05_Smedley_Chap05.indd 140 12/31/2012 8:48:36 PM SHIFT AND NIGHT WORK 141 Risk control Employees should \200 Drink coffee in the \201 rst half of the shift only \200 Take s hort \200\230power naps \200\231 \200 Take small breaks at least every hour \200 Take a main meal break between midnight and 01.00 hours \200 Take a smaller food break between 03.00 and 04.00 hours \200 Be aware of subjective feelings of inertia for 15min after wa king \200 Avoid driving to and from work after prolonged periods of night shifts Eat healthily and keep \201 t/active \200 Design and de \201 ne their own shifts whene ver possible \200 Take up \202 exible working if possible \200 Advice is available fo r shift workers on how to cope with the demands of night working. The HSE offers tips on dealing with sleep problems, eating, physi cal \201 tness, and social contact. (http://www. hse.gov.uk/humanfactors/topics/shift-wor kers.htm). Employers should \200 Minimize permanent nights \200 Ensure safe travel to and from wor k at unusual hours \200 Limit consecutive night shifts to no more than four \200 If pos sible allow 24h between two night shifts \200 Some weekends should be completely free of night shifts \200 Consider making night shifts shorter than day shifts \200 Avoid compr essed working periods \200 The length of night shifts should be related to the tasks perf ormed \200 Forward rotation of shifts is preferable to continuous night shifts \200 Mor ning shifts should start later rather than sooner \200 Rotas should be as regular as poss ible \200 Allow opportunities to swap shifts and change handover times \200 Avoid exces sive short-term rota changes \200 Good notice should be given of changes in shift pattern s \200 Allow return to day work without penalty (especially older workers) \200 Ensure availability of hot food and drinks, rest areas, and \201 rst aid \200 Night workers ne ed the same access to training as other workers \200 Allow access to union representation or daytime meetings \200 Offer access to health checks for night workers. 2 The ability to cope with changed sleep patterns varies considerably and should be conside red when selecting night workers. Relevant legislation Workers who normally work at night ( excluding those who only occasion- ally work nights) are protected under the Working Time R egulations (see b p. 574, Working Time Regulations 1998). This includes provision of health checks for night workers. 05_Smedley_Chap05.indd 141 12/31/2012 8:48:36 PM CHAPTER 5 Psychosocial hazards 142 Long working hours De \201 nition \200\230Long-hours \200\231 workers are those who work >48h/wk. Epidemiology \200 The average length of the European working week is decreasing. In the European member states, it has fallen from 40.5h in 1991 to 37.5h in 2010 The proportion of the working population in Europe working longer than 48h has fallen from 15% in 2000 to 12% in 2010 Long working hours are more common in men than women. Health effects \200 Generalized fatigue, both physical and psychological \200 Anxiety/d epression. Effects on function \200 Poor performance \200 i Risk of accident or injury: exponential increase with long hours \200\224by the twelfth hour of work risk is double that during the \201 rst 8h not taking a regular break linearly i the risk of injury \200\224the risk of injury 1.5h a fter taking a break is twice that when resuming work immediately after the break. Risk factors A number of factors increase the likelihood of adverse effects from work- ing longer hours: \200 Female sex \200 Older age \200 Poor diet \200 Little exercise \200 Pre-existing poor health: examples of medical conditions that may be adversely affect ed include asthma, depression, and diabetes. These need to be considered before selecting i ndividuals for long working hours duties (although they are not an absolute contraindicatio n to long hours) Complex or demanding domestic situation. Relevant legislation The European Working Time Directive enforces standards on working time (see b p. 574, Working Time Regulations 1998). Further information and guidance European Foundations for the Improvement of Living and Wor king Conditions. (2010). Changes over time \200\224First \201 ndings from the \201 fth European Working Conditions Survey . Available at: M http:// www.eurofound.europa.eu/pubdoc s/2010/74/en/3/EF1074EN.pdf 05_Smedley_Chap05.indd 142 12/31/2012 8:48:36 PM This page intentionally