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BMC Infect Dis. 2017 Mar 22;17(1):222. doi: 10.1186/s12879-017-2299-7.
Influenza and respiratory syncytial virus in infants study (IRIS) of hospitalized and non-ill infants aged <1 year in four countries: study design and methods.
Thompson MG1,2, Hunt DR3, Arbaji AK4, Simaku A5, Tallo VL6, Biggs HM7, Kulb C3, Gordon A8, Khader IA4, Bino S5, Lucero MG6, Azziz-Baumgartner E9, Shifflett P3, Sanchez F10, Marar BI11, Bakalli I12, Sim?es EA13,14, Levine MZ9, Meece JK15, Balmaseda A16, Al-Sanouri TM4, Dhimolea M17, de Jesus JN6, Thornburg NJ7, Gerber SI7, Gresh L18; IRIS Network.
Collaborators (22)
Author information
Abstract
BACKGROUND:
This multi-country prospective study of infants aged <1 year aims to assess the frequency of influenza virus and respiratory syncytial virus (RSV) infections associated with hospitalizations, to describe clinical features and antibody response to infection, and to examine predictors of very severe disease requiring intensive care.
METHODS/DESIGN:
We are enrolling a hospital-based cohort and a sample of non-ill infants in four countries (Albania, Jordan, Nicaragua, and the Philippines) using a common protocol. We are currently starting year 2 of a 2- to 3-year study and will enroll approximately 3,000 infants hospitalized for any acute illness (respiratory or non-respiratory) during periods of local influenza and/or RSV circulation. After informed consent and within 24 h of admission, we collect blood and respiratory specimens and conduct an interview to assess socio-demographic characteristics, medical history, and symptoms of acute illness (onset ≤10 days). Vital signs, interventions, and medications are documented daily through medical record abstraction. A follow-up health assessment and collection of convalescent blood occurs 3-5 weeks after enrollment. Influenza and RSV infection is confirmed by singleplex real time reverse transcriptase polymerase chain reaction (rRT-PCR) assays. Serologic conversion will be assessed comparing acute and convalescent sera using hemagglutination inhibition assay for influenza antibodies and enzyme-linked immunosorbent assay (ELISA) for RSV. Concurrent with hospital-based enrollment, respiratory specimens are also being collected (and tested by rRT-PCR) from approximately 1,400 non-ill infants aged <1 year during routine medical or preventive care.
DISCUSSION:
The Influenza and RSV in Infants Study (IRIS) promises to expand our knowledge of the frequency, clinical features, and antibody profiles of serious influenza and RSV disease among infants aged <1 year, quantify the proportion of infections that may be missed by traditional surveillance, and inform decisions about the potential value of existing and new vaccines and other prevention and treatment strategies.
KEYWORDS:
Burden; Hospital; Infant; Influenza; Respiratory syncytial virus; Serology
PMID: 28330443 DOI: 10.1186/s12879-017-2299-7
Influenza and respiratory syncytial virus in infants study (IRIS) of hospitalized and non-ill infants aged <1 year in four countries: study design and methods.
Thompson MG1,2, Hunt DR3, Arbaji AK4, Simaku A5, Tallo VL6, Biggs HM7, Kulb C3, Gordon A8, Khader IA4, Bino S5, Lucero MG6, Azziz-Baumgartner E9, Shifflett P3, Sanchez F10, Marar BI11, Bakalli I12, Sim?es EA13,14, Levine MZ9, Meece JK15, Balmaseda A16, Al-Sanouri TM4, Dhimolea M17, de Jesus JN6, Thornburg NJ7, Gerber SI7, Gresh L18; IRIS Network.
Collaborators (22)
Author information
Abstract
BACKGROUND:
This multi-country prospective study of infants aged <1 year aims to assess the frequency of influenza virus and respiratory syncytial virus (RSV) infections associated with hospitalizations, to describe clinical features and antibody response to infection, and to examine predictors of very severe disease requiring intensive care.
METHODS/DESIGN:
We are enrolling a hospital-based cohort and a sample of non-ill infants in four countries (Albania, Jordan, Nicaragua, and the Philippines) using a common protocol. We are currently starting year 2 of a 2- to 3-year study and will enroll approximately 3,000 infants hospitalized for any acute illness (respiratory or non-respiratory) during periods of local influenza and/or RSV circulation. After informed consent and within 24 h of admission, we collect blood and respiratory specimens and conduct an interview to assess socio-demographic characteristics, medical history, and symptoms of acute illness (onset ≤10 days). Vital signs, interventions, and medications are documented daily through medical record abstraction. A follow-up health assessment and collection of convalescent blood occurs 3-5 weeks after enrollment. Influenza and RSV infection is confirmed by singleplex real time reverse transcriptase polymerase chain reaction (rRT-PCR) assays. Serologic conversion will be assessed comparing acute and convalescent sera using hemagglutination inhibition assay for influenza antibodies and enzyme-linked immunosorbent assay (ELISA) for RSV. Concurrent with hospital-based enrollment, respiratory specimens are also being collected (and tested by rRT-PCR) from approximately 1,400 non-ill infants aged <1 year during routine medical or preventive care.
DISCUSSION:
The Influenza and RSV in Infants Study (IRIS) promises to expand our knowledge of the frequency, clinical features, and antibody profiles of serious influenza and RSV disease among infants aged <1 year, quantify the proportion of infections that may be missed by traditional surveillance, and inform decisions about the potential value of existing and new vaccines and other prevention and treatment strategies.
KEYWORDS:
Burden; Hospital; Infant; Influenza; Respiratory syncytial virus; Serology
PMID: 28330443 DOI: 10.1186/s12879-017-2299-7