An epidemiological study of RSV infection in the Gambia

OBJECTIVE: To describe the epidemiology of respiratory syncytial virus (RSV) infection in a developing country. METHODS: The work was carried out in three hospitals for primary cases and in the community for secondary cases in the western region of the Gambia, West Africa. RSV infection was diagnosed by immunofluorescence of nasopharyngeal aspirate samples in children younger than two years admitted to hospital with acute lower respiratory infection (ALRI). Routine records of all children with ALRI were analysed, and the incidence rates of ALRI, severe RSV-associated respiratory illness and hypoxaemic RSV infections were compared. A community-based study was undertaken to identify secondary cases and to obtain information about spread of the virus. FINDINGS: 4799 children with ALRI who were younger than two years and lived in the study area were admitted to the study hospitals: 421 had severe RSV-associated respiratory illness; 55 of these were hypoxaemic. Between 1994 and 1996, the observed incidence rate for ALRI in 100 children younger than one year living close to hospital was 9.6 cases per year; for severe RSV-associated respiratory illness 0.83; and for hypoxaemic RSV-associated respiratory illness 0.089. The proportion of all ALRI admissions due to RSV was 19%. Overall, 41% of children younger than five years in compounds in which cases lived and 42% in control compounds had evidence of RSV infection during the surveillance period. CONCLUSION: RSV is an important cause of ALRI leading to hospital admission in the Gambia. Morbidity is considerable and efforts at prevention are worthwhile.     

Contribution of RSV to bronchiolitis and pneumonia-associated hospitalizations in English children,April 1995-March 1998

Estimates of the number of hospitalizations attributable to specific pathogens are required to predict the potential impact of vaccination. All hospital admissions for lower respiratory tract infection (LRI) in children < 5 years in England in 1995-8 were reviewed. Most admissions (76.8%) were not associated with specific organisms. Seasonality in pathogens that cause bronchiolitis and pneumonia was used to predict the proportion of cases with unspecified aetiology attributable to different organisms using multiple linear regression. Of 12,298 admissions for LRI, 17.5% were due to RSV infection. An estimated 74.8% (95% CI, 72.0-77.7%) of 'unspecified bronchiolitis' admissions and 16.3% (95% CI, 13.7-18.8%) of unspecified pneumonia' admissions were RSV related. The total mean annual incidence of hospital admissions attributable to RSV is 28.3/1000 children < 1 year of age, and 1.3/1000 children 1-4 years old. The greater burden of RSV infection than indicated through discharge data is revealed through applying simple statistical methods.     

Number needed to immunize to prevent RSV with extended half-life monoclonal antibody

BackgroundRespiratory syncytial virus (RSV) is one of the most important respiratory pathogens in young children. Infants <6 months of age and infants and young children with extreme pre-term birth, and cardiac and pulmonary co-morbidities experience the highest incidence of severe RSV disease. There are no licensed vaccines; immunoprophylaxis is recommended for the highest risk children. Extended half-life RSV monoclonal antibodies (EHL-mAbs) are under development intended for immunization of all infants and high-risk children <2 years of age. We modeled the anticipated public health benefits of RSV EHL-mAb immunization using the number needed to immunize (NNI).MethodsWe combined RSV hospitalization, outpatient and outpatient lower respiratory tract infection (LRI) incidence estimates and a range of immunization efficacies to estimate the annual NNI. We calculated the absolute incidence rate reduction (ARR) by multiplying the incidence rates by immunization efficacy. NNI was calculated as the reciprocal of the ARR.ResultsFor an RSV EHL-mAb with 70% efficacy, 6–18 infants would need to be immunized to prevent one RSV-associated outpatient visit, and 13–33 infants would need to be immunized to prevent one RSV-associated LRI outpatient visit. To prevent one RSV-associated hospitalization, 37–85 infants 0–5 months of age, and 107–280 infants 6–11 months of age would need to be immunized.ConclusionsPublic health benefits, such as disease cases averted due to immunization, are essential elements in consideration of candidate vaccines for a national immunization program. An RSV EHL-mAb of moderate efficacy could have high impact. These data provide an additional perspective for public health decision making.     

