A community-based cluster survey on preferences for treatment of diarrhoea and dysentery in Zhengding county, Hebei province, China

Passive surveillance on the burden of disease due to diarrhoea will underestimate the burden if families use healthcare providers outside the surveillance system. To study this issue, a community-based cluster survey was conducted during October 2001 in the catchment area for a passive surveillance study in Zhengding county, a rural area of northern China. Interviews were conducted at 7 randomly-selected households in each of 39 study villages. The respondents indicated where they sought initial care for cases of diarrhoea or dysentery among children or adults. In the absence of diarrhoea and dysentery cases in the household in the preceding four weeks, the respondents were asked about healthcare use for a hypothetical case. Overall, 80% (95% confidence interval [CI] 67-93%) would chose the village clinic, 11% village pharmacy (95% CI 1-22%), 4% township hospital (95% CI -1-10%), 4% self-treatment (95% CI 1-8%), and 1% county hospital (95% CI 0-2%). Approximately, 84% of patients would seek treatment for diarrhoea and dysentery at centres participating in passive surveillance, suggesting that passive surveillance will provide a relatively accurate assessment of burden of diarrhoea in Zhengding county.     

Gastroenteritis in older people living in the community: results of two Australian surveys

SUMMARY We analysed two large national surveys conducted in 2001 and 2008 to examine incidence and outcomes of gastroenteritis in older Australians. A case was someone reporting ?3 loose stools or ?1 episode of vomiting in 24 h, excluding non-infectious causes. We compared cases arising in the elderly (?65 years) and in other adults (20-64 years). Elderly people experienced 0·33 [95% confidence interval (CI) 0·24-0·42] episodes of gastroenteritis/person per year, compared to 0·95 (95% CI 0·74-1·15) in other adults. Elderly cases reported less stomach cramps, fever and myalgia than younger cases, and were more likely to be hospitalized, although this was not statistically significant. In multivariable analysis, gastroenteritis in elderly people was associated with travelling within the state (odds ratio 1·35, 95% CI 1·07-1·71). Elderly people were less concerned about food safety than other adults. Older Australians were less likely to report gastroenteritis and experienced different symptoms and outcomes from other adults.     

Burden of acute gastrointestinal illness in Denmark 2009: a population-based telephone survey

A cross-sectional telephone survey was conducted in Denmark throughout 2009 to determine the incidence of acute gastrointestinal illness (AGI). Using the Danish population register, a random population sample stratified by gender and age groups was selected and mobile or landline phone numbers found. Representative numbers of interviews were performed by gender, age group and month. A recently proposed international case definition of AGI, including cases with diarrhoea and/or vomiting in a 4-week recall period, was used. A total of 1853 individuals were included and 206 (11·1%) fulfilled the case definition; 78% reported diarrhoea. This corresponds to an overall standardized incidence rate of 1·4 (95% CI 1·2-1·6) episodes of AGI per person-year. The incidence rate was generally higher in the younger age groups; only being 2·3, 1·9 and 0·80 per person-year in the 0-9, 10-39 and ≥40 years age groups, respectively. The incidence rate estimates were considerably higher when calculated from shorter recall periods.     

The burden of infectious intestinal disease (IID) in the community: a survey of self-reported IID in The Netherlands

In 2009, a 1-year retrospective survey was performed in The Netherlands to estimate the incidence and the disease burden of infectious intestinal disease (IID) in the community, to study the selection of patients consulting a general practitioner and to identify potential risk factors for IID in the community. A questionnaire was sent to 6000 persons selected at random from the population registries of 28 municipalities, with 500 persons being approached per month. A total of 1975 (33%) persons participated. The incidence rate of IID was 964/1000 person-years. Potential risk factors associated with IID in the community were young age (0-4 years) [odds ratio (OR) 3.9, 95% confidence interval (CI) 1.5-10.5], having asthma as a child (OR 3.4, 95% CI 1.1-10.3) and use of gastric acid suppressive medication by persons aged ≥ 45 years (OR 2.8, 95% CI 1.4-5.6). Of the 146 cases with IID, 11 (8%) consulted a physician. Cases with a long duration of symptoms, blood in the stool, children with IID and cases with a low level of education were more likely to consult a physician. Two cases had a stool sample taken and one was admitted to hospital. In conclusion, IID is common and has a significant burden of illness in The Netherlands. Our data indicate that about 15.9 million episodes of IID occur in The Netherlands per year. The incidence rate is substantially higher than the rate of 283/1000 person-years as estimated in 1999 in The Netherlands. This is probably largely due to the retrospective nature of the present study and, to a lesser extent, to differences in case definitions.     

