Ricardo Pereira Igreja

Prof. Dr. Ricardo Pereira Igreja

orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
25 October 2017 in Parasites & Vectors
Verified
Journal Article
Open access
PDF file
CVCarolina Valença-Barbosa
Carolina Valença-Barbosa
RBRosemary de Jesus Batista
Rosemary de Jesus Batista
RIRicardo Pereira Igreja
Ricardo Pereira Igreja
CDClaudia M d’Avila-Levy
Claudia M d’Avila-Levy
HMHeloisa Werneck de Macedo
Heloisa Werneck de Macedo
HSHelena Lucia Carneiro Santos
Helena Lucia Carneiro Santos
Blastocystis is a cosmopolitan protist parasite found in the human gastrointestinal tract and is highly prevalent in developing countries. Recent molecular studies have revealed extensive genetic diversity, which has been classified into different subtypes (STs) based on sequence analysis of small subunit ribosomal RNA gene. Blastocystis is one of the most common fecal parasites in Brazil, but the diversity of subtypes remains unknown in the country. This study aimed to determine the distribution of Blastocystis STs in an urban community in Duque de Caxias, Rio de Janeiro, Brazil. A total of 64 stool samples positive for Blastocystis in Pavlova’s medium were subtyped by PCR and sequenced using primers targeting the small subunit rRNA gene, in addition to phylogenetic analysis and subtype-specific PCR using sequence-tagged-site (STS) primers. Endolimax nana (14%), Entamoeba complex (10.5%), Taenia sp. (0.6%), Trichuris trichiura (1.3%) and Enterobius vermicularis (1.3%) were detected in Blastocystis-positive samples. Of the 64 samples tested by PCR/DNA sequencing, 55 were identified as ST1 (42%), ST3 (49%), ST2 (7%) and ST4 (2%), and the presence of mixed ST (ST1 + ST3) infection was detected in nine samples (14%). DNA sequencing and phylogenetic analysis of Brazilian Blastocystis isolates identified four different subtypes. To our knowledge, this study provided the first genetic characterization of Blastocystis subtypes in an urban area of Rio de Janeiro, Brazil. We also identified ST4 for the first time in Brazil. Further studies are necessary to determine the distribution of STs across human populations in Rio de Janeiro.

1 October 2007 in Pathogens and Global Health
Verified
Journal Article
Closed access
RIRicardo Pereira Igreja
Ricardo Pereira Igreja
JMJ. A. Matos
J. A. Matos
MGM. M. L. Gonçalves
M. M. L. Gonçalves
MBM. M. Barreto
M. M. Barreto
JPJose Mauro Peralta
Jose Mauro Peralta
In areas where there is a low prevalence of schistosomiasis mansoni, faecal examination is a relatively insensitive method of detection and infected people may also be missed because most show only mild morbidity. In such settings, serology may be a more useful diagnostic tool than microscopy. In the present study, the clinical and biochemical characteristics of individuals who were stool-positive for Schistosoma mansoni eggs were compared with those of individuals, from the same low-prevalence area of Brazil, who were stool-negative but seropositive for the parasite. Overall, 269 subjects were checked both for schistosome eggs in their faeces (using Kato-Katz smears and Lutz sedimentation) and for anti-S. mansoni IgG in their sera (using an ELISA). Although 128 (48%) of these subjects were found seropositive, only 26 (10%) were found to be egg excretors and two of the egg excretors were seronegative. Compared with the seropositive egg-negatives, the egg excretors had significantly higher frequencies of fatigue, melaena, jaundice and swelling of the abdomen. The egg excretors also had higher frequencies of hepatomegaly (20% v. 16%) and splenomegaly (4% v. 1%). In both groups of subjects, mean concentrations of serum proteins and haemoglobin and mean leucocyte counts were in the normal range whereas most blood concentrations of alanine aminotransferase and many of those of aspartate aminotransferase were slightly elevated. Although the egg excretors tended to have low-intensity infections, it seems possible that the seropositive nonexcretors had even milder infections that could not be detected by faecal examination. The high frequency of cure observed when the egg excretors were given praziquantel at 40 mg/kg (94%) is probably another indication that most had light infections when they were treated.

15 May 2025 in Pathogens
Verified
Journal Article
Open access
PDF file
RIRicardo Pereira Igreja
Ricardo Pereira Igreja
Priscila Marques de MacedoPriscila Marques de Macedo
Priscila Marques de Macedo
Maria Cristina SchneiderMaria Cristina Schneider
Maria Cristina Schneider
The vision that everything is connected in this world is not new

1 June 2009 in Revista da Sociedade Brasileira de Medicina Tropical
Verified
Journal Article
Open access
PDF file
RIRicardo Pereira Igreja
Ricardo Pereira Igreja
Counseling for human immunodeficiency virus infected travelers is becoming increasingly specialized. Previous studies have reported the experience of HIV-infected travelers from temperate-climate countries but little is known about HIV-infected travelers from tropical countries. A retrospective study was conducted on HIV-infected travelers presenting at a travel health clinic in Rio de Janeiro. Eleven journeys by ten people were recorded. Brazil (Amazon region and Northeast) was the destination for six journeys. Other destinations were Peru, Angola, Europe and Asia. Nine attendees were undergoing antiretroviral therapy. Few HIV-infected people from Rio de Janeiro consulted a travel medicine specialist before traveling. Since they travel to destinations in Brazil and abroad where there are endemic diseases not encountered in Rio de Janeiro, careful pre-travel planning needs to be undertaken. Strategies for increasing the frequency of pre-travel consultations need to be developed, such as closer collaboration between HIV clinics and travel health clinics.

1 September 2008 in International Journal of STD & AIDS
Verified
Journal Article
Closed access
RIRicardo Pereira Igreja
Ricardo Pereira Igreja
Summary: The number of HIV-infected persons who travel is increasing. This increase arises from those who have benefited from advances in antiretroviral therapy. The key to successful travel is careful pre-trip planning although many patients do not obtain advice before travelling. Travel advice for HIV patients is becoming increasingly specialized, and includes travel vaccination and highly active antiretroviral therapy-related issues. A closer collaboration between HIV and travel health clinics could provide better care for HIV-infected individuals.

15 February 2010 in Clinical Infectious Diseases
Verified
Journal Article
Open access
PDF file
RIRicardo Pereira Igreja
Ricardo Pereira Igreja
TO THE EDITOR—The International Olympic Committee has chosen the Brazilian city of Rio de Janeiro to host the 2016 Olympic Games, making it the first South Amer