Research and analysis

HPR volume 11 issue 40: news (10 November)

Updated 15 December 2017

RSV activity starting to increase in England and Wales

As conveyed in PHE’s latest Weekly National Influenza Report [1], levels of respiratory syncytial virus (RSV) activity are increasing in the UK – as expected for this time of year.

RSV activity typically occurs in the UK within the period from October to March each year, with most infections occurring in a relatively short epidemic of about six weeks. Peak numbers of RSV infections are reported in December and January every winter, although the size of the peak varies from winter to winter [2]. For the majority of cases, the infection is mild and its symptoms can be treated at home: further advice is available on the NHS Choices website [3]. For a small proportion of cases, the infection is severe enough to require hospital treatment.

RSV is the most common cause of severe respiratory illness, such as bronchiolitis (inflammation of the bronchioles), in children under five years [4], and highest current levels of RSV are in children in this age group. Repeat infection throughout life is common, causing significant morbidity and mortality in the elderly population [5].

Clinicians should now be considering the monthly administration of prophylactic palivizumab, which is licensed for use in young children at risk of severe bronchiolitis. This includes children under two with chronic lung disease and oxygen dependency, and infants under six months with severe congenital heart disease.

Further information is available from the RSV chapter (27a) of Immunisation against Infectious Disease (the Green Book) [6].

References

1. PHE website (9 November). Weekly National Influenza Report: week 45 report (up to week 44 data)
2. PHE website. Respiratory syncytial virus (RSV): symptoms, transmission, prevention, treatment.
3. NHS Choices website. Bronchiolitis.
4. Reeves RM et al (2017). Estimating the burden of respiratory syncytial virus (RSV) on respiratory hospital admissions in children less than five years of age in England, 2007-2012. Influenza Other Respir Viruses 11(2): 122-129.
5. Elliot AJ, Fleming DM (2008). Influenza and respiratory syncytial virus in the elderly. Expert Rev Vaccines 7(2): 249-58.
6. PHE (2013). Immunisation against infectious disease: the green book – Respiratory syncytial virus, chapter 27a.

Malaria Prevention Guidelines for UK Travellers (2017) in summary

The PHE Advisory Committee on Malaria Prevention (ACMP) recently completed the annual update of its Malaria Prevention Guidelines for Travellers from the UK [1], taking account of the changing landscape for malaria prevention and, in particular, the WHO’s finding that there had been a 37% reduction in global malaria incidence between 2000 and 2015 [2].

The ACMP guidelines are primarily intended for use by healthcare workers who advise travellers from the UK, but they may also be of use to prospective travellers who wish to read about the options themselves. They also inform the recommendations provided by the National Travel Health Network and Centre (NaTHNaC) [3].

The ACMP reviewed laboratory and epidemiological data – from UK travellers, the WHO, and information from in-country experts – before deciding on the recommendation for each destination country. Each country’s risk was assessed and a recommendation for bite avoidance only, or bite avoidance plus chemoprophylaxis, was produced.

Changed recommendations on use of chemoprophylaxis

For some countries in Central and South America and Southeast Asia, and for Pakistan, prevention recommendations have been substantially revised in the updated guidelines. For some of these countries, the level of risk has been re-classified and routine chemoprophylaxis is no longer recommended; the focus is now on bite avoidance and risk awareness. However, much of sub-Saharan Africa remains at high risk for malaria and the advice has not changed.

Country recommendations have been supplemented with additional maps, provided by NaTHNaC in collaboration with ACMP, showing areas and level of risk together with malaria prevention measures.

Recommendations for antimalarials should be appropriate for the destination and tailored to the individual traveller, as part of a personal, stringent risk assessment, and taking into account possible risks and benefits to the traveller. The guidelines reinforce guidance for groups at increased risk of severe or complex malaria, such as the elderly, immunosuppressed, those with complex co-morbidities and pregnant women.