Better newborn vitamin D status lowers RSV-associated bronchiolitis in infants

Each year 1.5 million children under the age of 5 years die from pneumonia. In the United States, respiratory syncytial virus (RSV) is the number one cause of bronchiolitis and pneumonia in children under 1 year of age. Low serum 25(OH)D is associated with an increased risk of lower respiratory tract infections (LRTI). Two recent studies have provided important information concerning the association between cord blood 25(OH)D and subsequent risk of developing respiratory infection in very young children. These findings support the need in future studies to determine the extent to which an intervention to change the vitamin D status of mothers during pregnancy can reduce the risk of RSV-associated LRTI in their offspring. An answer to this question would have significant worldwide public health importance given the high prevalence of low vitamin D status worldwide and the high mortality burden accompanying infectious lung diseases in young children.     

Road traffic injuries in urban Africa and Asia: a policy gap in child and adolescent health

OBJECTIVE: This study highlights the burden of urban road traffic injuries (RTIs) in children and young adults in South Asia and Sub-Saharan Africa to heighten awareness of current limitations in child health policies, and to direct future research and intervention development. METHODS: Comparative analysis of recent Sub-Saharan Africa and South Asia reviews of RTIs, World Health Organization (WHO) Global Burden of Disease statistics, and the Bangladesh Health and Injury Survey. PARTICIPANTS: Children aged 0-18 years in South Asia and Sub-Saharan Africa reviews, aged 0-14 years in the WHO data, and aged 1-17 years in the Bangladeshi data. RESULTS: Child pedestrians comprise the largest proportion of urban RTI victims. More healthy life years were lost per 1000 children aged 0-18 years in South Asia than Sub-Saharan Africa. Disability-adjusted life years lost per 1000 children aged 0-14 years was greater in Africa than South-east Asia. South-east Asia has the greatest overall incidence of RTIs; however, Africa has poorer reported outcomes for children aged 0-14 years. CONCLUSION: These data sources point to the salience of intervening in RTIs in children to prevent a predicted boom in the RTI burden in children, particularly in the poorest regions of the world. However, child health policies in these regions have not yet embraced RTI, either in research or programmes.     

Rate-difference method proved satisfactory in estimating the influenza burden in primary care visits

OBJECTIVE: To compare different methods to estimate the disease burden of influenza, using influenza and respiratory syncytial virus-(RSV) associated primary care data as an example. STUDY DESIGN AND SETTING: In a retrospective study in the Netherlands over 1997-2003, primary care attended respiratory episodes and national viral surveillance data were used to compare the rate-difference method to other, more complex methods. RESULTS: The influenza-associated excess estimated by the different methods varied. The estimates provided by the rate-difference model lay well within this range. According to the rate-difference method, influenza-associated primary care consultations were present for all ages, including low-risk adults. The highest influenza-associated burden was demonstrated for children below the age of 5 years. The RSV-associated primary care burden was highest in the youngest age category and well above that associated with influenza. Significant RSV-associated excess was also recorded among adults, particularly in high-risk adults and the elderly. CONCLUSION: The straightforward rate-difference model seemed satisfactory to estimate the influenza-associated burden. Significant influenza-associated excess was demonstrated among persons not yet recommended for influenza vaccination in The Netherlands. The RSV-associated burden was highest for the youngest children, but also significant for adults.     

Sero-epidemiological studies of respiratory syncytial and adenoviruses in children in Ibadan, Nigeria, 1985-1988.

