Currently, the diagnosis of vCJD can only be con \201 rmed following pathological examinat ion of brain tissue, usually at post-mortem. Treatment and prognosis \200 vCJD is a progressive and ultimately fatal disease \200 Th ere is currently no proven treatment for the underlying process. Risk control Careful adherence to standard infection control procedures should pre- vent oc cupational exposure. 06_Smedley_Chap06.indd 160 12/31/2012 8:50:42 PM VARIANT CREUTZFELDT \200\223JAKOB DISEASE 161 Surveillance The Health Protection Agency and the National CJD Research and Surveillance Un it have set up a registry to \201 nd out more about the risk from exposures to CJD and ot her TSEs to health care and laboratory workers. In these occupational groups, percutaneous or mucocutaneous inoculation of tissues or blood from probable or con \201 rmed cases of a ll types of human prion diseases including CJD or TSE infected animals or tissues must be r eported to the registry. Details on how to report an exposure are available on the Health P rotection Agency website. The reg- istry will provide long-term monitoring of the exposed w orkers. Further information HSE (2007). BSE occupational guidance, Advisory Committee on Dangerous Pathogens. Available at: M http://www.hse.gov.uk/pubns/web22.pdf Department of Health (2003). Guidance from the ACDP TSE Risk Management Subgroup (formerly TSE Working Group). Available at: M http://www.dh.gov.uk/ab/ACDP/TSEguidance/index.htm Heal th Protection Agency (2012). Creutzfeldt-Jakob Disease (CJD) . Available at: M http://www.h pa. org.uk/Topics/InfectiousDiseases/InfectionsAZ/CreutzfeldtJakobDisease/ 06_Smedley_Chap06.indd 161 12/31/2012 8:50:43 PM CHAPTER 6 Occupational infections 162 Bovine spongiform encephalopathy BSE is a transmissible prion disease of cattle. Epidemiology A major problem with infection in UK cattle herds in the 1990s was associ- ate d with transmission to humans (as the human variant Creutzfeldt \200\223Jakob disease) via the food chain. In theory, the disease can also be acquired occupationally, although occupa tional cases have not been described in the UK. Statutory controls on animal feeding should have eliminated BSE in cat- tle born after 1 Au gust 1996. Therefore, the incidence of the disease in cattle coming to slaughter should hav e decreased year on year to exceed- ingly low levels. Clinical features See b p. 160, Variant Creutzfeld \200\223Jakob disease. Causal exposures/industries Transmission to humans could occur from exposure to the neural tis- sue of infected cattle through the percutaneous or mucocutaneous route (through breach of the skin, or direct contact with non-intact skin or intact mucous membranes): \200 Fa rmers \200 Abbatoir workers \200 Meat processors. Prevention Prevention is through good hygiene practices in agriculture and meat processing (including abbatoirs). This is covered in detail in b p. 112, Animals and animal products ( animals and animal products). Relevant legislation \200 BSE in animals is noti \201 able to the Department for the Env ironment, Food, and Rural Affairs (DEFRA) Any infection reliably attributable to work would be noti \201 able to HSE under RIDDOR. Further information and guidance HSE (2007). BSE occupational guidance, Advisory Committee on Dangerous Pathogens . Available at: M http://www.hse.gov.uk/pubns/web22.pdf HSE Controlling the risk of exposure to bovine spongiform encephalopathy (BSE) . Available at: M http://www.hse.gov.uk/biosafety/diseases/bovine.htm 06_Smedley_Chap06.indd 162 12/31/2012 8:50:43 PM This page intentionally left blank CHAPTER 6 Occupational infections 164 Meningococcal infection These infections are a collection of systemic disorders caused by t he bac- terium Neisseria meningitidis . Humans are the only known reservoir for the organis m. Epidemiology \200 10% of the population (and up to 25% of 15 \200\22319-yr-olds) carry N. meningitidis asymptomatically in the nasopharyx. It only causes disease in a small proporti on Most cases are sporadic, but <5% occur as clusters \200 Strong seasonal variation; highes t incidence in winter \200 Most cases in the UK are caused by subtypes B and C \200 Occ upational cases are very rare. Clinical features \200 Early features non-speci \201 c: fever, malaise, vomiting \200 Characteristic petechial rash \200 Progression from onset to death can be extremely rapid (few hours) \200 Septicaemia (can be complicated by multi-organ failure) \200 Meningit is. Causal exposures/industries \200 Transmission is through very close contact: inhaling res piratory secretions from the mouth or kissing HCWs (documented case in ambulance technician): only if very close contact with aerosolized respiratory secretions University students: OH professionals who provide services to universities may be asked to advise Occupational travelers to endemic countries (sub-Saharan Africa, Middle East). Clinical assessment Blood cultures. Treatment and prognosis \200 Penicillin or third-generation cephalosporins intravenously (IV). In view of the risk of rapid progression, GPs are guided to treat with a bolus of IV benzylpenicillin (1.2g intramuscular (IM)/IV) prior to admission if the diagnosis is suspec ted. Intensive support is needed for severe cases 90% recover, 10% fatal. Prevention Post-exposure prophylaxis \200 Cipro \202 oxacin 500mg single oral dose (unli censed indication) OR rifampicin 600mg bd for 2 days for: \200 HCWs who have taken part in resuscitation, endot racheal intubation, suctioning, or post-mortem without wearing appropriate respiratory protection students who are prolonged close contacts of cases 06_Smedley_Chap06.indd 164 12/31/2012 8:50:43 PM MENINGOCOCCAL INFECTION 165 Vaccination \200 Subgroup C vaccination (MenC) in students living in halls of residence \200 A+C vaccine for travelers where indicated by advisory sources (see b p. 418) There is no vaccine for subgroup B. Education OH departments may be involved in informing H CWs/students to report suspicious symptoms early. Compensation A HCW who contracted meningococcal infection at work, and lost pay as a result , would be eligible for NHS Injury Bene \201 t. Relevant legislation \200 Meningococcal septicaemia is noti \201 able (to Local Authorit y Proper Of \201 cers) under the Health Protection (Noti \201 cation) Regulations 2010 Meningococcal infection that is readily attributable to work is reportable to HSE under RIDDOR. Further information HPA (2006). Guidance for public health management of meningococcal dise ase in the UK . Health Protection Agency. Available at: M http://www.hpa.org.uk/infections/ topics_az/meningo/menin- gococcalguidelines.pdf Managing meningococcal disease (meningitis or septicaemia in higher educational institution s . Available at: M http://www.universitiesuk.ac.uk/Publications/Pages/Publication-218.aspx 06_Smedley_Chap06.indd 165 12/31/2012 8:50:43 PM CHAPTER 6 Occupational infections 166 Tuberculosis Epidemiology TB noti \201 cations declined in the UK until the mid-1980s. Sub sequently, there have been small increases in annual incidence. The incidence is high- est in people of Indian subcontinent and black African origin. Around 9000 cases of TB are curr ently reported each year in the UK. Most cases occur in major cities, particularly in Londo n. Clinical features TB can affect many body sites; therefore, the range of presenting symp- t oms may be wide and non-speci \201 c. TB may be asymptomatic (latent). \200 Consider TB in anyone with intermittent fever and weight loss \200 Symptoms: chronic cough, night swe ats, and haemoptysis. Causal exposures/industries Transmission is by inhalation of droplets following close perso nal contact with a sputum-positive case. At risk occupations include: \200 HCWs having co ntact with patients or clinical specimens, especially if involved in aerosol-generating procedures (bronchoscopy, nebulization) Veterinary staff who handle animal species that are susceptible to TB \200 Staff of priso ns, old people \200\231s homes, and hostels for the homeless or refugees. Individual susceptibility \200 Contacts, including people from the same household sharing kitchen facilities, boy- or girlfriend, and frequent visitors to the home of the index cas e. A contact at work may be close enough to be equivalent to a household contact; therefore , a risk assessment is imperative \200 Those who have lived in, who travel to, or receive visitors from places where TB is \200\230common \200\231 (incidence >40 per 100,000 per year) \200 HIV infect ion, children and elderly, homeless, drug or alcohol dependency Hostel dwellers, and those living in poor or crowded housing \200 Individuals who are imm unocompromised. Clinical assessment and diagnosis \200 Diagnosis of latent TB: tuberculin skin test (TST) , i.e. Mantoux or interferon-gamma testing if available locally. Those with a positive TST or gamma-interfero n test should be assessed for active infection and if not actively infected they should be considered for treatment for latent TB Respiratory TB: CXR, multiple sputum samples, or bronchial washings for microscopy and culture Non-respiratory TB: biopsy for culture or needle aspiration for cytology, computed tomography (CT)/MRI/ultrasound/echocardiogram depending on suspected site. CXR to exclude co-existing respiratory TB. 06_Smedley_Chap06.indd 166 12/31/2012 8:50:43 PM TUBERCULOSIS 167 Treatment and prognosis Sputum +ve respiratory TB is usually rendered non-infectious after 2wks treatment with quadruple therapy. However, individuals with multidrug resistant TB (MD R-TB) may be intermittently sputum +ve for long peri- ods. British HIV Association Guidelin es should be consulted when caring for any patient who is or might