Adult intensive-care patients with 2009 pandemic influenza A(H1N1) infection

In France, the surveillance of hospitalized cases of pandemic influenza was implemented in July 2009 and restricted to intensive-care unit (ICU) patients in November. We described the characteristics of the 1065 adult patients admitted to ICUs and analysed risk factors for severe outcome (mechanical ventilation or death). Eighty-seven percent of cases were aged 15-64 years. The case-fatality ratio was 20%. The risk for severe outcome increased with age and obesity while this association was negative for chronic respiratory disease. Late antiviral therapy was associated with a severe outcome in ICU patients with risk factors (adjusted OR 2·0, 95% CI 1·4-3·0). This study confirms the considerable contribution of young adults to A(H1N1) 2009 mortality. It shows the role of obesity as an independent risk factor for severe disease, and of early antiviral therapy as a protective factor, at least in patients with risk factors.     

The burden of acute gastrointestinal illness in Ontario, Canada, 2005-2006

A retrospective, cross-sectional telephone survey (n=2090) was conducted in Ontario, Canada, between May 2005 and April 2006, to determine the burden of acute gastrointestinal illness in the population. The 4-week prevalence was 8.56% (95% CI 7.36-9.76); in households with more than one resident, 35% of cases reported someone else in their household had similar symptoms at the same time. The annual adjusted incidence rate was 1.17 (95% CI 0.99-1.35) episodes per person-year, with higher rates in females, rural residents, and in the winter and spring. Health care was sought by 22% of cases, of which 33% were asked to provide a stool sample. Interestingly, 2.2% of cases who did not visit a health-care provider reported self-administering antibiotics. Overall, acute gastrointestinal illness appears to pose a significant burden in the Ontario population. Further research into the specific aetiologies and risk factors is now needed to better target intervention strategies.     

Under-recognition and reporting of dengue in Cambodia: a capture-recapture analysis of the National Dengue Surveillance System

Robust disease burden estimates are important for decision-making concerning introduction of new vaccines. Dengue is a major public health problem in the tropics but robust disease burden estimates are lacking. We conducted a two-sample, capture-recapture study in the largest province in Cambodia to determine disease under-recognition to the National Dengue Surveillance System (NDSS). During 2006-2008, community-based active surveillance for acute febrile illness was conducted in 0- to 19-year-olds in rural and urban areas combined with testing for dengue virus infection. Of 14 354 individuals under active surveillance (22 498 person-seasons), the annual incidence ranged from 13·4 to 57·8/1000 person-seasons. During the same period, NDSS incidence rates ranged from 1·1/1000 to 5·7/1000, which was 3·9- to 29·0-fold lower than found in the capture-recapture study. In hospitalized cases, the rate of under-recognition was 1·1- to 2·4-fold. This study shows the substantial degree of under-recognition/reporting of dengue and that reported hospitalized cases are not a good surrogate for estimating dengue disease burden.     

Preferences for treatment of diarrhoea and dysentery in Kaengkhoi district, Saraburi province, Thailand

To estimate the proportion of cases missed in a passive surveillance study of diarrhoea and dysentery at health centres and hospitals in Kaengkhoi district, Saraburi province, Thailand, a community-based cluster survey of treatment-seeking behaviours was conducted during 21-23 June 2002. Interviews were conducted at 224 households among a study population of 78,744. The respondents reported where they sought care for diarrhoea and dysentery in children aged less than five years and adults aged over 15 years. Health centres or hospitals were the first treatment choice for 78% of children with dysentery (95% confidence interval [CI] 63-94%), 64% of children with diarrhoea (95% CI 54-74%), 61% of adults with dysentery (95% CI 40-82%), and 35% of adults with diarrhoea (95% CI 17-54%). A high degree of heterogeneity in responses resulted in a relatively large design effect (D=3.9) and poor intra-cluster correlation (rho=0.3). The community survey suggests that passive surveillance estimates of disease incidence will need to be interpreted with caution, since this method will miss nearly a quarter of dysentery cases in children and nearly two-thirds of diarrhoea cases in adults.     

