First report of hare treponematosis seroprevalence of European brown hares (Lepus europaeus) in the Czech Republic: seroprevalence negatively correlates with altitude of sampling areas

BACKGROUND

The aim of this study was to quantify the seroprevalence of hare treponematosis in European brown hare (Lepus europaeus) populations in the Czech Republic and to test for an association between treponematosis prevalence and the altitude of the areas in which hares were sampled. We tested 289 serum samples of brown hares collected between 2015 and 2017. The sampling areas included 12 districts (73 villages) distributed throughout the Czech Republic. Serum samples were tested for the presence of antibodies against the causative agent of hare treponematosis (Treponema paraluisleporidarum ecovar Lepus, TPeL) using two serological tests for human syphilis that cross-react with TPeL: the Treponema pallidum hemagglutination assay (TPHA) and the fluorescent treponemal antibody absorption (FTA-ABS) test. To account for the imperfect diagnostic sensitivity and specificity of each test, apparent prevalence estimates of TPeL were converted to true prevalence estimates using the Rogan Gladen estimator. The correlation between TPeL true seroprevalence and altitude of sampling areas was analyzed using Pearson's correlation coefficient at three levels of spatial resolution: (1) four groups, each composed of two merged districts, with ≥20 samples collected, differing in their altitude median (206, 348, 495, and 522 m above sea level); (2) separately tested eight districts, where ≥20 samples were collected per district; and (3) 27 groups composed of villages of the same altitude level distributed across the whole dataset.

RESULTS

One hundred and seven of the 289 samples were seropositive to both tests, the FTA-ABS test was positive for an additional 47 samples. Seropositive samples were found in all 12 districts. True seroprevalence of TPeL in the sampled hares was 52% (95% confidence interval 46 to 58%). A statistically significant negative correlation between TPeL seroprevalence and altitude was identified at the district level (Pearson's r = - 0.722, p = 0.043).

CONCLUSIONS

Between 2015 and 2017 hare treponematosis was present at a relatively high prevalence in brown hares in all 12 districts in the Czech Republic where sampling was carried out. The seroprevalence of TPeL in brown hares was negatively correlated with the altitude of the areas in which hares were sampled.

Which theory for the origin of syphilis is true?

INTRODUCTION

There are four theories about the origin of syphilis, of which the mostly represented one is the Columbian theory. This theory suggests that syphilis was brought into Europe in 1493 ad by the ship from Caribbean islands.

AIM

The aim of this study is to test all theories on a sample of 403 skeletons: 135 from prehistory, 134 from antique, and 134 from medieval period and new age from the Dalmatia (Croatia).

METHODS

All skeletons were examined using standard anthropological methods. Paleopathological analysis was performed on each skeleton as well as additional radiographic method on one isolated skeleton.

MAIN OUTCOME MEASURES

Paleopathological changes on skeletal remains connected with treponematosis.

RESULTS

Paleopathological analysis revealed one skeleton from the antique period (second to 6th century A.D.) that exhibited skeletal markers similar to those described in one clinical case in which congenital syphilis was confirmed by a Wasserman reaction. Skeletal remains of this person were examined macroscopically and radiographically, and the differential diagnostics eliminated other considered pathologies as well as trauma.

CONCLUSIONS

The finding of skeletal markers of syphilis on a skeleton from the antique supports the theory of pre-Columbian syphilis origin.