Q Fever

Paul McDermott/Mike Paton

Biological Agents Unit

Health & Safety Executive

Route Map

• Background to Biological Agents Unit

• Outbreak – Scotland 2006

• Issues raised

• Vaccination

• Emerging guidance

HSE’s Biological Agents Unit

• Located at HQ in Bootle

• 14 x Specialist Health & Safety Inspectors– Microbiology & Molecular Biology Disciplines

• Approximate total of 26 staff with UK wide remit

Biological Agents Unit

Hazardous Installations Directorate• Chemicals • Off-shore• Specialised Industries – explosives, gas/pipelines, • mines, microbiology & genetic modification (SI4)

FMDV Pribright 2007

Laboratory work

Cooling towers

HCAI

Biological Agents Unit

• Our work is aimed at ensuring that risks in the workplace from microbiological hazards are properly controlled

• Cover all aspects of GM and biotechnology related to human health and environmental safety

• Escape of Animal Pathogens from containment

Animal Pathogens

High containment

Q Fever - background

• highly infectious zoonosis - Coxiella burnetii

• widespread globally (including UK) among livestock - sheep, cattle and goats

• infection in animals is usually asymptomatic, but some abortions and stillbirths

• livestock - high concentrations of bacteria found in mammary glands, placental tissue and milk (lesser extent in urine and faeces)

Q fever – Human Infection

• Q fever endemic in the UK; ~70 UK cases of Q fever per year

• actual number of cases may be ~ 700 (1% of chronic atypical pneumonia)

• periodic outbreaks i.e. 4 major outbreaks in the UK over 17 years

• acute symptomatic human infection characterised by an influenza-like-illness (self limiting)

• chronic infection less common (~10% cases) but can result in pneumonia or endocarditis

• clinical diagnosis of Q fever difficult (presentation as non-specific illness)

• highest incidence of infection in humans in the UK spring/early summer (lambing season)

Outbreaks in UK

• Birmingham outbreak (1989):– similar wind borne spread outbreak from farms

engaged in outdoor lambing and calving (147 cases, 85% male, 90% adults)

• Newport outbreak (2002):– 106 cases out of 250 workers from a factory ? due to

release of spore-like particles from drilling into strawboard ceilings during renovation works in a cardboard box manufacturing plant

• Stirling, Scotland outbreak (2006):– Meat processing plant outbreak thought to be related to

a ewe that had aborted in May 2006. 138 cases.

• Cheltenham (2008):– 31 diagnosed cases in urban setting

Route of transmission

• Usually inhalation of contaminated aerosols– Windblown spore-like particles– E.g. meat processing plants (Scotland

2006), straw materials embedded in constructions (Newport 2002)

• Ingestion of unpasteurised milk

• Little or no human to human spread (except possibly by inhalation of organisms contaminating clothing)

• Infectious dose very low ? 1 organism (in lab setting) – may be different in field

• Incubation period 14-39 days (may be shorter if there is a high infectious dose)

Scottish Outbreak

• Late June 2006, local GPs reported increasing numbers of sick people from meat processing plant (by end of outbreak >100 people confirmed positive);

• HSE asked to investigate possible source of legionella

• 17 July disease confirmed as Q Fever

• Environmental conditions – very hot, dry weather in early summer

• Plant processed ~2000 sheep per day (150 cows per day)

• No specific job/role within plant linked to exposure

• Source linked to sheep lairage and aborted foetus within exposure period

Meat Processing

Lamb Chill

Fat Plant

Slaughter

Meat Processing

Ca

nte

en

Loading Bay

Cattle Lairage

RunYard

Sheep Lairage

Car Park

Car Park

Entrance

Offices

Zoonoses – Q fever

Smokers shed

Access DoorVentilation fan C

anteen

Q-Fever Outbreak Scotland, June 2006

Sheep Lairage

Ventilation System

Lairage supply fans

Fire Door

Canteen entrance

lairagefire exit

Contributory Factors

• General lack of understanding of the zoonotic risks

• Sheep aborted on site

• Site Layout (proximity animals/canteen)

• Ventilation (type & operation)

• Weather (hot/dry/dusty – access via fire door)

• Cleaning regime (infrequent)

• Throughput (2000 sheep per day)

• Cross contamination (hygiene measures/movement of staff)

• Animal welfare

Action Taken

• Raise awareness of zoonoses risk (risk assessment, training)

• Re-design of lairage interior (assist cleaning; not possible to relocate)

• New ventilation system fitted with an air scrubber

• Increased frequency cleaning of holding areas

• Procedures for disposal of birth products and other high risk material

• Hygiene procedures (segregation clean/dirty activities)

Advisory Committee on Dangerous Pathogens (ACDP)

• ACDP provides scientific and technical advice to HSE and others on the risks from exposure infectious microorganisms – independent, respected advice

• raised concerns over outbreak and emphasised need for further research - relationship between exposure, immunity and disease

• Supported the proportionate line of control taken by HSE

• Referred vaccination issue to JCVI

• Supported approach of raising awareness with industry

Guidance for Employers

• HSE worked with British Meat Processors Association to develop guidance – available on BMPA website

• Annual HSE/Defra press release related to risks to pregnant workers during spring lambing, calving and kidding (updated to reflect Q fever)

• VLA/HPA/Defra/HSE published a guidance note for farmers (Defra website)

• HSE articles in National Sheep Association magazine "Sheep Farmer" and British Veterinary Association magazine "In Practice“

• HSE revised its agriculture supplement to reflect changes in working practices

Coxiella burnetii

Health and Safety Executive

Health & Safety ExecutiveField Operations Directorate

Biological Agents Unit

Agriculture sector

Occupational Health specialists

Occupational Hygiene specialists

Other Government Departments Health Protection ScotlandHealth Protection AgencyDepartment for Environment, Food, Rural AffairsVeterinary Laboratory Agency

IndustryScot Beef LtdBritish Meat Processors Association

Acknowledgements

Thank you for your attention

Any questions?

Q Fever Vaccine - Joint Committee for Vaccination & Immunisation (JCVI)

• HSE referred the matter to JCVI, who

Considered data from Australia & questioned supporting efficacy against UK strains

Potential uses of vaccine e.g. for outbreak scenarios or prophylactic use or specific occupations (abbatoir, vets, farmers)

Raised issue of severe reaction in vaccinees previously exposed to Q fever (severe reaction at inoculation site) and incidence pre-exposure (In NI, >50% farmers seropositive; 10%< urban population)

Met with scientists from Australia to discuss vaccine data

• JCVI yet to reach decision hence Q-Vac still not licensed for use in UK