Weather variability and paediatric infectious gastroenteritis

Investigations of the relationship between weather variability and infectious gastroenteritis (IG) are becoming increasingly important in light of international interest in the potential health effects of climate change. However, few studies have examined the impact on children, despite the fact that children are considered particularly vulnerable to climate change. We acquired data about cases of IG in children aged <15 years and about weather variability in Fukuoka, Japan from 2000 to 2008 and used time-series analyses to assess how weather variability affected IG cases, adjusting for confounding factors. The temperature-IG relationship had an inverted V shape, with fewer cases at temperatures lower and higher than ~13°C. Every 1°C increase in temperature below the threshold (13°C) was associated with a 23·2% [95% confidence interval (CI) 16·6-30·2] increase, while every 1°C increase in temperature above the threshold (13°C) was associated with an 11·8% (95% CI 6·6-17·3) decrease in incidence. The increase in cases per 1% drop in relative humidity was 3·9% (95% CI 2·8-5·0). The percentage increase of IG cases was greatest in the 0-4 years age group and tended to decrease with increasing age. We found a progressive reduction in weather-related IG cases in children aged >4 years. Our results suggest that public health interventions aimed at controlling weather-related IG may be most effective when focused on young children.     

Enhanced disease surveillance through private health care sector cooperation in Karachi, Pakistan: experience from a vaccine trial

INTRODUCTION: In research projects such as vaccine trials, accurate and complete surveillance of all outcomes of interest is critical. In less developed countries where the private sector is the major health-care provider, the private sector must be included in surveillance systems in order to capture all disease of interest. This, however, poses enormous challenges in practice. The process and outcome of recruiting private practice clinics for surveillance in a vaccine trial are described. METHODS: The project started in January 2002 in two urban squatter settlements of Karachi, Pakistan. At the suggestion of private practitioners, a phlebotomy team was formed to provide support for disease surveillance. Children who had a reported history of fever for more than three days were enrolled for a diagnosis. RESULTS: Between May 2003 and April 2004, 5540 children younger than 16 years with fever for three days or more were enrolled in the study. Of the children, 1312 (24%) were seen first by private practitioners; the remainder presented directly to study centres. In total, 5329 blood samples were obtained for microbiology. The annual incidence of Salmonella typhi diagnosed by blood culture was 407 (95% confidence interval (95% CI), 368-448) per 100 000/year and for Salmonella paratyphi A was 198 (95% CI, 171-227) per 100 000/year. Without the contribution of private practitioners, the rates would have been 240 per 100 000/year (95% CI, 211-271) for S. typhi and 114 (95% CI, 94-136) per 100 000/year for S. paratyphi A. CONCLUSION: The private sector plays a major health-care role in Pakistan. Our experience from a surveillance and burden estimation study in Pakistan indicates that this objective is possible to achieve but requires considerable effort and confidence building. Nonetheless, it is essential to include private health care providers when attempting to accurately estimate the burden of disease in such settings.     

What is the evidence for giving chemoprophylaxis to children or students attending the same preschool, school or college as a case of meningococcal disease?

We performed a systematic literature review to assess the effectiveness of chemoprophylaxis for contacts of sporadic cases of invasive meningococcal disease (IMD) in educational settings. No studies directly compared IMD risk in contacts with/without chemoprophylaxis. However, compared to the background incidence, an elevated IMD risk was identified in settings without a general recommendation for chemoprophylaxis in pre-schools [pooled risk difference (RD) 58·2/10?, 95% confidence interval (CI) 27·3-89·0] and primary schools (pooled RD 4·9/10?, 95% CI 2·9-6·9) in the ~30 days after contact with a sporadic IMD case, but not in other educational settings. Thus, limited but consistent evidence suggests the risk of IMD in pre-school contacts of sporadic IMD cases is significantly increased above the background risk, but lower than in household contacts (pooled RD for household contacts with no chemoprophylaxis vs. background incidence: 480·1/10?, 95% CI 321·5-639·9). We recommend chemoprophylaxis for pre-school contacts depending on an assessment of duration and closeness of contact.     

