Longitudinal study of acute respiratory diseases in Rio de Janeiro: occurrence of respiratory viruses during four consecutive years

The occurrence of different viruses in nasopharyngeal secretions from children less than 5 years old with acute respiratory infections (ARI) was investigated over a period of 4 years (1982-1985) in Rio de Janeiro. Of the viruses known to be associated with ARI, all but influenza C and parainfluenza types 1, 2 and 4 were found. Viruses were found more frequently in children attending emergency or pediatric wards than in outpatients. This was clearly related to the high incidence of respiratory syncytial virus (RSV) in the more severe cases of ARI. RSV positive specimens appeared mainly during the fall, over four consecutive years, showing a clear seasonal ocurrence of this virus. Emergency wards provide the best source of data for RSV surveillance, showing sharp increase in the number of positive cases coinciding with increased incidence of ARI cases. Adenovirus were the second most frequent viruses isolated and among these serotypes 1,2 and 7 were predominant. Influenza virus and parainfluenza virus type 3 were next in frequency. Influenza A virus were isolated with equal frequency in outpatient departments, emergency and pediatric wards. Influenza B was more frequent among outpatients. Parainfluenza type 3 caused outbreaks in the shanty town population annually during the late winter or spring and were isolated mainly from outpatients. Herpesvirus, enterovi-rus and rhinovirus were found less frequently. Other viruses than RSV and parainfluenza type 3 did not show a clear seasonal incidence.

Impact of the antipneumococcal conjugate vaccine on the occurrence of infectious respiratory diseases and hospitalization rates in children

INTRODUCTION: In 2010, to reduce the occurrence of serious pneumococcal disease, the Ministry of Health in Brazil incorporated the 10-valent pneumococcal vaccine in the immunization schedule of children younger than two years of age. The objective of this study was to evaluate the impact of vaccination on the incidence of infectious respiratory diseases in infants before and after the introduction of the 10-valent pneumococcal vaccine. METHODS: This cross-sectional study involved primary care and hospital networks from a city in Minas Gerais State, Brazil, between 2009 and 2012. RESULTS: A 40% reduction in the prevalence of community-acquired pneumonia (CAP) was observed after introducing the pneumococcal conjugate vaccine. Male children were 28% more likely to develop the disease. The prevalence ratio ([PR] = 1.96, 95% CI: 1.52 to 2.53, p < 0.05) suggested that not being vaccinated was associated with the occurrence of pneumonia. The prevalence of CAP was 70% lower (PR 0.30, 95% CI: 0.24 to 0.37, p<0.05) in children vaccinated as recommended compared to children with delayed vaccination, suggesting that the updated vaccine schedule improves protection. CONCLUSIONS: Immunization with the 10-valent pneumococcal vaccine appeared to reduce the number of pneumonia cases in children during the study period. Prospective studies are needed to confirm the efficacy of the vaccine against the occurrence of pneumococcal pneumonia.

Association between NOx exposure and deaths caused by respiratory diseases in a medium-sized Brazilian city

Exposure to nitrogen oxides (NOx) emitted by burning fossil fuels has been associated with respiratory diseases. We aimed to estimate the effects of NOx exposure on mortality owing to respiratory diseases in residents of Taubaté, São Paulo, Brazil, of all ages and both sexes. This time-series ecological study from August 1, 2011 to July 31, 2012 used information on deaths caused by respiratory diseases obtained from the Health Department of Taubaté. Estimated daily levels of pollutants (NOx, particulate matter, ozone, carbon monoxide) were obtained from the Centro de Previsão de Tempo e Estudos Climáticos Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System. These environmental variables were used to adjust the multipollutant model for apparent temperature. To estimate association between hospitalizations owing to asthma and air pollutants, generalized additive Poisson regression models were developed, with lags as much as 5 days. There were 385 deaths with a daily mean (±SD) of 1.05±1.03 (range: 0-5). Exposure to NOx was significantly associated with mortality owing to respiratory diseases: relative risk (RR)=1.035 (95% confidence interval [CI]: 1.008-1.063) for lag 2, RR=1.064 (95%CI: 1.017-1.112) lag 3, RR=1.055 (95%CI: 1.025-1.085) lag 4, and RR=1.042 (95%CI: 1.010-1.076) lag 5. A 3 µg/m3 reduction in NOx concentration resulted in a decrease of 10-18 percentage points in risk of death caused by respiratory diseases. Even at NOx concentrations below the acceptable standard, there is association with deaths caused by respiratory diseases.

