Title: Communicable Diseases: Definition
1Communicable Diseases Definition
- Defined as
- any condition which is transmitted directly or
indirectly to a person from an infected person or
animal through the agency of an intermediate
animal, host, or vector, or through the inanimate
environment. - Transmission is facilitated by the following
(IOM) - more frequent human contact due to
- Increase in the volume and means of
transportation (affordable international air
travel), - globalization (increased trade and contact)
- Microbial adaptation and change
- Breakdown of public health capacity at various
levels - Change in human demographics and behavior
- Economic development and land use patterns
2CD- Modes of transmission
- Direct
- Blood-borne or sexual HIV, Hepatitis B,C
- Inhalation Tuberculosis, influenza, anthrax
- Food-borne E.coli, Salmonella,
- Contaminated water- Cholera, rotavirus, Hepatitis
A - Indirect
- Vector-borne- malaria, onchocerciasis,
trypanosomiasis - Formites
- Zoonotic diseases animal handling and feeding
practices (Mad cow disease, Avian Influenza)
3Importance of Communicable Diseases
- Significant burden of disease especially in low
and middle income countries - Social impact
- Economic impact
- Potential for rapid spread
- Human security concerns
- Intentional use
4Communicable Diseases account for a significant
global disease burden
- In 2005, CDs accounted for about 30 of the
global BoD and 60 of the BoD in Africa. - CDs typically affect LIC and MICs
disproportionately. - Account for 40 of the disease burden in low and
middle income countries - Most communicable diseases are preventable or
treatable.
5Communicable Disease Burden Varies Widely Among
Continents
6Communicable disease burden in Europe
7Causes of Death Vary Greatly by Country Income
Level
8CDs have a significant social impact
- Disruption of family and social networks
- Child-headed households, social exclusion
- Widespread stigma and discrimination
- TB, HIV/AIDS, Leprosy
- Discrimination in employment, schools, migration
policies - Orphans and vulnerable children
- Loss of primary care givers
- Susceptibility to exploitation and trafficking
- Interventions such as quarantine measures may
aggravate the social disruption
9CDs have a significant economic impact in
affected countries
- At the macro level
- Reduction in revenue for the country (e.g.
tourism) - Estimated cost of SARS epidemic to Asian
countries 20 billion (2003) or 2 million per
case. - Drop in international travel to affected
countries by 50-70 - Malaria causes an average loss of 1.3 annual GDP
in countries with intense transmission - The plague outbreak in India cost the economy
over 1 billion from travel restrictions and
embargoes - At the household level
- Poorer households are disproportionately affected
- Substantial loss in productivity and income for
the infirmed and caregiver - Catastrophic costs of treating illness
10International boundaries are disappearing
- Borders are not very effective at stopping
communicable diseases. - With increasing globalization
- interdependence of countries more trade and
human/animal interactions - The rise in international traffic and commerce
makes challenges even more daunting - Other global issues affect or are affected by
communicable diseases. - climate change
- migration
- Change in biodiversity
11Human Security concerns
- Potential magnitude and rapid spread of
outbreaks/pandemics. e.g. SARS outbreak - No country or region can contain a full blown
outbreak of Avian influenza - Bioterrorism and intentional outbreaks
- Anthrax, Small pox
- New and re-emerging diseases
- Ebola, TB (MDR-TB and XDR-TB), HPAI, Rift valley
fever.
12 Tuberculosis
- 2 billion people infected with microbes that
cause TB. - Not everyone develops active disease
- A person is infected every second globally
- 22 countries account for 80 of TB cases.
- gt50 cases in Asia, 28 in Africa (which also has
the highest per capita prevalence) - In 2005, there were 8.8 million new TB cases 1.6
million deaths from TB (about 4400 a day) - Highly stigmatizing disease
13Tuberculosis and HIV
- A third of those living with HIV are co-infected
with TB - About 200,000 people with HIV die annually from
TB. - Most common opportunistic infection in Africa
- 70 of TB patients are co-infected with HIV in
some countries in Africa - Impact of HIV on TB
- TB is harder to diagnose in HIV-positive people.
