Transcript Strange Germs, New Plagues, Weird Bacteria, Oh My!

“Strange Germs, New
Plagues, Weird Bacteria,
Oh My!
Michelle A. Barron, M.D.
Associate Professor of Medicine
University of Colorado Denver
Division of Infectious Diseases
Medical Director, Infection Prevention and
Control – University of Colorado Hospital
Objectives
Discuss new and not so new bacterial infections
(MRSA), viral infections (seasonal influenza,
avian influenza, the H1N1 pandemic, SARS,
West Nile Virus, Hantavirus), and Tuberculosis
–
–
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–
What are they?
How are they transmitted?
How do you know if you have it?
What do you do if you do get it?
Discuss ways to prevent infections
– Hand Hygiene
– Immunizations
“[it] is time to close the book on infectious
diseases and declare the war against
pestilence won…”
Attributed to:
US Surgeon General William H. Stewart
1967
The Antibiotic Era: An
Evolutionary Perspective
What is Staphylococcus aureus?
Often referred to
as “staph”
Bacteria that is
commonly carried
on the skin or nose
of healthy people
Epidemiology of S aureus
Predominant reservoir of organisms = human
beings
Approximately 15% – 35% of healthy people
harbor S. aureus in their nose or throat at any
given point
People can become carriers of Staph without
having an infection (colonization):
– 30% prolonged, 50% intermittent, 20% never
– Vaginal carriage in ~10% of premenopausal women
– Rectal and perineal carriage also occur
Sheagren. N Engl J Med. 1984;310:1368-1373.
Rimland et al. J Clin Microbiol. 1986;24:137-138.
Centers for Disease Control (CDC). MMWR Morb Mortal Wkly Rep. 1982;31:605-607.
What is Methicillin Resistant
Staphylococcus aureus (MRSA)?
Some Staph bacteria are resistant to
antibiotics
MRSA is a type of Staph that is resistant
to antibiotics called beta-lactams
Beta-lactam antibiotics include antibiotics
such as methicillin, amoxicillin, and
penicillin
Approximately 1% of the population is
colonized with MRSA
Epidemiology of MRSA
Organism usually spread by direct person-toperson contact
Spread from inanimate objects is rare, but has
been documented, such as outbreaks among
football players, river raft guides, etc.
Patients with MRSA infections may have high
prevalence (60%) of gut colonization or carriage
Common denominator: repeated trauma in
defined area
Who Gets Staph Infections?
Staph infections, including MRSA, occur
frequently in persons in hospitals and
healthcare facilities
People with diabetes, HIV or AIDS, and
chronic kidney failure on dialysis may be
colonized with Staph more frequently than
others
Increasing number of otherwise healthy
people are being reported as having
MRSA infections
What is Community Associated
MRSA (CA-MRSA)?
MRSA infections that are acquired by
persons who have not been recently
hospitalized (within the past year)
Staph or MRSA infections in the
community generally occur in otherwise
healthy people
A study in 2003, suggests that 12% of
MRSA infections are community
associated but this varies by geographic
region and population
Epidemiology of HA- and
CA-MRSA Infections
Prevalence of MRSA
increasing in hospitals
and in the community1
Infections associated
with CA-MRSA (n = 131)2
Other 8%
Urinary tract 1%
Bloodstream 4%
Methicillin-resistant S aureus
Resistant isolates (%)
100
Respiratory tract 6%
Otitis media/externa7%
Nosocomial infection
75
Community-acquired infection
Skin/Soft tissue 75%
50
Infections associated
with HA-MRSA (n = 937)2
Other 12%
25
Urinary tract 20%
Skin/Soft tissue 37%
0
1970
1980 1990
Year
2000
Bloodstream 9%
Otitis media/externa 1%
1. McDonald LC. Clin Infect Dis. 2006;42:S65-S71. 2. Naimi TS, et al. JAMA. 2003;290:2976-2984.
Respiratory tract 22%
Risk Factors for Colonization or
Infection with MRSA
History of injecting drug use
Homelessness
Underlying dermatologic disease
Prior steroid therapy
Prior antibiotic therapy
Presence of a central venous catheter
Prolonged hospital stays
Onorato, M, et al. ICHE. 1999. 20 (1):26-30.
Miller, M, et al. Eur J Clin Micro Infect Dis 2003. 22:463-69.
CA-MRSA Infections Among Competitive
Sports Participants, 2000 – 2003
Outbreaks of skin and soft tissue infections
(SSTIs) due to CA-MRSA reported from
Colorado, Indiana, Pennsylvania, and Los
Angeles County from 2000 to 2003
Sports involved included fencing, wrestling,
and football
Centers for Disease Control and Prevention (CDC). MMWR Morb Mortal Wkly Rep.