be co-infected with HIV. All TB should be managed by a specialist, usually a respiratory physician. Management of occupational risk NICE guidance covers the assessment of the contacts of airc raft crew, school teachers, and childcare workers who are diagnosed with TB. Workplace cont acts are at low risk of contracting TB from an infected indi- vidual, but a risk assessment is imperative. HCWs (including students and temporary staff) and prison staff should have the same pre-employment screening for TB. New staff should be screened according to the NIC E clinical algorithm. HCWs should not work with patients or clinical speci- mens until an o ccupational health (OH) assessment has been undertaken or documented within the past 12mths . Assessment should include: \200 Symptoms and signs enquiry \200 Documentary evidence of a BCG scar checked by an occupational health professional TST or interferon-gamma result within the last 5yrs, if available. All staff should be reminded to report symptoms suggestive of TB promptly to their OH depar tment. HIV positive staff are at increased risk of TB and may require modi \201 cations to their work. A tuberculin or interferon-gamma negative HCW who declines BCG vaccination sho uld have the risks explained and supplemented by written advice, which should be signed by the individual. They should not work where there is a known risk of exposure to TB. Personal protective equipment HCWs caring for people with TB need not use PPE unless MDR-TB is suspected or aerosol or cough-inducing procedures are being performed. For the latter, \201 ltering respirator masks (FFP3) are required. Relevant legislation and guidance \200 TB is noti \201 able (to Local Authority Proper O f \201 cers) under the Health Protection (Noti \201 cation) Regulations 2010 Occupationally acquired TB is prescribed (B5) for Industrial Injuries Disablement Bene \201 t Additional information from Health Protection Agency and World Health Organization. See M http://www.hpa.org.uk/Topics/ InfectiousDiseases/InfectionsAZ/Tu berculosis/ and http://www.who.int/ topics/tuberculosis/en/ NICE guideline: NICE guideline: Clinical diagnosis and management of tuberculosis, and meas ures for its prevention and control. Available at: M http://guidance.nice.org.uk/CG117/Guid ance 06_Smedley_Chap06.indd 167 12/31/2012 8:50:43 PM CHAPTER 6 Occupational infections 168 Legionnaires \200\231 disease Legionnaires \200\231 disease is an uncommon bacterial infect ion caused by the bacterium Legionella pneumophila . The organism is found living naturally in environmental water sources. Epidemiology The majority of cases are sporadic (single), but outbreaks can occur. There ar e approximately 300 \200\223400 reported cases in England annually, of which 30 \200\22350% are acquired abroad. Clinical features \200 Incubation 2 \200\22319 days (median 6 \200\2237 days) \200 In \202 uenza-like illness with fatigue, myalgia, fever, headache, and dry cough Diarrhea and confusion \200 Atypical pneumonia. Causal exposures/industries Transmission is by inhalation of infected aerosols. In workplac es, L. pneu- mophila is found in air-conditioning units, cooling towers, and showers. Any o ccupation working in air-conditioned buildings might be affected. Occupational travelers wh o stay in hotels can be exposed to infected droplets in showers. Individual susceptibility \200 Age > 50yrs \200 Men are three times more likely than wo men to be affected \200 Smoking \200 Underlying chronic disease \200 Immunosuppressiv e treatment. Clinical assessment \200 Rapid urine antigen test \200 Culture of respiratory secretion s \200 Serology. Treatment and prognosis Treatment is with antibiotics, particularly erythromycin. Most case s recover, but 10 \200\22315% are fatal (higher in susceptible groups). Prevention Prevention is through treating water systems, and detailed speci \201 c guidanc e is available from HSE (see b p. 168, Relevant legislation and guidance). Relevant legislation and guidance \200 Legionnaires \200\231 disease is noti \201 able ( to Local Authority Proper Of \201 cers) under the Health Protection (Noti \201 cation) Regulations 2010 Legionellosis that is readily attributable to work is reportable to HSE under RIDDOR 06_Smedley_Chap06.indd 168 12/31/2012 8:50:43 PM LEGIONNAIRES \200\231 DISEASE 169 Legionnaires disease: The Control of Legionella Bacteria in Water Systems. Approved Code of Practice and Guidance. HSE, 2000. M http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1263812 807228 06_Smedley_Chap06.indd 169 12/31/2012 8:50:43 PM CHAPTER 6 Occupational infections 170 Tetanus Tetanus is caused by neurotoxin produced by Clostridium tetani , an anaero- bic spo re-forming bacillus. C. tetani is present in the GI tract of horses and other animals. It i s widespread in the environment, including soil, where it can survive