Comparison of virological profiles of respiratory syncytial virus and rhinovirus in acute lower tract respiratory infections in very young Chilean infants, according to their clinical outcome.

BACKGROUND: Respiratory syncytial virus (RSV) and rhinovirus (HRV) are the main cause of acute lower respiratory tract infections (ALRTIs) in infants. Viral and host-related risk factors for severe disease have also not been clearly established. OBJECTIVE: To assess whether certain viral features of RSV and, or HRV are associated with severe ALRTI. STUDY DESIGN: RSV and HRV were studied in nasopharyngeal samples of infants by immunofluorescence, Luminex(®) and/or real-time RT-PCR assays. Quantitation and genotyping of RSV and HRV by PCR were done. RESULTS: Of 124 virus positive specimens, 74 (59.7%) had RSV; 22 (17.7%) HRV and 28 (22.6%) RSV-HRV co-infection. Hospitalization was required in 57/74 RSV infants (77.0%); in 10/22 HRV cases (45.5%) (p=0.006) and in 15/28 co-infected by both viruses (53.6%) (p=0.003). Severe cases were 33/74 (44.6%) RSV infections, 2/22 HRV cases (9.1%), (p<0.002) and 6/28 (21.4%) patients co-infected by RSV-HRV (p<0.026). Three genotypes (NA1, B7, B9) of RSV circulated during the study. In 33 severe infants, NA1 was detected in 19 cases (57.6%); B7 in 13 (39.4%) and B9 in 1 (3.0%) (p<0.01; OR=10.0). RSV loads were similar between outpatients and hospitalized infants (p=0.7) and among different severities (p=0.7). NA1 loads were higher than other strains (p=0.049). Three geno-groups of HRV circulated homogeneously. CONCLUSION: In very young infants, RSV cause more severe disease than HRV. Co-infection does not increase the severity of illness. NA1 RSV genotype was associated with major frequency of hospitalization, severe respiratory disease and higher viral load.

SP-A1, SP-A2 and SP-D gene polymorphisms in severe acute respiratory syncytial infection in Chilean infants.

Respiratory syncytial virus (RSV) is the principal pathogen that causes acute lower respiratory tract infection (ALRI) in infants. Severe RSV-ALRI has been associated with the host genetic susceptibility. To assess whether severe RSV disease in infants is associated with certain single nucleotide polymorphism (SNP) into the gene of SP-A1, SP-A2 and SP-D, a prospective study was performed among blood donors and RSV-infected infants aged

[Seroprevalence of IgG antibodies against parvovirus B19 among blood donors from Santiago, Chile]. / Seroprevalencia de anticuerpos IgG contra parvovirus B19 en donantes de sangre de hospitales en Santiago, Chile.

BACKGROUND: Parvovirus B19 (B19) is associated with a wide range of disease manifestations, whose severity depends on the immunological and hematological status of the host. Infection with B19 has been reported worldwide and the prevalence of immunoglobulin G antibodies against B19 increases with age and varies by location and time of the last B19 epidemic. AIM: To evaluate the prevalence of IgG antibodies against Parvavirus B19 virus in a population of volunteer blood donors at two hospital blood banks in Santiago, Chile. MATERIAL AND METHODS: A total of 400 serum samples from blood donors aged 18 to 65 years, were examined for the presence of IgG antibodies against Parvovirus B19. RESULTS: The overall prevalence of IgG antibodies was 54.8%. No significant difference was found between men and women (57.6% and 49.3%, respectively). CONCLUSIONS: IgG antibody seroprevalence against Parvovirus B19, was 55% in this sample of Chilean blood donors. This figure is in agreement with previous reports from abroad.

Seroprevalencia de anticuerpos IgG contra parvovirus B19 en donantes de sangre de hospitales en Santiago, Chile / Seroprevalence of IgG antibodies against parvovirus B19 among blood donors from Santiago, Chile

Background: Parvovirus B19 (B19) is associated with a wide range of disease manifestations, whose severity depends on the immunological and hematological status of the host. Infection with B19 has been reported worldwide and the prevalence of immunoglobulin G antibodies against B19 increases with age and varies by location and time of the last B19 epidemic. Aim: To evaluate the prevalence of IgG antibodies against Parvavirus B19 virus in a population of volunteer blood donors at two hospital blood banks in Santiago, Chile. Material and Methods: A total of 400 serum samples from blood donors aged 18 to 65 years, were examined for the presence of IgG antibodies against Parvovirus B19. Results: The overall prevalence of IgG antibodies was 54.8 percent. No significant difference was found between men and women (57.6 percent and 49.3 percent, respectively). Conclusions: IgG antibody seroprevalence against Parvovirus B19, was 55 percent in this sample of Chilean blood donors. This figure is in agreement with previous reports from abroad.