2003;52:793-795.
Clinical Syndromes
Prevention of MRSA
Adequate coverage of abrasions or draining
lesions
Limiting inappropriate antimicrobials use
Use of Infection prevention practices (e.g.
washing hands or using alcohol based gels)
Advice for people who live with you:
– Good hygiene – hot showers, use of antimicrobial
soaps, and disinfectants
– Avoid sharing towels, razors, or clothing
Tacconelli, E., et al. JAC. 2004. 53:474-9.
Zetola, N., et al. Lancet. 2005. 5:275-86.
Kowalski, TJ, et al. Mayo Clin Proc. 2005. 80(9):1201-8.
Influenza
What is Influenza?
Contagious respiratory illness caused by
the influenza virus
– Influenza A, B and C
subtypes: H1N1, H5N1, H3N2, pandemic H1N1, etc.
Causes mild to severe illness and can lead
to death
Yearly, 5-20% of the population will become
infected influenza
> 200,000 are hospitalized annually with
severe complications from influenza
About 36,000 die annually from flu-related
illness
How is it spread ?
Spread is usually person to person via large virus-laden droplets when
coughing/sneezing, poor hand hygiene compliance, poor compliance with
respiratory etiquette
What is the period of infectivity period?
Infectivity is one day prior to symptom onset and up to 5 days after onset.
Children and those with weakened immune systems may be infectious for 10
days or more after onset of symptoms.
Viral Shedding and Transmission
30-50% of seasonal influenza infections may not
result in illness
Viral shedding in healthy adults with influenza
occurs 24-48 hours prior to onset of illness
Titers of infectious virus peak during 1st 24-72
hrs of illness
– Undetectable titers by day 5 of illness
Children may have asymptomatic viral shedding
3-6 days before illness onset
– Median duration of virus detection is 7-8d after illness
resolves
Clinical Features - Adults
Incubation period of 1-5 days
Abrupt onset of severe headache, chills, and nonproductive cough
Also prominent muscle aches accompanied by high
fevers
– Fever peaks on the first day and may decrease over
the next 72 hours
Decreased energy and appetite are universal
Mild-moderate cases usually resolve in 7 days
Weakness, cough, and lack of energy may persist for
weeks after clinical resolution
Avian influenza A (H5N1)
December 2003
 19,000 of 24,000 chickens on a farm in Korea die in a week
 Epidemic of the highly pathogenic avian influenza H5N1 strain found as
the cause of the poultry deaths
 More than 1.3 million chickens and ducks have died or been destroyed
January 2004
 Outbreak of severe respiratory illness in 12 previously healthy children
and 1 adult hospitalized in Viet Nam reported to WHO – 8 cases are
fatal
 Test on samples from two of the fatal cases confirm infection with H5N1
avian influenza virus strain
February 2004
– 34 human cases with 23 deaths reported in Thailand and Vietnam
WHO. 2004
Avian influenza A (H5N1)
August/September/October 2004
– 4 human deaths from avian influenza H5 infection reported in Vietnam; 4
fatal cases in Thailand
– 1 case of possible human-to-human transmission reported
December 2004
 Resurgence of poultry outbreaks and human cases reported in Vietnam.
 Suggested transmission to at least two persons through consumption of
uncooked duck blood
 February 2, 2005
 The first of 4 human cases of H5N1 infection from Cambodia was reported
 July 21, 2005
 First human case of H5N1 in Indonesia was reported
 Indonesia has continued to report human cases in August, September, and
October 2005
 January 2006
 Two cases of avian influenza in Turkey
WHO. 2004
Pandemic Potential of H5N1
Pros:
 Novel virus (Avian origin, similar to 1918 flu)
 Highly infectious
 No vaccine availability
 Spread easily between sick poultry and humans
 Migrating birds can serve as potential worldwide vector
Cons:
 Mass culling of infected birds, limiting spread
 Limited human to human spread
Just When You Thought It Was Safe…
January 24, 2012
Ministry of China
notified WHO of a
human case of H5N1
infection in a 39 year old
male who was
hospitalized and
subsequently died.
Investigation into source
of infection on-going.
No other cases so far…
Pandemic H1N1 Influenza –
April 23, 2009
CDC dispatch:
Human cases of
swine influenza A
(H1N1) virus
infection have
been identified in
San Diego County
and Imperial
County, California
as well as in San
Antonio, Texas.
