Ira B. Fishman, M.D., Q.M.E. Board Certified, Internal Medicine Multiple QME evaluation offices

1. A Medical Legal Primer of Infectious Diseases in the Workplace Abscess to ZoonosisCAAA, San Francisco, June 28, 2012 Ira B. Fishman, M.D., Q.M.E. Board Certified, Internal Medicine Multiple QME evaluation offices Los Angeles, San Diego, El Centro

2. HEPATITIS B • Disease: Caused by the hepatitis B (HBV) virus. In general, clinical picture of any viral hepatitis is extremely variable, ranging from asymptomatic infection without jaundice to a fulminating disease and death in a few days. • Progression: Chronic hepatitis B develops in only 1-2% of immunocompetent adults with acute hepatitic B but in a substantial higher portion of immunocompromised adults

3. HEPATITIS B • Viral Disease Markers: • HbsAg: Hepatitis B surface antigen first evidence of infection; persistence>6 months indicates chronic hepatitis B. • Anti-HBs: Specific antibody to HbsAg. Appears in most individuals after HbsAg has cleared but also after hepatitis B vaccination. • Anti-HBc: Present during acute hepatitis B. • HBeAg: Secretory form of HBcAg indicates viral replication and infectivity; if persistent after 3 months, chronic hepatitis likely. • HBV DNA: Most sensitive and precise marker of viral replication and infectivity.

4. HEPATITIS B • Epidemiology: Groups at risk • Men who have sex with men • Injection drug users and prisoners • Those with history of sexually transmitted disease • Doctors, dentists and nurses • Patients and staff at hemodialysis centers • Laboratory and blood bank staff

5. HEPATITIS C • Disease: Caused by the hepatitis C (HCV) virus. In general, clinical picture is often mild and usually asymptomatic. • Progression: Chronic hepatitis C develops in greater than 80% of immunocompetent adults with acute hepatitic C. • Chronic hepatitis C progresses very slowly in non alcohol drinkers. • Cirrhosis still develops in up to 30%. Coinfections increase risk and there is also risk of liver cancer.

6. HEPATITIS C • Viral disease markers • Genotypes 1,2, 3 with different response to treatment • Anti-HCV: Antibody to HCV • HCV RNA (PCR): Marker for viral particles in blood • ALT: Alanine aminotransferase, a liver enzyme that is a marker of liver inflammation when increased

7. HEPATITIS C • Epidemiology: Those at risk • Injection drug use and incarceration • Body piercing, tattoos and hemodialysis • Multiple sex partners • Remote history blood transfusion (before 1990) • Inadequate disinfection endoscopy equipment • Needle sticks; blood contact with infected individual

8. MethicilinResistent Staphylococcus Aureus (MRSA) Skin and Soft Tissue (SST) Infection • Disease: Localized skin infections, often abscesses. Disease may start around hair follicle: folliculitis. If stays localized: foruncle. If spreads to adjoining skin and deeper soft tissue: carbuncle. Deep abscesses involving muscle or fascia may occur. Necrotizing fasciitis (“flesh eating” disease) may occur. Initial red skin lesion often ascribed to a “spider bite”.

9. MRSA SST Infections • Diagnosis: characteristic appearance of abscess. Culture of wound or abscess material almost always yield a Gram positive organism that is resistant to the antibiotics penicillin, and oxacillin or methacillin. • After treatment, individual can be an asymptomatic nasal carrier of MRSA. Carriage can precede infection which occurs as a consequence of disruption of cutaneous barrier or impairment of host defenses. Nasal swab culture will grow MRSA in a nasal carrier.

10. MRSA SST Infections • Epidemiology: Those at risk • Athletes and individuals using gyms • Certain ethnic populations • Children, newborns • Homeless persons • Homosexual men • Household members of infected people • HIV-infected patients • Intravenous drug abusers • Military personnel • Pregnant and postpartum women • Tattoo recipients • Urban dwellers of lower socioeconomic status in crowded living conditions • Prisoners in correctional institutions and their custodians • Hospital patients and those recently hospitalized • Nasal carrier of MRSA

11. Coccidioidomycosis(Valley Fever, Cocci) • Disease: Infection results from the inhalation of arthroconidia of Coccidioidesimmitisor Coccidioidesposadasii; both are molds that grow in soil in certain arid regions of the southwestern United States, in Mexico, Central and South America. Primary disease presents in 40% of infections as an influenza like illness with malaise, fever, backache, headache and cough, erythema nodosum, then pneumonia. Dissemination may result in meningitis, bony and joint lesions or skin and soft tissue abscesses.

