National healthcare-associated infections surveillance programs: A scoping review

Background National surveillance of healthcare-associated infections (HAIs) is necessary to identify areas of concern, monitor trends, and provide benchmark rates enabling comparison between hospitals. Benchmark rates require representative and large sample sizes often based on pooling of surveillance data. We performed a scoping review to understand the organization of national HAI surveillance programs globally. Methods The search strategy included a literature review, Google search and personal communications with HAI surveillance program managers. Thirty-five countries were targeted from four regions (North America, Europe, United Kingdom and Oceania). The following information was retrieved: name of surveillance program, survey types (prevalence or incidence), frequency of reports, mode of participation (mandatory or voluntary), and infections under surveillance. Results Two hundred and twenty articles of 6,688 identified were selected. The four countries with most publications were the US (48.2%), Germany (14.1%), Spain (6.8%) and Italy (5.9%). These articles identified HAI surveillance programs in 28 of 35 countries (80.0%), operating on a voluntary basis and monitoring HAI incidence rates. Most HAIs monitored surgical site infections in hip (n=20, 71.4%) and knee (n=19, 67.9%) and Clostridoides difficile infections (n=17, 60.7%). Conclusion Most countries analyzed have HAI surveillance programs, with characteristics varying by country. Patient-level data reporting with numerators and denominators is available for almost every surveillance program, allowing for reporting of incidence rates and more refined benchmarks, specific to a given healthcare category thus offering data that can be used to measure, monitor, and improve the incidence of HAIs.


Introduction
Healthcare-associated infections (HAI) are acquired by patients during the process of care for other health conditions (1). They are the most frequently reported adverse event in healthcare delivery (2), affecting millions of patients each year worldwide and leading to significant morbidity, mortality and financial costs to healthcare programs. In the beginning of 2000, HAI prevalence in high-income countries ranged between 3.5% and 12%; in Europe, for example, the average prevalence is 7.1%, representing over four million people infected each year (3).
The emergence of antimicrobial-resistant organisms (AROs) complicates the situation, making HAIs more difficult to treat. The Public Health Agency of Canada estimated that approximately 2% of patients admitted to large academic Canadian hospitals will have acquired an infection during their hospital stay (4) and that at any time, 3%-10% of hospitalized patients are either infected with or a carrier of an ARO (5).
Surveillance of HAIs is considered a necessary component of infection prevention and control, public health and patient safety. National surveillance requires representative and large enough sample sizes to produce meaningful infection rates for benchmarking, detection of trends and prioritization of interventions at a regional or local level, and for specific populations.
Many countries have national HAI surveillance programs, but a comprehensive review of these countries' program characteristics is not currently available. We conducted a scoping review to identify national HAI surveillance programs globally and summarized their characteristics to inform decisions on possible national programs for Canada.

Research question
The main research question was: What are the characteristics of HAI surveillance programs in a selected sample of high-income countries, defined by the World Bank as countries with a gross national income per capita of at least US$12,696 (6) We added the following sub-questions to have a more complete picture: Is the program mandatory or voluntary? Is it based on incidence or prevalence analysis? What are the infections or procedures under surveillance? What is the frequency of public reporting?

Scoping review
The first step was a scoping review using Medline. We performed a search strategy developed with a medical research librarian. Keywords and MeSH were created in Medline with the following four concepts: nosocomial, epidemiology, surveillance and administration ( Table S1). The inclusion criteria consisted of articles identifying surveillance of HAIs in four selected highincome regions in the world: North America, Europe through the European Centre for Disease Prevention and Control (ECDC), United Kingdom (UK) and Oceania. The ECDC encompassed 27 countries (26 countries and ECDC itself), for a total of 35 countries in these four regions. Surveillance needed to be reported at the national level. We included articles published between January 1, 1996, and December 31, 2020, written in English or French. Government publications or reports and grey literature that contained any surveillance data on HAI were kept. Opinion, editorial, news reports, abstracts from conferences or meetings were excluded. Only human health articles were considered. We searched Medline, grey literature and communicated with key people.

