Research and analysis

HPR volume 9 issue 39: news (6 November)

Updated 29 December 2015

1. Eleventh annual review of infections among UK blood, tissue and organ donors and transfusion recipients

The NHSBT/PHE Epidemiology Unit’s annual review, Safe Supplies: Uncovering Donor Behaviour, describes infections among blood, tissue, and organ donors and transfusion recipients during 2014 [1]. New to 2014’s report are initial findings from the PHE UK blood donor survey [2] and, for the first time, platelet screening data for all UK blood services.

During 2014, almost 2.2 million blood donations were tested in the UK. There were 212 confirmed markers: syphilis (82), HBV (68), HCV (38), HIV (13), and HTLV (11). This is a rate of 9.7 confirmed positive donations per 100,000, a 4% decrease compared with 2013. New donors accounted for 8% of the donor population but 84% of the positives. Four acute and two occult HBV infections were reported. Occult HBV is not usually reported in the general population but is identified in blood donations as both serology and nucleic acid testing are used in screening. HBV and HCV infections are notified to local health protection teams (HPTs).

The donor survey showed that donor adherence to selection criteria is very high (99.3%) but each year a small number of non-compliant donors with markers of infection are observed. In 2014, there were eight of these donors: five of whom reported sex between men. This is the third full reporting year since the change in blood donor selection policy for men who have sex with men (MSM): from a permanent to a 12-month deferral. Although the data should be interpreted with caution, there is no evidence that this change has resulted in increased risk of a transfusion transmissible infection entering the blood supply.

New risk estimates for infectious but undetected infections suggest that testing will miss approximately one HBV infection every year, one HCV infection every 12 years and one HIV infection every three years.

1.1 HEV screening

During 2014, a local HPT initiated a blood service investigation following a report of a hospital patient with acute hepatitis E following transfusion which led to confirmation of a hepatitis E transfusion transmission. HEV screening will be implemented by the UK blood services in 2016 [3]. There were two near-miss cases of Staphyloccus Aureus in platelet packs – vigilance of hospital staff before transfusion led to the discovery of clumps which allowed preventative action to be taken with associated packs.

During 2014, 3,825 organs from 1,241 deceased solid organ donors were transplanted in the UK. Testing of these donors for markers of infection revealed that Epstein-Barr virus (EBV) and cytomegalovirus (CMV) were detected in 93% and 52%, respectively, of donors for whom a test result was available. Initial screening results were also obtained for: HBV core antibodies (33 donors); HBV surface antigen (3); HCV antibodies (12); Toxoplasma Gondii (212); and treponemal antibodies (4).The Unit is currently working to quantify the risk of a transmission occurring through transplantation.

NHSBT also tested a total of 2,375 cord blood donors: two were reactive for markers of HCV infection and two for HTLV. Positive donors are referred for specialist advice, particularly on the risk of maternal HTLV transmission through breast feeding.

1.2 References

1. NHSBT/PHE Epidemiology Unit (November 2015). Safe supplies: uncovering donor behaviour: annual review.
2. Davison KL, Reynolds CA, Andrews N, Brailsford SR and on behalf of the UK Blood Donor Survey Steering Group (2015). Getting personal with blood donors – the rationale for, methodology of and an overview of participants in the UK blood donor survey. Transfusion Medicine, 25: 265–275.
3. Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO). Extraordinary meeting: Tuesday 7 July 2015.

2. Ebola virus disease: international epidemiology summary (at 1 November 2015)

As of 4 November 2015, a total of 28,622 clinically compatible cases of Ebola virus disease (EVD) (15,246 confirmed) have been reported associated the West African outbreak, 11,314 of which have died.

A total of seven confirmed cases were reported in October, all in Guinea, compared to 13 in the previous month (seven in Guinea, six in Sierra Leone). Case incidence in West Africa has now remained at five or fewer confirmed cases for 14 consecutive weeks.

Of the seven cases reported in Guinea in October, five were registered contacts and six were associated with the Forécariah branch of the recent Ratoma, Conakry chain of transmission. Although the remaining case was from the Ratoma area of the city, genomic analyses suggest he was not infected with the strain of Ebola virus responsible for the most recent cases in Conakry and Forécariah. Over 350 contacts remain under follow up in Guinea across Conakry and Forécariah, of which 141 are considered high-risk. In the past 42 days, one contact in Forécariah has been lost to follow up.

There have been no confirmed cases reported in Sierra Leone for seven consecutive weeks: so the country is set to be declared free of EVD transmission on 7 November [1].

A UK survivor of EVD was re-hospitalised on 6 October due to late EVD-related complications. She is being treated for viral meningitis caused by the persistence of the virus and is said to be in a serious but stable condition in hospital.

Number of new confirmed cases reported per week (25 October to 1 November 2015) in affected countries in West Africa. (Data source: WHO Ebola Situation Report 4 November 2015)

More detailed information on the epidemiological situation can be found in PHE’s Ebola epidemiological update.

2.1 Reference

1. GOV.UK news story (6 November 2015). The end of Ebola in Sierra Leone.

3. Particulate air pollution PHOF indicator updated

More than five per cent of mortality in England is attributable to long-term exposure to particulate air pollution – making air pollution the largest environmental risk linked to deaths each year – according to the latest data published in the Public Health Outcomes Framework (PHOF) for England [1].

This assessment is based on the estimates, published in the report Estimating Local Mortality Burdens Associated with Particulate Air Pollution last year [2], that long-term exposure to particulate air pollution has ‘an effect equivalent to’ around 25,000 deaths a year in England.

Further information about the PHOF air pollution indicator, including references to background documents, is provided in a recent article published on the PHE’s Public Health Matters blog webpages, ‘Understanding the impact of particulate air pollution’ [3].

3.1 References

1. PHE Official Statistics (November 2015). Public health outcomes framework: November 2015 data update.
2. PHE (April 2014). Estimating local mortality burdens associated with particulate air pollution.
3. PHE (3 November 2015). Public Health Matters blog.