Research and analysis

HPR volume 11 issue 6: news (10 February)

Updated 15 December 2017

1. Study of public health interventions that contributed to CDI control

The results of a retrospective ecological study on the reasons for the emergence and control of the Clostridium difficile epidemic in England, which peaked in 2007, have been published in the journal Lancet Infectious Diseases [1,2].

The study was a large collaborative project between Public Health England, University of Leeds, Imperial College and University of Oxford – as well as two PHE-partnered Health Protection Research Units.

The analysis made use of national ESPAUR and C. difficile data – combined with extensive whole genome sequence data – to achieve both a classical statistical and phylogenetic analysis.

The study demonstrated that the CDI epidemic emerged through selection of four quinolone-resistant strains (genetic lineages); also that it was controlled by a near-50% reduction in quinolone use across England. The incidence of C. difficile disease subsequently declined by 80% nationally with the disappearance of the quinolone-resistant strains.

The persisting disease is caused by quinolone-susceptible isolates, which have occurred with an unchanged incidence over the past 15 years, the study found. The paper thus elegantly highlights the importance of antimicrobial stewardship in the control of antimicrobial-resistant pathogens and healthcare-associated infection outbreaks.

1.1 References

1. Dingle DE, Didelot X, Quan TP, Eyre DW, Stoesser N, Golubchik T, et al (24 January 2017). Effects of control interventions on Clostridium difficile infection in England: an observational study. Lancet Infectious Diseases (online).
2. Overuse of antibiotics the main cause of C.diff epidemic, University of Leeds, Faculty of Medicine and Health press release, 9 February 2017.

2. One in three 30-year-old women shown to have had exposure to chlamydia

A recently-published paper reports how samples from a series of nationally-representative surveys for antibodies to chlamydia were used to investigate the proportion of people in the general population in England who had ever been exposed to chlamydia infection [1].

The findings suggest that at least one in three women aged 30-to-34 had had exposure to chlamydia in the past (based on data for the period 1994-2012). While many young adults are currently accessing chlamydia screening, the study also showed that a substantial proportion of infections may still be going undiagnosed.

Untreated chlamydia infections can lead to serious complications including pelvic inflammatory disease, ectopic pregnancy and infertility. The National Chlamydia Screening Programme (NCSP) aims to control chlamydia through early detection and treatment of asymptomatic infection, so reducing onward transmission and the consequences of untreated infection. The programme recommends that young adults are tested for chlamydia once a year and whenever they change sexual partners. Screening is available in a range of testing venues including sexual and reproductive health services, general practice and via the internet [2].

2.1 References

1. Woodhall, Wills, Horner, et al (27 January). Chlamydia trachomatis Pgp3 antibody population seroprevalence before and during an era of widespread opportunistic chlamydia screening in England (1994-2012), PLoS One.
2. NCSP webpages.

3. HIV response in EU/EEA member states: an overview

Around 30,000 newly-diagnosed HIV infections have been reported each year, over the last decade, in the EU/EEA – yet one in six of those diagnosed were not on treatment in 2015. Of those diagnosed who were on treatment, nine out of 10 were virally suppressed – and therefore unable to transmit the virus to others – underlining the effectiveness and public health benefit of treatment. Overall, there has been good progress on HIV prevention, testing and treatment across Europe in recent years. But this statement masks the fact that national-level performance varies significantly between countries.

These are among the conclusions of a special report, The Status of the HIV Response in the EU/EEA, published by ECDC [1], that summarises progress made since the Dublin Declaration of 2012 [2].

Other key messages from the ECDC report are that:

• HIV is still a significant public health problem in the EU/EEA
• coverage and uptake of prevention interventions is insufficient to reduce the number of new HIV infections
• a significant proportion of people living with HIV infection in the EU/EEA have not been diagnosed and, among those diagnosed, nearly half are diagnosed late
• one in six people in the EU/EEA diagnosed with HIV in 2015 were still not on treatment.

3.1 References

1. ECDC (31 January). The status of the HIV response in the EU/EEA: 2016.
2. “Monitoring national implementation of the Dublin declaration on HIV”, HPR 7(24), 14 June 2013.

4. Infection reports in this issue of HPR

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

• Common animal associated infections (England and Wales): fourth quarter 2016

• Creutzfeldt-Jakob disease biannual update (UK)

• Salmonella infections (faecal specimens, England and Wales), reports to PHE: December 2016.
• Common GI infections (England and Wales), laboratory reports: weeks 1-4/2017.
• Less common pathogens: weeks 44-52/2016.
• Suspected and laboratory-confirmed reported norovirus outbreaks in hospitals: outbreaks occurring in weeks 1 to 4, 2017.