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Biomedical subjects

R Welliver

Publications and source records attributed to R Welliver.

8 recordsLinked to original sources
PubMed2001

Effectiveness of oseltamivir in preventing influenza in household contacts: a randomized controlled trial.

CONTEXT: Influenza virus is easily spread among the household contacts of an infected person, and prevention of influenza in household contacts can control spread of influenza in the community. OBJECTIVE: To investigate the efficacy of oseltamivir in preventing spread of influenza to household contacts of influenza-infected index cases (ICs). DESIGN AND SETTING: Randomized, double-blind, placebo-controlled study conducted at 76 centers in North America and Europe during the winter of 1998-1999. PARTICIPANTS: Three hundred seventy-seven ICs, 163 (43%) of whom had laboratory-confirmed influenza infection, and 955 household contacts (aged >/=12 years) of all ICs (415 contacts of influenza-positive ICs). INTERVENTIONS: Household contacts were randomly assigned by household cluster to take 75 mg of oseltamivir (n = 493) or placebo (n = 462) once daily for 7 days within 48 hours of symptom onset in the IC. The ICs did not receive antiviral treatment. MAIN OUTCOME MEASURE: Clinical influenza in contacts of influenza-positive ICs, confirmed in a laboratory by detection of virus shedding in nose and throat swabs or a 4-fold or greater increase in influenza-specific serum antibody titer between baseline and convalescent serum samples. RESULTS: In contacts of an influenza-positive IC, the overall protective efficacy of oseltamivir against clinical influenza was 89% for individuals (95% confidence interval [CI], 67%-97%; P<.001) and 84% for households (95% CI, 49%-95%; P<.001). In contacts of all ICs, oseltamivir also significantly reduced incidence of clinical influenza, with 89% protective efficacy (95% CI, 71%-96%; P<.001). Viral shedding was inhibited in contacts taking oseltamivir, with 84% protective efficacy (95% CI, 57%-95%; P<.001). All virus isolates from oseltamivir recipients retained sensitivity to the active metabolite. Oseltamivir was well tolerated; gastrointestinal tract effects were reported with similar frequency in oseltamivir (9.3%) and placebo (7.2%) recipients. CONCLUSION: In our sample, postexposure prophylaxis with oseltamivir, 75 mg once daily for 7 days, protected close contacts of influenza-infected persons against influenza illness, prevented outbreaks within households, and was well tolerated.

Acetamides↗
PubMed1994

Efficacy and safety of aerosolized ribavirin in young children hospitalized with influenza: a double-blind, multicenter, placebo-controlled trial.

We randomly assigned children hospitalized with influenza who had been ill < or = 48 hours and who had a temperature > or = 37.8 degrees C to receive either ribavirin or placebo. All patients had evaluations performed for fever reduction, use of acetaminophen for temperature > or = 38.3 degrees C, duration and severity of influenza symptoms, and feeding behavior. Sixty-two patients (35 in the placebo group, 27 in the ribavirin group) had a diagnosis of influenza confirmed by laboratory study. The groups did not differ significantly in age, initial signs and symptoms, or in distribution of influenza A or B infections. The time to reduction of temperature < or = 38.3 degrees C for the ribavirin group was 8.9 hours compared with 22.6 hours for the placebo group (p = 0.04). The mean duration of acetaminophen use was 7.4 hours in the ribavirin group and 16.3 hours in the placebo group (p = 0.14). There were no significant differences between the groups in outcome of respiratory rate, pulse rate, cough, or level of consciousness. Convalescent influenza antibody geometric mean titer for the placebo group was 9.8 compared with 3.6 for the ribavirin group (p = 0.04). Ribavirin was more effective than placebo in accelerating normalization of temperature but there were no other significant differences.

Acetaminophen↗
PubMed1982

Natural history of parainfluenza virus infection in childhood.

In order to determine the natural history of parainfluenza virus infection in early life, we followed prospectively 130 infants and children from birth or a few months of age for evidence of infection with PV. Using rapid diagnostic techniques, standard tissue culture infectivity, and serologic techniques we were able to document primary PV infection in 92% of these infants, and repeated infection with heterotypic or homotypic PV strains in 49% by 30 months of age. Increasing patient age had no significant effect in reducing the incidence of lower respiratory tract illness as a result of PV infection. Infection with one PV serotype provided no protection against LRTI at the time of subsequent infection with a heterotypic PV strain. In contrast, primary PV infection provided a brief period of immunity to LRTI upon homotypic reinfection. Secretory IgA responses to PV were determined by immunofluorescent techniques. Antibody response to PV strains causing primary infection and heterotypic repeated infection were transient and of low magnitude. Homotypic reinfection resulted in significantly enhanced production of secretory antibody to PV. At least in early life, repeated exposures to PV appear to be essential for maintaining immunity to severe forms of illness caused by PV infection.

Age Factors↗
PubMed1981

Cell-mediated immune responsiveness to measles. Its occurrence as a result of naturally acquired or vaccine-induced infection and in infants of immune mothers.

Studies of cell-mediated immunity (CMI) to measles were carried out in patients with natural measles infection, in recipients of live measles vaccine, and in umbilical cord blood specimens from infants of mothers who were seropositive for measles. Evidence of CMI to measles was found in 100% of patients with natural infection but in only 62% of vaccine recipients and, interestingly, in 40% of umbilical cord blood specimens. Eight of these infants were subsequently studied at 4 to 5 months of age, at which time evidence of measles CMI was still detectable in three. Sufficient stimulation of cell-mediated immune mechanisms may be a prerequisite for the development of life-long immunity to measles. The effect of congenitally acquired CMI to measles on the outcome of immunization or of exposure to natural measles during the first year of life remains to be determined.

Adolescent↗