for long periods. Tra nsmission from human to human does not occur. Epidemiology Tetanus infection in humans is rare. Up to 7 cases per year were noti- \201 ed in the UK between 2005 and 2010. The majority of cases are non- occupational. Clinical features \200 Localized muscle spasm \200 Generalized tetany (lockjaw). Causal exposures/industries Transmission is through non-intact skin following contamination with soil or other infected material. Outdoor workers who might sustain skin cuts or abras ions are at risk: \200 Forestry workers \200 Farm workers \200 Veterinary practitione rs. Clinical assessment Usually a clinical diagnosis, but the following con \201 rmatory tests may help: \200 Tetanus toxin in serum \200 Isolation of C. tetani from the wound \200 Tetanus toxin antibodies in serum. Treatment and prognosis \200 IV TIG \200 Wound debridement \200 Metronidazole \200 29% fatality rate. Prevention \200 Tetanus is preventable by immunization, for which there is a national program (in childhood). A reinforcing dose of vaccine is not likely to boost immunity suf \201 ciently quickly after a tetanus-prone wound. Therefore for high risk wounds, human TIG should be given irrespective of vaccination history. 1 Cover cuts and abrasions if working with soil or outdoors \200 Individuals who are expose d to tetanus organisms at work (e.g. in microbiology laboratories) must be protected by imm unization. 1 Department of Health Immunization against Infectious Disease (The Green Book). Available at: M http://www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/@dh/@en/documents/digita- lasset/dh_103982.pdf 06_Smedley_Chap06.indd 170 12/31/2012 8:50:43 PM TETANUS 171 Relevant legislation \200 Tetanus is noti \201 able (to Local Authority Proper Of \201 cers) under the Health Protection (Noti \201 cation) Regulations 2010 RIDDOR. Tetanus that is readily attributable to work is reportable to HSE under 06_Smedley_Chap06.indd 171 12/31/2012 8:50:44 PM CHAPTER 6 Occupational infections 172 Severe acute respiratory syndrome Epidemiology The \201 rst known case of severe acute re spiratory syndrome (SARS) occurred in Guangdong province, China, in November 2002 and was r ec- ognized as a global threat in March 2003. The aetiological agent, the SARS coronovirus (SARS-CoV) is believed to be an animal virus that crossed the species barrier to humans. By the end of the epidemic in July 2003, SARS CoV had resulted in 8098 SARS cases in 26 count ries, with 774 deaths. HCWs accounted for 1707 (21%) of the reported cases. Since then, the few sporadic cases have been mainly due to exposure in laboratories. During the epidemic f our probable cases of SARS were reported in the UK and the risk of infection in the UK rema ins very low. The possibility of SARS re-emergence remains and there is a need for continui ng vigilance. Clinical features SARS-CoV causes a spectrum of clinical illness from severe respiratory di sease to mild or atypical presentations. When transmission has occurred from a single point source, the incubation period has been 2 \200\22310 days. Symptoms include: \200 Fever (cid:3) 38 C \200 Cough, dif \201 culty in breathing, an d shortness of breath \200 Non-speci \201 c symptoms: malaise, headache, myalgia \200 Profuse watery diarrhea. Caution should be exercised in diagnosing non-speci \201 c viral pneumonia without detaile d inquiry to ascertain risk factors for SARS in the 10 days before the onset of the illness . Causal exposures/industries Transmission occurs through inhalation of droplets following cl ose per- son-to-person contact. At-risk occupations include: \200 HCWs in clinical contac t with SARS-CoV \200 Workers in laboratories where the virus is stored \200 Contacts in cluding those who have cared for, lived with, or had direct contact with the respiratory se cretions, body \202 uids, and/or excretions of cases of SARS Travelers to an area at risk of SARS-CoV transmission from animal reservoirs or a recent outbreak of SARS. Clinical assessment and diagnosis \200 For de \201 nitions of probable, con \201 rmed, and discarded cases of SARS see the British Thoracic Society website (M http://www.brit-tho racic. org.uk/guidelines/severe-acute-respiratory-syndrome-guideline.aspx) Specimens must only be sent for laboratory testing after the Communicable Disease Surveillance Center (CDSC) has been 06_Smedley_Chap06.indd 172 12/31/2012 8:50:44 PM SEVERE ACUTE RESPIRATORY SYNDROME 173 informed of the suspected case. All specimens should be double bagged and labeled as biohaz ard. Health surveillance \200 Maintain a list of all staff who have had contact with SARS-CoV \200 All staff should be vigilant for symptoms of SARS in the 10 days following exposure and should not come to work if they have a fever Inform CDSC of any contacts and their details to ensure follow-up. Risk controls in the health care