Retrospective and prospective serological surveys to determine the prevalence of respiratory syncytial virus (RSV) and adenovirus (ADV) infections in children with respiratory diseases were carried out from 1985 to 1988 at the University College Hospital, Ibadan, Nigeria. 306 sera from subjects between 3 months and 12 years old were assayed by complement fixation test for antibodies to both viruses. Second samples were available from 42 of the subjects for antibody conversion testing. The rate varied with age, period of the year and virus. Overall prevalences of 23.5% and 18.3% were obtained for RSV and ADV respectively. 2.6% of the subjects had antibodies to both viruses. Among 42 paired samples tested, 61.9% and 33.3% showed positive antibody conversion to RSV and ADV respectively. Although there was evidence of active circulation of both viruses throughout the year, infection with RSV was higher from September to January, while ADV infection was significantly higher during February and March. Antibody prevalence to both viruses increased with age up to a peak of 39.1% for RSV in children 5-6 years old and 32% for ADV in children 3-4 years old. None of the subjects aged 10 years and above was positive for both viruses. Both RSV and ADV are important agents of acute respiratory infection in children in Nigeria.     

Portrait of outpatient visits and hospitalizations for acute infections in Nunavik preschool children

OBJECTIVE: Inuit children from around the world are burdened by a high rate of infectious diseases. The objective of this study was to evaluate the incidence rate of infections in Inuit preschool children from Nunavik (Northern Québec). METHODS: The medical chart of 354 children from a previously recruited cohort was reviewed for the first five years of life. All outpatient visits that led to a diagnosis of acute infection and all admissions for acute infections were recorded. RESULTS: Rates of outpatient visits for acute otitis media (AOM) were 2314, 2300, and 732 events/1000 child-years for children 0-11 months, 12-23 months, and 2-4 years, respectively. Rates of outpatient visits for lower respiratory tract infections (LRTI) were 1385, 930, and 328 events/1000 child-years, respectively. Rates of hospitalization for pneumonia were 198, 119, and 31 events/1000 child-years, respectively. CONCLUSION: Inuit children from Nunavik have high rates of AOM and LRTI. Such rates were higher than that of other non-native North-American populations previously published. Admission for LRTI is up to 10 times more frequent in Nunavik compared to other Canadian populations.     

Natural history and epidemiology of respiratory syncytial virus infection in the Middle East: Hospital surveillance for children under age two in Jordan

Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and viral pneumonia in infants and young children worldwide. In the Middle East and Arab countries, the burden of RSV-associated hospitalizations is not well characterized. We sought to determine the burden and clinical/epidemiological characteristics of RSV hospitalization in young children in Amman, Jordan. We investigated risk factors for severity including vitamin D levels.MethodsWe conducted viral surveillance with clinical and demographic data in children <2 years admitted with respiratory symptoms and/or fever at the Al-Bashir Government Hospital from March16, 2010 to March 31, 2013. Nasal/throat swabs were obtained and placed into lysis buffer, and frozen at −80 °C until testing by real-time RT-PCR for 11 respiratory viruses. Heel stick blood or sera samples for 25-hydroxyvitamin D [25(OH)D] levels were obtained and sent to a central laboratory for mass spectrometry.ResultsOf the 3168 children, >80% testing positive for one virus, with RSV the most common virus detected (44%). The RSV-associated hospitalization rate was highest in children <6 months with an annual range of 21.1–25.9 per 1000, compared to 6.0–8.0 in 6–11-month-olds and 1.6–2.5 in 12–23-month-olds. RSV-positive children compared with RSV-negative were more likely to be previously healthy without underlying medical conditions, less likely to be born prematurely, had a higher frequency of supplemental oxygen use, and had lower median vitamin D levels. Risk factors for oxygen use in RSV-positive children included underlying medical conditions, lack of breastfeeding, younger age, and higher viral load.ConclusionRSV is a major cause of illness in hospitalized Jordanian children and is associated with increased severity compared to other respiratory viruses. Children with RSV in the Middle East would benefit from future RSV vaccines and antiviral therapy.     

Deaths Associated with Respiratory Syncytial and Influenza Viruses among Persons ≥5 Years of Age in HIV-Prevalent Area,South Africa, 1998–20091

We estimated deaths attributable to influenza and respiratory syncytial virus (RSV) among persons >5 years of age in South Africa during 1998–2009 by applying regression models to monthly deaths and laboratory surveillance data. Rates were expressed per 100,000 person-years. The mean annual number of seasonal influenza–associated deaths was 9,093 (rate 21.6). Persons >65 years of age and HIV-positive persons accounted for 50% (n = 4,552) and 28% (n = 2,564) of overall seasonal influenza-associated deaths, respectively. In 2009, we estimated 4,113 (rate 9.2) influenza A(H1N1)pdm09–associated deaths. The mean of annual RSV-associated deaths during the study period was 511 (rate 1.2); no RSV-associated deaths were estimated in persons >45 years of age. Our findings support the recommendation for influenza vaccination of older persons and HIV-positive persons. Surveillance for RSV should be strengthened to clarify the public health implications and severity of illness associated with RSV infection in South Africa.     

