RESUMO
BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of respiratory infections in children. Palivizumab (PZ) is the only RSV-specific immunoprophylaxis approved by the U.S. Food and Drug Administration. Mutations leading to amino acid substitutions in the PZ binding site of the RSV F protein have been associated with breakthrough RSV infections in patients receiving PZ. OBJECTIVE: To detect PZ resistance conferring mutations in RSV strains from children who received PZ. STUDY DESIGN: Children aged ≤ 24 months on October 31 who were hospitalized or had outpatient visits for respiratory illness and/or fever during October-May 2001-2008 in 3 US counties were included. PZ receipt was obtained from parent interviews and medical records among children subsequently infected with RSV. Archived nasal/throat swab specimens were tested for RSV by real-time RT-PCR. The coding region of the PZ binding site of the RSV F protein was sequenced using both Sanger and pyrosequencing methods. RESULTS: Of 8762 enrolled children, 375 (4.3%) were tested for RSV and had a history of PZ receipt, of which 56 (14.9%) were RSV-positive and 45 of these had available archived specimens. Molecular typing identified 42 partial F gene sequences in specimens from 39 children: 19 single RSV subgroup A, 17 subgroup B and 3 mixed infections. Nucleotide substitutions were identified in 12/42 (28.6%) RSV strains. PZ resistance mutations were identified in 4 (10.2%) of the 39 children, of which one had documented PZ receipt. CONCLUSIONS: Although RSV PZ resistance mutations were infrequent, most RSV-associated illnesses in children with a history of PZ receipt were not due to strain resistance.
Assuntos
Antivirais/uso terapêutico , Palivizumab/uso terapêutico , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Vírus Sinciciais Respiratórios/genética , Antivirais/farmacologia , Criança , Pré-Escolar , Farmacorresistência Viral/genética , Feminino , Humanos , Masculino , Mutação , Palivizumab/farmacologia , Análise de Sequência de DNA , Fatores de Tempo , Estados UnidosRESUMO
BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of acute respiratory illness (ARI). Little is known about RSV disease among older children and adults in Central America. METHODS: Prospective surveillance for ARI among hospital patients and clinic patients was conducted in Guatemala during 2007-2012. Nasopharyngeal and oropharyngeal swab specimens were tested for RSV, using real-time reverse-transcription polymerase chain reaction. RESULTS: Of 6287 hospitalizations and 2565 clinic visits for ARI, 24% and 12%, respectively, yielded RSV-positive test results. The incidence of RSV-positive hospitalization for ARI was 5.8 cases/10 000 persons per year and was highest among infants aged <6 months (208 cases/10 000 persons per year); among adults, the greatest incidence was observed among those aged ≥ 65 years (2.9 cases/10 000 persons per year). The incidence of RSV-positive clinic visitation for ARI was 32 cases/10 000 persons per year and was highest among infants aged 6-23 months (186 cases/10 000 persons per year). Among RSV-positive hospital patients with ARI, underlying cardiovascular disease was associated with death, moribund discharge, intensive care unit admission, or mechanical ventilation (odds ratio, 4.1; 95% confidence interval, 1.9-8.8). The case-fatality proportion among RSV-positive hospital patients with ARI was higher for those aged ≥ 5 years than for those aged <5 years (13% vs 3%; P < .001). CONCLUSIONS: The incidences of RSV-associated hospitalization and clinic visitation for ARI were highest among young children, but a substantial burden of ARI due to RSV was observed among older children and adults.
Assuntos
Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/fisiopatologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Doença Aguda , Idoso , Pré-Escolar , Feminino , Guatemala/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Lactente , Masculino , Vigilância da População/métodos , Estudos Prospectivos , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in young children globally, with the highest burden in low- and middle-income countries where the association between RSV activity and climate remains unclear. METHODS: Monthly laboratory-confirmed RSV cases and associations with climate data were assessed for respiratory surveillance sites in tropical and subtropical areas (Bangladesh, China, Egypt, Guatemala, Kenya, South Africa, and Thailand) during 2004-2012. Average monthly minimum and maximum temperatures, relative humidity, and precipitation were calculated using daily local weather data from the US National Climatic Data Center. RESULTS: RSV circulated with 1-2 epidemic periods each year in site areas. RSV seasonal timing and duration were generally consistent within country from year to year. Associations between RSV and weather varied across years and geographic locations. RSV usually peaked in climates with high annual precipitation (Bangladesh, Guatemala, and Thailand) during wet months, whereas RSV peaked during cooler months in moderately hot (China) and arid (Egypt) regions. In South Africa, RSV peaked in autumn, whereas no associations with seasonal weather trends were observed in Kenya. CONCLUSIONS: Further understanding of RSV seasonality in developing countries and various climate regions will be important to better understand the epidemiology of RSV and for timing the use of future RSV vaccines and immunoprophylaxis in low- and middle-income countries.