Incidence of acute respiratory tract infections (2006–2015) and influenza (2006–2013) among French armed forces

ObjectivesWe aimed to assess the incidence of respiratory tract infections in military settings between 2006 and 2015.Patients and methodsWe performed a retrospective epidemiological study of the entire military population from 2006 to 2015. Comprehensive data was collected from all medical centers, operational medical units, naval services, and army training hospitals and provided by the epidemiological surveillance of the armies.ResultsThe annual average population of the study was 331,394 soldiers. For acute respiratory tract infections (2006–2015), 22,818 cases were reported in metropolitan France, 3,211 cases in French overseas territories, 1,595 cases in the French Navy, and 1,318 cases in external military operations for a total of 28,942 cases. For influenza (2006–2013), 934 cases were reported in metropolitan France, 101 cases in French overseas territories, and 23 cases in external operations, for a total of 1,058 cases. The mean incidence rate of acute respiratory tract infections expressed as case number per 1,000 person-years (PY) was 8.7 PY (95% CI [8.6–8.8]) with an exceptional increased incidence rate in 2009 (25.9 PY, 95% CI [25.4–26.4]). The mean incidence rate of influenza was 0.35 PY (95% CI [0.33–0.37]) with a peak incidence rate of 1.9 PY in 2009.ConclusionAcute respiratory tract infections are at the forefront of infectious episodes in the French armies. Although not necessarily severe, current prevention measures are not enough to reduce the incidence threshold of these infections and need to be improved.     

Repeat capture-recapture studies as part of the evaluation of the surveillance of Legionnaires' disease in France

We evaluated improvements made to the mandatory notification surveillance system for Legionnaires' disease in France by estimating its sensitivity in 1995 and 1998 using a repeat capture-recapture method. A case of Legionnaires' disease was defined as a person treated for pneumonia in whom legionella had been detected. Patient details were collected from (1) mandatory notifications; (2) the National Reference Centre for Legionella; (3) a postal survey of all hospital laboratories. The three sources were cross-matched and 715 individual cases were identified. A log-linear model, which included an interaction term between mandatory notifications and both the National Reference Centre and Laboratory sources, provided an estimated total of 1124 cases (95% CI 973-1275) in 1998, a twofold increase compared with 1995. The sensitivity of the surveillance system improved from 10% in 1995 to 33% (95% CI 29-38%) in 1998. Capture-recapture methods are important tools in the evaluation of surveillance systems.     

Mumps: Burden of disease in France

This article provides a review of the epidemiological data on mumps in France since 1986. The results of 26 years of monitoring in general practice by the Sentinel network are analysed, such as hospitalisation data between 2004 and 2010, as well as mortality data between 2000 and 2009. The annual incidence rate has plummeted between 1986 and 2011, from 859 cases per 100,000 inhabitants [95% CI: 798–920] to 9 cases per 100,000 inhabitants [95% CI: 4–14]. A change in the age distribution is significant with an increase of Relative Illness Ratio (RIR) for patients over 20 years. Since 2000, vaccine status has also changed, and the majority of recent mumps cases occur among previously vaccinated patients. The average annual hospitalisation rate is 3.2 per 1 million inhabitants. Mumps was identified as the initial cause of death in 1 case every 5 years. This study estimates the burden of mumps disease in France.     

