Guilherme Calvet

Dr. Guilherme Calvet

National Institute of Infectious Diseases, Fiocruz
orcid

Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

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

Representative Publications

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15 December 2016 in New England Journal of Medicine
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PBPatrícia Brasil
Patrícia Brasil
JPJosé P. Jr. Pereira
José P. Jr. Pereira
MMM. Elisabeth Moreira
M. Elisabeth Moreira
RNRita M. Ribeiro Nogueira
Rita M. Ribeiro Nogueira
LDLuana Damasceno
Luana Damasceno
KNKarin Nielsen-Saines
Karin Nielsen-Saines
Zika virus (ZIKV) has been linked to central nervous system malformations in fetuses. To characterize the spectrum of ZIKV disease in pregnant women and infants, we followed patients in Rio de Janeiro to describe clinical manifestations in mothers and repercussions of acute ZIKV infection in infants. We enrolled pregnant women in whom a rash had developed within the previous 5 days and tested blood and urine specimens for ZIKV by reverse-transcriptase–polymerase-chain-reaction assays. We followed women prospectively to obtain data on pregnancy and infant outcomes. A total of 345 women were enrolled from September 2015 through May 2016; of these, 182 women (53%) tested positive for ZIKV in blood, urine, or both. The timing of acute ZIKV infection ranged from 6 to 39 weeks of gestation. Predominant maternal clinical features included a pruritic descending macular or maculopapular rash, arthralgias, conjunctival injection, and headache; 27% had fever (short-term and low-grade). By July 2016, a total of 134 ZIKV-affected pregnancies and 73 ZIKV-unaffected pregnancies had reached completion, with outcomes known for 125 ZIKV-affected and 61 ZIKV-unaffected pregnancies. Infection with chikungunya virus was identified in 42% of women without ZIKV infection versus 3% of women with ZIKV infection (P<0.001). Rates of fetal death were 7% in both groups; overall adverse outcomes were 46% among offspring of ZIKV-positive women versus 11.5% among offspring of ZIKV-negative women (P<0.001). Among 117 live infants born to 116 ZIKV-positive women, 42% were found to have grossly abnormal clinical or brain imaging findings or both, including 4 infants with microcephaly. Adverse outcomes were noted regardless of the trimester during which the women were infected with ZIKV (55% of pregnancies had adverse outcomes after maternal infection in the first trimester, 52% after infection in the second trimester, and 29% after infection in the third trimester). Despite mild clinical symptoms in the mother, ZIKV infection during pregnancy is deleterious to the fetus and is associated with fetal death, fetal growth restriction, and a spectrum of central nervous system abnormalities. (Funded by Ministério da Saúde do Brasil and others.)

1 June 2016 in The Lancet Infectious Diseases
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Journal Article
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GCGuilherme Calvet
Guilherme Calvet
RARenato Aguiar
Renato Aguiar
AMAdriana S O Melo
Adriana S O Melo
SSSimone A Sampaio
Simone A Sampaio
IFIvano de Filippis
Ivano de Filippis
AFAna Maria Bispo de Filippis
Ana Maria Bispo de Filippis

12 April 2016 in PLOS Neglected Tropical Diseases
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PBPatrícia Brasil
Patrícia Brasil
GCGuilherme Calvet
Guilherme Calvet
ASAndré Machado Siqueira
André Machado Siqueira
MWMayumi Wakimoto
Mayumi Wakimoto
PSPatrícia Carvalho De Sequeira
Patrícia Carvalho De Sequeira
TJThomas Jaenisch
Thomas Jaenisch
In 2015, Brazil was faced with the cocirculation of three arboviruses of major public health importance. The emergence of Zika virus (ZIKV) presents new challenges to both clinicians and public health authorities. Overlapping clinical features between diseases caused by ZIKV, Dengue (DENV) and Chikungunya (CHIKV) and the lack of validated serological assays for ZIKV make accurate diagnosis difficult. The outpatient service for acute febrile illnesses in Fiocruz initiated a syndromic clinical observational study in 2007 to capture unusual presentations of DENV infections. In January 2015, an increase of cases with exanthematic disease was observed. Trained physicians evaluated the patients using a detailed case report form that included clinical assessment and laboratory investigations. The laboratory diagnostic algorithm included assays for detection of ZIKV, CHIKV and DENV. 364 suspected cases of Zika virus disease were identified based on clinical criteria between January and July 2015. Of these, 262 (71.9%) were tested and 119 (45.4%) were confirmed by the detection of ZIKV RNA. All of the samples with sequence information available clustered within the Asian genotype. This is the first report of a ZIKV outbreak in the state of Rio de Janeiro, based on a large number of suspected (n = 364) and laboratory confirmed cases (n = 119). We were able to demonstrate that ZIKV was circulating in Rio de Janeiro as early as January 2015. The peak of the outbreak was documented in May/June 2015. More than half of the patients reported headache, arthralgia, myalgia, non-purulent conjunctivitis, and lower back pain, consistent with the case definition of suspected ZIKV disease issued by the Pan American Health Organization (PAHO). However, fever, when present, was low-intensity and short-termed. In our opinion, pruritus, the second most common clinical sign presented by the confirmed cases, should be added to the PAHO case definition, while fever could be given less emphasis. The emergence of ZIKV as a new pathogen for Brazil in 2015 underscores the need for clinical vigilance and strong epidemiological and laboratory surveillance. Zika virus (ZIKV) has been identified in 2015 in Brazil for the first time, causing outbreaks of an illness characterized by skin rash and absent or low grade and short-termed fever. It is difficult to distinguish ZIKV from Dengue (DENV) or (CHIKV) based on the acute clinical presentation. The virus is closely related to DENV, and therefore antibody tests also have problems distinguishing between the two viruses due to cross-reactivity. Recent findings suggest that in a minority of ZIKV cases neurological disease can develop, and that babies born from mothers reporting a ZIKV-like illness during pregnancy may suffer from congenital abnormalities, in many cases a small head or brain. Here we report about an outbreak of ZIKV disease in Rio de Janeiro in the first half of the year 2015, which reached its peak in May/June 2015. This is the first published description of a ZIKV outbreak in Latin America. It is interesting to note that confirmed cases appeared as early as January 2015. Cases were confirmed based on the detection of the viral genome in the blood of the patients. The clinical characterization of the confirmed cases and unconfirmed cases proved to be very similar. Itching or itching rash has been suggested to be added to the case definition issued by the Pan American Health Organization (PAHO).