left blank CHAPTER 5 Psychosocial hazards 144 Time zone changes Crossing time zones is commonly associated with jobs that require frequen t international travel. Health effects Transmeridian displacement, or dysrhythmia (jet lag) is a disturbance of the internal circadian rhythm (body clock) caused by crossing inter- national time zones. Cros sing time zones when traveling east (traveling back in time) is usually worse than when tra veling west (forward in time). Symptoms include: \200 Tiredness \200 Disorientation \200 Lack of concentration \200 Broken sleeping/night wakefulness \200 Cognitive impai rment \200 Irritability \200 GI upset. Epidemiology of health effects The impact of jet lag upon long-haul travelers is particular ly high, with approximately 90 \200\22394% of travelers feeling some \200\223 ve effects a fter \202 ying. Some surveys have shown that 96% of experienced \202 ight attendants co n- tinue to feel jet-lagged after long-haul \202 ights. Risk factors \200 Number of tim e zones crossed ( (cid:3) \201 ve time zones greatly i risk) \200 Cabin pressure \200 Being a person of \200\230set routine \200\231 \200 Pre- \202 ight condition (e.g. tir edness, stressed, nervous, drunk/hung-over) \200 Caffeine, alcohol, fruit juice \200 De hydration \200 Poor fresh air supply \200 Limited movement/stretching \200 Flying at night time \200 Older age. Risk control There are a number of preventive measures that travelers can take. Pre- \202 ight \200 Ensure a good night \200\231s sleep before travel \200 Be calm \200 Exercise the day before the \202 ight. Flight factors \200 Direction of \202 ig ht (if possible) \200\224may be a personal preference \200 Daytime \202 ights preferabl e to night time \202 ights. 05_Smedley_Chap05.indd 144 12/31/2012 8:48:36 PM TIME ZONE CHANGES 145 In- \202 ight behavior \200 Drink plenty of water or other non-alcoholic \202 uids \200 Using sleeping aids: pillows, neck-rests, blindfolds, earplugs \200 Remove footwear \200 Exercise as much as possible \200 Take walks at stop-overs if possible \200 Sho wer if available (refreshing, and activates muscles and circulation). Management Some resea rch suggests that phototherapy and bright-light therapy can be useful in speeding up the ci rcadian adaptation in those who are suffering ill effects. The ef \201 cacy of melatonin i s uncertain. 05_Smedley_Chap05.indd 145 12/31/2012 8:48:36 PM This page intentionally left blank Section 2 Occupational diseases 6 Occupational infections 7 Respiratory and cardiovascular disorders 8 Skin disorders 9 Mus culoskeletal disorders 10 Gastrointestinal and urinary tract disorders 11 Eye disorders 12 Neurological disorders 13 Psychiatric disorders 14 Reproductive disorders 15 Hematological disorders 16 Medically unexplained occupational disorders 149 197 241 253 263 277 287 305 317 323 331 06_Smedley_Chap06.indd 147 12/31/2012 8:50:41 PM This page intentionally left blank 149 Chapter 6 Occupational infections Blood-borne viruses 150 Hepatitis B 152 Hepatitis C 154 Human immunode \201 ciency virus 1 56 Viral haemorrhagic fevers 158 Variant Creutzfeldt \200\223Jakob disease 160 Bovine spong iform encephalopathy 162 Meningococcal infection 164 Tuberculosis 166 Legionnaires \200\231 disease 168 Tetanus 170 Severe acute respiratory syndrome 172 In \202 uenza 174 Anthrax 1 76 Glanders 178 Leptospirosis 180 Streptococcus suis 182 Brucellosis 184 Lyme disease 186 C hlamydia infections 188 Q fever 190 Enteric zoonoses 192 Zoonotic skin infections 194 06_Smedley_Chap06.indd 149 12/31/2012 8:50:41 PM CHAPTER 6 Occupational infections 150 Blood-borne viruses An important group of occupational infections characterized by their bl ood-borne route of transmission. The most common examples are: \200 HBV \200 HCV \200 HIV. Others include: \200 HDV \200 Viral haemorrhagic fevers (VHF). Sources of exposure/industries Transmission can occur after exposure to infected biological material (see b p. 816, Management of needlestick and contamination incidents). Epidemiology 3773 signi \201 cant occupational exposures to infected blood and body \202 uids were reported to the Health Protection Agency surveillance scheme dur- ing 1996 \200 \2232007. Among these were 15 seroconversions (12 HCV, 1 HIV, and 2 co-infections). Factors affecting exposure and risk assessment The risk of transmission is determined by: \200 Details of incident including body \202 uid involved and exposure route \200 Sour ce patient infectivity. Risk assessment is described in detail in b p. 816, Management of n eedle- stick and contamination incidents. Biological material associated with transmission of BBV \200 Blood \200 Blood-stained \202 uid \200 Pleural \202 uid \200 Pericardial \202 uid \200 Peritoneal \202 uid \200 Cerebrospinal \202 uid Synovial \202 uid \200 Amniotic \202 uid \200 Breast milk \200 Semen \200 Vagin al secretions \200 Un \201 xed tissues and organs Health effects These are described separately for each virus HBV, HCV, HIV, VHF (see b p. 1 52, Hepatitis B; b p. 154, Hepatitis C; b p. 156, Human immuno- de \201 ciency virus; b p. 158, Viral haemorrhagic virus). Risk controls \200 Reduce exposure to infected blood and body \202 uids by adherence to standard infection control precautions, e.g. hand hygiene, use of PPE 06_Smedley_Chap06.indd 150 12/31/2012 8:50:41 PM BLOOD-BORNE VIRUSES 151 Occupations at risk from BBV \200 HCWs, in particular : * There is a lower, but signi \201 cant, risk among: \200 Embalmers \200 Crematorium wor kers \200 Cleaners \200 Police \200 Prison workers \200 Social workers \200 Milit ary personnel \200 Sewage workers \200 Fire \201 ghters surgeons \200 theater nurses \200 dentists \200 midwives \200 anesthetists \200 d ialysis technicians \200 ambulance technicians \200 mortuary technicians \200 laborat ory workers \200 chiropodists \200 acupuncture practitioners This list is not intended to be exhaustive Gloves should be worn for any procedures that involve a risk of contamination with infected material. Double gloves are recommended where surgical procedures are performed on patient s known to be infected with BBV Aprons, goggles, and mask required where there is a risk of splashing \200 Other risk con trols include: use of safer sharps devices \200 avoidance of re-sheathing needles \200 correct disposa l of sharps \200 correct disposal of infected waste \200 correct transportation of spec imens Immunization against HBV \200 Prompt management of sharps and contamination incidents in the workplace. Speci \201 c guidance \200 Guidance for Clinical Health Care Workers: Protection Against Infection with Blood-borne viruses. Recommendations of the Expert Advisory Group on AIDS an d The Advisory Group on Hepatitis. M http://www.dh.gov.uk/en/Publicationsandstatistics/Lett ersandcirculars/ Healthservicecirculars/DH_4003818/ Guidance on risk controls in hospitals and laboratory environments is published by the HSE Health Services Advisory Committee (HSAC) and Advisory Committee on Dangerous Pathogens (AC DP). M http:// www.hse.gov.uk/biosafety/biologagents.pdf Further information M http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/Bloodbor neVirusesAndOccupational Exposure/ M http://www.hse.gov.uk/biosafety/diseases/blood-borne-virus.htm HPA (2008). Eye of the nee dle: UK surveillance of signi \201 cant occupational exposure to blood-borne viruses in he althcare workers. Available at: M http://www.hpa.org.uk/webc/HPAwebFile/ HPAweb_C/122768812 8096 06_Smedley_Chap06.indd 151 12/31/2012 8:50:42 PM CHAPTER 6 Occupational infections 152 Hepatitis B Epidemiology \200 HBV is a DNA virus \200 350 million people worldwide are chronically infected \200 Endemic in many developing countries, where it affects up to 10 % of the population; acquired mainly in childhood The epidemiology in westernized countries is quite different. In the UK, the prevalence of chronic HBV is 0.3%. Infection occurs mainly in young adulthood follo wing sexual contact or intravenous drug misuse \200 Occupational transmission to HCWs is well documented historically, but the incidence has reduced since the availability of vacci nation. Among 296 occupational exposures to HBV reported to the HPA surveillance scheme 199 6 \200\2232007, there were no HBV seroconversions. Clinical features \200 Incubation period 40 \200\223160 days \200 Acute illness: malais e, fatigue, in \202 uenza-like symptoms, myalgia, nausea, vomiting, abdominal pain, and jaundice. About 30% of cases are asymptomatic Most patients clear the infection spontaneously \200 2 \200\22310% develops chronic carri age. Causal exposures/industries See b p. 105. Clinical assessment and diagnosis In the occupational setting, cases of HBV infection are u sually diagnosed: \200 When a HCW fails to respond to hepatitis B vaccine \200 Followin g pre-employment assessment of \201 tness for exposure prone