Childhood injuries: a population-based study of emergency room visits in Jerusalem

A study of childhood injuries of 0-17-year-old Jewish children based on emergency room records of the four major hospitals and the first aid stations was conducted in Jerusalem during 1986. The incidence of visits was 99.7/1000 child-years with 95% confidence intervals (CI) = 98.0-101.5. The rate was 97.2/1000 child-years (CI = 94.4-100.0) among the 0-5-year-old, 114.6/1000 child-years (CI = 111.3-118.0) in the 6-12 age group, and was 93.6/1000 child-years (CI = 90.1-97.1) among 13-17-year-old. The male to female rate ratio was 1.7 for the 0-5-year-olds, 2.1 for the 6-12-year-olds and 2.3 for the 13-17-year-olds. The most frequent causes of injuries were falls, 38.5/1000 child-years (CI = 37.4-39.6), being struck or caught, 21.1/1000 child-years (CI = 20.3-21.9), and road accidents, 5.4/1000 child-years (CI = 5.0-5.8). Only burns among children aged 6 years and over and poisoning among 13-17-year-olds showed a higher incidence among females than among males. The head was the most frequently injured part of the body (45.2/1000 child-years, CI = 44.0-46.4). Head injuries decreased as age increased, while injuries to the extremities and trunk increased with increasing age. Two per cent of the injured children were admitted to hospital.     

Epidemiology of respiratory syncytial virus infection among paediatric patients in Hong Kong: seasonality and disease impact

In a 5-year retrospective survey of respiratory syncytial virus (RSV) infections among hospitalized children, 1340 cases were identified of which, 98.4% were children < 5 years old with a male:female ratio of 1.5: 1. Most cases occurred from April to September showing a significant positive correlation with temperature and relative humidity. Community-acquired infections accounted for 92.5% of the cases with a mean hospital stay of 5 days. The estimated annual incidence of RSV infection requiring hospitalization was 2.5/1000 children < 5 years old with a mortality of 0.15% among hospitalized cases. On average, 248 children were admitted each year to the 1400-bed acute regional hospital accounting for an expenditure of HK S1.94 ((approximately US +/-0.25) million for hospitalization costs which equates to an annual cost in excess of HK $6.67 (approximately US $0.86) million for the whole of Hong Kong. An RSV vaccine should be a priority.     

A multi-tiered time-series modelling approach to forecasting respiratory syncytial virus incidence at the local level

Respiratory syncytial virus (RSV) is the most common cause of documented viral respiratory infections, and the leading cause of hospitalization, in young children. We performed a retrospective time-series analysis of all patients aged <18 years with laboratory-confirmed RSV within a network of multiple affiliated academic medical institutions. Forecasting models of weekly RSV incidence for the local community, inpatient paediatric hospital and paediatric intensive-care unit (PICU) were created. Ninety-five percent confidence intervals calculated around our models' 2-week forecasts were accurate to ±9·3, ±7·5 and ±1·5 cases/week for the local community, inpatient hospital and PICU, respectively. Our results suggest that time-series models may be useful tools in forecasting the burden of RSV infection at the local and institutional levels, helping communities and institutions to optimize distribution of resources based on the changing burden and severity of illness in their respective communities.     

