Browsing by Author "Nascimento, Maria São José"
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- Crimean-Congo hemorrhagic fever virus circulating among sheep of Portugal: a nationwide serosurvey assessmentPublication . Mesquita, João; Cruz, Rita; Esteves, Fernando; Santos, Carla; Pousa, Humberto; Coelho, Catarina; Mega, Cristina; Nóbrega, Carmen; Vala, Helena; Peyrefitte, Christophe Nicolas; Nascimento, Maria São José; Barradas, Patrícia FerreiraCrimean-Congo hemorrhagic fever virus (CCHFV) is a widespread zoonotic pathogen that can cause mild to severe hemorrhagic disease in humans. CCHFV may be transmitted through direct contact with tissue or blood of viremic animals; however, the primary transmission route is through infected tick bites. CCHFV RNA has been detected in ticks feeding on domestic and wild animals in western Spain, suggesting an established circulation of CCHFV in Western Europe. Ruminants have been recognized as important CCHFV reservoirs and have been linked to human cases in endemic regions. Given the emergence of CCHF in neighboring Spain, and a report of two CCHFV seropositive humans in southern Portugal in 1985, we investigated the potential circulation of this virus in the country by performing a nationwide anti-CCHFV IgG serosurvey in sentinel sheep of Portugal. Sera (n = 459) randomly selected from widely distributed farms (n = 20) of Portugal were tested using a commercial double-antigen enzyme-linked immunosorbent assay, yielding an overall seroprevalence of 0.4% (95% confidence interval [CI] 0.04-1.56%). Positive sheep were from the southern region of Portugal (Alentejo region), which raise the seroprevalence of this region to 0.74% (95% CI 0.09-2.66%). This is the first study reporting the presence of CCHFV antibodies in sheep of Portugal, thus suggesting a geographical expansion of CCHFV to this country. It seems likely that CCHFV may exist focally in southern Portugal.
- Measles antibodies in cord blood in Portugal: Possible consequences for the recommended age of vaccinationPublication . Gonçalves, Guilherme; Nunes, Carla; Mesquita, João R.; Nascimento, Maria São José; Frade, JoãoThe optimum age to give the first dose of measles vaccine must balance the risks of disease and vaccine failure. Both are influenced by the levels of transplacentally acquired maternal antibodies. This study was conducted in the Obstetric service of Portuguese hospital, in 2012-2013. Mothers were recruited after informed consent. Measles IgG was measured in 206 cord sera, using a commercial immunoassay. Geometric mean concentrations (and 95% CI) were 1849mIU/ml (1196-2857) and 790mIU/ml (618-1008) in cord sera of newborns from unvaccinated and vaccinated mothers respectively. Maternal age and vaccination status were both associated with the concentration in cord sera, but maternal age was the major predictor. The likely explanation is the same already mentioned in other studies: as a vaccination program progresses, vaccination coverage increases as measles incidence decreases. That results newborns from younger vaccinated mothers having less measles antibodies while the older mothers are more likely to have been infected with the wild virus. As the proportion of vaccinated mothers increase, developed countries tend to anticipate the recommended age of the first dose to 12 months of age. Models using hypothetical measles antibody decay rates in infancy were explored. Anticipating the first dose of MMR1 in Portugal to the age of 12 months might have not been the best decision but results were not conclusive, and arguments supporting or not the anticipation were discussed.
- Seroprevalence of Hepatitis E Virus Antibodies in Portuguese ChildrenPublication . Oliveira, Ricardo; Mesquita, João R.; Pereira, Sara; Abreu-Silva, Joana; Teixeira, Joana; Nascimento, Maria São JoséHepatitis E virus (HEV) has become a growing Public Health concern in industrialized countries. Most of the HEV seroprevalence studies have focused on adult populations and reports regarding HEV seroepidemiology among children are scarce in these countries. The aims of the present work were to perform a nationwide seroprevalence study on HEV infection in Portuguese children and to compare the HEV seropositivity in this 2015 children cohort with results in sera performed 20 years earlier.