Charlotte Marianna Hársi

Hantavirus Pulmonary Syndrome, Central Plateau, Southeastern, and Southern Brazil

This syndrome is an increasing health problem because of human encroachment into habitats of rodent reservoirs.

Risk factors for wheezing in a subtropical environment: Role of respiratory viruses and allergen sensitization

Abstract Background Risk factors for acute wheezing among children in subtropical areas are largely unknown. Objective To investigate the role of viral infections, allergen sensitization, and exposure to indoor allergens as risk factors for acute wheezing in children 0 to 12 years old. Methods One hundred thirty-two children 0 to 12 years of age who sought emergency department care for wheezing and 65 children with no history of wheezing were enrolled in this case-control study. Detection of respiratory syncytial virus antigen, rhinovirus and coronavirus RNA, adenovirus, influenza, and parainfluenza antigens was performed in nasal washes. Total IgE and specific IgE to mites, cockroach, cat, and dog were measured with the CAP system. Major allergens from mites, cockroach, cat, and dog were quantified in dust samples by ELISA. Univariate and multivariate analyses were performed by logistic regression. Results In children under 2 years of age, infection with respiratory viruses and family history of allergy were independently associated with wheezing (odds ratio, 15.5 and 4.2; P = .0001 and P = .008, respectively). Among children 2 to 12 years old, sensitization to inhalant allergens was the major risk factor for wheezing (odds ratio, 2.7; P = .03). High-level allergen exposure, exposure to tobacco smoke, and lack of breast-feeding showed no association with wheezing. Conclusions Some risk factors for wheezing previously identified in temperate climates were present in a subtropical area, including respiratory syncytial virus infection in infants and allergy in children older than 2 years. Rhinovirus was not associated with wheezing and did not appear to be a trigger for asthma exacerbations.

Severity of viral coinfection in hospitalized infants with respiratory syncytial virus infection

OBJECTIVE To compare the severity of single respiratory syncytial virus (RSV) infections with that of coinfections. METHODS A historical cohort was studied, including hospitalized infants with acute RSV infection. Nasopharyngeal aspirate samples were collected from all patients to detect eight respiratory viruses using molecular biology techniques. The following outcomes were analyzed: duration of hospitalization and of oxygen therapy, intensive care unit admission and need of mechanical ventilation. Results were adjusted for confounding factors (prematurity, age and breastfeeding). RESULTS A hundred and seventy six infants with bronchiolitis and/or pneumonia were included in the study. Their median age was 4.5 months. A hundred and twenty one had single RSV infection and 55 had coinfections (24 RSV + adenovirus, 16 RSV + human metapneumovirus and 15 other less frequent viral associations). The four severity outcomes under study were similar in the group with single RSV infection and in the coinfection groups, independently of what virus was associated with RSV. CONCLUSION Virus coinfections do not seem to affect the prognosis of hospitalized infants with acute RSV infection.

Detection of Rotavirus in Sewage and Creek Water: Efficiency of the Concentration Method

Simian rotavirus SA-11 experimentally seeded, was recovered from raw domestic sewage by a two-step concentration procedure, using filtration through a positively charged microporous filter (Zeta Plus 60 S) followed by ultracentrifugation, effecting an 8,000-fold concentration. By this method, a mean recovery of 81% +/- 7.5 of the SA-11 virus, was achieved.

Genetic characterization of adenovirus strains isolated from patients with acute conjunctivitis in the city of São Paulo, Brazil

Genome analysis was carried out on adenovirus strains isolated from patients with acute follicular conjunctivitis in the city of São Paulo, Brazil. Eighteen conjunctival scrapings, collected between December 1993 and March 1994, were analyzed by two methods: a combination of polymerase chain reaction with restriction fragment length polymorphism and viral DNA restriction analysis, carried out using 10 restriction endonucleases: BamHI, BglI, BglII, HindIII, KpnI, SacI, SalI, SmaI, XbaI, and XhoI. Among 11 adenovirus detected by cell culture isolation, nine were Ad8, and two were Ad7. By restriction analysis the Ad8 isolates were typed as two new variants–Ad8/D11 (seven of nine samples) and Ad8/D12 (two of nine samples). Ad7 isolates were identified as a subtype of the widespread genome type Ad7b and the virulent type Ad7h, a predominant genome type circulating in Argentina, Chile, and Uruguay but absent in Brazil until 1991. J. Med. Virol. 61:143–149, 2000.

Longitudinal study on occurrence of adenoviruses and hepatitis A virus in raw domestic sewage in the city of Limeira, SÃo Paulo.