May 3, 2009 – WHO
What Are the Differences Between
Seasonal and pandemic H1N1 Influenza?
Seasonal Influenza
Influenza strains A and B
Spread via droplets
Signs/symptoms:
– Fever, cough, sore throat,
runny nose, body aches,
headaches, chills and fatigue
– Vomiting and diarrhea more
common in children
Risk for complications:
– >65 yo, asthma, diabetes,
suppressed immune
systems, heart disease,
kidney disease, and
pregnancy
Pandemic H1N1 Influenza
Influenza A strain only
Spread via droplets
Signs/symptoms:
– Fever, cough, sore throat,
runny nose, body aches,
headaches, chills and fatigue
– Vomiting and diarrhea in all
age groups
Risk for complications:
– Asthma, diabetes, suppressed
immune systems, heart
disease, kidney disease, and
pregnancy
– Elderly not at higher risk for
infection
67 of the 147 deaths in 2008-2009 were due to H1N1;
29 have occurred since August 30, 2009
Prevention and Good Health Habits
Vaccination is the key prevention strategy
Stay home when you are sick
Avoid direct contact with people that are
coughing or sneezing
Cover your mouth when you cough or
sneeze
Wash your hands frequently or use
antibacterial gels frequently
Severe Acute Respiratory Syndrome
SARS
First reported in Nov 2002 in China
Spread worldwide by Feb-Mar 2003
Contained by July 2003
Worldwide:
– 8098 probable cases
21% healthcare workers
– 774 deaths (case/fatality ratio 9.6%)
United States:
– 164 total cases
– 137 suspect, 19 probable, and 8 confirmed
– No deaths
Source: WHO; CDC
SARS Transmission
Most important
– Close personal contact
– Large droplet nuclei
Airborne spread
– Role of aerosol-generating procedures
(intubation, suctioning, nebulization,
bronchoscopy)
– ? point in disease
Potential role of fomites
Fecal spread implicated in one outbreak
Source: www.cdc.gov
Summary of Clinical Manifestations
Week 1: Febrile prodrome
– Fever, myalgia, headache, sore throat, cough
– 5-10% diarrhea
– CXR may be normal
Week 2: Respiratory phase
– Rapid progression SOB, cough, hypoxia; ARDS in 10-20%
usually by day 7-8
– Radiographic progression
– Exam may be unremarkable
Week 3: Resolution vs Death vs Chronic Disease
– Resolution of Sx from ~ day 11-14
Real Life Occupational Exposure
SARS (Toronto experience)
SGH
Index Case
Mr. T
(Mother)
(Son)
Friday, March 7, 2003
Slide provided courtesy of Allison McGeer, MD
Night of March 7th:
Observation Unit ER SGH
Mr T
Mr P
Mr D
Slide provided courtesy of Allison McGeer, MD
Mr. P
Mr. P’s
wife
Mr. D
Index
Case
(Mother)
Mr T
(Son)
Slide provided courtesy of Allison McGeer, MD
Mr. P
Mr. P’s
wife
24 persons
9 persons
Mr. D
Index Case
(Mother)
Mr T
(Son)
Mr. R
?
Slide provided courtesy of Allison McGeer, MD
Mr. P
Mr. P’s
wife
24 persons
9 persons
Mr. D
Index Case
(Mother)
Mr T
(Son)
21 persons
Mr. R
?
Slide provided courtesy of Allison McGeer, MD
Mr. P
Mr. P’s
wife
24 persons
9 persons
Mr. D
Index Case
(Mother)
21 persons
Mr T
(Son)
15 persons
Mr. R
?
Slide provided courtesy of Allison McGeer, MD
Current Status of SARS: Will it Return?
July 2003
– 3 recent cases reported in China
– Lab-acquired case in Singapore
April 2004
– 9 cases of SARS in China
1 person died
– No further cases since 4/29/04
West Nile Virus
West Nile Virus
What is it?
– A potentially serious illness that affects the
central nervous system.
Can cause inflammation of the brain (encephalitis)
or around the brain (menigitis) and can also cause
polio-like paralysis.
How is it spread?
– Typically by the bite of an infected mosquito.
– Mosquitoes become infected by feeding on
birds with the virus.
West Nile Virus
What are the signs and symptos of
infection?
– About 20% of patients will have a “flu-like
illness”
Fever, malaise, anorexia, nausea, vomiting,
headache, muscle pain, occasional rash
– 1 in 150 infections will be severe
Fever, weakness, gastrointestinal symptoms,
change in mental status Higher risk in individuals
over age 50 years old
West Nile Virus
How can it be prevented?