Grey literature
Grey literature was used to compile unidentified HAI surveillance programs from Medline. National organizations' websites of the four regions cited in the inclusion criteria were considered. Once the program name was retrieved, usually from published articles, a Google search was performed to get publicly available information on the HAI surveillance program, aiming to obtain protocols or surveillance reports. For this search, no language limitation was applied.
We used Google to identify surveillance programs in countries that were not found through our Medline search and to validate identified programs to obtain publicly available protocols and surveillance reports. We compiled each surveillance program's characteristics, as not all programs publish their results as peerreviewed articles.

Personal communication
When information was not available in official surveillance protocols or on organizations' websites, an email was sent to authors or program managers to get publicly available documents, such as annual reports of the surveillance performed. A reminder was sent if no answer was received after two weeks from the first communication. Only one reminder was sent.

Data management
Studies meeting the inclusion criteria were uploaded to DistillerSR (Evidence Partners, Ottawa, Canada), which was used to remove duplicates. Independent screening for title/ abstract and full text was performed by the first two authors. If the HAI surveillance program name was available in this section, the information was extracted and validated with a Google search. If the program name was correct, full text review was not performed. If the program name was not found in the title or the abstract for the country, these articles' full texts were read. Conflicts were resolved through discussion until a consensus was reached.

Data extraction and quality assessment
An electronic data form was developed on DistillerSR. The following information was extracted from articles, websites and government reports: general information, name of national HAI surveillance programs, HAIs included in the program, jurisdiction, modes of participation (mandatory or voluntary), survey type (incidence or prevalence), reporting periodicity, percentage of facilities involved in the surveillance, microorganisms, medical devices, type of data (individual or aggregated) and official website.

Results
We identified 6,688 articles with the selected keywords and MeSH. From these, 261 duplicate articles were removed. An additional 6,206 articles were removed because no HAI surveillance program was identified in full-text review. A total of 220 articles (Data S1) were used in this review ( Figure S1). Some articles identified programs for more than one country and were counted more than once, which is why the number of articles in Table S2 is 245. The four countries most represented were the US (n=106, 48.2%), Germany (n=31, 14.1%), Spain (n=15, 6.8%) and Italy (n=13, 5.9%).

SCOPING REVIEW
We identified surveillance programs for 20 of 35 countries. A Google search identified eight additional programs, for a total of 28 of 35 countries (80.0%) having a national program. For the remaining nations (Cyprus, Estonia, Greece, Iceland, Latvia, Malta, and Slovenia), a HAI surveillance program could not be found, but four participated in at least one annual ECDC project. Only 5 of 19 (26.3%) contacted program managers replied ( Table 1 summarizes the information).    We kept information from national HAI surveillance programs as we aimed to understand how alliance of regions pooled data; thus, programs that were not at least national in scope and those for which we could not differentiate between communityacquired or hospital-acquired infections were excluded.

Surveillance programs
We identified 38 national HAI surveillance programs for 28 countries with a national surveillance program (Table 1). Some countries have two or more surveillance programs. Most national surveillance programs reported yearly incidence on a voluntary basis. Surgical site infection (SSI) surveillance was done in 21 of 35 countries ( Table 2). Infections and procedures under surveillance are detailed in Table 1. Twenty-six programs for which data was available used active surveillance. None reported use of administrative surveillance as the only source of data.
The HAI surveillance network (HAI-NET) from the ECDC performs two types of surveillance: 1) a point prevalence survey (PPS) of HAIs in European acute care hospitals (7), every five years; and 2) three annual incidence surveillance for Clostridoides difficile infections (CDI) (8), infections acquired in intensive care unit (ICU) (9) and SSI (10) ( Table S3). In total, 33 countries/regions (29 ECDC countries and four UK regions) participated in the PPS (7,11,12). Four periods were selected for data collection (April-June and September-November of each year), avoiding the summer holidays (lower staffing) and the winter period (higher antimicrobial use). Denominator data could be either: patientbased (optional) or unit-based (mandatory). Patient present on the ward at 8 a.m. and not discharged during the survey were counted in the denominator.     (15). To be considered in the denominator, a patient must stay for at least three days in the ICU. HAI surveillance is recommended for three to six months each year.