industry Full infection control precautions, including use of personal protective equipment (gloves, gowns, and masks), should be instituted, and HCW s must strictly adhere to these. \200 The patient should be admitted to a designated isol ation unit in a negative pressure room Visitors should be kept to a minimum and all entrants to the isolation room must be logged Those who deliver clinical care must wear an FFP3 \200 Aerosol-generating procedures (neb ulizers, bronchoscopy) constitute a particular risk, and the minimum number of personnel sh ould be present when these are carried out. Contingency planning Guidance from the World Health Organization on contingency planning is available on M http://www.who.int/csr/sars/en/index.html Relevant legislation and guidance \200 SARS is noti \201 able (to Local Authority Proper Of \201 cers) under the Health Protection (Noti \201 cation) Regulations 2010 Detailed guidance, including advice on risk controls when managing a suspected case of SARS , is available on the HPA website. M http:// www.hpa.org.uk/infections/topics_az/SARS/Guide lines.htm 06_Smedley_Chap06.indd 173 12/31/2012 8:50:44 PM CHAPTER 6 Occupational infections 174 In \202 uenza In \202 uenza is a virus that is found in animals and humans. Many strains are recognized, and these tend to infect different species. An important char- acteristic o f the organism is the propensity to undergo minor or major changes in antigenic pro \201 l e (antigenic drift or shift, respectively). In \202 uenza is transmitted from human to hum an. Moreover, transmission between species has been described (although is still uncommon). Epidemiology Seasonal in \202 uenza In \202 uenza infection in the general population sho ws strong seasonal varia- tion with highest incidence in the winter (December \200\223March in the north- ern hemisphere). WHO \201 gures suggest that worldwide 7500,000 people die of in \202 uenza each year in non-pandemic years. In England, in \202 uenza activity is measured according to new GP consultations for in \202 uenza and in \202 uenza-like illne ss (ILI), and normal winter seasonal levels are 30 \200\223200 cases per 100 000 population per week . 1 A very small proportion of cases of seasonal in \202 uenza are acquired occu pationally. Epidemic in \202 uenza Normal seasonal activity crosses threshold (>200 new cases per 100 000 per week in England) into severe \200\230epidemic \200\231 activity unpredictably. Pandemic in \202 uenza Pandemics, with high rates of transmission worldwide, have occurred when new strains emerge which have high transmissibility against a background of absent he rd resistance. Previous pandemics in 1918 \200\2231919, 1957, and 1968 resulted in high glo bal mortality (40 \200\22350 million in 1918 \200\2231919), par- ticularly among susceptibl e groups. The H5N1 strain, which infects birds (avian in \202 uenza), has been transmitted to small numbers of humans, but has not transmitted easily between humans. The most recent pandemic in \202 uenza virus (H1N1 \200\230swine \202 u \200\231) emerged in Mexico in 2009. Swine \202 u was transmitted between humans, but in most cases the disease was mil d. Severe illness and death did occur in a small proportion of cases, particu- larly among pregnant women and young adults. There is currently global concern about the possibility of a future in \202 uenza pandemic and the UK has a preparedness strategy for this event. Clinical features \200 Fever >38 C \200 Headache \200 Myalgia \200 Severe malais e \200 Complications include pneumonia. 1 HPA. (2012). De \201 nitions and rates vary in Wales and Scotland because of different r eporting methods . Available at: M http://www.hpa.org.uk/infections/topics_az/in \202 uenz a/seasonal/uk_data_ sources.htm 06_Smedley_Chap06.indd 174 12/31/2012 8:50:44 PM INFLUENZA 175 Causal exposures/industries Most occupations do not have a greater risk than the general po pulation. The following groups are at increased risk: \200 HCWs who: look after infected patients \200 handle in \202 uenza organisms in the laboratory Teachers and care workers in institutions. Individual susceptibility The working age population is at increased risk if they have chro nic disease (e.g. diabetes mellitus, renal failure, cancer, chronic respiratory illness). Clinical assessment \200 Serology \200 Near patient test can be useful for instant diag nosis. Treatment and prognosis Treatment is with anti-viral agents (oseltamivir, zanamivir, or ama ntadine). 