is linked to HLA-DRB1*0401 (DR4) and
related alleles. In contrast, patients whose Lyme arthritis resolves within 3
months postinfection show an increased frequency of HLA-DRB1*1101 (DR11). The
aim of this study was to analyze the underlying mechanism by which HLA-DR
alleles confer genetic susceptibility or resistance to antibiotic-refractory
Lyme arthritis. Continued
By Bryan Rosner on Nov 29, 2009 in Infections | comments(0)
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
By Linda on Nov 29, 2009 in Infections | comments(0)
Encephalopathy is like fine art: Most people know it when they see it, but there is very little agreement on how to define it. At the 14th International Lyme Disease Conference, Brian A. Fallon, MD,[1] of Columbia University and the New York State Psychiatric Institute, New York, NY, tried to do just that. More importantly, he described the different ways one can define encephalopathy, the strengths and limitations of each approach, and significantly, what other aspects of life can give the impression of encephalopathy where none exists. First, one must evaluate patients with persistent Lyme encephalopathy by asking the following questions:
Is the diagnosis correct?
Are there comorbid psychiatric disorders that could be treated better? Does the patient have a psychogenic medical illness? What was the patient’s response to prior antibiotics?
Was previous treatment adequate? How long was the course, and what was the route of administration? Was there a subsequent relapse Continued
By Linda on Nov 29, 2009 in Infections | comments(0)
Encephalopathy is like fine art: Most people know it when they see it, but there is very little agreement on how to define it. At the 14th International Lyme Disease Conference, Brian A. Fallon, MD,[1] of Columbia University and the New York State Psychiatric Institute, New York, NY, tried to do just that. More importantly, he described the different ways one can define encephalopathy, the strengths and limitations of each approach, and significantly, what other aspects of life can give the impression of encephalopathy where none exists.
First, one must evaluate patients with persistent Lyme encephalopathy by asking the following questions:
Is the diagnosis correct?
Are there comorbid psychiatric disorders that could be treated better? Does the patient have a psychogenic medical illness? What was the patient’s response to prior antibiotics?
Was previous treatment adequate? How long was the course, and what was the route of administration? Was there a subsequent relapse Continued
By Linda on Nov 16, 2009 in Infections | comments(0)
DEHLI (Reuters Health) – Diagnosis of malaria by polymerase chain reaction (PCR) testing of saliva is non-invasive and comparable to the current gold standard blood smear examination, a multicenter group of researchers reports.
A rapid test for malaria that has a high sensitivity and specificity “could potentially avert more than 100,000 malaria-related deaths each year and save nearly $200 million that is spent on unnecessary treatments annually,” Dr. Davis C. Nwakanma from the Medical Research Council, Fajara, Banjul, Gambia and his team and colleagues estimate. Continued