– Apply insect repellent when you are going to be
outdoors. Even if you don’t notice mosquitoes there is
a good chance that they are around.
– When weather permits, wear long-sleeved shirts and
long pants whenever you are outdoors.
– Place mosquito netting over infant carriers when you
are outdoors with infants.
– Consider staying indoors at dawn, dusk, and in the
early evening, which are peak mosquito biting times.
– Install or repair window and door screens so that
mosquitoes cannot get indoors.
– Drain sources of standing water
Hantavirus
Hantavirus Pulmonary Syndrome
What is Hantavirus pulmonary syndrome?
– A serious, often deadly disease caused by the
Sin Nombre virus.
How is it transmitted?
– The virus is carried by rodents and passed on
to humans through rodent urine, saliva, and
droppings.
The deer mouse is the primary carrier of the virus.
– It is not spread person to person.
Confirmed Cases of Hantavirus by
State from 1993-2011
Hantavirus Pulmonary Syndrome (HPS)
What are the symptoms of HPS?
– First symptoms are generally flu-like
Fever, headache, abdominal pain, back pain and
joint pain
– Main symptom is increasing shortness of
breath
What is the treatment?
– Mainly supportive. Key is getting to the
hospital right away.
Hantavirus Pulmonary Syndrome
How can you prevent getting infected?
– Open up and air out unused or abandoned cabins
before occupying the building.
– If you’re sleep outdoors, check campsites for rodent
dropping and burrows.
– D not disturb rodents, burrows, or dens.
– Avoid sleeping near woodpiles or gargbage
– Avoid sleeping on bare ground; use a mat or elevated
cot if available
– Store food in rodent-proof containers and discard,
bury, or burn all garbage.
Multidrug Resistant Tuberculosis
One third of the world’s
population are infected with
TB.
In 2010, a total of 8.8 million
people worldwide became
sick with TB disease, most of
whom (82%) live in one of
the 22 high burden countries
for TB.
TB is a leading killer of
people living with HIV.
Multidrug-Resistant Tuberculosis
What is tuberculosis (TB)?
– It is a disease caused by germs that are
spread from person to person through the air.
– It typically affects the lung but can infect the
brain as well as gone.
What is multi-drug resistant TB (MDRTB)?
– It is TB that is resistant to at least two of the
best anti-TB drugs, isoniazid and rifampicin.
Multidrug-Resistant TB
What is extensively drug resistant TB
(XDR TB)?
– It is a relatively rare type of MDR TB. It is
defined as TB which is resistant to multiple
anti-TB drugs.
– It is of particular concern in HIV patients as
they are more likely to develop active disease
and have a higher risk of death.
Multi-Drug Resistant TB
What are the symptoms of TB?
– Weight loss, fever, and night sweats.
– Also may include coughing and coughing up
blood.
How is TB spread?
– TB germs are put into the air when someone
infected with TB in the lungs coughs,
sneezes, speaks, or sings. Another person
then breathes in the germs and can become
infected.
Multidrug Resistant TB
Who can get MDR-TB?
– Patients not taking their TB medications correctly.
– Patients from areas where the disease is endemic.
– Patients that have spent time with someone known to
have drug-resistant TB
How can you prevent getting TB or MDR TB?
– Get tested for possible exposure (ppd test yearly) and
get treatment if needed
– If you have TB, take all of your medications as
directed.
Hand Hygiene Works!
Hand contamination after patient contact
(A) and after washing with an alcohol
NEJM. 2009
based sanitizer (B)
Alcohol is more effective than
plain soap and water
Alcohol based hand sanitizers
– 5 log10 reduction in bacteria after 15 s
application
Soap and water
– 0.6-1.1 log10 after 15 s application
More effective at reducing MDROs from
hands than soap and water
Potential for added emoillients = comfort
DOES NOT have activity against spores
– e.g. Clostridium difficile, Bacillus anthracus,
etc.
Preventative Vaccines
Immunizations Available for 24
Infectious Diseases*
Anthrax
Diphtheria
H. influenzae infection
Hepatitis A
Hepatitis B
Herpes zoster
Human Papillomavirus
infection
Influenza
Japanese Encephalitis
Measles
Meningococcal Disease
Monkeypox
Mumps
Pertussis
Pneumococcal Disease
Polio
Rabies
Rotavirus infection
Rubella
Smallpox (Vaccinia)
Tetanus
Tuberculosis (BCG)
Typhoid Fever
Varicella
Yellow Fever
* Vaccines for Cholera, Lyme Disease, and Plague are no longer
commercially available
“Chance Favors the Prepared Mind.”
Louis Pasteur
Questions?