Influence of referral bias on the clinical characteristics of patients with Gram-negative bloodstream infection

Referral bias can influence the results of studies performed at tertiary-care centres. In this study, we evaluated demographic and microbiological factors that influenced referral of patients with Gram-negative bloodstream infection (BSI). We identified 2919 and 846 unique patients with Gram-negative BSI in a referral cohort of patients treated at Mayo Clinic Hospitals and a population-based cohort of Olmsted County, Minnesota, residents between 1 January 1998 and 31 December 2007, respectively. Multivariable logistic regression analysis was used to determine factors associated with referral. Elderly patients aged ≥80 years with Gram-negative BSI were less likely to be referred than younger patients [odds ratio (OR) 0·43, 95% confidence intervals (CI) 0·30-0·62] as were females (OR 0·63, 95% CI 0·53-0·74). After adjusting for age and gender, bloodstream isolates of Escherichia coli (OR 0·50, 95% CI 0·43-0·58) and Proteus mirabilis (OR 0·49, 95% CI 0·30-0·82) were underrepresented in the referral cohort; and Pseudomonas aeruginosa (OR 2·26, 95% CI 1·70-3·06), Enterobacter cloacae (OR 2·31, 95% CI 1·53-3·66), Serratia marcescens (OR 2·34, 95% CI 1·33-4·52) and Stenotrophomonas maltophilia (OR 17·94, 95% CI 3·98-314·43) were overrepresented in the referral cohort. We demonstrated that demographic and microbiological characteristics of patients with Gram-negative BSI had an influence on referral patterns. These factors should be considered when interpreting results of investigations performed at tertiary-care centres.     

Seroepidemiological study of livestock brucellosis in a pastoral region

A seroepidemiological study of Brucella infections in multiple livestock species in the Borana pastoral system of Ethiopia was performed between December 2007 and October 2008. A cross-sectional multi-stage sampling technique was employed to select 575 cattle, 1073 camels and 1248 goats from the target populations. Sera were collected from the animals, and serially tested using Rose Bengal test and complement fixation test. Overall prevalence and prevalence with respect to explanatory variables were established, and potential risk factors for seropositivity were analysed using a multivariable logistic regression. The results showed that 8·0% (95% CI 6·0-10·6), 1·8% (95% CI 1·1-2·8) and 1·6% (95% CI 1·0-2·5) of the tested cattle, camels and goats, respectively, had antibodies to Brucella antigen. Positive reactors were found in 93·8% of the villages with more frequent detection of positive cattle (93·3%) than camels (56·3%) and goats (37·5%). Risk factors identified for cattle were: keeping more livestock species at household level (OR 4·1, 95% CI 1·9-8·9), increasing age of the animal (OR 2·8, 95% CI 1·3-6·0) and wet season (OR 3·3, 95% CI 1·6-6·9). Increase in household-level species composition (OR 4·1, 95% CI 1·2-14·2) and wet season (OR 3·7, 95% CI 1·5-9·1) were found to be risk factors for seropositivity in camels and goats, respectively. Existence of more than one seroreactor animal species in most villages and association of increased livestock species composition with seropositivity may add more credence to the possibility of cross-species transmission of Brucella infections. Although no attempt to isolate Brucella spp. was made, our results suggest that cattle are more likely maintenance hosts of Brucella abortus which has spread to goats and camels. This should be substantiated by further isolation and identification of Brucella organisms to trace the source of infection and transmission dynamics in various hosts kept under mixed conditions. In conclusion, the present study suggests the need for investigating a feasible control intervention and raising public awareness on prevention methods of human exposure to brucellosis.     

Record-linkage between two anonymous databases for a capture-recapture estimation of underreporting of AIDS cases: France 1990-1993. The Clinical Epidemiology Group from Centres d'Information et de Soins de l'Immunodéficience Humaine

OBJECTIVE: To estimate the completeness of the French mandatory AIDS surveillance system (Declaration Obligatoire DO) over the 1990-1993 period using a capture-recapture approach, by matching the mandatory reports with the AIDS cases present in the French Hospital Database on HIV infection (FHDH). METHODS: An anonymous record-linkage algorithm was developed to identify those cases common to both anonymous surveillance systems. The linkage was based on sex, date of birth, and infection risk group, all strictly matched, and on the dates of AIDS diagnosis and of death, the places of diagnosis and residence, and the AIDS-defining diseases at diagnosis. The total number of AIDS cases and completeness of both surveillance systems were estimated using a capture-recapture approach, assuming independence of the ascertainment sources. RESULTS: The completeness of the mandatory reporting was estimated at 83.6% (95% CI: 82.9-84.3), and that of the FHDH at 47.6% (95% CI: 46.9-48.3) for the surveillance of AIDS cases diagnosed among adults in France between 1990 and 1993. The completeness of the system based on FHDH increased over the study period as more hospitals joined the project, while the completeness of the DO surveillance system remained stable. CONCLUSION: This approach was useful in estimating the underreporting of AIDS cases in France. Regularly performed, it will allow the impact of underreporting to be monitored over time.     

