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- A Nationwide Seroepidemiologic Study on Q Fever Antibodies in Sheep of PortugalPublication . Cruz, Rita; Esteves, Fernando; Nóbrega, Carmen; Santos, Carla; Ferreira, Ana S.; Mega, Cristina; Coelho, Ana C.; Vala, Helena; Mesquita, JoãoIntroduction: Q fever is an almost global zoonotic disease caused by Coxiella burnetii. Human infections can produce acute and chronic disease that can lead to abortions and stillbirths in pregnant women, usually infected by the inhalation of C. burnetii-contaminated aerosols or through consumption of contaminated products. Sheep are one of the primary animal reservoirs with disease being associated with vast shedding of bacteria in placentas, feces, milk, and birth fluids. Although almost neglected in the past, recent outbreaks of sheep origin have alerted the public and the scientific community. Materials and Methods: An epidemiologic survey to estimate the seroprevalence of Q fever antibodies was performed in a representative number of sheep of all regions of continental Portugal (n = 1068), using a commercial ELISA (ID Screen Q Fever Indirect Multi-species Kit; IDvet, Montpellier, France). Results and Discussion: An anti-C. burnetii seroprevalence of 11.4% (95% confidence interval 9.6–13.5) was found, with a clear distinction between the Center region with highest seroprevalence, and the rest of the territory. Sheep traditional farming is widely present in Portugal and is part of the cultural and gastronomical background of the country. This close proximity to small ruminants may contribute to the zoonotic transfer to humans.
- Outbreaks of abortions byCoxiella burnetiiin small ruminant flocks and a longitudinal serological approach on archived bulk tank milk suggest Q fever emergence in Central PortugalPublication . Cruz, Rita; Esteves, Fernando; Vasconcelos-Nóbrega, Carmen; Santos, Carla; Ferreira, Ana S.; Mega, Cristina; Coelho, Ana C.; H, Vala; Mesquita, João R.Q fever is a worldwide zoonotic infectious disease caused by Coxiella burnetii and sheep and goats are known to be the main reservoir for human infection. This study describes the epidemiological and laboratory findings of C. burnetii outbreaks affecting sheep and goat flocks and also provides the results of a prospective serosurvey in bulk tank milk samples to assess C. burnetii circulation in a population of sheep living in close contact to the human population in Central Portugal. In the epizooties, C. burnetii was identified in tissues of the resulting abortions by qPCR. As for the serological survey, 10.2% (95%CI: 4.5‐19.2) of the 78 bulk tank milk samples collected in 2015 presented IgG antibodies against C. burnetii. The same farms were visited and sampled in 2016 and 25.6% (95%CI: 16.4‐36.8) were positive. This steep increase in the number of anti‐C. burnetii farms between the 2015 and 2016 collections showed to be statistically significant (p = 0.020) and is strongly suggestive of Q fever emergence in Central Portugal. Measures on animal health and on disease spread control to the human population should be considered.
- Increased risk of hepatitis E virus infection in workers occupationally exposed to sheepPublication . Mesquita, João; Santos-Ferreira, Nanci; Ferreira, Ana S.; Albuquerque, Carlos; Nóbrega, Carmen; Esteves, Fernando; Cruz, Rita; Vala, Helena; Nascimento, Maria S. J.Hepatitis E virus (HEV) is an enteric RNA virus from the family Hepeviridae with five genotypes (genotypes 1–4 and 7) known to infect humans. HEV infection is known to have a zoonotic swine origin in industrialized countries. The role of pigs and wild boars as major reservoirs for human infection is today well-established; however, the list of new animal reservoirs is ever-expanding as new HEV strains are continuously being found in a broad host range. The recent detection of HEV in sheep stools brings concerns on the possibility of HEV transmission from these animals to humans, particularly in those occupationally exposed. The present work investigated the potential occupational risk of HEV infection in shepherds and sheep milk cheesemakers—workers occupationally exposed to ovine (WOEOs; N = 96)—from a region of the Centre of Portugal (‘Serra da Estrela’) based on the differences of anti-HEV IgG seroprevalence rates between these professionals and the general population (N = 192). The presence of HEV-specific antibodies in sheep (N = 90) from the same region was also evaluated. The HEV seroprevalence in WOEOs (29.3%) was found to be significantly higher (p = .0198) when compared with population controls (16.1%) which suggests an increased risk for HEV infection in these workers. HEV-specific antibodies were also found in 16.6% of the studied sheep showing that HEV circulates in these animals. Further studies are needed to confirm the zoonotic potential of sheep HEV.
- Bulk-Tank Milk Longitudinal Serosurvey Reveals Decreasing Schmallenberg Virus Circulation in a Confined Population of Portuguese SheepPublication . Esteves, Fernando; Cruz, Rita; Nóbrega, Carmen; Santos, Carla; Ferreira, Ana S.; Petrovic, Tamas; Cardoso, Luís; Vala, Helena; Nascimento, Maria S.J.; Mesquita, João R.Introduction: In 2011, Schmallenberg virus (SBV) was first detected in dairy cattle herds in The Netherlands and Germany having since then spread across Europe. Today studies are starting to show a decrease in new SBV infections, a circumstance that raises alerts for possible re-emergence if ideal conditions for vector development occur. To assess the potential decrease in SBV circulation, we performed a 2-year longitudinal serological investigation for SBV infection at the herd level by using bulk-tank milk of a specific sheep breed from central Portugal. Materials and Methods: Bulk-tank milk samples from 68 flocks were collected in both 2015 and 2016, and lactosera were tested for IgG anti-SBV by EIA. Results and Discussion: Results show that in 2015, 92.6% (95% confidence interval [CI]: 83.9–96.8) of the bulk-tank milk samples were positive, whereas in 2016 only 77.9% (95% CI: 66.7–86.1 of the samples from the same flocks were positive. Differences in the 2015/2016 seroprevalences showed to be statistically significant (p = 0.027). This significant decrease at the herd level seems to be in agreement with reported data from other European countries and raise alerts, since increasingly favorable conditions (higher number of susceptible animals) are now present, potentially favoring SBV epidemics if improved conditions for midge replication occur in the future.