Transmission of hepatitis A by transfusion of blood products.

The transmission of hepatitis A by blood products has been thought to occur rarely or not at all. By measuring IgM antibody to hepatitis A virus, we diagnosed a case of hepatitis A transmitted by the transfusion of a unit of fresh frozen plasma. Since the commercial availability of methods for measuring IgM antibody to hepatitis A, four other well-defined cases of hepatitis A transmitted by blood products have been reported in the literature. We detail our case and the natural history and importance of this clinical entity.

Isolation and characterization of mouse nasal lymphocytes.

A method for isolation of mouse nasal lymphocytes is described. Lymphocyte-enriched suspensions are examined for their morphologic, surface immune staining and mitogenic characteristics. This method will allow testing of immune function in the upper respiratory tract of the mouse.

Immunomodulators.

Cytokine immunomodulators have received considerable attention. Interferon-alpha has broad clinical application for treatment of a number of viruses. The neutrophil-stimulatory effects of interferon-gamma are useful in neutrophil disorders. TNF antagonists are useful in rheumatoid arthritis but carry the risk of activating intracellular organisms. Hemopoietic growth factors have considerable clinical effect in patients receiving immunosuppressive chemotherapy. A number of cytokines and cytokine antagonists are undergoing research development.

Effect of passive maternal antibody on influenza illness in children: a prospective study of influenza A in mother-infant pairs.

To determine the effect of passive antibody on the incidence of influenza in infants, infants born to mothers with serum antibody to influenza A (immune) and those born to mothers without evidence for this serum antibody (non-immune) were followed during the influenza H1N1 epidemic of 1979. Immune mothers had higher H1-specific antibody titers before the epidemic (P less than 0.001), were less frequently culture positive, showed fewer titer rises (P less than 0.001) and were less symptomatic than were nonimmune mothers. Infants of immune mothers had higher H1-specific passive antibody titers that correlated with their mother's antibody titers. Although infants of both groups showed no difference in incidence of influenza infection, infants of immune mothers had influenza symptoms that were delayed in onset (P = 0.02) and were of shorter mean duration compared with infants of nonimmune mothers. These findings suggest that passive maternal antibody delays the onset and decreases the severity of influenza disease in young infants.

Safety and immunogenicity of concurrent administration of measles-mumps-rubella-varicella vaccine and PedvaxHIB vaccines in healthy children twelve to eighteen months old. The MMRV Study Group.

OBJECTIVE: To determine the safety and immunogenicity of concurrent administration of measles-mumps-rubella-varicella vaccine (MMRV) and PedvaxHIB (Haemophilus influenzae type b conjugate vaccine) vs. M-M-R II and PedvaxHIB followed by an optional dose of VARIVAX 6 weeks later. DESIGN: Healthy children, 12 to 18 months of age, were randomly assigned to two groups to receive (1) MMRV and PedvaxHIB given concurrently or (2) M-M-R II and PedvaxHIB followed by an optional dose of VARIVAX 6 weeks later. SUBJECTS: The study group included 294 healthy children, ages 12 to 18 months, with a negative history of measles, mumps, rubella and varicella. MAIN OUTCOME MEASURES: The seroconversion rate and magnitude of antibody responses when MMRV was given concurrently with PedvaxHIB compared with the antibody responses when VARIVAX was given 6 weeks after M-M-R II and PedvaxHIB. RESULTS: Healthy children, 12 to 18 months of age, who received MMRV and PedvaxHIB concurrently showed immune responses similar to those in the control group who received M-M-RII vaccine with PedvaxHIB followed by VARIVAX 6 weeks later. Antibody titers for varicella were significantly lower when MMRV was administered than when varicella vaccine was given separately (0.712-fold difference, P = 0.028). No vaccine-related serious adverse reactions were reported, and no clinically significant differences were seen in the safety profiles of the two treatment groups. CONCLUSIONS: There were no statistically significant differences in the seroconversion rates between the two treatment groups for any of the antigens tested at 6 weeks and 1 year. Significantly lower geometric mean titers for varicella were noted in the group who received MMRV compared to VARIVAX given alone. Six-week seroconversion rates, persistence of immune responses at 1 year and the frequency of local and systemic reactions were comparable when MMRV was administered with PedvaxHIB compared with M-M-R II and PedvaxHIB followed by VARIVAX 6 weeks later.

Comparative safety and efficacy of clarithromycin and cefadroxil suspensions in the treatment of mild to moderate skin and skin structure infections in children.

