Methodological issues of retrospective surveys for measuring mortality of highly clustered diseases: case study of the 2014-16 Ebola outbreak in Bo District, Sierra Leone.

BACKGROUND: There is a lack of empirical data on design effects (DEFF) for mortality rate for highly clustered data such as with Ebola virus disease (EVD), along with a lack of documentation of methodological limitations and operational utility of mortality estimated from cluster-sampled studies when the DEFF is high. OBJECTIVES: The objectives of this paper are to report EVD mortality rate and DEFF estimates, and discuss the methodological limitations of cluster surveys when data are highly clustered such as during an EVD outbreak. METHODS: We analysed the outputs of two independent population-based surveys conducted at the end of the 2014-2016 EVD outbreak in Bo District, Sierra Leone, in urban and rural areas. In each area, 35 clusters of 14 households were selected with probability proportional to population size. We collected information on morbidity, mortality and changes in household composition during the recall period (May 2014 to April 2015). Rates were calculated for all-cause, all-age, under-5 and EVD-specific mortality, respectively, by areas and overall. Crude and adjusted mortality rates were estimated using Poisson regression, accounting for the surveys sample weights and the clustered design. RESULTS: Overall 980 households and 6,522 individuals participated in both surveys. A total of 64 deaths were reported, of which 20 were attributed to EVD. The crude and EVD-specific mortality rates were 0.35/10,000 person-days (95%CI: 0.23-0.52) and 0.12/10,000 person-days (95%CI: 0.05-0.32), respectively. The DEFF for EVD mortality was 5.53, and for non-EVD mortality, it was 1.53. DEFF for EVD-specific mortality was 6.18 in the rural area and 0.58 in the urban area. DEFF for non-EVD-specific mortality was 1.87 in the rural area and 0.44 in the urban area. CONCLUSION: Our findings demonstrate a high degree of clustering; this contributed to imprecise mortality estimates, which have limited utility when assessing the impact of disease. We provide DEFF estimates that can inform future cluster surveys and discuss design improvements to mitigate the limitations of surveys for highly clustered data.

Main findings: For humanitarian organizations it is imperative to document the methodological limitations of cluster surveys and discuss the utility.Added knowledge: This paper adds new knowledge on cluster surveys for highly clustered data such us in Ebola virus disease.Global health impact of policy and action: We provided empirical estimates and discuss design improvements to inform future study.

ECDC Round Table Report and ProMed-mail most useful international information sources for the Netherlands Early Warning Committee.

The Netherlands Early Warning Committee (NEWC) aims to identify infectious diseases causing a potential threat to Dutch public health. Threats are assessed and published as (information) alerts for public health experts. To identify threats from abroad, the NEWC screens 10 sources reporting disease outbreaks each week. To identify the sources essential for complete and timely reporting, we retrospectively analysed 178 international alerts published between 31 January 2013 and 30 January 2014. In addition, we asked the four NEWC coordinators about the required time to scan the information sources. We documented the date and source in which the signal was detected. The ECDC Round Table (RT) Report and ProMED-mail were the most complete and timely sources, reporting 140 of 178 (79%) and 121 of 178 (68%) threats respectively. The combination of both sources reported 169 (95%) of all threats in a timely manner. Adding any of the other sources resulted in minor increases in the total threats found, but considerable additional time investment per additional threat. Only three potential relevant threats (2%) would have been missed by only using the ECDC RT Report and ProMed-mail. We concluded that using only the ECDC RT Report and ProMed-mail to identify threats from abroad maintains a sensitive Early Warning System.

To notify or not to notify: decision aid for policy makers on whether to make an infectious disease mandatorily notifiable.

Mandatory notification can be a useful tool to support infectious disease prevention and control. Guidelines are needed to help policymakers decide whether mandatory notification of an infectious disease is appropriate. We developed a decision aid, based on a range of criteria previously used in the Netherlands or in other regions to help decide whether to make a disease notifiable. Criteria were categorised as being effective, feasible and necessary with regard to the relevance of mandatory notification. Expert panels piloted the decision aid. Here we illustrate its use for three diseases (Vibrio vulnificus infection, chronic Q fever and dengue fever) for which mandatory notification was requested. For dengue fever, the expert panel advised mandatory notification; for V. vulnificus infection and chronic Q fever, the expert panel concluded that mandatory notification was not (yet) justified. Use of the decision aid led to a structured, transparent decision making process and a thorough assessment of the advantages and disadvantages of mandatory notification of these diseases. It also helped identify knowledge gaps that required further research before a decision could be made. We therefore recommend use of this aid for public health policy making.

[Nosocomial outbreaks and resistant microorganisms]. / Ziekenhuisuitbraken en resistente micro-organismen.