SCOPING REVIEW
The National Healthcare Safety Network (NHSN, US) is separated in six components with HAI surveillance included in Patient Safety (16). Participating hospitals must produce a monthly reporting plan of what will be under surveillance and an annual facility survey. In acute care, six infections/procedures are monitored: CLABSI, CA-UTI, ventilator associated event (VAE) and paediatric VAE, SSI, multidrug-resistant organisms (MDRO) and CDI (16).
Many rates are produced for CDI and MDRO (16). For MDRO, prevalence rates are calculated for inpatients, community onset, healthcare facility onset, and outpatients, MDRO infection/ colonization incidence or incidence density rates are also calculated ( Table 3). In the last NHSN report (17) (21). The other surveyed procedures are voluntary ( Table 2). Patients are followed for 30 days (non-implant procedures) and one year (prosthetic implant procedures). In the last available report, 156 hospitals reported for hip and knee replacements. In comparison, only 20 and 16 hospitals reported for large bowel surgery and spinal and breast surgeries (voluntary program), respectively. Public Health England analyzes submitted data quarterly to identify high (hospitals whose SSI risk is greater than the 90 th percentile) and low outliers (less than the 10 th percentile). Low outliers are supported to ensure all cases are being reported. High outliers are asked to explore their clinical practices to identify possible reasons to explain high rates. CDI and BSI are mandatory programs (22). Public Health England receives data from all hospitals and publicly shares monthly or annual rates on their website.

Discussion
The objective of this scoping review was to synthesize characteristics of national HAI surveillance programs from 35 selected countries to inform decisions on possible national programs for Canada. Most surveillance was done on a voluntary basis. CDI, hip and knee prosthesis surgery and caesarean sections were the four main infections and procedures under surveillance.
Characteristics of surveillance programs appear to vary, including for frequency of reporting to ministries. Some countries use prevalence point surveys as their main method of surveillance. The percentages of participating hospitals vary (from 1.4% to 100%). With 9.5% to 11.0% participation, CNISP is in the lower range ( In view of other national surveillance programs, some elements must be considered for HAI surveillance in Canada. Although provinces have their own surveillance programs, there is a need for large enough sample sizes to stratify infection rates for specific units (e.g. cardiac, neonatal or paediatric ICUs): this will require data to be pooled at the national level. Data transmitted from provinces to the federal surveillance program could be aggregated, but numerators and denominators and harmonized surveillance definitions are required. The CNISP is currently using harmonized definitions across the country with patient or unit-level data, but it currently lacks representativeness, as it represents only a fraction of Canadian healthcare, with a bias towards teaching urban hospitals. Recruitment of new hospitals into CNISP requires funding. Voluntary participation of all Canadian hospitals in CNISP is being considered but the risk of selection bias remains.

Limitations
This study has several limitations. First, for us to be able to identify a program, the country must publicly report it. Non-English websites or grey literature reports were translated using two tools. The first was the internet navigator itself, using Google Chrome tools for website translation. The second tool was the software DeepL Translator (DeepL, Cologne, Germany). Although these tools may have inherent limitations, data extracted were objective and straightforward and did not require any subtle interpretation. The risk of selection bias from published literature was mitigated by a web search for each identified country. Although we may have missed some smaller national programs, we think that most elements of a HAI surveillance program have been captured via larger national or multinational programs, such as ECDC. Other information (process and not results) was extracted from official available protocols and reports from the program website or by speaking to the program's manager.

Conclusion
In the four regions studied, 80% of high-income countries had national HAI surveillance programs. Although some differences exist, the overarching theme was that national surveillance programs had individual-level data, or at least aggregated data at a hospital level, with a numerator and a denominator and not just an overall incidence rate by region. Infections and procedures under surveillance are quite uniform. This literature scan is the first step towards identifying the best approach for a national HAI surveillance program for Canada.

Funding
This work was funded by MITACS Accelerate with Healthcare Excellence Canada.

Supplemental material
These documents can be accessed on the Supplemental material file. Table S1: Keywords and MeSH classification of the four concepts identified for the scoping review Data S1: List of 220 articles identified by systematic review through Medline Figure S1: Flow chart of the scoping review