As always, it is a pleasure to present the Health Protection Surveillance Centre epidemiological report which provides an analysis of the most important infectious diseases affecting Ireland during 2014.
In Ireland, the 2014/2015 influenza season was more severe than recent seasons. Influenza A (H3N2) viruses predominated, with an increase in the predominance of influenza B viruses later in the season. The impact of influenza during the 2014/2015 season predominantly affected those aged 65 years and older. This was seen by the large numbers of outbreaks in residential care facilities, high hospitalisation rates, an increase in deaths reported in notified influenza cases and excess mortality which was significantly higher than recent seasons. Over 1,000 confirmed influenza cases were reported as hospitalised during the 2014/2015 season, a similar number to the 2009 pandemic. There was a significant increase in the overall hospitalisation rate for those aged 65 years and older compared to previous seasons, reaching the highest rate (81.4/100,000 population) ever reported for this age group. As most of those with complications from influenza do not get tested for influenza infection, another way to see the impact of influenza is to examine the excess deaths that occur while influenza is circulating. The estimated number of excess deaths reported during the 2014/2015 season for those aged 65 years and older in Ireland was 726. It is likely that influenza contributed significantly to these excess deaths, although adverse winter weather conditions and other respiratory infections may have also contributed.
In Ireland and most Northern Hemisphere countries, the emergence of A(H3N2) viruses antigenically and genetically drifted from the 2014/2015 vaccine strain resulted in reduced vaccine effectiveness (VE). The Irish overall adjusted VE in preventing confirmed influenza infection in primary care was very low. Excess all-cause mortality among people aged 65 years and older, concomitant with increased influenza activity and the predominance of drifted A(H3N2) viruses was observed in Ireland for nine consecutive weeks between weeks 2 and 10 2015.
Antimicrobial resistance remains one of the priority challenges facing the Irish healthcare services. For the eighth consecutive year, the proportion of S. aureus bloodstream infections (BSI) attributable to meticillin resistant S. aureus (MRSA) further declined to 19.5%, the lowest reported level since Ireland joined EARS-Net in 1999. Unfortunately, antimicrobial resistance in other important BSI causative pathogens increased further and remains a cause for concern. Following the establishment of the national multi-drug resistant K. pneumoniae (MDRKP) outbreak control team (OCT) in 2013 to look at the emerging problem of MDRKP, initial recommendations were made to try to control the spread of MDRKP strains in healthcare settings. A welcome reduction in the proportion of K. pneumoniae BSI that were MDRKP was seen in 2014 (to 8.1% of isolates) and this may be in part due to some of the control measures put in place during 2014. However, many of the recommendations have still not been fully implemented and the OCT proposed that a national task force should be established with greater powers to influence and implement changes in policy and infrastructure needed. This task force has been established in 2015 and is working to strengthen control measures in both acute and non-acute healthcare settings. The findings of biannual hand hygiene compliance audit reports from acute hospitals in 2014, reported continued improvement to 86% compliance, but this fell short of the 90% compliance target set by HSE.
As well as improvements in the proportions of MRSA BSI, there were small improvements in Clostridium difficile infections that were categorised as healthcare-associated. (2.3 cases per 10,000 bed days used, a decrease from 2.4 in 2013).
There was a small improvement in the rates of antimicrobial consumption in both the community and acute hospital settings, but further work is required to restrict the use of certain antibiotics for essential care and the new HSE task force addressing the MDRKP outbreak will issue recommendations on this in the near future.
There were 33 reported cases (20 confirmed) of measles in 2014 – the lowest number since reporting began in 1948. There were no confirmed rubella cases and one probable case which was acquired outside Ireland. This reflects the excellent progress made in improving immunisation coverage with MMR vaccine, now at 93% almost reaching the 95% target. Unfortunately the mumps component of this vaccine has not been as successful in controlling mumps and there were over 740 cases reported in 2014, with the highest number of cases reported in 15-24 year olds. Chickenpox (Varicella) is a childhood infection that is now prevented through the use of a vaccine in many countries (not yet routinely used in Ireland). Chickenpox can be associated with serious complications and 61 cases required hospitalisation in 2014. Seven cases of varicella were complicated by invasive group A streptococcal disease (iGAS), a life threatening bacterial infection.
In 2014, the incidence of tuberculosis continued to fall in Ireland with 318 cases notified (incidence rate of 6.9/100,000). The rate in the indigenous Irish born population was lower again at 4.7 per 100,000. This decline has prompted a review of the need for universal BCG vaccination and it is likely that universal BCG vaccination will be discontinued in the near future.
Campylobacter infection remains the commonest cause of bacterial gastroenteritis in Ireland and Europe. Rotavirus is the commonest viral cause of gastroenteritis in children. Again a vaccine is available and hopefully the rotavirus vaccine will shortly be introduced into the vaccination schedule to protect Irish children. Shigella is a bacterial cause of gastroenteritis and affected 57 people in Ireland in 2014.
Hepatitis C remains the most significant infectious cause of liver disease in Ireland with 710 cases notified in 2014. There have been major advances in the treatment of hepatitis C in recent years and there is cautious optimism that the national programme of treatment established in the HSE in 2015 will avert the serious complications such as cirrhosis and cancer of the liver in many of those affected.
There was an increase in the number of people notified with HIV infection in 2014 – 377 cases an 11% increase from 2014. It is of concern that the number of new diagnoses among men who have sex with men has trebled (from 60 to 183) in the last ten years. Recent initiatives offering screening to attendees of some emergency departments in Dublin may result in earlier detection in those who may otherwise be unaware of their infection.
Four hundred and thirty five outbreaks of infectious disease were investigated by Departments of Public Health throughout the country. The highest numbers ill were reported from nursing homes, community hospitals and acute hospitals.
As alluded to with measles immunisation, coverage for all vaccines in the childhood schedule continues to improve and for the fourth consecutive year exceeded the target of 95% for the 6in-1 vaccine given to infants. Almost 85% of girls in first year in the 2013/2014 academic year were vaccinated against HPV infection which reflects a great collaboration of those working in school immunisation teams, administrative staff and those working nationally in the National Immunisation Office. We still have a long way to go to improve influenza vaccine coverage in healthcare workers (HCW) – while not advocating mandatory HCW vaccination as they do in the US we do advocate mandatory assessment of coverage data in all acute and long term care facilities (LTCF). Not all hospitals and LTCF report their data and in those that do not all staff report their flu vaccination status. Well done to the four hospitals and 24 LTCF who reached the 40% target last year.
Well done also to the CIDR team who maintained IS27001 Information Security Accreditation in 2014. Maintenance of this standard is vital to ensuring the information security of the data we hold on infectious diseases and essential to reassure our partners and the public of the importance of the privacy and confidentiality of their data.
Once again, I would like to express my gratitude to all those who provide data and participate in committees and to staff in HPSC and elsewhere in the HSE. This report is a testament to all of those who are managing to do more with less and continue to support the prevention and control of infectious disease in Ireland.
Darina O'Flanagan, HPSC
