News Archives |
Volume 4 No 8; 26 February 2010
- Ongoing outbreak of Q fever in the Netherlands: HAIRS group considers risk for UK
- Substantial increase in cases of Lymphogranuloma venereum (LGV) in UK
- Pandemic WHO influenza vaccine recommendations for 2010-11
Ongoing outbreak of Q fever in the Netherlands: HAIRS group considers risk for UK
The spread of Q fever in the Netherlands – a human and public health challenge that first emerged in 2007 and had led to over 3000 human cases being notified by the end of 2009 in that country – has not led to a significant increase in human cases in neighbouring areas of other countries and is highly unlikely to be repeated in the UK, according to two recent official risk assessments.
Notifications of Q fever in the Netherlands – that in earlier years averaged 17 human cases annually [1] – increased to 168 cases in 2007, 1000 in 2008, and over 2000 in 2009 [2]. The most affected area is the highly agricultural southern province of Noord Brabant, but cases have also been reported from neighbouring provinces. The disease has now been confirmed on a total of 73 dairy goat farms and two sheep farms [3]. The specific epidemiology of Q fever in the Netherlands is most likely related to intensive goat farming in the proximity of densely populated areas.
Control measures in the Netherlands
Dutch authorities have introduced a number of measures to try to control the spread of the outbreak. These include mandatory vaccination of small ruminants (initially in the affected regions but extended throughout the country in 2010 to include holdings of more than fifty sheep or dairy goats, and premises such as petting farms and zoos), a general ban on breeding, and fortnightly Q fever bulk milk testing on all farms with 50 or more dairy goats or dairy sheep. In December 2009 a cull commenced of all pregnant dairy goats, whether vaccinated or unvaccinated, on infected farms. Non-pregnant females were spared but are banned from use for breeding purposes during their lifetime.
ECDC threat assessment
In December 2009 the European Centre for Disease Prevention and Control (ECDC) undertook a threat assessment concluding that “to date, there is no evidence for a significant increase in the number of human cases of Q-fever since 2007 in other European countries. In Belgium and Germany, goat population density is much less than in the Netherlands and ‘intensive’ farming is not practised in the same way. Therefore, sporadic occupational cases and localised outbreaks could be expected in other countries, including neighbouring Germany and Belgium, if infected animals reach the farms. However, the spread to the general population is unlikely to reach the extent it has in the Netherlands, as farms are not so often in the proximity of densely populated areas and goats are not kept in the same way.”
Implications for the UK
The Human Animal Infections Risk Surveillance (HAIRS) group is a multi-agency and cross-disciplinary horizon scanning group with members from the HPA, Defra, Veterinary Laboratories Agency, Department of Health, Food Standards Agency, Animal Health, and the Devolved Administrations [4]. The HAIRS group met in January 2010 to discuss the implications of the Dutch situation for the UK, considering evidence from the Dutch outbreak and the ECDC threat assessment, together with UK Q fever surveillance data and information on UK farming practices.
Current surveillance of Q fever in humans and animals does not indicate any recent increase in numbers of cases in the UK. There are between 50-100 cases per year in humans in the UK, with no apparent increase seen in 2009. Less than 10 cases in animals were identified in Great Britain annually between 2006 and 2008, and none were diagnosed in 2009 to the end of September. Further information on the background level of Q fever infection in sheep and goats will be available from a Q fever seroprevalence study, commissioned by Defra, that involves screening blood samples (from approximately 6000 sheep and 500 goats) collected during the 2008 routine Brucella screening programme. Preliminary results are expected in early 2010.
There are significant differences in the pattern of husbandry and density of stocking of goats between the UK and the Netherlands. The goat industry in the UK is not intensive and there are very few large dairy goat farms, most goat farming being small-scale and not concentrated in any one area.
The HAIRS group concluded that, due to these differences, it is highly unlikely that the events in the Netherlands could be repeated in the UK. In addition, current scientific evidence does not support the suggestion that a hypervirulent strain may be contributing to the extent of the outbreak in the Netherlands. HAIRS will continue to monitor the situation closely.
References
2. Data from the National Institute for Public Health and the Environment, RIVM (http://www.rivm.nl/cib/themas/Q-koorts/).
3. Food and Consumer Product Safety Authority of Ministry of Agriculture (Netherlands), list of positive farms: http://www.vwa.nl/cdlpub/servlet/CDLServlet?p_file_id=47562.
4. The Human Animal Infections Risk Surveillance group. Information available at: http://www.hpa.org.uk/HPA/Topics/InfectiousDiseases/InfectionsAZ/1206575051338/.