Assuntos
Países em Desenvolvimento/estatística & dados numéricos , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/epidemiologia , Adulto , Bangladesh/epidemiologia , Centers for Disease Control and Prevention, U.S. , Criança , Pré-Escolar , China/epidemiologia , Clima , Surtos de Doenças , Egito/epidemiologia , Feminino , Guatemala/epidemiologia , Humanos , Lactente , Agências Internacionais , Quênia/epidemiologia , Masculino , Vigilância da População/métodos , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/virologia , Estações do Ano , África do Sul/epidemiologia , Tailândia/epidemiologia , Estados Unidos , Tempo (Meteorologia)RESUMO
BACKGROUND: There have been few population-based studies from Central America on respiratory syncytial virus (RSV) infections in young children. We report population-based incidence rates and describe epidemiological and clinical characteristics of children <5 years old hospitalized with RSV infections in Guatemala. METHODS: Prospective, active hospital-based surveillance for acute respiratory infections in children <5 years old was conducted at 3 hospitals in Guatemala from November 2007 through July 2010. RSV hospitalization rates were calculated for areas where the catchment population could be defined. Comparisons were made between children who were RSV-positive and RSV-negative. RESULTS: RSV was detected in 549 (25%) of enrolled children. Overall, annual rates of RSV hospitalizations ranged from 5.9 to 45.9 and 2.0 to 13.7 per 1000 children <1 year old and <5 years old, respectively, but varied by location and calendar year. Rates generally decreased with age--children <6 months had rates up to 30 times higher than older children, but children >12 months old still had rates up to 5.5 per 1000 per year and accounted for 42% of deaths. Children with RSV infections were more likely to have signs of respiratory distress (85% versus 63%, P < 0.001) compared with those without RSV infections, but case fatality ratios were similar (3-4%). CONCLUSIONS: The large burden and severity of RSV infections in young Guatemalan children is similar in magnitude and age distribution to RSV disease burdens found in other developing countries and suggests that this population would benefit from prevention strategies, including vaccines against RSV that are currently under development.
Assuntos
Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/patologia , Distribuição por Idade , Pré-Escolar , Feminino , Guatemala/epidemiologia , Hospitalização , Hospitais , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/patologia , Vírus Sincicial Respiratório Humano/isolamento & purificaçãoRESUMO
OBJECTIVE: To determine the population-based inpatient disease burden of parainfluenza virus in children <5 years of age. STUDY DESIGN: The New Vaccine Surveillance Network (NVSN) enrolled children <5 years of age who were hospitalized with febrile or acute respiratory illnesses. Surveillance hospitals admitted >95% of all hospitalized children from each county. Combined nasal turbinate/throat swabs were tested for parainfluenza virus (PIV), respiratory syncytial virus, and influenza virus with culture and reverse-transcription-polymerase chain reaction. Both parental interviews and medical chart reviews were conducted. Age-specific population-based hospitalization rates were calculated. RESULTS: From October 2000 through September 2004, 2798 children were enrolled. A total of 191 PIVs were identified from 189 children (6.8% of enrolled: 73 PIV type 1, 23 PIV type 2, and 95 PIV type 3), compared with 521 respiratory syncytial viruses and 159 influenza viruses. Mean PIV hospitalization rates were 3.01, 1.73, 1.53, 0.39, and 1.02 per 1000 children per year for ages 0 to 5 months, 6 to 11 months, 12 to 23 months, 24 to 59 months, and 0 to 59 months, respectively. CONCLUSIONS: PIV accounted for 6.8% of all hospitalizations for fever, acute respiratory illnesses, or both in children <5 years of age. The pediatric PIV inpatient burden is substantial and highlights the need to find an effective vaccine candidate.