2 Prognosis varies according to the strain and the level of herd immunity. Prevention In \202 uenza immunization \200 The Chief Medical Of \201 cer has recommende d annual immunization against seasonal in \202 uenza for \201 t HCWs (i.e. in the absence of speci \201 c med ical indications). As well as protecting HCWs from occupational transmission, there is reas onable evidence that immunization reduces mortality in their elderly patients Many OH providers offer in \202 uenza immunization to staff outside the health care sector , even in the absence of increased occupational risk. This is usually justi \201 ed on the basis that it might reduce sickness absence, although the evidence base for this assumptio n is incomplete. Preventing exposure In the health care industry, exposure to staff is minimized by: \200 Wearing masks for close clinical contact \200 Observing infection control procedures \200 Wearing \201 ltering respirators, gowns, and goggles for aerosol- inducing procedures (bronchoscopy, post-mortems, intubation, chest physiotherapy, nebulizat ion). Pandemic planning OH professionals who provide services to health care or emergency service s ( \201 re, police, and ambulance) have a major role in advising about pandemic preparedn ess. Detailed guidance is given on the HPA website. Further information HPA (2012). In \202 uenza . Available at: M http://www.hpa.org.uk/Topi cs/ InfectiousDiseases/InfectionsAZ/In \202 uenza/ 2 NICE (2003). Flu prevention \200\224amantadine and oseltamivir (TA67) . Available at: M h ttp://www. nice.org.uk/page.aspx?o=86770 06_Smedley_Chap06.indd 175 12/31/2012 8:50:44 PM CHAPTER 6 Occupational infections 176 Anthrax Anthrax is a rare zoonosis caused by Bacillus anthracis , a spore-forming Gram + ve bacterium that can survive in soil for long periods. Epidemiology Anthrax occurs mainly in herbivores and is endemic in the Middle East, Africa, and Asia. It is transmitted to humans from infected animal products, but not human-to-huma n spread. Nineteen con \201 rmed cases were noti \201 ed in England and Wales 1981 \200 \2232009 (most were occupational). Since 2009 large outbreaks have occurred in drug users f rom infected heroin. Clinical features There are three clinical forms of anthrax; cutaneous anthrax is the most common. Occupationally acquired anthrax is usually cutaneous. Inhalational anthrax in non-e ndemic areas raises the possibility of bioterrorism. Cutaneous anthrax Skin lesion appears days or weeks after exposure, usually on the head, ne ck, arms, or hands. The lesion is surrounded by oedema and develops into a characteristic p ainless ulcer with a black center (eschar). Cutaneous anthrax can be complicated by septica emia. Gastrointestinal anthrax Acquired by consuming undercooked infected meat. Inhalational anthrax Much rarer than cutaneous anthrax but i mortality. Characterized by in \202 u- enza-like illness; onset up to 48h after exposure. Causal exposures/industries \200 Laboratory staff handling anthrax spores or infected mat erial \200 Workers handling infected hides, e.g. leather tanners \200 Workers handling infected animals, e.g. abbatoir workers, veterinary practitioners Postal workers (deliberate release) (see b p. 830, Biological weapons). Clinical assessment and diagnosis Suspected cases should be investigated in liaison with th e Special Pathogens Reference Unit (SPRU) 1 which offers diagnostic services for rare patho - genic organisms. Investigation includes: \200 Detailed exposure history \200 Serology \200 Blood cultures \200 Swab of lesion \202 uid for stain and culture \200 Biopsy lesion : polymerase chain reaction (PCR) for b. Anthracis DNA \200 Additionally, for inh alational anthrax, CXR, CT scan of thorax, LFTs. 1 M http://www.hpa.org.uk/ProductsServices/InfectiousDiseases/SpecialPathogensReferenceUnit / 06_Smedley_Chap06.indd 176 12/31/2012 8:50:44 PM ANTHRAX 177 Prognosis Untreated, 5 \200\22320% of cutaneous anthrax cases are fatal. Inhalational anthr ax is often fatal (775% despite optimal treatment). Prevention Inactivated acellular vaccine available from the HPA. Vaccination only offered t o occupational groups at i risk of exposure (laboratory staff handling spores/infected mate rial). Vaccine not indicated in the public unless exposed. Medical management Undertaken in liaison with the HPA Center for Infections. Cutaneous anth rax is treatable with oral antibiotics; cipro \202 oxacin is the drug of choice. Managemen t of inhalational anthrax is very specialized, involving IV cipro \202 oxacin plus two oth er antibiotics. Post-exposure prophylaxis Following exposure, antibiotic treatment vaccination is indica ted. \200 Antibiotics for 60 days: initial 3 days \200\224oral cipro \202 oxacin 500mg bd \200 remaining 57 days \200\224or al cipro \202 oxacin 500mg bd OR oral doxycycline 100mg bd Immunization: three doses at 0, 3, and 6wks after exposure \200 given with vaccine, duration of post-ex posure prophylaxis (PEP) antibiotics can be d to 4wks further doses at 6mths and 1yr, if continuing exposure \200 PEP not required for case \200\231s contacts unless exposed to original source. Compensation \200 In the UK anthrax is a prescribed disease (B1) for Industrial Injuries