procedures (EPPs) Rarely, infection might be detected following an exposure incident. The main focus of investigation is to establish the degree of infectivity in order to asses s the risk of transmission in the work setting. The OH professional should facilitate refer ral of active cases to a hepatologist for clinical management (if this has not already been done). Serological mark- ers for HBV infection are shown in Table 6.1. Medical management and prognosis \200 HBV is treatable with interferon-alpha, leading to reversal of the carrier state in 40% of cases Untreated, 20 \200\22325% of chronic cases infected as adults will develop chronic liver disease, of whom 15 \200\22325% will die. Prevention \200 HBV is preventable by immunization: 1 recombinant vaccines provide protection in >90% of recipients 1 Department of Health (2009). Hepatitis B. In: Immunization against infectious disease Available at: M http://www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/@dh/@en/documen ts/ digitalasset/dh_108820.pdf 06_Smedley_Chap06.indd 152 12/31/2012 8:50:42 PM HEPATITIS B 153 Table 6.1 HBV serology Serological markers Interpretation Anti-HBc (core antibody) +ve and HbsAg (surface antigen) +ve Current infection or infectious carrier Anti-HBc +ve, HbsAg +ve and HBeAg (e antigen) +ve Current infection or infectious carrier with particularly high infectivity Anti-HBc +ve and HBsAg \200\223ve Previous infection with natural immunity and non-infectious non-response to vaccine is associated with age >40yrs and immune suppression following immunization surface antibody levels (anti-Hbs) >100IU/L are protective, but thos e at continuing risk of occupational exposure should have a single booster dose after 5yrs. Poor responders (10 \200\223100IU/L) require an immediate booster and a reinforcing dose a t 5yrs. Non-responders (<10IU/L) should be tested for previous HBV infection, and if negati ve receive a second course Reduce exposure (see b p. 150, Blood-borne viruses, Risk controls). Fitness for work Modi \201 cations to work are required to prevent occupational transmissi on. This is usually only required in the health care setting. Exposure prone procedures may only be carried out by infectious carriers of HBV under speci \201 cally de \201 ned cir cumstances and with appropriate ongoing monitor- ing of viral load (see b p. 150, Blood-bor ne viruses). Compensation \200 Viral hepatitis (including HBV) is a prescribed disease (B8) for Industrial Injuries Disablement Bene \201 t among those who have worked with human blood o r blood products, or a source of viral hepatitis \200 NHS Injury Bene \201 t (both tempo rary and permanent) would be payable to an NHS employee who lost remuneration because of HB V infection attributable to his or her NHS employment. Relevant legislation \200 HBV infection that is acquired occupationally (new case exposed to human blood or human blood products, or any source of HBV at work) is reportable to HSE under RIDDOR 1995 Acute infectious hepatitis is noti \201 able (to Local Authority Proper Of \201 cers) under the Health Protection (Noti \201 cation) Regulations 2010. Further information M http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/Hepatiti sB/ 06_Smedley_Chap06.indd 153 12/31/2012 8:50:42 PM CHAPTER 6 Occupational infections 154 Hepatitis C Epidemiology \200 HCV is an RNA virus \200 It is estimated that 170 million people worldwide are chronically infected (3% of the world \200\231s population) Prevalence rate for chronic HCV infection in England is estimated at 0.4% Most common in men, 25 \200\22344yr age group \200 In the UK, >90% of cases are caused by intravenous drug use and 5% by blood transfusion or exposure to blood products. In contras t with other blood-borne viruses, sexual transmission is rare (2% of cases) \200 Fewer th an 1% of cases are acquired occupationally. Twelve cases of occupationally acquired HCV have been reported in the UK during the period 1996 \200\223200 7. 1 Clinical features \200 Incubation period of 6 \200\2239wks \200 Acute illness mild (mal aise and jaundice) \200 2 80% asymptomatic. \200 2 Only 20 \200\22340% of cases clear t he virus spontaneously after acute infection. 