The ACMP recommends that health professionals stick to using one resource when advising the traveller about malaria; while acknowledging other sources of advice and guidance on malaria prevention are available, health professionals working in England, Wales or Northern Ireland are advised to use the ACMP guidelines as their preferred resource.

While the focus of these guidelines is on malaria prevention, it should be emphasised that malaria prevention is only one aspect of pre-travel advice. A comprehensive risk assessment-based package of travel health advice should be provided to the traveller.

References

1. PHE website (October 2017). Malaria prevention guidelines for travellers from the UK: 2017.
2. WHO (2015). World Malaria Report.
3. NaTHNaC website. Country information

National Reference Laboratory workshop: microbiological challenge test and shelf-life studies in food

Challenge testing and shelf-life assessment are important to ensure the microbiological quality and safety of foods, including foods where contamination with Listeria monocytogenes, Clostridium botulinum and other organisms may occur. These studies inform the “use by” and “best before” dates given to particular batches of a food product, based on the length of time that they remain both safe to eat and of acceptable quality.

Although food business operators (FBO) are responsible for defining a shelf-life, food microbiologists from Official Control Laboratories and environmental health officers from local authorities are often presented with challenge testing and shelf life data that may need to be critically assessed or discussed with FBOs.

The National Reference Laboratory for Food Microbiology at Public Health England (Colindale) recently hosted a one-day workshop on these themes, attended by more than 170 delegates from OCLs, LAs, and the Food Standards Agency (FSA) [1].

The workshop began by highlighting the issues from the perspective of the FSA and EHOs. Domestic guidelines and EU legislation relevant to shelf-life testing was described. This was put into real-life context by presentations describing the difficulties faced by EHOs and OCLs interpreting or generating shelf-life data for FBOs.

Technical expertise was presented by scientists from Campden BRI, a private organisation that provides the food and drink industry with the practical scientific, technical and advisory services needed to ensure product safety and quality, process efficiency and product and process innovation. Aspects of shelf-life covered included: durability studies, predictive microbiological modelling, challenge testing, and process validation.

Different approaches to shelf-life testing were described, including: experimental designs that mimic real practice for the storage and processing (time and temperature) of the food product; simulation of product abuse; etc. It was also emphasised that a shelf-life, once specified, is not fixed: any significant change to a product’s specification – including raw ingredients, recipe, processing or packaging – will require revalidation of the shelf-life.

The differences between durability studies and challenge testing, in particular with regards to Listeria, were described – to increase awareness of why and when these assessments are performed. The use of predictive modelling software as a useful tool to estimate shelf-life and growth potential was discussed, although it was recommended that this be performed alongside laboratory studies to ensure these predictions are reliable.

Public Health England (then the Health Protection Agency) was awarded a contract in 2011 – by UK’s Competent Authority, the Food Standards Agency – to provide the service of UK National Reference Laboratory for food microbiology, under EU Regulation 882/2004. One of the NRL’s functions is to provide advice, training and other support to the other OCLs in the UK for Listeria monocytogenes, coagulase positive Staphylococci, Escherichia coli (incl. VTEC), Campylobacter, Salmonella and antimicrobial resistance in relevant organisms [2].

This workshop on shelf-life testing was complementary to the NRL’s main activities and allowed PHE to organise a unique cross-stakeholder event to deliver the same material to a wide range of delegates.

References

1. ‘National Reference Laboratory workshop: microbiological challenge test and shelf-life studies in food’, 30 October 2017, PHE Colindale.
2. PHE website (March 2017). Report of UK National Reference Laboratory for Food Microbiology (2016/2017): Activities for Listeria monocytogenes, coagulase positive staphylococci, Escherichia coli (including VTEC), Campylobacter, Salmonella and antimicrobial resistance.

Infection reports in this issue of HPR

The following reports are published in this issue of HPR. The links below are to the relevant webpage collections or publications.

Infection reports

• Salmonella and shigella infections (faecal specimens, E&W): September/October 2017
• Common GI infections (laboratory reports, E&W): weeks 40-43/2017
• Norovirus outbreaks in hospitals: weeks 40-43/2017