Disablement Bene \201 t in workers who have contact with anthrax spores, including contact with animals infected by anthrax, or those involved in handling, loading, unloading, or tr ansportation of a type susceptible to infection with anthrax or of the products or residues of such animals \200 HCWs are eligible for NHS Injury Bene \201 t if they contract anth rax at work and lose pay as a result. Relevant legislation \200 Anthrax is noti \201 able (to Local Authority Proper Of \201 cers) under the Health Protection (Noti \201 cation) Regulations 2010 Anthrax that is readily attributable to exposure to B. anthracis at work is noti \201 able to HSE under RIDDOR An exposure in the workplace would be noti \201 able to HSE under RIDDOR as a dangerous occurrence. Further information HPA (2012). Anthrax. Available at: M http://www.hpa.org.uk/infections/t opics_az/anthrax/menu.htm CDC. Emergency preparedness and response . Available at: M http:/ /www.bt.cdc.gov/agent/anthrax/faq/ HPA (2012). Deliberate and accidental release . Availabl e at: M http://www.hpa.org.uk/infections/ topics_az/deliberate_release/Anthrax/Homepage.asp ?Source=Professional&Agent=Anthrax&D ocument=Homepage 06_Smedley_Chap06.indd 177 12/31/2012 8:50:44 PM CHAPTER 6 Occupational infections 178 Glanders Glanders is a zoonotic infection, caused by the bacterium Burkholderia mallei . It is essentially a disease of equine species, including horses, don- keys, and mules. It is rarely found in dogs, cats, and goats. Epidemiology Glanders has been eradicated in the UK, but still occurs in Europe and the Far East. Clinical features The incubation period is 10 \200\22314 days, but long latency (up to 30yr s) has been described. Presentation depends on the route of infection, which can be through non-intact skin or mucous membranes, inhalation, and poten- tially ingestion. Once infecte d, it can affect any organ system. \200 Acute infection: skin infection, with ulceration and local lymphadenopathy \200 mucosal upper respiratory tract infection, with bloody nasal discharge pneumonia, with pleural effusion and lung abscess \200 septicaemia Chronic infection: with abscess formation in skin, muscle, liver, and spleen. Causal exposures/industries Glanders does not occur in the environment. It can only be acqu ired through prolonged contact with infected animals, although the infectivity of secretion s is extremely low. Realistically, the only occupational cases in the West are likely to be laboratory workers: \200 Laboratory workers handling B. mallei \200 Veterinary practit ioners \200 Horse handlers, grooms, and breeders. Treatment and prognosis Glanders can be treated with antibiotics. Historically, treatment w as with sulphonamides, but newer antibiotics including co-trimoxazole may be effective (the disease disappeared before these could be evaluated). Untreated, it is rapidly fatal in >9 0% of cases (particularly if acquired through the inhalational route). For this reason, it is a potential candidate for bioterrorism (see b p. 830, Biological weapons), although no i nci- dents have occurred to date. Prevention There is currently no vaccine for glanders. Compensation Glanders is a prescribed disease for Industrial Injuries Disablement Bene \201 t in workers who have contact with equine animals or their carcasses. Relevant legislation Glanders that is readily attributable to work would be reportable to H SE under RIDDOR. 06_Smedley_Chap06.indd 178 12/31/2012 8:50:45 PM This page intentionally left blank CHAPTER 6 Occupational infections 180 Leptospirosis Leptospirosis is a zoonotic disease caused by a spirochaete bacterium of the genus Leptospira . There are many different pathogenic varieties that use different animal hosts. Common carriers in the UK are rats ( L. ictohae- mhorrhagica ), cattle ( L. hardjo ) , and pigs. Person to person transfer is rare, if it occurs at all. Epidemiology Leptospirosis is uncommon. Between 28 and 81 cases per year have been noti \201 ed in the UK over the past 10yrs. Some of these are acquired during leisure activities or overseas. In 2010, 42 cases were noti \201 ed in the UK, including 10 of occupational origin. Clinical features \200 Incubation most commonly 7 \200\22314 days (range 2 \200\22330 day s) \200 Biphasic clinical illness. Acute bacteraemic phase Bacteria are disseminated to e very organ system. Characterized by in \202 uenza- like symptoms, headache, chills, and my algia. Most cases are mild and resolve without treatment, but rarely severe illness occurs (Weil \200\231s disease). Immune phase Follows acute phase in some cases. Recurrence of fever, associated with jaundi ce, conjunctivitis, abdominal pain, and rash. Can be complicated by multi-organ failure. Causal exposures/industries Transmission is by direct or indirect contact with infected ani mal urine or contaminated water. This usually occurs through intact mucous mem- branes or n on-intact skin: \200 Farm workers \200 Sewerage workers \200 Dog handlers \200 Abba toir workers \200 Veterinary practitioners. Clinical assessment and diagnosis Serological tests are available through the Leptospira Re ference Unit (LRU). 