2 80% go on to develop chronic infection. Clinical assessment and diagnosis \200 HCV antibodies (anti-HCV) are usually detectable 3 mths after infection, but rarely may take up to 6mths to develop. The presence of anti-HCV indicates w hether an individual has been infected, but does not distinguish between active and previou s infection In the occupational setting, assessment of infectivity, on which advice about the likelihoo d of transmission to others is based, includes quantitative assessment of viral load (HCV R NA) New occupational cases should be referred to a hepatologist for clinical assessment (liver function tests (LFTs) liver biopsy) and treatment. Prognosis \200 Untreated, most chronic cases have a normal life expectancy \200 5 \200 \22320% of chronic cases develop liver cirrhosis over 20yrs, and a small proportion of these develop liver cancer Risk factors for more rapid progression to severe liver disease (once infected) include >40 yr age group, male gender, alcohol consumption, co-infection with HIV or HBV, and immunosup pression Combination antiviral therapy is successful in clearing HCV in around 50% of cases (range 45 \200\22380% depending on genotype). 1 HPA (2008). Eye of the needle \200\224UK surveillance of signi \201 cant occupational ex posure to blood- borne viruses in health care workers. 2008 Health Protection Agency. Avail able at: M http://www. hpa.org.uk/webc/HPAwebFile/HPAweb_C/1227688128096 06_Smedley_Chap06.indd 154 12/31/2012 8:50:42 PM HEPATITIS C 155 Prevention There is no vaccine or post-exposure prophylaxis for HCV. The mainstay of preven tion is avoiding exposure (see b p. 150, Blood-borne disease, Risk controls). Medical management \200 Treatment of chronic HCV infection is indicated for moderate to severe disease NICE guidelines recommend pegylated interferon-alpha (weekly subcutaneous injection) in combination with ribavirin (daily oral dose). Fitness for work Modi \201 cations to work are required to prevent occupational transmissi on. This is usually only required in the health care setting, where exposure prone procedur es should not be carried out by infectious carriers of HCV (see b p. 494, Fitness for expos ure prone procedures). Compensation \200 Viral hepatitis (including HCV) is a prescribed disease (B8) for Industrial Injuries Disablement Bene \201 t in occupations exposed to human blood and body \202 uids HCWs who acquire HCV infection occupationally, and lose remuneration as a result, are eligible for Temporary and Permanent NHS Injury Bene \201 t. Relevant legislation and bene \201 ts \200 HCV infection that is acquired occupationally (new case exposed to human blood or human blood products, or any source of HCV at work) is reportable to HSE under RIDDOR 1995 Acute infectious hepatitis is noti \201 able (to Local Authority Proper Of \201 cers) under the Health Protection (noti \201 cation) Regulations 2010. Further information HPA (2012). Hepatitis C. Available at: M http://www.hpa.org.uk/Topics/ InfectiousDiseases/InfectionsAZ/HepatitisC/ 06_Smedley_Chap06.indd 155 12/31/2012 8:50:42 PM CHAPTER 6 Occupational infections 156 Human immunode \201 ciency virus Epidemiology \200 HIV is an RNA virus \200 Worldwide (2009) 33.3 million people are infected with HIV \200 In the UK (2009) 86 500 adults have HIV, of which a fourth are unaware of their infection >90% of HIV infection is sexually acquired; 2% is associated with injecting drug use Occupationally acquired HIV is rare (see Table 6.2). Five de \201 nite cases have been recorded historically in the UK. However, only one new case of de \201 nite occu pational transmission was documented in the UK between 1996 and 1999, and no new cases have occurred between 1999 and 2007. 1 Clinical features \200 Seroconversion illness: mild non-speci \201 c in \202 uenza-like symptoms and lymphandenopathy 2 \200\2234wks after infection Long asymptomatic phase (years) with gradually increasing immune suppression Acquired immune de \201 ciency syndrome (AIDS) characterized by opportunistic infections. Causal exposures/industries Healthcare work \200 Nurses and laboratory workers \200 Sur geons \200 Other doctors. Clinical assessment and diagnosis \200 Following acute infect ion HIV antibodies become positive \200 The degree of immune suppression is assessed by m easurement of CD4 count (normal range 500 \200\2231500 \227 10 6 cells/mm 3 ): \200 bacterial infectio ns, candida and mycobacterial infections arise when CD4 <500 (symptomatic phase) AIDS is associated with CD4 <200 \227 10 6 cells/mm 3 , and infection with (e.g.) pneumocystis, toxoplasma, cryptosporidia. Infectivity is measured by HIV RNA viral load. Early in the illness, viral load can be seve ral million copies/mL. This stabilizes during the chronic phase. HIV RNA is the best indica tor of overall prognosis. Medical management and prognosis The advent of anti-retroviral therapy (ART) in HIV-positiv e patients has improved the prognosis of HIV infection dramatically. Current triple drug re gimes (ART, and highly active ART (HAART)) aim to reduce viral load below detectable levels in the chronic phase. This is a rapidly changing \201 eld, with frequent introduction of new agents and combination regimens. 