A prospective, randomized, single (investigator) blind multicenter study was performed to compare the safety and efficacy of clarithromycin and cefadroxil oral suspensions in the treatment of mild to moderate skin and skin structure infections in children. Male and female patients ages 6 months to 12 years were enrolled at 24 study centers in the United States. Patients had signs and symptoms consistent with mild to moderate skin or skin structure infections judged suitable for oral antimicrobial therapy. Clarithromycin oral suspension was given to 118 children in a dose of 7.5 mg/kg (maximum of 500 mg) twice daily; cefadroxil oral suspension was given to 113 children in a dose of 15 mg/kg (maximum of 1000 mg) twice daily. Among clinically evaluable patients clinical success rates (cure plus improvement) were 96% (71 of 74) for clarithromycin and 98% (83 of 85) for cefadroxil (P = 0.664). Bacteriologic cure rates in evaluable clarithromycin and cefadroxil patients were 96% (72 of 75) and 99% (89 of 90), respectively (P = 0.331). Pathogen eradication rates based on 204 evaluable pathogens were 97% in the clarithromycin group and 99% in the cefadroxil group (P = 0.326). Adverse events were mild or moderate and were reported in 25% of clarithromycin and 35% of cefadroxil patients (P = 0.085). In both groups adverse events involved primarily the digestive tract. No significant laboratory changes were noted. Clarithromycin oral suspension appears to be a safe and effective alternative to cefadroxil for the treatment of pediatric skin and skin structure infections.

Efficacy and safety of low dosage amantadine hydrochloride as prophylaxis for influenza A.

The efficacy and safety of prophylactic low dose amantadine hydrochloride was assessed in two double-blind, placebo-controlled, randomized studies. In a study of 476 subjects aged 18 to 55 years, adverse reactions were not significantly different between the group receiving 100 mg/day amantadine and the placebo group but significantly greater in the group given 200 mg/day (P less than 0.009). The influenza attack rate in this study was too low to assess efficacy. In an experimental challenge study of influenza A/Beth/1/85 in 78 subjects of similar age the prophylactic administration of 50 mg, 100 mg or 200 mg/day doses of amantadine were more effective than placebo in preventing influenza illness (P less than 0.02, 66, 74 and 82% protection, respectively), and in suppressing viral replication (P = 0.02). There was no significant difference between amantadine groups in influenza illness or viral shedding. Compared with the placebo group the 100 and 200 mg amantadine groups showed a significant decrease in infection rate (100 mg: 40% protection: P = 0.012; 200 mg: 32% protection: P = 0.045) whereas the 50 mg group did not (20% protection: P = 0.187). These results suggest that 100 mg/day of amantadine will reduce toxicity but maintain the prophylactic efficacy seen with 200 mg/day.

Influenza-specific ELISA IgA and IgG predict severity of influenza disease in subjects prescreened with hemagglutination inhibition.

Four influenza A challenge studies were performed over a period of three years using the same dose of one virus pool. The first three studies were conducted two influenza seasons apart from the last study. In all four studies only subjects with screening hemagglutination inhibition (HAI) antibody titers less than or equal to 1:8 in sera were accepted as study subjects. The rate of infection after influenza challenge was 96% (25 of 26) in the first three studies, and only 73% (8 of 11) in the last study (P less than 0.04). The rate of influenza illness in the first three studies was 62% (16 of 26), and only 9% (1 of 11) in the last study (all subjects: P = 0.003; infected subjects: P = 0.01). Even though screening HAI titers were comparable between groups, prechallenge serum influenza-specific IgG titers correlated inversely with respiratory symptoms (P = 0.04). Prechallenge nasal wash influenza-specific IgA titers were lower in subjects who developed influenza illness (P = 0.03). Prechallenge influenza-specific nasal wash ELISA-IgA titers and serum ELISA-IgG titers predicted influenza severity in patients prescreened by HAI during influenza challenge studies.

The importance of nosocomial transmission of measles in the propagation of a community outbreak.

In late January 1985, a measles outbreak occurred at a community hospital in Columbia county, Florida. The outbreak spread throughout the county and to two neighboring counties (Alachua and Marion), resulting in 79 cases with a 29% hospitalization rate. Hospitals represented the site with the highest frequency of transmission. At the Alachua county hospitals, where strict respiratory isolation measures were taken, no secondary cases occurred among hospitalized patients. Two independent risk factors existed for hospitalization: measles exposure in a hospital setting (P less than 0.05) and nonvaccination (P less than 0.001). Of the total measles cases, 24% were under the age of 16 months and 47% of those aged 16 months or older had a history of appropriate vaccination. Columbia county, which experienced 86% of the cases, had a 5% frequency of unvaccinated students compared to 0.6% frequency at Alachua (P less than 0.001) where only 10% of the cases occurred. This outbreak demonstrates the role of uncontrolled nosocomial transmission of measles in the propagation of a community outbreak.

Uncontrolled nosocomial rotavirus transmission during a community outbreak.