1 Treatment and prognosis Oral penicillin or doxycycline. IV antibiotics, and intensive suppo rt are required for severe cases. Prognosis is good if the diagnosis is made early and appr o- priate treatment started. Emergency and Intensive Care Units in rural areas should be aw are of the possibility of leptospirosis in febrile icteric illnesses. 1 HPA (2012). Leptospira Reference Unit (LRU). M http://www.hpa.org.uk/ProductsServices/ In fectiousDiseases/LaboratoriesAndReferenceFacilities/LeptospiraReferenceUnit/ 06_Smedley_Chap06.indd 180 12/31/2012 8:50:45 PM LEPTOSPIROSIS 181 Prevention \200 There is no vaccine for humans \200 Prophylactic doxycycline (200mg wee kly) can be given for high-risk occupational tasks Reduce rodent populations by avoiding garbage accumulation and culling Infected farm animals can be immunized and treated \200 PPE (especially waterproof gloves and footwear) for jobs that entail splashing or immersion in rivers, puddles, or sewage Advise workers of risk and symptoms; information cards are often used for this purpose Cover cuts and abrasions with waterproof dressings. Wash new cuts thoroughly if acquired near potentially contaminated water. Compensation Leptospirosis is prescribed (B3) for Industrial Injuries Disablement Bene \201 t for those who work in places which might be infested by rats, \201 eld mice, voles , or other small mammals, in dog kennels or the care or handling of dogs, or in contact wit h bovine animals or their meat products, or pigs or their meat products. Relevant legislation \200 Since 2010, leptospirosis is no longer noti \201 able under pu blic health legislation Leptospirosis that is reliably attributable to work is reportable to HSE under RIDDOR. 06_Smedley_Chap06.indd 181 12/31/2012 8:50:45 PM CHAPTER 6 Occupational infections 182 Streptococcus suis Strep. suis is a zoonotic infection, of which 35 subtypes have been identi- \201 ed. The organism is an important pathogen in pigs, but can occur in cattle and other animals. Epidemiology Transmission to humans is rare, but it is probably under-diagnosed. Only a few hundred human cases have been reported worldwide, and the annual incidence in England and Wales is around two cases. Clinical features Severe febrile illness, with systemic disease: \200 Meningitis \200 S epticaemia \200 Endocarditis \200 Deafness. Causal exposures/industries Transmission is through non-intact skin from infected pig produ cts, although overall the risk of infection is low. There have been no reported cases of tr ansmission through inhalation: \200 Abbatoir workers \200 Butchers \200 Farmers \200 Veterinary practitioners. Individual susceptibility Immunosuppressed (particularly asplenic) individuals are at incre ased risk. Medical management Penicillin is the treatment of choice. Prevention \200 There is no human vaccine \200 The mainstay of prevention is good hygie ne practice in slaughterhouses and butchers. Thorough washing of hands and arms before and after touching pig products is essential Exposed workers must be educated about hygiene, and should report suspicious symptoms (febr ile illness) immediately, declaring their exposure to the treating doctor. Compensation Strep. suis is a prescribed disease (B9) for Industrial Injuries Disablement B ene \201 t among those who are in contact with pigs infected by Strep . suis , or with inf ected carcasses, pig products, or residues. 06_Smedley_Chap06.indd 182 12/31/2012 8:50:45 PM STREPTOCOCCUS SUIS 183 Relevant legislation \200 Strep. suis is not reportable under public health legislation \200 Strep. suis that is readily attributable to work is reportable to HSE under RIDDOR. Further information and guidance HSE (2008). Common zoonoses in agriculture . Agriculture I nformation Sheet No.2 (rev). Available at: M http://www.hse.gov.uk/pubns/ais2.pdf 06_Smedley_Chap06.indd 183 12/31/2012 8:50:45 PM CHAPTER 6 Occupational infections 184 Brucellosis A group of zoonoses caused by the bacterial species Brucella : \200 B. melite nsis : sheep and goats \200 B. abortus : cattle \200 B. suis : pigs. The main source of non-occupational brucellosis is unpasteurized milk products. Epidemiolog y Brucellosis is rare in the UK. The 10 cases per year seen in the UK are almost always acq uired abroad (the disease is still endemic in Africa, the Middle East, Asia, and South Amer ica). There is likely to be under-report- ing of laboratory \200\223acquired occupational infection. Clinical features \200 2 \200\2238wks incubation \200 Non-speci \201 c ILI: fever and malaise \200 arthralgia \200 can affect any organ system.