- TB progresses faster in HIV-infected people.
- TB in HIV-positive people is almost certain to be
fatal if undiagnosed or left untreated. - TB occurs earlier in the course of HIV infection
than many other opportunistic infections.
14Global Prevalence of TB cases (WHO)
15Tuberculosis
16(No Transcript)
17Tuberculosis Control
- Challenges for tuberculosis control
- MDR-TB - In most countries. About 450000 new
cases annually. - XDR-TB cases confirmed in South Africa.
- Weak health systems
- TB and HIV
- The Global Plan to Stop TB 2006-2015.
- an investment of US 56 billion, a three-fold
increase from 2005. The estimated funding gap is
US 31 billion. - Six step strategy Expanding DOTS treatment
Health Systems Strengthening Engaging all care
providers Empowering patients and communities
Addressing MDR TB, Supporting research
18Malaria
- Every year, 500 million people become severely
ill with malaria - And it causes 30 of Low birth weight in newborns
globally. - gt1 million people die of malaria every year. One
child dies from it every 30 seconds - 40 of the worlds population is at risk of
malaria. Most cases and deaths occur in SSA. - Malaria is the 9th leading cause of death in LICs
and MICs - 11 of childhood deaths worldwide attributable to
malaria - SSA children account for 82 of malaria deaths
worldwide
19Annual Reported Malaria Cases by Country (WHO
2003)
20Global malaria prevalence
21Malaria Control
- Malaria control
- Early diagnosis and prompt treatment to cure
patients and reduce parasite reservoir - Vector control
- Indoor residual spraying
- Long lasting Insecticide treated bed nets
- Intermittent preventive treatment of pregnant
women - Challenges in malaria control
- Widespread resistance to conventional
anti-malaria drugs - Malaria and HIV
- Health Systems Constraints
- Access to services
- Coverage of prevention interventions
22HIV/AIDS
- In 2005, 38.6 million people worldwide were
living with HIV, of which 24.7 million
(two-thirds) lived in SSA - 4.1 million people worldwide became newly
infected - 2.8 million people lost their lives to AIDS
- New infections occur predominantly among the
15-24 age group. - Previously unknown about 25 years ago. Has
affected over 60 million people so far.
23HIV Co-infections
- Impact of TB on HIV
- TB considerably shortens the survival of people
with HIV/AIDS. - TB kills up to half of all AIDS patients
worldwide. - TB bacteria accelerate the progress of AIDS
infection in the patient - HIV and Malaria
- Diseases of poverty
- HIV infected adults are at risk of developing
severe malaria - Acute malaria episodes temporarily increase HIV
viral load - Adults with low CD4 count more susceptible to
treatment failure
24Global HIV Burden
25HIV/AIDS
- Interventions depend on
- Epidemiology mode of transmission, age group
- Stage of epidemic concentrated vs. generalized
- Elements of an effective intervention
- Strong political support and enabling
environment. - Linking prevention to care and access to care and
treatment - Integrate it into poverty reduction and address
gender inequality - Effective monitoring and evaluation
- Strengthening the health system and Multisectoral
approaches - Challenges in prevention and scaling up treatment
globally include - Constraints to access to care and treatment
- Stigma and discrimination
- Inadequate prevention measures.
- Co-infections (TB, Malaria)
26Avian Influenza
- Seasonal influenza causes severe illness in 3-5
million people and 250000 500000 deaths yearly - 1st H5N1 avian influenza case in Hong Kong in
1997. - By October 2007 331 human cases, 202 deaths.
