Chapter 30: Transmission of Pathogens in Dental Settings

Copyright © 2017, Elsevier Inc. All Rights Reserved.
Transmission of Pathogens
in Dental Settings
Chapter 30
1

Learning Objectives
Lesson 30.1: Transmission of
Pathogens in Dental Settings
1. Describe instances where the Herpes virus,
Pseudomonas aeruginosa, and Legionella
pneumophila were transmitted in dental
settings.
2. Describe various instances where Hepatitis B
was spread in a dental setting.
3. Describe instances where Hepatitis C, HIV,
and Mycobacterium abscessus were
transmitted in a dental setting. Also, discuss
other infection control breaches.
2

Introduction
 The dental profession long ago adopted
infection control procedures
 As a result, the transmission of disease in dental
facilities is very rare
 View Table 30.1 to see examples of
transmissions of pathogens in dental settings.
3

Transmission of Herpes Virus in a
Dental Setting in the United States
4

Transmission of Herpes Virus in a
Dental Setting in the United States
 Figure 30.1 on the previous slide is a flow diagram
showing how herpes simplex virus can transmit in
a dental setting.
 In 1981, an ungloved hygienist with dermatitis on
her hands and fingers cared for a patient with
active herpes labialis. About a week later, the
hygienist developed herpetic whitlow. It was
eventually found out that that hygienist had spread
the virus to at least 20 other patients.
 Dermatitis greatly reduces the effectiveness of
handwashing in removing contaminating disease
agents. 5

Transmission of Pseudomonas aeruginosa
to Dental Patients in England
 A report from England in 1987 described how
two cancer-weakened dental patients
acquired oral infections with P. aeruginosa
that originated with dental unit water
 An additional 78 patients treated at the same
dental unit were colonized orally for 4 to 10 weeks
• None of the patients developed harmful infections with
the Pseudomonas bacterium
• Pseudomonas aeruginosa is a gram-negative
environmental bacterium whose natural habitat is on
plants, in soil, and in natural waters.
6

Transmission of Legionella pneumophila
to a Dental Patient in Italy
 Most cases of this disease result from
inhalation of water from water-handling
systems
 An 82-year-old woman died in Rome, Italy, in
2011 from Legionnaires disease that she
contracted from a dental office
 Shows that the disease can be acquired from
dental unit water during routine dental treatment
7

Transmission of Legionella pneumophila
to a Dental Patient in Italy
 Legionnaires disease is a type of pneumonia
caused by L. pneumophila that lives in many
natural and domestic water environments.
 At the time of this writing, there is no
confirmed case of Legionnaires disease
spread from dental unit water in the United
States.
8

Spread of Hepatitis B
in Dental Settings
 From dentist to patient
 Chances of patients acquiring any disease in a
dental office are low
 The drop in the spread of HBV from dentists to
patients after 1987 coincides with the time (around
1984) when infection control in dentistry was
reemphasized
 Hepatitis B was apparently spread from six oral
surgeons and five general dentists to a total of 175
patients as documented in 11 separate instances
between 1974 and 1987.
9

 From patient to patient
 After a lull of 14 years, HBV raised its ugly head again
in 2001
• Hepatitis B was spread from one patient to another patient on
the same day in 2001 in an oral surgery practice
• Because no clear-cut mode of viral spread was identified in
this case, the CDC investigators could only speculate on the
mechanism of transmission involved.
• This case alerts us to the continued importance of the
potential spread of HBV in dentistry and the importance of
HBV vaccination.
• The spread of this virus in this case was likely limited by the
high incidence of HBV immunity in the staff and patients.
10
in Dental Settings (Cont.)

 In a portable dental clinic in West Virginia
 In 2009, a portable dental clinic was used to treat 1137
adults
• Local and state health departments identified a cluster of five
persons with acute HBV infections; they were three patients and
two volunteers
• Training on bloodborne pathogens had not been provided to the
volunteers
• The three patients had extractions; one also had a dental
prophylaxis and another also had restorations.
• Genetic analysis of the viruses from two of the three patients and
both volunteers indicated that the four viruses were of the same
genotype.
• Although the CDC was unable to identify specific modes of
infection, they did identify several breaches in infection control.
11

 Hepatitis B in dental workers
 In 1972, blood screening showed that about 13%
of dental students or dentists had previous HBV
infection
 In 2005, the screening shows that 8.5% of dentists
and 6.8% of dental hygienists tested had past or
current HBV infection
 Several blood-testing surveys of dental workers
conducted at annual meetings of the ADA
attempted to determine how many of the different
types of dental works had been infected with HBV.
12

Transmission of Hepatitis C Virus
from Patient to Patient in Oklahoma
 Occurred in 2013
 First documented report of hepatitis C spread
from patient to patient in a dental setting in
the United States
 Site-visits of practice discovered several
breaches in infection control procedures
 It has been suggested that lapses in infection
safety may have occurred
 Reuse of a contaminated vial may have led to
transmission of HCV to the next patient
13

Transmission of Hepatitis C Virus
from Patient to Patient in Oklahoma
 The health department notified 6000 current
and past patients from this practice informing
them of possible exposure.
 4200 patients were then tested and it was
discovered that 96 patients had hepatitis C, 6
had hepatitis B, and 3 had HIV disease.
14

Transmission of HIV to Dental Patients
 Risk for dental patient of acquiring HIV disease in the
office from a member of the dental team is extremely
low
 Spread of HIV is suggested in only one instance in
dentistry
 A dentist infected with HIV infected 6 of his patients who
were treated in his Florida dental office during the years of
1987 to 1990
 The CDC and the Florida Department of Health suggested
that direct spread from the dentist to the patients was most
likely, rather than spread from contaminated instruments,
equipment, or surfaces.
15

Transmission of Waterborne
Mycobacterium abscessus to Pediatric Dental Patients
 In 2015, the Georgia Department of Public
Health was notified by a hospital of a cluster
of 9 children with Mycobacterium abscessus
odontogenic infections
 Patients ranged in age from 3 to 11 years
 No deaths as of April 5, 2016
16

Transmission of Waterborne
Mycobacterium abscessus to Pediatric Dental Patients
 The probable cases were defined as having
facial or neck granulomatous swellings.
 The dental practice used tap water for
irrigation during the pulpotomies and did not
perform any microbial water analyses or
completely follow the dental unit
manufacturer’s directions for bleach
treatment of the waterlines.
 This outbreak was caused by contaminated
dental unit water.
17

Other Infection Control Breaches
 In 2010, technicians in the sterilizing facility of
St. Louis VA hospital were improperly cleaning
dental instruments before sterilization
 About 1800 veterans were seen in the dental clinic
and were contacted for pathogens testing
 A Dayton, Ohio veterans hospital offered free
HIV and hepatitis tests to more than 500 dental
patients to determine whether they were infected
between 1992 and 2010 by a dentist who failed
to change gloves or sterilized handpieces
between patients
18

Other Infection Control Breaches
 In the St. Louis case, the technicians were
apparently hand-scrubbing the contaminated
instruments rather than processing them
through the mechanical instrument washer.
19

Chapter 30: Transmission of Pathogens in Dental Settings

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Chapter 30: Transmission of Pathogens in Dental Settings

Similar to Chapter 30: Transmission of Pathogens in Dental Settings (20)

More from HeatherSeghi

More from HeatherSeghi (20)

Recently uploaded

Recently uploaded (20)

Chapter 30: Transmission of Pathogens in Dental Settings