Susceptibility of asthmatic children to respiratory infection

OBJECTIVE: A case-control study of patients with pneumonia was conducted to investigate whether wheezing diseases could be a risk factor. METHODS: A random sample was taken from a general university hospital in S. Paulo City between March and August 1994 comprising 51 cases of pneumonia paired by age and sex to 51 non-respiratory controls and 51 healthy controls. Data collection was carried out by two senior paediatricians. Diagnoses of pneumonia and presence of wheezing disease were independently established by each paediatrician for both cases and controls. Pneumonia was radiologically confirmed and repeatability of information on wheezing diseases was measured. Logistic regression analysis was used to identify risk factors. RESULTS: Wheezing diseases, interpreted as proxies of asthma, were found to be an important risk factor for pneumonia with an odds ratio of 7.07 (95%CI= 2.34-21.36), when the effects of bedroom crowding (odds ratio = 1.49 per person, 95%CI= 0.95-2.32) and of low family income (odds ratio = 5.59 against high family income, 95%CI= 1.38-22.63) were controlled. The risk of pneumonia attributable to wheezing diseases is tentatively calculated at 51.42%. CONCLUSION: It is concluded that at practice level asthmatics should deserve proper surveillance for infection and that at public health level pneumonia incidence could be reduced if current World Health Organisation's guidelines were reviewed as to include comprehensive care for this illness.

Economic burden of expected epidemiological changes in diseases related to tobacco, Mexico

OBJECTIVE: To determine health care costs and economic burden of epidemiological changes in diseases related to tobacco consumption. METHODS: A time-series analysis in Mexico (1994-2005) was carried out on seven health interventions: chronic obstructive pulmonary diseases, lung cancer with and without surgical intervention, asthma in smokers and non-smokers, full treatment course with nicotine gum, and full treatment course with nicotine patch. According with Box-Jenkins methodology, probabilistic models were developed to forecast the expected changes in the epidemiologic profile and the expected changes in health care services required for selected interventions. Health care costs were estimated following the instrumentation methods and validated with consensus technique. RESULTS: A comparison of the economic impact in 2006 vs. 2008 showed 20-90% increase in expected cases depending on the disease (p<0.05), and 25-93% increase in financial requirements (p<0.01). The study data suggest that changes in the demand for health services for patients with respiratory diseases related to tobacco consumption will continue showing an increasing trend. CONCLUSIONS: In economic terms, the growing number of cases expected during the study period indicates a process of internal competition and adds an element of intrinsic competition in the management of preventive and curative interventions. The study results support the assumption that if preventive programs remain unchanged, the increasing demands for curative health care may cause great financial and management challenges to the health care system of middle-income countries like Mexico.

PRESENCE OF RESPIRATORY VIRUSES IN EQUINES IN BRAZIL

Equines are susceptible to respiratory viruses such as influenza and parainfluenza. Respiratory diseases have adversely impacted economies all over the world. This study was intended to determine the presence of influenza and parainfluenza viruses in unvaccinated horses from some regions of the state of São Paulo, Brazil. Blood serum collected from 72 equines of different towns in this state was tested by hemagglutination inhibition test to detect antibodies for both viruses using the corresponding antigens. About 98.6% (71) and 97.2% (70) of the equines responded with antibody protective titers (≥ 80 HIU/25µL) H7N7 and H3N8 subtypes of influenza A viruses, respectively. All horses (72) also responded with protective titers (≥ 80) HIU/25µL against the parainfluenza virus. The difference between mean antibody titers to H7N7 and H3N8 subtypes of influenza A viruses was not statistically significant (p > 0.05). The mean titers for influenza and parainfluenza viruses, on the other hand, showed a statistically significant difference (p < 0.001). These results indicate a better antibody response from equines to parainfluenza 3 virus than to the equine influenza viruses. No statistically significant differences in the responses against H7N7 and H3N8 subtypes of influenza A and parainfluenza 3 viruses were observed according to the gender (female, male) or the age (≤ 2 to 20 years-old) groups. This study provides evidence of the concomitant presence of two subtypes of the equine influenza A (H7N7 and H3N8) viruses and the parainfluenza 3 virus in equines in Brazil. Thus, it is advisable to vaccinate equines against these respiratory viruses.