12. Coccidioidomycosis(Valley Fever, Cocci) • Diagnosis (imaging): Chest x-ray shows patchy, nodular pulmonary infiltrates, hilar lymphadenopathy. • Diagnosis (serology): Immunodiffusion tube precipitin test (done at UCDMC) detects IgM antibodies early in disease process. Later a persistent rising IgG complement fixation titer (equal or greater than 1:16 is suggestive of disseminated disease. • Diagnosis (biopsy): Spherules filled with endospores can be found in biopsy specimens of soft tissues and bone.

13. Coccidioidomycosis(Valley Fever, Cocci) • Epidemiology: Obscure illness in any individual who has lived in or visited an endemic area particularly those exposed to dust and dirt. • Filipinos, blacks, pregnant women of any ethnicity are all especially susceptible to disseminated disease. Any organ may be so involved.

14. Lyme Disease(Lyme Borreliosis) • Disease: The most common tickborne illness in the United States caused by spirochete B burgdorferi. The vector of Lyme disease in California is the Ixodespacificus.Stage 1: flu-like illness and typical skin rash (erythema migrans at tickbite site, often groin, axilla or thigh); Stage 2: weeks to months later: facial (cranial nerve VII) palsy and meningitis; Stage 3, months to years later arthritis. Considerable overlap in these 3 Stages of disease.

15. Lyme Disease(Lyme Borreliosis) • Diagnosis: A person with exposure to a potential tick habitat (within the 30 days just prior to developing erythema migranswith (1) erythema migrans diagnosed by a physician or (2) at least one late manifestation of the disease (neurologic, musculoskelatal, and more rarely skin) and (3) laboratory confirmation fulfilling the criteria for Lyme disease. (Two stage testing with ELISA and Western blot) Serologic tests not subject to any national standard and caution is advised. Some labs report on a variety of unreliable tests. Patients with a variety of chronic symptoms are misdiagnosed with chronic Lyme Disease.

16. Lyme Disease(Lyme Borreliosis) • Epidemiology: Tick bite in endemic area. Note that ticks must feed for at least 24-36 hours or longer to transmit infections. In particular, attachment greater than 72 hours associated with higher rates of infection. Attachment of less than 24 hours is rarely associated with infection. The percentage of ticks infected varies by region. In California, only 2% of I. pacificusare infected. Adult female is only 2-3 mm in size with red body and black legs. Use fine tipped tweezers to pull firmly and repeatedly on tick’s mouth (not body); save removed tick in bottle of alcohol for future identification.

17. Other potential infectious diseases in the workplace • Q fever: livestock handlers • AIDS, Herpes and other STDs: adult film industry • TB: health care workers and anyone in contact with recent immigrants from endemic areas, travelers outside USA • Hepatitis A: travel to third world • Traveler’s diarrhea: travel • Brucellosis: exposure to livestock outside USA • Malaria: travel to endemic areas without taking drug prophylaxis • Legionnaire’s Disease: atypical pneumonia caused by exposure to contaminated air conditioning cooling towers. • Measles: eliminated in USA in 2000; few reported cases since are largely imported. • Pneumonia: Community acquired with cause unidentified in up to 60% of cases. Difficult to assign causation to the workplace.

18. Worker initial interview • Establish diagnosis of infectious disease • Look for chronic disease and impact on various organ systems • Assess nonindustrial risk factors for infection • Confirm that worker belongs to a group at risk by virtue of a specific work location or task • The further the worker strays from the standard epidemiology of the disease in question, the harder it is to prove industrial causation. The closer the worker comes to the general population at risk for a disease process, the less likely the infectious disease can be considered industrial (for example, the flu, sore throat, bronchitis, sinusitis, upper respiratory infection, shingles, non-specific viral illness, etc.) • Although technically and in some hepatitis case law, there can be two contributing factors to an infectious disease, in general these cases are all or nothing, either work caused the infectious disease or it did not.

19. The Fishman Rule • Borrowed liberally from David Hume, English philosopher • Contiguity and causation are not the same. • In other words, just because two events intersect in time, that does not necessarily mean that the two events are related in any way. • Workers, patients and therefore attorneys often retrospectively and erroneously conclude that two contiguous events have a causal link.

20. Compensation for Infectious Diseases • Workers fully recovered from an infectious disease usually have no compensable consequences nor routine need for future medical care. • Chronic or recurrent infection and/or a persistent consequence of infection is generally rated by using the AMA Guides, 5th edition section(s) for the individual body part(s) affected by the chronic or recurrent infectious disease process. • HIV infection is specifically discussed on pages 198-200 but within the context of the viral infection impact on a specific organ system: white blood cells, reinforcing need to rate the consequences of infectious disease by considering the individual body part(s) affected.