1 April 2016 in The Lancet
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Journal Article
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PBPatrícia Brasil
Patrícia Brasil
PSPatricia Carvalho Sequeira
Patricia Carvalho Sequeira
AFAndrea D'Avila Freitas
Andrea D'Avila Freitas
HZHeruza Einsfeld Zogbi
Heruza Einsfeld Zogbi
GCGuilherme Calvet
Guilherme Calvet
TSTom Solomon
Tom Solomon

19 June 2016 in AIDS
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Journal Article
Closed access
TSTimothy R. Sterling
Timothy R. Sterling
NSNigel A. Scott
Nigel A. Scott
JMJose M. Miro
Jose M. Miro
GCGuilherme Calvet
Guilherme Calvet
ARAlberto La Rosa
Alberto La Rosa
MVM. Elsa Villarino
M. Elsa Villarino
Objective: Compare the effectiveness, tolerability, and safety of 3 months of weekly rifapentine and isoniazid under direct observation (3HP) versus 9 months of daily isoniazid (9H) in HIV-infected persons. Design: Prospective, randomized, and open-label noninferiority trial. Setting: The United States , Brazil, Spain, Peru, Canada, and Hong Kong. Participants: HIV-infected persons who were tuberculin skin test positive or close contacts of tuberculosis cases. Intervention: 3HP versus 9H. Main outcome measures: The effectiveness endpoint was tuberculosis; the noninferiority margin was 0.75%. The tolerability endpoint was treatment completion; the safety endpoint was drug discontinuation because of adverse drug reaction. Results: Median baseline CD4+ cell counts were 495 (IQR 389–675) and 538 (IQR 418–729) cells/μl in the 3HP and 9H arms, respectively (P = 0.09). In the modified intention-to-treat analysis, there were two tuberculosis cases among 206 persons [517 person-years (p-y) of follow-up] in the 3HP arm (0.39 per 100 p-y) and six tuberculosis cases among 193 persons (481 p-y of follow-up) in the 9H arm (1.25 per 100 p-y). Cumulative tuberculosis rates were 1.01 versus 3.50% in the 3HP and 9H arms, respectively (rate difference: −2.49%; upper bound of the 95% confidence interval of the difference: 0.60%). Treatment completion was higher with 3HP (89%) than 9H (64%) (P < 0.001), and drug discontinuation because of an adverse drug reaction was similar (3 vs. 4%; P = 0.79) in 3HP and 9H, respectively. Conclusion: Among HIV-infected persons with median CD4+ cell count of approximately 500 cells/μl, 3HP was as effective and safe for treatment of latent Mycobacterium tuberculosis infection as 9H, and better tolerated.

28 April 2021 in PLOS ONE
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Journal Article
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GCGuilherme Calvet
Guilherme Calvet
Sandro PereiraSandro Pereira
Sandro Pereira
MOMaria Ogrzewalska
Maria Ogrzewalska
Alex Pauvolid-CorrêaAlex Pauvolid-Corrêa
Alex Pauvolid-Corrêa
PRPaola Cristina Resende
Paola Cristina Resende
RMRodrigo Caldas Menezes
Rodrigo Caldas Menezes
Background: Infection by SARS-CoV-2 in domestic animals has been related to close contact with humans diagnosed with COVID-19. Objectives: To assess the exposure, infection, and persistence by SARS-CoV-2 of dogs and cats living in the same households of humans that tested positive for SARS-CoV-2, and to investigate clinical and laboratory alterations associated with animal infection.Methods: Animals living with COVID-19 patients were longitudinally followed and had nasopharyngeal/oropharyngeal and rectal swabs collected and tested for SARS-CoV-2. Additionally, blood samples were collected for laboratory analysis, and plaque reduction neutralization test (PRNT90) to investigate specific SARS-CoV-2 antibodies.Results: Between May and October 2020, 39 pets (29 dogs and 10 cats) of 21 patients were investigated. Nine dogs (31%) and four cats (40%) from 10 (47.6%) households were infected with or seropositive for SARS-CoV-2. Animals tested positive from 11 to 51 days after the human index COVID-19 case onset of symptoms. Three dogs tested positive twice within 14, 30, and 31 days apart. SARS-CoV-2 neutralizing antibodies were detected in one dog (3.4%) and two cats (20%). In this study, six out of thirteen animals either infected with or seropositive for SARS-CoV-2 have developed mild but reversible signs of the disease. Using logistic regression analysis, neutering, and sharing bed with the ill owner were associated with pet infection.Conclusions: The presence and persistence of SARS-CoV-2 infection have been identified in dogs and cats from households with human COVID-19 cases in Rio de Janeiro, Brazil. People with COVID-19 should avoid close contact with their pets during the time of their illness.