The aim of this study was to verify the presence and annual distribution of adenoviruses and hepatitis A virus in domestic sewage in the city of Limeira, Sao Paulo. Fifty samples with a volume of 8 liters each were collected weekly from December 2004 to December 2005. The viruses were concentrated by filtration through positively charged ZP60S filter membranes, followed by ultracentrifugation. Human adenoviruses (HAdV) were detected by PCR followed by nested-PCR and screening for species F was done by restriction of the PCR product with TaqI endonuclease. Virus infectivity assays were performed by inoculation of concentrates onto HEp-2 cell monolayers. RT-PCR was used for the detection of hepatitis A virus. HAdV were detected in all samples, and 64% of samples were positive for infectious virus. Species F was present in 82% of the samples. Hepatitis A virus was detected in 48% of the samples. These results demonstrate that HAdV and HAV were present in the domestic sewage of Limeira throughout the period of study, demonstrating the importance of an adequate treatment before the disposal in the environment.

Infection kinetics of human adenovirus serotype 41 in HEK 293 cells

The purpose of this work was to acquire an overview of the infectious cycle of HAdV-41 in permissive HEK 293 cells and compare it to that observed with the prototype of the genus, Human adenovirus C HAdV-2. HEK 293 cells were infected with each virus separately and were harvested every 12 h for seven days. Infection kinetics were analysed using confocal and electronic microscopy. The results show that, when properly cultivated, HAdV-41 was not fastidious. It had a longer multiplication cycle, which resulted in the release of complete viral particles and viral stocks reached high titres. After 60 h of infection, the export of viral proteins from the infected cell to the extracellular milieu was observed, with a pattern similar to that previously described for HAdV-2 penton-base trafficking after 30 h of infection. HAdV-41 had a non-lytic cycle and the infection spread from the first infected cell to its neighbours. The release process of the viral particles is unknown. The results observed for HAdV-41 infection in HEK 293 cells show how different this virus is from the prototype HAdV-2 and provides information for the development of this vector for use in gene therapy.

Humoral immunity patterns based on antibody reactivity to rotavirus antigens in Brazilian children under 5 years of age

The age distribution of antibody to simian rotavirus (SA‐11) was studied in serum specimens obtained from 399 children aged to 5 years and living in the city of Recife (PE), located in the north eastern region of Brazil. Sera were examined for group‐specific rotavirus antibody using a blocking enzyme immunoassay (bELISA) and a hemagglutination inhibition antibody (HIA) test, and for anti‐VP2, anti‐VP4, anti‐VP6, and anti‐VP7 antibodies using an immunoblotting assay (IBA). Antibody prevalence was similar in all bELISA and HIA assays, showing a steep rise in the 6‐ to 17‐month‐old age groups. The results indicate early acquisition of antibody to rotavirus. The majority of children aged 2 to 4 years had bELISA (50% to 60%) and HIA (70% to 81%) antibodies. There was an association in prevalence data obtained by HIA and bELISA with immunoblotting (IBA), revealing four serologic profiles. Children with profiles I and II (60%) respectively had HAI and ELISA antibody or HAI antibody alone and all had immunoprotective antibodies to VP4 and/or VP7. These children were regarded as “immune,” resembling convalescent patients with a rotavirus infection. Children with profile III (4%) had no HIA antibody and only non‐protective anti‐VP6 and/or VP7 antibody, and were considered to be “partially immune.” Children with profile IV (36%) had no detectable antibody and were classified as “nonimmune.” These children should be considered to be susceptible to rotavirus infection, with the risk of developing clinically severe diarrhea.

Factors that can interfere with virus concentration from wastewater when using zeta plus 60S filter membranes

Zeta plus filter membranes (ZP60S) have been shown to be efficient for rotavirus concentration from wastewater and for the reduction of cytotoxicity for cell cultures. Recently a variability in both properties was observed. In view of the low costs and the high virus recovery rates obtained in the past, we re-evaluated the application of ZP60S filter membranes for virus concentration from environmental samples. Some factors that could interfere with the concentration strategy using ZP60S were also considered and assessed including the type of water to be filtered and the possible release of toxic substances from the membrane matrix during filtration.

Duplex-PCR assay for the detection of adenovirus and respiratory syncytial virus in nasopharyngeal samples

Human adenovirus (HAdV) and human respiratory syncytial virus (HRSV) are important etiologic agents of acute respiratory infections. In this study, a duplex polymerase chain reaction (PCR) assay was developed for the simultaneous detection of HAdV and HRSV in clinical samples. Sixty previously screened nasopharyngeal aspirates were used: 20 HAdV-positive, 20 HRSV-positive and 20 double-negative controls. Eight samples were positive for both viruses. The duplex PCR assay proved to be as sensitive and specific as single-target assays and also detected the mixed infections with certainty. The identification of both viruses in a single reaction offers a reduction in both cost and laboratory diagnostic time.