Research and analysis

HPR volume 11 issue 21: news (16 June)

Updated 15 December 2017

1. PHE publishes full annual STIs data for 2016

PHE has released its annual data on sexually transmitted infections in England [1-2] comprising:

• a review report, Sexually Transmitted Infections and Chlamydia Screening in England, 2016 [1], and
• Monitoring Rates of Chlamydia Re-testing within the English National Screening Programme [2].

The review report provides an overview of trends for the STIs of most concern in England: syphilis; gonorrhoea; genital herpes; chlamydia; and genital warts.

The latest data show that circa. 420,000 STIs were reported in England in 2016; a decline of 4% compared to 2015. While STI diagnoses decreased overall, there was a 12% increase in syphilis to 5,920 diagnoses, the largest number reported since 1949.

Chlamydia remains the most commonly diagnosed STI in England – more than 128,000 diagnoses having been made among young people aged 15-24 years of age in 2016. Retesting for young adults who test positive for the infection has been recommended since 2013 and the separate report on chlamydia retesting provides an update on rates of retesting across the country [2].

1.1 References

1. PHE (6 June 2017). Sexually transmitted infections and chlamydia screening in England, 2016. HPR 11(20) Advance Access report.
2. PHE (9 June 2017). Monitoring rates of chlamydia re-testing within the English National Screening Programme (January 2013 to June 2016). HPR 11(20).

2. Mandatory HCAI reports quarterly trends: January to March 2017

PHE’s latest quarterly epidemiological commentary on trends in reports of Staphylococcus aureus (MRSA and MSSA) and Escherichia coli bacteraemia, and of Clostridium difficile infections, mandatorily reported by NHS acute Trusts in England up to January-March 2017, has been published on the GOV.UK website [1].

The report includes tabular and graphical presentation of data for the January-March 2017 quarter and updates the previous report published in March 2017. Some key facts are listed below.

2.1 MRSA bacteraemia

There was a a steep decline in the rates of all reported and trust-apportioned cases between April-June 2007 (April-June 2008 for trust-apportioned cases) and January-March 2014 – 85% (10.2 to 1.5 cases per 100,000 population) and 79% (4.9 to 1.0 cases per 100,000 bed-days), respectively.

However, there has been a 14% increase in the rates of all reported cases (1.5 to 1.8 cases per 100,000 population) and a 4% increase in trust-apportioned cases (1.0 to 1.1 cases per 100,000 bed-days), respectively, between that time and the most recent quarter (January-March 2014 to January-March 2017).

The PIR process for all MRSA bacteraemia cases began in April 2013. Between April 2013 and March 2014, the rates of trust-assigned cases remained stable at 1.2 cases per 100,000 bed-days while rates of CCG-assigned cases decreased by 22% from 1.0 to 0.8 cases per 100,000 population.

Following the introduction of a third-party assignment category in April 2014, counts and rates of CCG-assigned cases have decreased from 91 to 72 cases and 0.7 to 0.5 cases per 100,000 population, respectively, between April-June 2014 and the most recent quarter (January-March 2017). This decrease is mostly due to the introduction of the new assignment category, as several cases which would be classified as CCG-assigned are now classified as third-party assigned.

Over the same period (April-June 2014 to January-March 2017), counts and rates of trust-assigned cases increased from 73 to 99 cases and 0.8 to 1.1 cases per 100,000 bed-days respectively. Similarly within the same period, counts and rates of third-party assigned cases increased from 17 to 66 cases and 0.1 to 0.5 cases per 100,000 population respectively.

2.2 MSSA bacteraemia

The counts of MSSA bacteraemia have increased by 36% (2,199 in Q1 2011 to 2,995 in Q1 2017) and the rates have increased by 31% (16.9 cases per 100,000 population in Q1 2011 to 22.2 in Q1 2017). However, over the same period (January-March 2011 to January-March 2017) counts and rates of trust-apportioned MSSA bacteraemia increased at a much slower pace: 5% (from 735 to 774 cases) and 4% (8.4 to 8.7 cases per 100,000 bed-days), respectively.

Rates of all reported and trust-apportioned cases from earlier quarters between January-March 2011 and October-December 2013 were relatively stable, fluctuating between 16-17 cases per 100,000 population and 7- 8 cases per 100,000 bed-days, respectively. However, subsequent quarters (January-March 2014 to January-March 2017) saw an increase in the rates of all reported and trust-apportioned MSSA bacteraemia by 23% (18.1 to 22.2 cases per 100,000 population) and 10% (7.9 to 8.7 cases per 100,000 bed-days), respectively.

While the number of all reported MSSA bacteraemia increased throughout the surveillance period (January-March 2011 to January-March 2017), the percentage of all cases that were defined as trust-apportioned decreased over the same the period from 33% to 26%, indicating that over time there has been a greater increase in community-onset cases compared to trust-apportioned (hospital-onset) cases.

2.3 E. coli bacteraemia

The counts and rates of all reported E. coli bacteraemia has increased steadily since the initiation of mandatory surveillance of E. coli bacteraemia in July 2011. Counts and rates of all reported E. coli bacteraemia increased by 18% (8,275 to 9,724 cases) and 17% (61.7 to 72.1 cases per 100,000 population), respectively, between July-September 2011 and January-March 2017, with seasonal peaks generally reported between July and September each year. While these seasonal fluctuations are present, beginning from April-June 2013, each quarter of each year has been higher than the same quarter in the preceding year, implying an overall increase over the time period.

This overall increase is also observed in the most recent quarters. Between January- March 2016 and January-March 2017, there was a 3% increase in counts (9,417 to 9,724 cases) and a 5% increase in rates (69.0 to 72.1 cases per 100,000 population) of all reported cases. The highest rate of all reported cases since the beginning of the mandatory reporting of E. coli bacteraemia was also reported within this period: 79.0 cases per 100,000 populations in July-September 2016. .

2.4 C. difficile infection (CDI)

Since the initiation of CDI surveillance in April 2007, there has been an overall decrease in the counts and rates of all reported and trust-apportioned cases of C. difficile infection (CDI). Seasonal peaks are present in the July-September quarter of most years, this is particularly apparent among trust-apportioned cases. The bulk of this decrease occurred between April-June 2007 and January-March 2012 with a 78% and 79% reduction in both counts and rates (16,864 to 3,711 cases and 131.5 to 28.0 cases per 100,000 population, respectively), followed by a 20% and 21% reduction in the counts (3,711 to 2,985 cases) and rates (28.0 and 22.1 cases per 100,000 population) of CDI between January-March 2012 and the most recent quarter (January-March 2017).

A similar trend was observed in trust-apportioned CDI counts and rates between April-June 2007 and January-March 2017: 85% (10,436 to 1,613 cases) and 84% (112.5 to 18.2 cases per 100,000 bed-days), respectively. This was then followed by a further 22% in both counts and rates of trust-apportioned cases (1,163 to 1,094 cases and 18.2 to 12.3 cases per 100,000 bed-days, respectively) between January-March 2012 and the most recent quarter.

This shows that there has been a greater decline among trust-apportioned CDI cases compared to all reported CDI cases during the surveillance period.

2.5 Reference

1. PHE (8 June 2017). Quarterly Epidemiological Commentary: Mandatory MRSA, MSSA and E. coli bacteraemia, and C. difficile infection data (up to January-March 2017).

3. Infection reports in this issue of HPR

The following infection report is published in this issue of HPR. The link below is to the relevant webpage collection.

3.1 Bacteraemia report

• Laboratory surveillance of Proteus, Morganella and Providencia species bacteraemia in England, Wales and Northern Ireland: 2016.