1 HPA (2008). Eye of the needle \200\224UK surveillance of signi \201 cant occupational ex posure to blood- borne viruses in health care workers. Available at: M http://www.hpa.org.u k/webc/HPAwebFile/ HPAweb_C/1227688128096 06_Smedley_Chap06.indd 156 12/31/2012 8:50:42 PM HUMAN IMMUNODEFICIENCY VIRUS 157 Table 6.2 Occupationally acquired HIV Location Documented HIV seroconversion after occupational exposure Possible occupational transmissions of HIV Worldwide 106 238 UK 5 14 Data (up to 2002) collated by Health Protection Agency. Fitness for work in HIV-infected employees Modi \201 cations to work are sometimes appropr iate: \200 To prevent occupational transmission to others: only important in a small number of special circumstances. HIV is not spread through casual contact at work HIV-positive HCWs must not undertake exposure prone procedures (see b p. 494, Fitness for exposure prone procedures 1) To accommodate impairment in function: usually only necessary in the late symptomatic stages (AIDS) \200 most HIV +ve employees in the clinical latent phase can work normally. Adjustments to work in AIDS \200 If fatigue is a problem: part-time or \202 exible work , or d physical work \200 Restrict from activities where exposure to infection is a risk, e.g. care of patients who are sputum-positive for multi-drug-resistant TB \200 HIV-posit ive employees should not be given live vaccines (including bacillus Calmette \200\223Gu rin (BCG)), but can be immunized with recombinant or killed vaccines. Compensation \200 HIV is not a prescribed disease, but HIV acquired through discrete acci dental exposure at work might be eligible as an industrial injury HCWs who acquire HIV infection occupationally, and lose remuneration as a result, are eligible for Temporary and Permanent NHS Injury Bene \201 t. Relevant legislation HIV infection that is acquired occupationally (new case exposed to hum an blood or human blood products, or any source of HIV at work) is reportable to HSE under RIDDOR 1995. Further information Department of Health. Sexual health and HIV . Available at: M http://ww w.dh.gov.uk/ PolicyAndGuidance/HealthAndSocialCareTopics/HIV/fs/en HPA (2012). HIV. Available at: M http://www.hpa.org.uk/Topics/InfectiousDiseases/Infections AZ/HIV/ 06_Smedley_Chap06.indd 157 12/31/2012 8:50:42 PM CHAPTER 6 Occupational infections 158 Viral haemorrhagic fevers The viral haemorrhagic fevers are a group of zoonotic infections caused by various families of viruses. They are all transmitted from primary wild ani- mal hosts, none of which are natural residents in the UK. The diseases vary in severity and cli nical picture. However, a number of VHFs are important in occupational medicine because of the following key features: \200 High transmissibility from human to human \200 High ca se fatality rate \200 Dif \201 culty in diagnosis in the early stages. Disease \200 Lassa fever \200 Marburg virus \200 Ebola virus \200 Crimean/Congo hae morrhagic fever (CCHF) There are many more VHFs, but these are the most important with resp ect to occupational transmission. Virus family \200 Arenavirus \200 Filovirus \200 Filovirus \200 Bunyavirus Epidemiology \200 These diseases are endemic in parts of Africa, South America, and Asia. Primary cases in the UK are exceedingly rare, and can only arise from imported animal s or laboratory sources There have been eight cases of imported (i.e. acquired abroad) Lassa fever in the UK between 1980 and 2010. No cases of Ebola or Marburg virus had been imported to the UK up to 2010 There have been no cases of transmission to HCWs in the UK \200 One case of Ebola virus a nd two cases of Marburg virus infection in the UK have resulted from laboratory accidents. Clinical features Some cases are mild or subclinical. The hallmarks of severe infection are : \200 Fever \200 Multi-system failure \200 Bleeding in the terminal stages. Causal exposures/industries \200 Transmission in the UK is usually secondary (human to hu man rather than animal host to human). Infection occurs through exposure to blood and body \202 uids, and transmission to HCWs is well described in West Africa There is no evidence of transmission through the respiratory route \200 VHFs have potenti al to be used in bioterrorism. 