Browsing by Author "Barradas, P.F."
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- Pathogenic Rickettsia in ticks of spur-thighed tortoise (Testudo Graeca) sold in a Qatar live animal marketPublication . Barradas, P.F.; Mesquita, J.R.; Lima, C.; Cardoso, L.; Alho, A.M.; Ferreira, P.; Amorim, I.; De Sousa, R.; Gärtner, F.The dissemination of vector arthropods harbouring zoonotic pathogens through the uncontrolled transboundary trade of exotic and pet animals poses an important threat to Public Health. In the present report, we describe the introduction of pathogenic Rickettsia africae and R. aeschlimanni in ticks removed from imported tortoises in Qatar. A total of 21 ticks were collected from pet spur‐thighed tortoises (Testudo graeca) from Doha, May 2018, and studied for species identification and characterization of Rickettsia spp. Morphological and molecular analysis of ticks allowed their identification as Hyalomma aegyptium. Molecular analysis of partial ompA and gltA genes showed that Rickettsia sequences found on these ticks clustered with sequences classified as R. aeschilimanii and R. africae. Since pre‐adult stages of H. aegyptium also feed on humans, this tick species may play a role in the transmission of R. aeschilimanii and R. africae. We alert for the introduction of non‐native pets as vehicles for tick importation, known vectors for animal and human pathogenic agents. Importation of exotic species into non‐autochthonous countries deserves strict control to enforce robust surveillance and mitigate potential exotic diseases epidemics.
- Serological and molecular evidence of Bartonella henselae in cats from Luanda city, AngolaPublication . Barradas, P.F.; De Sousa, R.; Vilhena, H.; Oliveira, A.C.; Luz, M.F.; Granada, S.; Cardoso, L.; Lopes, A.P.; Gonçalves, H.; Mesquita, J.R.; Ferreira, P.; Amorim, I.; Gärtner, F.A total of 100 domestic cats from Luanda (Angola) were tested for the presence of antibodies against Bartonella henselae and spotted fever group of Rickettsia (SFGR) using indirect immunofluorescence assay (IFA). Molecular screening targeting the riboflavin synthase (ribC) gene for Bartonella and outer membrane protein B (ompB) gene for Rickettsia, using conventional PCR and sequencing was also performed in cat´s blood samples. Sixty-six percent of the cats from Luanda had IgG antibodies against Bartonella species but none of them had antibodies against SFGR. Of the total seroreactive cats for Bartonella henselae, 4.5% had an IgG titre of 64 (cut-off), 60.6% a titre of 128, 28.8% a titre of 256 and 6.1% a titre of 512. A statistically significant association was observed between seropositivity for Bartonella henselae and the lack of access to prophylaxis against ectoparasites (p = 0.018). Molecular detection and further sequence analysis of the positive amplicons allowed identification of Bartonella henselae in a 2-year old male cat. To the best of our knowledge this study confirms for the first time, the presence of Bartonela henselae circulating in domestic cats from Luanda. This fact call the attention for the possible cases of cat-scratch disease in humans.
- Serological Evidence of Rickettsia Exposure among Patients with Unknown Fever Origin in Angola, 2016-2017Publication . Barradas, P.F.; Neto, Z.; Mateus, T.L.; Teodoro, A. C.; Duarte, L.; Gonçalves, H.; Ferreira, P.; Gärtner, F.; Sousa, R.; Amorim, I.Spotted fever group Rickettsia (SFGR) is one among the aetiologies that cause fever of unknown origin in Angola. Despite their occurrence, there is little information about its magnitude in this country either because it is misdiagnosed or due to the lack of diagnostic resources. For this purpose, eighty-seven selected malaria- and yellow fever-negative serum specimens collected between February 2016 and March 2017 as part of the National Laboratory of Febrile Syndromes, from patients with fever (≥37.5°C) for at least 4 days and of unknown origin, were screened for Rickettsia antibodies through an immunofluorescence assay (IFA). Serological results were interpreted according to the 2017 guidelines for the detection of Rickettsia spp. Three seroreactive patients had detectable IgM antibodies to Rickettsia with an endpoint titre of 32 and IgG antibodies with endpoint titres of 128 and 256. These findings supported a diagnosis of Rickettsia exposure amongst these patients and highlight that rickettsioses may be among the cause of unknown febrile syndromes in Angola. Therefore, physicians must be aware of this reality and must include this vector-borne disease as part of aetiologies that should be considered and systematically tested in order to delineate appropriate strategies of diagnostic and control of Rickettsia in Angola.
- Seroprevalence of spotted fever group rickettsiae among a group of pet dogs from Luanda, AngolaPublication . Barradas, P.F.; Sousa, R.; Amorim, I.; Vilhena, H.; Gartner, F.; Cardoso, L.; Oliveira, A.; Granada, S.; Silva, P.Tick-transmitted spotted fever group Rickettsiae (SFGR) are considered emerging disease. This study aims to assess the seroprevalence of spotted fever group rickettsiae among a group of pet dogs from Luanda, Angola.