Hospitalization for respiratory syncytial virus in the paediatric population in Spain

The aim of this population-based retrospective study was to determine the incidence of hospitalization for community-acquired, laboratory-confirmed respiratory syncytial virus (RSV) infection in an unselected paediatric population from southern Europe. The study was performed in an area with 15,700 children aged less than 5 years attended by a single hospital. The presence of RSV in nasopharyngeal aspirates from children with acute respiratory infection treated in the hospital was investigated in four seasons (July 1996-June 2000). A total of 390 episodes of hospitalization for RSV infection were detected and 83.3% of the children were aged less than 1 year old. The annual hospitalization rate was 37/1000 for infants aged less than 6 months and 25/1000 for those aged less than 1 year. During the study period, 2.5% of the infants younger than 1 year and approximately 5% of those younger than 3 months were hospitalized for RSV infection. The mean length of hospital stay was 5.9 days. Seven per cent of the patients required admission to the intensive care unit and more than half of these children were aged less than 1 month. In Spain, community-acquired RSV infection is a highly frequent cause of hospitalization in young children, especially in those aged less than 1 year. Prevention of RSV infection, through the development of vaccines and/or other strategies, should be a public health priority.     

Burden of illness associated with Respiratory Syncytial Virus (RSV)-related hospitalizations among adults in Ontario,Canada: A retrospective population-based study

BackgroundGlobally, RSV is a common viral pathogen that causes 64 million acute respiratory infections annually. Our objective was to determine the incidence of hospitalization, healthcare resource use and associated costs of adults hospitalized with RSV in Ontario, Canada.MethodsTo describe the epidemiology of adults hospitalized with RSV, we used a validated algorithm applied to a population-based healthcare utilization administrative dataset in Ontario, Canada. We created a retrospective cohort of incident hospitalized adults with RSV between September 2010 and August 2017 and followed each person for up to two years. To determine the burden of illness associated with hospitalization and post-discharge healthcare encounters each RSV-admitted patient was matched to two unexposed controls based on demographics and risk factors. Patient demographics were described and mean attributable 6-month and 2-year healthcare costs (2019 Canadian dollars) were estimated.ResultsThere were 7,091 adults with RSV-associated hospitalizations between 2010 and 2019 with a mean age of 74.6 years; 60.4 % were female. RSV-coded hospitalization rates increased from 1.4 to 14.6 per 100,000 adults between 2010–2011 and 2018–2019. The mean difference in healthcare costs between RSV-admitted patients and matched controls was $28,260 (95 % CI: $27,728 - $28,793) in the first 6 months and $43,721 over 2 years (95 % CI: $40,383 – $47,059) post-hospitalization.ConclusionsRSV hospitalizations among adults increased in Ontario between 2010/11 to 2018/19 RSV seasons. RSV hospitalizations in adults were associated with increased attributable short-term and long-term healthcare costs compared to matched controls. Interventions that could prevent RSV in adults may reduce healthcare burden.     

Child health in South Africa -- past,present and future

April 27, 1994, marked the end of the apartheid era in South Africa, but still the infant mortality rate is 130/1000 live births for Blacks compared to 13/1000 for Whites. Diarrhea, acute respiratory infections, malnutrition, and measles account for an estimated ninefold excess of deaths among Black children under 5 years old relative to their White counterparts. In Cape Town the under-five-years mortality rate for the mixed Colored population is 20.5/1000 compared to 4.6/1000 for Whites. In 1992, 19,000 measles cases were recorded. Diarrhea accounts for 20% of the deaths in the under-five group. In Cape Town alone, intestinal infections accounted for 27% of deaths in children followed by acute respiratory infections at 16%, and nutritional deficiencies at 10%. About 100,000 new cases of tuberculosis occur annually. There are currently 350,000 to 400,000 HIV-infected people in South Africa, and the mounting numbers pose a major threat to the health services. The fragmented public health system of South Africa is undergoing rationalization. The new government has extended universal public health care to children under 6 years old and to pregnant mothers. This reform, however, has resulted in undue strain on health services because of financial and staff constraints. Many doctors are threatening to leave the public service because of the increased workload without a concomitant increase in medical or paramedical staffing. Numerous clinics are reporting complete exhaustion of supplies of essential drugs. Currently only 5% of the health care budget is being spent on primary health care and only 3.6% of the public sector GDP is spent on health care. Political commitment, upgrading of skills in public health, redefinition of the government's role, emphasis on education, communication, public-health legislation, direct involvement in health care and research, and greater participation in health issues are required.     