1 1 Health Protection Agency (2012). Deliberate and accidental releases. Available at: M http :// www.hpa.org.uk/infections/topics_az/deliberate_release/VHF/Homepage.asp?Source=Professi onal &Agent=VHF&Document=Homepage 06_Smedley_Chap06.indd 158 12/31/2012 8:50:42 PM VIRAL HAEMORRHAGIC FEVERS 159 At-risk occupations include: \200 Clinical HCWs caring for infected cases \200 Laborato ry workers handling viral material \200 Mortuary staff handling infected bodies. Clinical management and prognosis Management is very specialized, and suspected cases must be noti \201 ed and isolated in a high-security infectious diseases unit. Treatment is wit h the antiviral agent ribavirin. The overall fatality of Lassa fever is 1%, although 15 \200\22320% of those who are hospitalized will die. 2 There is no evidence to support the u se of ribavirin as post-exposure prophylaxis. Prevention \200 Specialized guidance is available from the Advisory Committee on Dangerous Pathogens covering: \200 risk assessment \200 isolation facilities \200 con tainment requirements \200 handling infected bodies \200 handling specimens \200 labo ratory facilities There is no vaccine for VHFs. Relevant legislation \200 VHFs are noti \201 able (to Local Authority Proper Of \201 ce rs) under the Health Protection (Noti \201 cation) Regulations 2010 VHFs that are reliably attributable to occupation are reportable under RIDDOR An incident or accident that resulted in exposure to VHFs at work would be reportable as a dangerous occurrence under RIDDOR. Further information and guidance Health Protection Agency (2012). Viral haemorrhagic fever. Available at: M http://www.hpa.org.uk/ infections/topics_az/VHF/menu.htm Center for Disease Control guidance (2011). Viral hemorrhagic fevers. Available at: M http: //www. cdc.gov/ncidod/dvrd/spb/mnpages/dispages/vhf.htm 06_Smedley_Chap06.indd 159 12/31/2012 8:50:42 PM CHAPTER 6 Occupational infections 160 Variant Creutzfeldt \200\223Jakob disease Epidemiology Approximately 85% cases of Creutzfel t-Jakob Disease (CJD) are sporadic with no known cause and 10 \200\22315% of cases are inhe rited. Variant CJD (vCJD) was \201 rst identi \201 ed in 1996. It has affected younger p atients (mean age 27yrs vs. 65yrs), with a longer course (median of 14 vs. 4.5mths). The ep idemic of vCJD peaked in mid-2000. It is strongly linked to exposure, probably through food , to a transmissible spongiform encephalopathy (TSE) of cattle called bovine spongiform enc ephalopathy (BSE). There is compelling scienti \201 c evidence that BSE and vCJD are cause d by the same infectious agent, suggesting that BSE in cattle is the source of the human di sease. All TSEs are caused by infectious proteins called prions. Clinical features \200 Initially psychiatric or behavioral symptoms: predominantly depression \200 less often, a schizophrenia-like psychosis Unusual sensory symptoms, such as \200\230stickiness \200\231 of the skin \200 Unsteadin ess, dif \201 culty walking, and involuntary movements \200 By the time of death, patien ts become completely immobile and mute. Causal exposures/industries There is a theoretical risk of transmission through occupationa l exposure to infected tissues. Occupations at risk include: \200 Abbatoir workers \200 Mortuary workers, neurosurgeons, and neuropathologists \200 3 No occupationally acquired infections have been reported \200 3 There are no reported cases of transmission to huma ns as a result of a surgical or dental procedure. Clinical assessment and diagnosis \200 The clinical presentation, progressive nature of t he disease, and failure to \201 nd any other diagnosis are the hallmarks of vCJD \200 Magnetic resonance imagin g (MRI) brain scan may show a characteristic abnormality in the posterior thalamic region (pulvinar sign) Tonsillar biopsy and cerebrospinal \202 uid tests may be helpful \200 The brainwave pat tern observed on electroencephalogram is usually abnormal, but waveforms characteristic of sporadic CJD do not occur 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