By Linda on Jan 19, 2011 in Infections | comments(0)
Excerpt:
Among the 20 tick species described in Switzerland, Ixodes ricinus, the most
frequent one, is implicated in the transmission of pathogenic agents. Lyme
borreliosis and tick-borne encephalitis (TBE) are the major tick-borne
diseases transmitted to human.
**Presently 5 Borrelia species, belonging to the group Borrelia burgdorferi,
are recognized as human pathogens**.
The risks of infection depend on the stage of the vector, the multiple
hosts, the pathogenic agent, as well as human behavior in nature.
The detection of other pathogenic agents in ticks: Anaplasma, Babesia and
Rickettsia predispose to infections or co-infections. Results of
sero-epidemiologic studies suggest human infections. Active surveillance by
physicians is necessary and clinical studies are required to evaluate the
importance of these infections in Switzerland.
By Linda on Dec 10, 2010 in Infections | comments(0)
Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=20929776&retmode=ref&cmd=prlinks
Excerpt:
Most hosts, including humans, are simultaneously or sequentially
infected with several parasites. A key question is whether
patterns of coinfection arise because infection by one parasite
species affects susceptibility to others or because of inherent
differences between hosts. We used time-series data from
individual hosts in natural populations to analyze patterns of
infection risk for a microparasite community, detecting large
positive and negative effects of other infections. Patterns
remain once variations in host susceptibility and exposure are
accounted for. Indeed, effects are typically of greater
magnitude, and explain more variation in infection risk, than the
effects associated with host and environmental factors more
commonly considered in disease studies. We highlight the danger
of mistaken inference when considering parasite species in
isolation rather than parasite communities.