Between Jan. 11 and March 31, 1983, 60 pediatric patients were diagnosed with rotavirus gastroenteritis. Of these cases 24 were community acquired, 29 were nosocomial, and 7 were of undetermined origin. Despite intensive infection control efforts, nosocomial transmission continued as long as patients with community-acquired cases were admitted. The use of disinfectants and germicides that were ineffective against rotavirus may have contributed to the continued nosocomial spread during a community outbreak.

Assessment of signs of influenza illness in the ferret model.

The ferret model of influenza A infection was evaluated to determine whether physical signs of influenza illness in addition to fever could be adequately followed. Ferrets were evaluated for nasal and systemic signs of influenza infection in a blinded, randomized protocol. Nasal signs were scored depending on the degree of nasal discharge and congestion. Systemic signs were evaluated on the basis of the activity level of ferrets. Nasal and systemic signs in ferrets challenged with influenza began to rise at peak virus shedding. This rise was coincident with the onset of the nasal inflammatory cell response. Nasal and systemic signs were statistically higher in challenged ferrets as compared with controls from 28 to 52 h after infection [P = 0.002 except at 28 h (P = 0.01)]. Despite precautions against influenza transmission, controls shed influenza virus associated with mild increases in nasal and systemic signs late in the course of the study. Our results suggest that severity of influenza illness can be adequately assessed in the ferret model using collective measurements of nasal and systemic signs, temperatures, and nasal cellular infiltration.

Intraventricular alpha interferon therapy for Rasmussen's syndrome.

A 4-year-old boy developed Rasmussen's syndrome and was treated with alpha interferon intraventricularly. An improvement in the epileptic and neurologic syndrome was noted for several weeks following interferon. No adverse side effects were encountered. Since hemispherectomy is the only established therapy in Rasmussen's Syndrome, further studies are needed to establish if intraventricular alpha interferon may halt the clinical progression of the syndrome.

Intrapulmonary BCG cell wall vaccination in mice.

Mice of two inbred strains, Balb/c and C3H/He, were given three dosages of mycobacterium bovis BCG (5 X 10(4), 5 X 10(2) and 5 colony forming units) by either the intravenous route or by a direct intratracheal (non-aerosol) route. The magnitude of the infectivity of these inoculae given by these routes was assessed by measurement of weight changes and mycobacterial multiplication in the spleen and lung. As expected, the Balb/c strain was more susceptible to infection than the C3H/He strain. However, for both strains, infection by the intratracheal route resulted in mycobacterial counts in the lungs which were more than seven-fold higher than mycobacterial counts after intravenous challenge. Naive Balb/c mice were immunized with BCG cell wall vaccine by the intratracheal route, by the intravenous route or by subcutaneous immunization. Four weeks later mice were challenged with live BCG by the intratracheal route. Following challenge, mycobacterial counts in the lungs of mice immunized by the intratracheal route, but not in the lungs of the mice immunized by the intravenous and subcutaneous routes, were significantly lower compared to controls. These results suggest that immunization with killed BCG by the intratracheal route imparts more effective mycobacterial intrapulmonary immunity than immunization by systemic routes.

Influenza infection in the infant mouse.

A nonlethal influenza infection [A/PC/1/73 (H3N2)] was given to infant mice to determine (1) the pathology of tracheal epithelium and lung, (2) the time course of viral shedding from the nose and lung, and (3) the subsequent development of protective immunity during adulthood. Both desquamation of the tracheal epithelium and lung pathology similar to that described in adults after influenza infection were observed in the infant. Animals infected at 3 days of age show virus shedding in 12 of 13 infant mice that persists for at least 2 days longer than in the adult. This longer duration of influenza infection did not result from either malnutrition or from intralitter transmission of virus. Recovery from virus shedding in both the upper and lower airway occurred in the absence of detectable serum antibody in six of seven mice. Infants that recover from infection, when rechallenged during adulthood, manifest complete protection in 11 of 13 mice after nonlethal challenge and no mortality after lethal challenge.

Similar subclass antibody responses after intranasal immunization with UV-inactivated RSV mixed with cholera toxin or live RSV.

To determine the effect of cholera toxin as a mucosal adjuvant on the class and subclass antibody response to RSV, mice were immunized intranasally with different doses of live RSV or UV-inactivated RSV mixed with cholera toxin. A single 10(6) pfu dose of live RSV and a single 50 micrograms dose of UV-inactivated RSV mixed with cholera toxin produced comparable serum IgG and respiratory secretion IgG and IgA antibody titers. Subclass antibody titers to whole RSV were also comparable between these two immunizing regimens. A predominance of IgG2a subclass to whole RSV was found for both regimens. The quantity of serum total IgG antibody to glycoprotein F or glycoprotein G did not differ between these regimens. The serum IgG subclass antibody response to both glycoprotein F and G was also not significantly different between regimens. Cholera toxin as a mucosal adjuvant can stimulate class and subclass antibody responses to UV-inactivated RSV that are similar in quantity and distribution to those after live RSV infection.