Research and analysis

HPR volume 9 issue 4: news (6 February)

Updated 29 December 2015

1. Ebola virus disease: international epidemiological summary (at 1 February 2015)

As of 1 February 2015, the World Health Organization reports a total of 22,495 clinically compatible cases (CCC) of Ebola virus disease (EVD), including 8,981 deaths, associated with the west African outbreak (table). Provided case totals and, particularly, deaths are known to still under-represent the true impact of the outbreak in west Africa. While the majority of cases have been reported from Guinea, Liberia and Sierra Leone, cases have also been reported from Mali, Nigeria, Senegal, Spain, the United Kingdom (UK) and the United States of America (USA).

Current reports indicate that the epidemiological situation in Guinea, Liberia and Sierra Leone continues to improve, although for the first time this year all three countries have reported an increase in confirmed cases.

In Guinea, reported case incidence remains low nationally but has showed an increase for the second week in a row (39 compared with 30 and 20 in the previous two weeks). The geographical distribution of cases continues to vary and shift, with another newly affected area reported this week (Tougué, in northern Guinea). As with last week, the western prefecture of Forécariah (bordering Sierra Leone) remains the worst affected area with 13 confirmed cases reported in the last seven days. A resurge of cases in the eastern prefecture of Lola was also noted this week as a result of an unsafe burial in January. Incidents of community resistance remain an issue and may impede progress in EVD control.

In Liberia, reported case incidence remains at a low level with five confirmed cases reported in the last week. All five confirmed cases were reported from Montserrado county, the district that includes the capital Monrovia.

While Sierra Leone continues to report the majority of new cases in the West African EVD outbreak with 80 confirmed cases recorded in the last week (a slight increase on the previous week’s total of 65), the latest figures still represent one of the lowest weekly totals of new confirmed cases reported since July 2014. Significant transmission continues however in the western districts, particularly in Freetown and Port Loko, where a combined total of 58 confirmed cases were reported in the last week. As in Guinea, community resistance to EVD control measures may hinder progress.

To date, a total of 24 EVD cases have been cared for outside of Africa. Of these, 18 repatriated cases (hospitalised in USA, Spain, UK, Germany, France, Norway, Switzerland, Italy and the Netherlands), three imported cases (diagnosed in the USA and the UK) and three incidents of local transmission (in Spain and the USA).

The table below summarises Ebola virus disease international epidemiological information as at 1 February 2015.

Country	Total CCCs	Total deaths	Current status
Guinea	2975	1944	Ongoing transmission
Liberia	8745	3746	Ongoing transmission
Sierra Leone	10,740	3276	Ongoing transmission
Mali	8	6	EVD free
Nigeria	20	8	EVD free
Senegal	1	0	EVD free
Spain	1	0	EVD free
UK	1	0	Single imported case
USA	4	1	Awaiting EVD free status
TOTAL	22,495	8981	–

Further information on the international epidemiological situation can be found in PHE’s weekly Ebola epidemiological update.

2. Hepatitis C in London annual report

London accounts for nearly a third of all newly diagnosed cases of hepatitis C reported in England, with 3,079 new laboratory reports of confirmed diagnoses reported in 2013, a rise of 12% since 2012. London also has the second highest rate of diagnosis per head of population, after Greater Manchester.

In terms of burden of disease resulting from chronic infection, London is among three regions of England with very high rates of hepatitis-related, end-stage liver disease (ESLD) and hepatocellular carcinoma (HCC). In 2013, nearly 2,000 people in London were admitted to hospital with a diagnosis of hepatitis C, and hepatitis C was the primary indication for just under a quarter of first liver transplants in London.

Nevertheless, there is some evidence that the trend in new infections (nationally and in London) is stable or declining in England and that the steady increase in the annual number of laboratory-confirmed new diagnoses of recent years reflects improved ascertainment (including higher levels of testing and reporting of laboratory results).

These are among the conclusions of PHE’s latest annual report for London [1] that presents epidemiological data, an assessment of the burden of disease and, in particular, describes progress made in preventing infection and improving rates of testing among the main risk groups – principally people who inject drugs (PWID) in the general population and in prisons (accounting for more than 90% of laboratory -confirmed cases in England).

It is estimated that over half of all PWID in London have hepatitis C (59%). In the past 10 years, sex between men has also emerged as an important route of transmission. Individuals originating from south Asia, where the prevalence of hepatitis C is high, are also particularly at risk.

The London report includes specific recommendations for different groups of health professionals: GPs, directors of public health, local authorities and commissioners of drug treatment services, Clinical Commissioning Groups (CCGs), NHS England, PHE London Centre and Region, laboratories, providers of prison health services, providers of drug treatment services, and providers of hepatitis C treatment services.

2.1 Reference

1. PHE (January 2015). Hepatitis C in London (annual review, 2013 data) [1 MB PDF].

3. Low effectiveness of seasonal flu vaccine in the 2014/15 season to date

The 2014/15 influenza season in the UK has been characterised by early circulation of influenza A(H3N2), which particularly impacts vulnerable groups such as the elderly. This has resulted in care home outbreaks, hospitalisations and excess mortality in those over 65 years of age.

In addition, mid-season estimates of influenza vaccine effectiveness (VE) across the UK indicate that the seasonal influenza vaccine has provided low protection, during the 2014/15 season, against the dominant circulating A(H3N2) strain, [1,2].

The findings on mid-season flu vaccine effectiveness in the UK are based on PHE co-ordinated research involving 1,314 patients presenting in primary care across the UK [1]. Vaccine effectiveness in preventing laboratory confirmed influenza in this group was estimated to have been 3% overall, compared with the approximately 50% vaccine effectiveness that has typically been seen in the UK in recent years.
PHE has also carried out antigenic and genetic analysis of influenza A(H3N2) viruses circulating this season and found evidence of drift compared to the A(H3N2) virus strain in the 2014/15 flu vaccine. The evidence of low vaccine effectiveness indicates that this drift has been significant, and resulted in a “mismatch” to this particular vaccine strain.

These UK findings follow publication of mid-season vaccine effectiveness estimates for the USA and Canada, where the vaccine was also shown to have provided little protection against circulating A(H3N2) viruses, which were also drifted.

PHE has stressed that the current vaccine will still protect against flu A(H1N1)pdm09 and flu B, both of which may yet circulate this season; unvaccinated members of at-risk groups are therefore still encouraged to obtain the vaccine.

Also, antiviral drugs remain an important and effective intervention to reduce the morbidity and mortality due to influenza infection in vulnerable groups, and physicians are urged to prescribe them for those at greatest risk of becoming seriously ill due to flu [2].

The PHE research paper concludes that: “The observation of low vaccine effectiveness this season highlights the vital importance of implementing other prevention and control measures, in particular the early use of influenza antivirals for post-exposure prophylaxis and treatment of vulnerable populations, such as the elderly, together with appropriate infection control measures”.

3.1 References

1. Pebody RG, Warburton F, Ellis J, Andrews N, Thompson C, von Wissmann , et al (Febuary 2015). “Low effectiveness of seasonal influenza vaccine in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2014/15 mid-season results”. Euro. Surveill. 20(5), 5 February.

2. “Flu vaccine shows low effectiveness against the main circulating strain seen so far this season”. PHE press release, 5 February.