Research and analysis

HPR volume 13 issue 5: news (8 February)

Updated 20 December 2019

Task force reports on AFP epidemiology

Results of a preliminary investigation, by a Public Health England (PHE) led task force, into the upsurge of acute flaccid paralysis (AFP) cases seen in the UK in 2018 have been published [1,2].

The investigation was initiated after PHE had originally alerted clinicians to reports of an increase in enterovirus D68, which was followed by reports of AFP [3].

The task force report describes the epidemiological, clinical and microbiological features of UK cases (reports of which peaked in November 2018) as at 21 January 2019.

AFP, historically caused by poliovirus infection prior to its elimination in the UK, is now rare but may be caused by other viral infections including non-polio enteroviruses, particularly enterovirus D68.

Aims of the task force include strengthening AFP surveillance and determining whether there has been a true increase in incidence in the UK population; and, if so, to determine the aetiology, in particular the potential contribution of enteroviruses, especially EV-D68. It also aims to act as a focal point for national and international collaboration and to share widely the findings from the ongoing investigation.

References

1. The United Kingdom Acute Flaccid Paralysis (AFP) Task Force (7 February 2019). An increase in reports of acute flaccid paralysis (AFP) in the United Kingdom, 1 January 2018 to 21 January 2019: early findings. Euro. Surveill. 24(6).
2. PHE website collection. Acute flaccid paralysis syndrome.
3. PHE investigating rise in reports of rare illness, PHE news story, 19 December 2018.

Identification of non-tuberculous mycobacteria in hospital waters

A new proficiency scheme for laboratories testing hospital waters for environmental mycobacteria, and species such as Mycobacterium chimaera, Mycobacterium avium and Mycobacterium intracellulare which do not cause tuberculosis but may cause infection in patients with underlying disease – is to be launched in April 2019. The scheme, organised by PHE’s Food and Environmental Proficiency Testing Unit (FEPTU), aims to raise awareness of laboratory testing methods, highlight challenges in isolation, and assist with interpretation of results.

Environmental mycobacteria may be of concern when they occur in the final rinse-water of instruments, such as endoscopes, that are used for diagnosis. These waters need to be free of environmental mycobacteria and therefore regular testing for environmental, non-pathogenic mycobacteria is a well-established practice [1].

More recently, a specific type of hospital water (from heater-cooler units) has been associated with non-tuberculous mycobacteria. M. chimaera, M. avium and M. intracellulare are slow-growing non-tuberculous mycobacteria (NTM) within the Mycobacterium avium complex (MAC). M. chimaera was originally thought to be less pathogenic than other species within MAC; however, since 2011, cases of invasive infection caused by M. chimaera have been reported in several European countries, including the UK, in patients who had previously undergone cardiac surgery.

Following a national UK investigation to assess the risk of invasive infection in cardiothoracic surgery, a significantly elevated risk was identified in those post-surgery compared to the general population [2]. In 2015, the European Centre for Disease Prevention and Control (ECDC) issued a protocol for case detection, laboratory diagnosis and environmental testing of M. chimaera infections potentially associated with heater-cooler units used in cardiovascular surgery [3]. The risk of infection following surgery remains low in the UK.

PHE supports hospitals in their environmental monitoring of endoscopy and heater-cooler waters for environmental mycobacteria and NTMs in several ways; this includes: provision of a hospital water testing service, provided by the Food, Water and Environmental Laboratory Network (FW&E): provision of laboratory control strains by the National Collection of Type Cultures (NCTC); and, now, through the provision of a proficiency testing scheme from the Food and Environmental Proficiency Testing Unit (FEPTU).

References

1. NHS. Management and decontamination of flexible endoscopes (HTM 01-06).

2. Chand M and others (2017). [Insidious risk of severe Mycobacterium chimaera Infection in cardiac surgery patients. Clin Infect Dis 64 (3): 335 to 342.

3. ECDC (2015). EU protocol for case detection, laboratory diagnosis and environmental testing of Mycobacterium chimaera infections potentially associated with heater-cooler units: case definition and environmental testing methodology.

Infection report in this issue

This issue includes:

Routine reports of gastrointestinal infections in humans, England and Wales: December 2018 and January 2019.