OBJECTIVE: To determine the number and duration of nosocomial outbreaks caused by highly resistant microorganisms (HRMO) posing a potential threat to public health, in order to undertake a risk assessment. DESIGN: Descriptive study. METHOD: Data on nosocomial outbreaks were collected from April 2012 to June 2014. The following characteristics were recorded at the start and end of each outbreak: type of microorganism, reason for reporting, phase of outbreak, number of patients colonised and infected, and infection prevention measures implemented. RESULTS: 47 medical institutions reported 87 outbreaks (mean: 3 outbreaks per month). 20 outbreaks were reported in 2012 (2.2/month), 39 in 2013 (3.3/month), and 28 in the first six months of 2014 (4.7/month). Outbreaks of vancomycin-resistant enterococci (n = 26), methicillin-resistant Staphylococcus aureus (MRSA; n = 23) and resistant or highly resistant Enterobacteriaceae (n = 17) were reported most frequently. 65 outbreaks (75%) were controlled within two months of reporting. CONCLUSION: Transparent reporting of HRMO outbreaks is important for correct public perceptions of the safety of hospitals and nursing homes in the Netherlands. Reports to the Hospital-acquired Infection and Antimicrobial Resistance Monitoring Group show that HRMO outbreaks are an almost daily occurrence in Dutch hospitals. However, most outbreaks are quickly controlled without posing a threat to public health.

An outbreak of Salmonella Typhimurium linked to a kebab takeaway shop.

This paper describes the public health investigation and response to a Salmonella Typhimurium outbreak in June 2010 in the Central Coast of New South Wales. Two complaints from people with acute gastrointestinal illness pointed to food from a kebab takeaway shop as the cause of their illness. Liaison between public health and food authorities ensured timely epidemiological and environmental investigations leading to prompt identification and elimination of the point source. A case series investigation identified 45 outbreak cases including 31 laboratory-confirmed and 14 epidemiologically-linked cases. The food vehicles identified were hommus and tabouli--93% of cases reported having one or both items in their kebab. S. Typhimurium with the same MLVA type was found in stool specimens from outbreak cases and in food (including hommus and tabouli) and environmental samples collected at the kebab takeaway shop. Education of commercial food handlers, reduction of poultry meat contamination and collaboration between public health and food authorities to ensure prompt identification and control of outbreaks are important strategies to reduce Salmonella related illness.

Improving resolution of public health surveillance for human Salmonella enterica serovar Typhimurium infection: 3 years of prospective multiple-locus variable-number tandem-repeat analysis (MLVA).

BACKGROUND: Prospective typing of Salmonella enterica serovar Typhimurium (STM) by multiple-locus variable-number tandem-repeat analysis (MLVA) can assist in identifying clusters of STM cases that might otherwise have gone unrecognised, as well as sources of sporadic and outbreak cases. This paper describes the dynamics of human STM infection in a prospective study of STM MLVA typing for public health surveillance. METHODS: During a three-year period between August 2007 and September 2010 all confirmed STM isolates were fingerprinted using MLVA as part of the New South Wales (NSW) state public health surveillance program. RESULTS: A total of 4,920 STM isolates were typed and a subset of 4,377 human isolates was included in the analysis. The STM spectrum was dominated by a small number of phage types, including DT170 (44.6% of all isolates), DT135 (13.9%), DT9 (10.8%), DT44 (4.5%) and DT126 (4.5%). There was a difference in the discriminatory power of MLVA types within endemic phage types: Simpson's index of diversity ranged from 0.109 and 0.113 for DTs 9 and 135 to 0.172 and 0.269 for DTs 170 and 44, respectively. 66 distinct STM clusters were observed ranging in size from 5 to 180 cases and in duration from 4 weeks to 25 weeks. 43 clusters had novel MLVA types and 23 represented recurrences of previously recorded MLVA types. The diversity of the STM population remained relatively constant over time. The gradual increase in the number of STM cases during the study was not related to significant changes in the number of clusters or their size. 667 different MLVA types or patterns were observed. CONCLUSIONS: Prospective MLVA typing of STM allows the detection of community outbreaks and demonstrates the sustained level of STM diversity that accompanies the increasing incidence of human STM infections. The monitoring of novel and persistent MLVA types offers a new benchmark for STM surveillance.A part of this study was presented at the MEEGID × (Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases) Conference, 3-5 November 2010, Amsterdam, The Netherlands.

Motorcycle rider training for the prevention of road traffic crashes.