Neonatal tetanus incidence in China, 1996-2001, and risk factors for neonatal tetanus, Guangxi Province, China

BACKGROUND: In China during 1995-1996 widespread tetanus toxoid (TT) mass vaccination of women of childbearing age in high-risk areas was conducted and neonatal tetanus (NT) surveillance was initiated as part of NT elimination efforts. Despite a subsequent decrease in the estimated rate of NT, the NT disease burden remains high in poorer areas of China. METHODS: To describe the recent epidemiology of NT in China and estimate its risk, we analysed national surveillance data in China 1996-2001 and conducted a case-control study in one high-risk county (Bobai): 60 hospitalized cases were sex- and calendar-birth year matched to 60 controls from the same or neighbouring villages. RESULTS: Reported national annual NT incidence decreased from 0.21/1000 live births (LB) in 1997 to 0.16/1000 LB in 2001. Case mothers were more likely to be aged >30 years (odds ratio [OR] = 6; 95% CI: 2.2, 20.2), unschooled (OR = 3.2; 95% CI: 1.1, 11.6), and with an annual income of <1000 yuan ($125 USD) (OR = 6.0; 95% CI: 1.9, 25.6). Only 28% of control mothers and 12% of case mothers reported any TT vaccination. In multivariate analysis, relative to hospital delivery, cases had a 64-fold increased odds of home delivery by a family member or neighbour (95% CI: 8.4, 982.2), and a 13-fold increased odds of home delivery by a traditional birth attendant (95% CI: 1.6, 322.6). CONCLUSIONS: Improved access to clean deliveries in high-risk areas is critically needed in China. Nonetheless, targeted TT vaccination appears to have helped reduce NT incidence in China.     

Risk factors associated with typhoid fever in children aged 2-16 years in Karachi, Pakistan

We analysed the data from the control group in a typhoid vaccine trial in Karachi to assess the differences in individual-, household- and cluster-level characteristics for developing typhoid fever. The annual incidence of typhoid in children aged 2-16 years in the control arm of the vaccine trial was 151/100 000 population. After adjustment, the risk of typhoid was lower with increasing age [risk ratio (RR) 0·89, 95% confidence interval (CI) 0·83-0·95], was higher with an increase in population density (RR 1·13, 95% CI 1·05-1·21) and was lower in the households using a safe drinking-water source (RR 0·63, 95% CI 0·41-0·99). Typhoid fever affects younger children living in areas of high population density and lack of access to safe water in Pakistan. A combination of environmental and biological interventions is required to prevent the continued epidemiological and economic impact of typhoid fever in high-risk areas of Pakistan.     

Hepatitis A surveillance in England--how many cases are not reported and does it really matter?

Underreporting of hepatitis A infection in England may be high and a number of outbreaks have occurred undetected by routine surveillance. We evaluated surveillance of hepatitis A cases by employing capture-recapture analysis on data from two distinct outbreaks of hepatitis A. The overall reporting of cases of hepatitis A was 81.7% (95% CI 55.3-95) in the first outbreak in North East England and reporting through Lab Base was 65.7% (95% CI 42.8-76.4). In the second outbreak in the East Midlands the overall reporting of hepatitis A cases was 27.8% (95% CI 19-38.7) and through Lab Base 16.6% (95% CI 11.4-23.1). Underreporting of hepatitis A cases is high. Public health interventions exist to prevent and control outbreaks of hepatitis A. The lack of reliable data on incidence and prevalence hampers effective public health management of this disease.