Spatial distribution and risk factors of Brucellosis in Iberian wild ungulates.
BACKGROUND
The role of wildlife as a brucellosis reservoir for humans and domestic livestock remains to be properly established. The aim of this work was to determine the aetiology, apparent prevalence, spatial distribution and risk factors for brucellosis transmission in several Iberian wild ungulates.


METHODS
A multi-species indirect immunosorbent assay (iELISA) using Brucella S-LPS antigen was developed. In several regions having brucellosis in livestock, individual serum samples were taken between 1999 and 2009 from 2,579 wild bovids, 6,448 wild cervids and4,454 Eurasian wild boar (Sus scrofa), and tested to assess brucellosis apparent prevalence. Strains isolated from wild boar were characterized to identify the presence of markers shared with the strains isolated from domestic pigs.


RESULTS
Mean apparent prevalence below 0.5% was identified in chamois (Rupicapra pyrenaica), Iberian wild goat (Capra pyrenaica), and red deer (Cervus elaphus). Roe deer (Capreolus capreolus), fallow deer (Dama dama), mouflon (Ovis aries) and Barbary sheep (Ammotragus lervia) tested were seronegative. Only one red deer and one Iberian wild goat resulted positive in culture, isolating B. abortus biovar 1 and B. melitensis biovar 1, respectively. Apparent prevalence in wild boar ranged from 25% to 46% in the different regions studied, with the highest figures detected in South-Central Spain. The probability of wild boar being positive in the iELISA was also affected by age, age-by-sex interaction, sampling month, and the density of outdoor domestic pigs. A total of 104 bacterial isolates were obtained from wild boar, being all identified as B. suis biovar 2. DNA polymorphisms were similar to those found in domestic pigs.


CONCLUSIONS
In conclusion, brucellosis in wild boar is widespread in the Iberian Peninsula, thus representing an important threat for domestic pigs. By contrast, wild ruminants were not identified as a significant brucellosis reservoir for livestock.
Muñoz
Pilar M
PM
Centro de Investigación y Tecnología Agroalimentaria del Gobierno de Aragón (CITA), Montañana, 930 50059, Zaragoza, Spain.
Boadella
Mariana
M
Arnal
Maricruz
M
de Miguel
María J
MJ
Revilla
Miguel
M
Martínez
David
D
Vicente
Joaquín
J
Acevedo
Pelayo
P
Oleaga
Alvaro
A
Ruiz-Fons
Francisco
F
Marín
Clara M
CM
Prieto
José M
JM
de la Fuente
José
J
Barral
Marta
M
Barberán
Montserrat
M
de Luco
Daniel Fernández
DF
Blasco
José M
JM
Gortázar
Christian
C
D000818:Animals; D000835:Animals, Wild / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D002003:Brucella abortus / Q000145:classification / Q000302:isolation & purification; D017347:Brucella melitensis / Q000145:classification / Q000302:isolation & purification; D041021:Brucella suis / Q000145:classification; D002006:Brucellosis / Q000453:epidemiology / Q000662:veterinary*; D016172:DNA Fingerprinting; D004197:Disease Reservoirs; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005838:Genotype; D005843:Geography; D006801:Humans; D011110:Polymorphism, Genetic; D011174:Portugal / Q000453:epidemiology; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012703:Serotyping; D013030:Spain / Q000453:epidemiology