BACKGROUND: Riding a motorcycle (a two-wheeled vehicle that is powered by a motor and has no pedals) is associated with a high risk of fatal crashes, particularly in new riders. Motorcycle rider training has therefore been suggested as an important means of reducing the number of crashes, and the severity of injuries. OBJECTIVES: To quantify the effectiveness of pre- and post-licence motorcycle rider training on the reduction of traffic offences, traffic crash involvement, injuries and deaths of motorcycle riders. SEARCH STRATEGY: We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library 2008, Issue 3), TRANSPORT, MEDLINE, EMBASE, CINAHL, WHOLIS (World Health Organization Library Information System), PsycInfo, LILACS (Latin American and Caribbean Health Sciences), ISI Web of Science: Social Sciences Citation Index (SSCI), ERIC, ZETOC and SIGLE. Database searches covered all available dates up to October 2008. We also checked reference lists of relevant papers and contacted study authors in an effort to identify published, unpublished and ongoing trials related to motorcycle rider training. SELECTION CRITERIA: We included all relevant intervention studies such as randomised and non-randomised controlled trials, interrupted time-series and observational studies such as cohort and case-control studies. DATA COLLECTION AND ANALYSIS: Two review authors independently analysed data about the study population, study design and methods, interventions and outcome measures as well as data quality from each included study, and compared the findings. We resolved differences by discussion with a third review author. MAIN RESULTS: We reviewed 23 studies: three randomised trials, two non-randomised trials, 14 cohort studies and four case-control studies. Five examined mandatory pre-licence training, 14 assessed non-mandatory training, three of the case-control studies assessed 'any' type of rider training, and one case-control study assessed mandatory pre-licence training and non-mandatory training. The types of assessed rider training varied in duration and content.Most studies suffered from serious methodological weaknesses. Most studies were non-randomised and controlled poorly for confounders. Most studies also suffered from detection bias due to the poor use of outcome measurement tools such as the sole reliance upon police records or self-reported data. Small sample sizes and short follow-up time after training were also common. AUTHORS' CONCLUSIONS: Due to the poor quality of studies identified, we were unable to draw any conclusions about the effectiveness of rider training on crash, injury, or offence rates. The findings suggest that mandatory pre-licence training may be an impediment to completing a motorcycle licensing process, possibly indirectly reducing crashes through a reduction in exposure. It is not clear if training (or what type) reduces the risk of crashes, injuries or offences in motorcyclists, and a best rider training practice can therefore not be recommended. As some type of rider training is likely to be necessary to teach motorcyclists to ride a motorcycle safely, rigorous research is needed.

Uncovering psychosocial needs: perspectives of Australian child and family health nurses in a sustained home visiting trial.

The first Australian trial of sustained nurse home visiting provided an opportunity to explore nurses' understanding of the situations that support mothers of infants to disclose personal and sensitive psychosocial information. Using a qualitative descriptive design, semi-structured interviews were conducted and transcripts were analysed drawing upon aspects of Smith's interpretative phenomenological analysis. Five themes pertaining to the experience of relationship building to foster disclosure of sensitive information emerged: (1) building trust is an ongoing process of giving and giving in return, (2) being 'actively passive' to develop trust, (3) the client is in control of the trust-relationship, (4) the association between disclosure of sensitive issues and a trust-relationship, and (5) empowerment over disclosure. This study provides a deeper understanding of how child and family health nurses develop relationships that lead women to entrust the nurse with personal, sensitive information, and may inform the practice of psychosocial needs assessment in other contexts.

Addressing decreasing blood lead screening rates in young children in Broken Hill, NSW.

This paper outlines the findings of a review commissioned in response to concerns about declining attendance of young children for blood lead screening in Broken Hill, NSW. A review of the literature and feedback from the local community revealed that reasons for reduced screening attendance elsewhere can be applied here, but that any proposed response should take account of local conditions.

Hospital costs of older people in New South Wales in the last year of life.

OBJECTIVE: To estimate hospital inpatient costs by age, time to death and cause of death among older people in the last year of life. DESIGN AND SETTING: Cross-sectional analytical study of deaths and hospitalisations in New South Wales from linked population databases. PARTICIPANTS: 70,384 people aged 65 years and over who died in 2002 and 2003. MAIN OUTCOME MEASURES: Hospital costs in the year before death. RESULTS: Care of people aged 65 years and over in their last year of life accounted for 8.9% of all hospital inpatient costs. Hospital costs fell with age, with people aged 95 years or over incurring less than half the average costs per person of those who died aged 65-74 years ($7028 versus $17,927). Average inpatient costs increased greatly in the 6 months before death, from $646 per person in the sixth month to $5545 in the last month before death. Cardiovascular diseases (43.1% of deaths) were associated with an average of $11,069 in inpatient costs, while cancer (25.0% of deaths) accounted for $16,853. The highest average costs in the last year of life were for people who died of genitourinary system diseases ($18,948), and the highest average costs in the last month of life were for people who died of injuries ($8913). CONCLUSION: Population ageing is likely to result in a shift of the economic burden of end-of-life care from the hospital sector to the long-term care sector, with consequences for the supply, organisation and funding of both sectors.