Substantial increase in cases of Lymphogranuloma venereum (LGV) in UK
Diagnoses of LGV have risen substantially over the winter of 2009/10 (see figure). Diagnoses were 91% higher for November 2009 to January 2010 (88) than in the previous three months (46), and 115% higher than that seen in the same period in 2008/09 (41).
Since enhanced surveillance of LGV was introduced in 2004, the general diagnostic profile has been consistent over time, most cases being seen in HIV-positive white men who have sex with men (MSM), presenting with proctitis, some of whom have a large number of sexual partners [1,2]. The cases are geographically dispersed although the epidemic is focused on London and, to a lesser extent, Brighton and Manchester.
Since 2004, outbreaks amongst MSM have occurred in major cities in Europe, the largest cohort of 1,070 cases being seen in the UK [3]. LGV, which is caused by the L serovars of Chlamydia trachomatis, is endemic to areas of Africa, Asia, South America and the Caribbean.
Our understanding of the epidemiology of LGV remains poor. It has been difficult to identify the reservoir, with only a small number of asymptomatic cases detected [4]. The mode of transmission has also been elusive, urethral infection is uncommon and, whilst infected individuals have high risk sexual behaviour and links to sex toys and sex parties have been described, no definitive associations have emerged [1].
Unlike other forms of C. trachomatis, LGV is invasive. Most cases seen in the UK have presented with proctitis but symptoms vary according to the site of infection and may include ulcers and inflamed and swollen lymph nodes in the groin (inguinal syndrome). If left untreated symptoms can become more severe and cause lasting damage to health. Treatment with three weeks of doxycycline BD 100 mg is recommended by BASHH [5].
Urgent further investigation of the increase in diagnoses will be the focus for the LGV Incident Group but the following recommendations will help limit spread:
- Testing for LGV should be offered during routine clinical care to HIV positive MSM who have symptoms of LGV infection and have a positive test for C. trachomatis;
- MSM should have a full sexual health screen annually. This should include testing for HIV where it is not already diagnosed;
- Behavioural modification is a key component of control strategies. Campaigns that increase awareness and knowledge of STIs and promote safer sex need to be intensified.
The Sexually Transmitted Bacteria Reference Laboratory (at the HPA’s Centre for Infections) is offering a reference service for symptomatic patients who are chlamydia positive or contacts of positive cases. Information on enhanced surveillance of LGV, including general information about LGV, and protocols for the submission of samples for testing, are available on the HPA website [6].
References
1. Ward H, Martin I, Macdonald N, Alexander S, Simms I, Fenton K, et al. Lymphogranuloma venereum in the United Kingdom. Clin Infect Dis 2007; 44: 26-32.
2. HPA. Lymphogranuloma venereum in the United Kingdom: data to end of June 2008, Health Protection Report 2(35) (29 August 2008).
3. Savage EJ, van de Laar MJ, Gallay A, et al. Lymphogranuloma venereum in Europe, 2003-2008. Euro Survell 2009; 14: 19428.
4. Ward H, Alexander S, Carder C, Dean G, French P, Ivens D, et al. The prevalence of Lymphogranuloma venereum (LGV) infection in men who have sex with men: results from a multi-centre case finding study. Sex Transm Inf 2009; 85(3): 173-5.
5. Clinical Effectiveness Group of the British Association for Sexual Health and HIV (CEG/BASHH). 2006 National Guideline for the Management of Lymphogranuloma venereum. Available at: http://www.bashh.org/documents/92/92.pdf (300 KB PDF).
6. HPA website: Products & Services ›Infectious Diseases ›Laboratories and Reference Facilities ›Sexually Transmitted Bacteria Reference Laboratory (STBRL).
WHO influenza vaccine recommendations for 2010-11
The World Health Organization (WHO) has published its recommendations for the composition of influenza virus vaccines for the forthcoming season in the northern hemisphere (November 2010 to April 2011): a trivalent vaccine including a pandemic influenza (H1N1) 2009 strain (an A/California/7/2009 (H1N1)-like virus; an A/Perth/16/2009 (H3N2)-like virus; and a B/Brisbane/60/2008-like virus.) [1].
HPA bulletins
Due to the low influenza activity in the UK, the HPA is currently publishing full National Influenza Reports on a fortnightly basis, with shorter summaries of activity being published in alternate weeks [2]. The next full report will be published on Thursday 4 March 2010 [3].
References
1. WHO. Recommended viruses for influenza vaccines for use in the 2010-2011 northern hemisphere influenza season, http://www.who.int/csr/disease/influenza/recommendations2010_11north/en/index.html.
2. HPA. Weekly National Influenza Report (week 8 - summary only), 25 February 2010 (PDF format, 154 KB),
3. HPA website: www.hpa.org.uk/swineflu/surveillance&epidemiology.