Urinary tract infection in full-term newborn infants: risk factor analysis

OBJECTIVE: To analyze the correlation of risk factors to the occurrence of urinary tract infection in full-term newborn infants. PATIENTS AND METHODS: Retrospective study (1997) including full-term infants having a positive urine culture by bag specimen. Urine collection was based on: fever, weight loss > 10% of birth weight, nonspecific symptoms (feeding intolerance, failure to thrive, hypoactivity, debilitate suction, irritability), or renal and urinary tract malformations. In these cases, another urine culture by suprapubic bladder aspiration was collected to confirm the diagnosis. To compare and validate the risk factors in each group, the selected cases were divided into two groups: Group I - positive urine culture by bag specimen collection and negative urine culture by suprapubic aspiration, and Group II - positive urine culture by bag specimen collection and positive urine culture by suprapubic aspiration . RESULTS: Sixty one infants were studied, Group I, n = 42 (68.9%) and Group II, n = 19 (31.1%). The selected risk factors (associated infectious diseases, use of broad-spectrum antibiotics, renal and urinary tract malformations, mechanical ventilation, parenteral nutrition and intravascular catheter) were more frequent in Group II (p<0.05). Through relative risk analysis, risk factors were, in decreasing importance: parenteral nutrition, intravascular catheter, associated infectious diseases, use of broad-spectrum antibiotics, mechanical ventilation, and renal and urinary tract malformations. CONCLUSION: The results showed that parenteral nutrition, intravascular catheter, and associated infectious diseases contributed to increase the frequency of neonatal urinary tract infection, and in the presence of more than one risk factor, the occurrence of urinary tract infection rose up to 11 times.

Prevention of respiratory syncytial virus infections

Respiratory syncytial virus is the most important cause of viral lower respiratory illness in infants and children worldwide. By the age of 2 years, nearly every child has become infected with respiratory syncytial virus and re-infections are common throughout life. Most infections are mild and can be managed at home, but this virus causes serious diseases in preterm children, especially those with bronchopulmonary dysplasia. Respiratory syncytial virus has also been recognized as an important pathogen in people with immunossupressive and other underlying medical problems and institutionalizated elderly, causing thousands of hospitalizations and deaths every year. The burden of these infections makes the development of vaccines for respiratory syncytial virus highly desirable, but the insuccess of a respiratory syncytial virus formalin-inactivated vaccine hampered the progress in this field. To date, there is no vaccine available for preventing respiratory syncytial virus infections, however, in the last years, there has been much progress in the understanding of immunology and immunopathologic mechanisms of respiratory syncytial virus diseases, which has allowed the development of new strategies for passive and active prophylaxis. In this article, the author presents a review about novel approaches to the prevention of respiratory syncytial virus infections, such as: passive immunization with human polyclonal intravenous immune globulin and humanized monoclonal antibodies (both already licensed for use in premature infants and children with bronchopulmonary dysplasia), and many different vaccines that are potential candidates for active immunization against respiratory syncytial virus.

Ligation of the thoracic duct for the treatment of chylothorax in heart diseases

In children, chylothorax occurs mainly after cardiac and thoracic surgeries. One of the recommended postsurgery treatments is ligation of the thoracic tract, when all other conservative treatments have failed. We report 4 cases of chylothorax in patients who were successfully treated with this approach, which resulted in a decrease in pleural drainage without recurrent chylothorax.

Isolation and identification of Adenovirus in hospitalized children, under five years, with acute respiratory disease, in Havana, Cuba

Nine Adenovirus (Ad) strains isolated in Cuba, from 128 nasopharingeal swab specimens of children below five years old, with acute respiratory diseases, during 1996 and 1997, were studied by restriction enzyme analysis of genomic DNA with two endonucleases BamH I and Sma I. All different fragment patterns were compared with the respective prototypes. The identified adenoviruses were Ad 1 (n=4), Ad 2 (n=1) and Ad 6 (n=4). Males were more frequently infected than females. The analysis of the occurrence of these Adenovirus strains of subgenus C revealed that Ad 1 and Ad 6 were the predominant serotypes in 1996 and in 1997, respectively.

