Occupational Infections Flashcards
SIDAW
Surveillance of infectious diseases at work
Closed in 2015
75% cases due to diarrhoea
ACDP
Advisory Committee on Dangerous Pathogens
Public Health Control of Diseases Act 1984
Must report notifiable infectious diseases to PH England
30 communicable diseases
Includes HepB, HepC, TB. NOT HIV
Hepatitis B Clinical Features (DNA)
Incubation 2-6 months
Acute sx - malaise, fatigue, jaundice, vomiting
30% are asymptomatic
Most patients clear infection spontaneously, 2-10% develop chronic carriage
Anti-HBc +
HBsAg +
Current infection or infectious carrier
Anti-HBc +
HBsAg +
HBeAg +
Current infection or infectious carrier with particularly high infectivity
Anti-HBc +
HBsAg -
Previous infection with natural immunity and non-infectious
Treatment of HBV
Interferon alpha, leading to reversal of the carrier state in 40%
Untreated 20-25% of chronic cases infected as adults will get chronic liver disease
Immunization of Hep B
Increases level of anti-HBs (surface antibody)
>100IU/L then booster every 5 years
<10IU/L indicates no immunity
Anti-HBc
Core antibody
HBsAg
Surface antigen
If NEGATIVE can do EPP
HBeAg
e antigen
anti-HBs
Surface antibody
Workers cannot do EPP if
HEP B - Have HBsAg and HBeAg
HEP C - Positive HCV RNA
Acute infection Hep C (RNA)
Incubation 6-9 weeks
Mostly asymptomatic. 50% become carriers
At risk of Chronic liver disease and Hep cancer
Anti-HCV
HCV antibodies - detectable 3 months after infection
Shows individual was infected but not if active or previous infection
Hep C treatment
Combination antiviral therapy successful in clearing HCV in 50% of cases.
Pegylated interferon-alpha weekly with ribavirin
There is no vaccine or PEP for HCV.
HIV Reporting
It is not a PD - can claim as an injury if at work
It is not notificable
It IS reportable to HSE under RIDDOR
HCW doing EPP with HIV
Can perform EPP if on retroviral therapy and have plasma viral load <200 copies/ml
Need 2 tests 3 months apart
Must remain under OH team
AIDS
Associated with CD4 <200
Then get pneumocystis, toxoplasma, cryptosporidia
HIV Infectivity
Measured by HIV RNA
PEP in HIV
AZT (Zidovudine) is effective in reducing seroconversion following injury
Tx- Truvada and raltegovir
Should be given within 2 hours but can be up to 72 hours
TB Vaccination
Offered to all Non-immune HCWs
Routine BCG of children aged 11-13 has stopped. Now for at risk, selective vaccination.
Pre-employment for HCW - TB
- Unexplained cough 3 weeks or more in past year
- Unexplained weight loss, night sweats, fever
- Previous tx for TB or family had tx for TB
- Been to a TB country last 12 months?
Check for BCG Scar. May need CR and IGRA
IGRA
Interferon gamma result. If + indicates latent TB
If negative offer vaccination
Hepatits C and EPP
Cannot work if anti-HCV positive AND HCV RNA positive
If HCV RNA negative after 12 months and HEP C antibody positive, then can return to EPP
Rubella
HCW should have immune status checked as risk of transmitting to pregnant ladies.
Varicella
Non immune HCW should not be in contact with pregnant women, immunocompromised, cancer, transplant and leukaemia patients.
MSRA
Tx- chlorhexidine mouthwash 5 days, topical mupirocin for 3 days
Salmonella Typhi
Not to return to work until 6 negative stool samples
Shigella
3 negative stool samples
Streptococcus suis
Rare infection of pig farmers, abattoir workers, butchers
PD B9
Giardia Intestinalis
Protozoan found in normal stools
Outbreaks in sewage workers
Hepatitis A
Small cluster in nurseries and hospitals
Also risk in sewage workers and farm workers
Legionnaires
From contaminated condensates from ACs
Pontiac Fever is a mild form of this
Hep B and EPP
If positive for HBsAg need to be tested for HBeAg
If HBeAg + cannot do EPP
If HBsAg negative, need to check HBV DNA
If HBV DNA>10^3 then can’t do EPP
