3.2 Seroprevalence and presence of viral DNA
The results obtained from the
serological tests and molecular analysis for each year are shown in
Table 2, Fig.1 and Fig.2. Antibodies recognising MYXV antigens were
detected in 57 Iberian hares. Interestingly, 5.4%
(CI95% 3.0-9.6%) of the samples randomly collected in
1994-1997, were seropositive (Table 2). In 2017, 1.7% of sera
(CI95% 0.3-8.9%) were seropositive, while in 2018-2019
the seropositivity was 17.4% (CI95% 12.3-24.2%). The
seropositivity in the found-dead subset of the sample was 39.1%
(CI95% 22.2-59.2%), more than double than in the
randomly collected sera subset.
For the samples collected between 1994-1999, only blood serum was
available. Sera were diluted 1:4 in PBS prior extraction to avoid
inhibition. MYXV-DNA was detected in four samples from 1994-1999 (all
corresponding to seronegative hares), in very low quantities as expected
(Cq values around 35.0 according with (Duarte et al., 2014)). Regarding
the samples collecter over 2017-2019, higher RI10 values were associated
to the qPCR positive samples (Fig. 3, green dots in left graph).
Contrarily, lower values of RI10 were observed in the group of qPCR
negative and non-tested hares (Fig. 3, red and blank dots in right
graph).
Seropositive samples were detected in two out of the five administrative
units included in the study in 1994-1999 as well as in 11 of 20 units
included in 2017-2019 (Fig. 4).