Serologische Untersuchungen zur endemischen Situation der Infektion mit dem FSME-Virus in einer südbadischen Pferde- und Hundepopulation

population in southwestern Germany To determine the expansion of
TBE infection of horses, this seroepidemiological study took place
in a known endemical area, the western Bodensee/ Hochrhein region,
in which the horses (n= 205) were chosen randomly. In this area the
anti-body development was tracked by testing the sample three times
over one year. The existence of TBE antibodies in dogs (n= 243)
were also checked in the same area over the same period. A
commercially obtainable ELISA (Labor Alomed, Radolfzell) was used
in this anti-body determination. Random samples of the results were
double checked by a neutralisation test (reference method,
Baxter-Immuno, A-Orth a.d. Donau, Austria). In the first
examination 48 out of 205 horses in the chosen population were
tested positive. The percentage of seropositive horses in the
examination area increased significantly from east to west (p=
0,001), which allowed the classification of a highly endemical area
(31 % positive) and a lower endemical area (4 % positive). The
anti-body titer increased significantly during the examination
period. The probability of the seropositivity of a horse depended
if (p= 0,001) and how often the horse visits pastures (p= 0,021).
The percentage of seroreagents increased with the age of the horses
(p= 0,011). A racial or sex disposition was not present. The
serological examination of the dogs resulted in 71 seroreagents out
of 243 (29,2 %). A geographical westward increase was noticed;
however the area could not be marked out as well as could be done
with the horses. This result can be explained by the higher
mobility of the dogs within an area in comparison to the horses.
The features: Length of fur (p= 0,015), Colour shades (p= 0,004),
frequent forest contact (p= 0,001) and age (p= 0,011) are
significant for dogs. A disposition for size and sex is not
relevant. The probability of seropositivity of a dog increased with
the features “long, fair fur” and “frequent forest contact”. The
seropositivity increased with the age of the dogs; dogs younger
than one year and older than 12 years had much less antibodies
against the TBE virus. Zusammenfassung 131 Dogs and horses are good
indicators for mapping endemical areas, because they often show
seroconversion and normally have a high exposure to ticks because
of the way they are kept. The proportion of the seroreagents of
dogs and their average number of antibody titers in the research
area were significantly higher than the average number of the.
horses. Due to the result of this serological research with dogs,
an endemical area can be spottet with a higher probability. Horses
can then be used to narrow in the endemic areas and to find “hot
spots” in low endemic areas. During the period of the research no
symptoms were observed, which could give hints of a possible TBE
infection, in either horses or dogs. In recent months some owners
of seropositive animals have reported occurrences of bad health and
temporary high temperatures which may or may not be related to TBE.