Influenza- and RSV-associated hospitalizations among adults

We estimated influenza- and respiratory syncytial virus (RSV)-associated hospitalizations by age, high-risk status and outcome, during the 1996/1997-1999/2000 respiratory seasons among adults who did not receive influenza vaccine. Using three health maintenance organization (HMO) databases and local viral surveillance data, we identified weeks when influenza and RSV were circulating and estimated influenza- and RSV-associated hospitalizations. Persons aged > or = 65 years with and without high-risk conditions had significantly increased rates of influenza-associated hospitalizations for pneumonia and influenza, and circulatory and respiratory diseases. Persons aged > or = 65 years with high-risk conditions also had significantly increased rates of influenza-associated hospitalizations for cardiac conditions (16.9 per 10,000 person periods). Relative to the influenza estimates for high-risk persons > or = 65 years, we found lower rates of RSV-associated hospitalizations for pneumonia and influenza diseases (23.4 per 10,000 person periods), cardiac diseases (4.3 per 10,000 person periods) and circulatory and respiratory diseases (44.0 per 10,000 person periods). Among low-risk persons aged 50-64 years, we did not identify significantly elevated rates of influenza- or RSV-associated hospitalizations. Excess hospitalization estimates among adults aged > or = 65 years and high-risk 50-64 year olds during the influenza season suggest that these groups should have priority for influenza vaccine during vaccine shortages.     

The preventable burden of pneumococcal disease in the developing world

The efficacy of pneumococcal conjugate vaccines (PCV) and their remarkable success in operational use in North America challenge us to define the burden of pneumococcal disease and the likely benefits of PCV use in developing countries. Community-based incidence studies of invasive pneumococcal disease (IPD) and vaccine probe analyses of efficacy trials suggest there are approximately 814,000 pneumococcal deaths in children aged <5 years in developing countries each year and 1-4 million episodes of pneumococcal pneumonia in Africa alone. PCV will be effective where there is a demonstrable burden of IPD attributable to vaccine serotypes but herd protection and serotype replacement effects are unpredictable given existing knowledge of pneumococcal epidemiology in developing countries. Operational use of PCV in well-monitored settings is required to estimate these effects.     

Towards estimating the burden of disease attributable to second-hand smoke exposure in Polish children

Objectives

To estimate the burden of disease attributable to second-hand smoke (SHS) exposure in Polish children in terms of the number of deaths and disability adjusted life years (DALYs) due to lower respiratory infections (LRI), otitis media (OM), asthma, low birth weight (LBW) and sudden infant death syndrome (SIDS).

Materials and Methods

Estimates of SHS exposure in children and in pregnant women as well as information concerning maternal smoking were derived from a national survey, the Global Youth Tobacco Survey, and the Global Adult Tobacco Survey in Poland. Mortality data (LRI, OM, asthma, and SIDS), the number of cases (LBW), and population data were obtained from national statistics (year 2010), and DALYs came from the WHO (year 2004). The burden of disease due to SHS was calculated by multiplying the total burden of a specific health outcome (deaths or DALYs) by a population attributable fraction.

Results

Using two estimates of SHS exposure in children: 48% and 60%, at least 12 and 14 deaths from LRI in children aged up to 2 years were attributed to SHS, for the two exposure scenarios, respectively. The highest burden of DALYs was for asthma in children aged up to 15 years: 2412, and 2970 DALYs, for the two exposure scenarios, respectively. For LRI, 419 and 500 DALYs, and for OM, 61 and 77 DALYs were attributed to SHS, for the two exposure scenarios, respectively. Between 13% and 27% of SIDS cases and between 3% and 16% of the cases of LBW at term were attributed to SHS exposure.

Conclusions

This study provides a conservative estimate of the public health impact of SHS exposure on Polish children. Lack of comprehensive, up to date health data concerning children, as well as lack of measures that would best reflect actual SHS exposure are major limitations of the study, likely to underestimate the burden of disease.