Ultrasound monitoring of structural urinary tract disease in Schistosoma haematobium infection

A major advance in our understanding of the natural history of Schistosoma haematobium-related morbidity has come through the introduction of the portable ultrasound machines for non-invasive examination of the kidneys and bladder. With the use of generators or battery packs to supply power in non-clinical field settings, and with the use of instant photography or miniaturized thermal printers to record permanent images, it is possible to examine scores of individuals in endemic communities every day. Broad-based ultrasound screening has allowed better definition of age-specific disease risks in urinary schistosomiasis. Results indicate that urinary tract abnormalities are common (18% overall prevalence) in S. haematobium transmission areas, with a 2-4% risk of either severe bladder abnormality or advanced ureteral obstruction. In longitudinal surveys, ultrasound studies have shown that praziquantel and metrifonate therapy are rapidly effective in reversing urinary tract abnormalities among children. The benefits of treating adults are less well known, but research in progress should help to define this issue. Similarly, the prognosis of specific ultrasound findings needs to be clarified, and the ease of sonographic examination will make such long-term follow-up studies feasible. In summary, the painless, quick, and reproducible ultrasound examination has become an essential tool in the study of urinary schistosomiasis.

Epithelial effects of proteinase-activated receptors in the gastrointestinal tract

The intestinal epithelium plays a crucial role in providing a barrier between the external environment and the internal milieu of the body. A compromised mucosal barrier is characteristic of mucosal inflammation and is a key determinant of the development of intestinal diseases such as Crohn's disease and ulcerative colitis. The intestinal epithelium is regularly exposed to serine proteinases and this exposure is enhanced in numerous disease states. Thus, it is important to understand how proteinase-activated receptors (PARs), which are activated by serine proteinases, can affect intestinal epithelial function. This review surveys the data which demonstrate the wide distribution of PARs, particularly PAR-1 and PAR-2, in the gastrointestinal tract and accessory organs, focusing on the epithelium and those cells which communicate with the epithelium to affect its function. PARs have a role in regulating secretion by epithelia of the salivary glands, stomach, pancreas and intestine. In addition, PARs located on subepithelial nerves, fibroblasts and mast cells have important implications for epithelial function. Recent data outline the importance of the cellular site of PAR expression, as PARs expressed on epithelia may have effects that are countered by PARs expressed on other cell types. Finally, PARs and their ability to promote epithelial cell proliferation are discussed in terms of colon cancer.

Respiratory viruses in children younger than five years old with acute respiratory disease from 2001 to 2004 in Uberlândia, MG, Brazil

The main viruses involved in acute respiratory diseases among children are: respiratory syncytial virus (RSV), influenzavirus (FLU), parainfluenzavirus (PIV), adenovirus (AdV), human rhinovirus (HRV), and the human metapneumovirus (hMPV). The purpose of the present study was to identify respiratory viruses that affected children younger than five years old in Uberlândia, Midwestern Brazil. Nasopharyngeal aspirates from 379 children attended at Hospital de Clínicas (HC/UFU), from 2001 to 2004, with acute respiratory disease, were collected and tested by immunofluorescence assay (IFA) to detect RSV, FLU A and B, PIV 1, 2, and 3 and AdV, and RT-PCR to detect HRV. RSV was detected in 26.4% (100/379) of samples, FLU A and B in 9.5% (36/379), PIV 1, 2 and 3 in 6.3% (24/379) and AdV in 3.7% (14/379). HRV were detected in 29.6% (112/379) of the negative and indeterminate samples tested by IFI. RSV, particularly among children less than six months of life, and HRV cases showed highest incidence. Negative samples by both IFA and RT-PCR might reflect the presence of other pathogens, such as hMPV, coronavirus, and bacteria. Laboratorial diagnosis constituted an essential instrument to determine the incidence of the most common viruses in respiratory infections among children in this region.

Adenoviruses C in non-hospitalized Mexican children older than five years of age with acute respiratory infection

Adenoviruses (AdV) are commonly involved in acute respiratory infections (ARI), which cause high morbidity and mortality in children. AdV are grouped in six species (A-F), which are associated with a wide range of diseases. The aim of this study was to identify the AdV species infecting non-hospitalized Mexican children with ARI symptoms, attending to the same school. For that, a PCR/RFLP assay was designed for a region of the hexon gene, which was chosen, based on the bioinformatical analysis of AdV genomes obtained from GenBank. A total of 100 children's nasopharyngeal samples were collected from January to June, 2005, and used for viral isolation in A549 cells and PCR/RFLP analysis. Only 15 samples produced cytopathic effect, and in all of them AdV C was identified. AdV C was also identified in eight additional nasopharyngeal samples which were negative for viral isolation. In summary, this outpatient population showed a rate of AdV infection of 23%, and only AdV C was detected.