27Avian Influenza
- Control depends on the phase of the epidemic
- Pre-Pandemic Phase
- Reduce opportunity for human infection
- Strengthen early warning system
- Emergence of Pandemic virus
- Contain and/or delay the spread at source
- Pandemic Declared
- Reduce mortality, morbidity and social disruption
- Conduct research to guide response measures
- Antiviral medications Oseltamivir, Amantadine
- Vaccine still experimental under development.
- Can only be produced in significant quantity
after an outbreak
28Confirmed human cases of H5N1
29Migratory pathway for birds and Avian influenza
30Neglected diseases
- Cause over 500,000 deaths and 57 million DALYs
annually. - Include the following
- Helminthic infections
- Hookworm (Ascaris, trichuris), lymphatic
filariasis, onchocerciasis, schistosomiasis,
dracunculiasis - Protozoan infections
- Leishmaniasis, African trypanosomiasis, Chagas
disease - Bacterial infections
- Leprosy, trachoma, buruli ulcer
31Communicable Disease and Human Security
- Part 2 - Mounting an Effective Global Response
32Approaches to Interventions
- Personal Responsibility and action
- Utilitarian Approaches Greatest good for the
greatest number - Including non Health Systems Interventions.
- Regulations and Laws
- Partnerships and Collaboration
- Enlightened Self Interest
33Personal Responsibility and action
- Improved hygiene and sanitation
- Hand washing, proper waste disposal, food
preparation and handling. - Information, education and behavior change
- Changing harmful household practices
- Livestock handling, knowledge about contagion
- Cultural and social norms
- Self reporting of illnesses and compliance with
interventions and treatment.
34Utilitarian Approaches Greatest good for the
greatest number
- Reliance on personal responsibility
- not always the optimal option given different
knowledge levels and values. - Public good nature of the interventions
- Social Isolation and Quarantine measures
- Home treatment Isolation
- Mass vaccination programs and campaigns
- Polio, small pox, DPT, Hepatitis, Yellow fever
- Mass treatment programs
- Onchocerciasis, de-worming programs.
- For some CDs, intervention in other sectors is
required - Environmental health elimination of breeding
sites, spraying - Agricultural practices such as poultry handling
and exposure to soil pathogens during farming.
35Regulations and Laws
- National response remains the bedrock of
intervention - National laws and capacities vary.
- International Regulations and laws introduced
- 1851 International Sanitary regulations in
Europe following cholera outbreak - 1951- international sanitary regulation by WHO.
- 1969- Replaced by the International Health
regulation - Minor changes in 1973 and 1981
- cholera, plague, yellow fever, smallpox,
relapsing fever and typhus - 2005 Revised International Health Regulation
- Challenge of enforceability of international
agreements.
36Regulation and laws WHO 2005 International
health regulation
- IHR (2005) is a legally binding agreement among
member states of WHO to cooperate on a set of
defined areas of public health importance. - Arrived at by consensus of all member countries
of WHO, with clear arbitration mechanisms - Its elements include
- Notification
- National IHR Focal Points and WHO IHR Contact
Points - Requirements for national core capacities
- Recommended measures
- External advice regarding the IHR (2005)
37Partnerships and Collaboration
- Collaboration vs. coercion
- Importance of partnerships
- MDG 8 Develop global partnerships for
development - Comparative advantage of partners
- Inclusiveness
- Examples of partnerships
- Over 70 Global health partnerships available
- Examples include the Stop-TB program, GFATM, RBM,
UNAIDS, GAVI, Global Outbreak Alert and Response
Network, GAIN, bilateral and multilateral
organizations.
38Isnt Donor Collaboration Wonderful?
INT NGO
WHO
CIDA
3/5
UNAIDS
GTZ
RNE
UNICEF
Norad
WB
Sida
MOF
USAID
T-MAP
UNTG
PMO
CF
DAC
GFCCP
PRSP
PEPFAR
HSSP
GFATM
MOEC
MOH
SWAP
CCM
NCTP
CTU
CCAIDS
NACP
PRIVATE SECTOR
CIVIL SOCIETY
LOCALGVT
Source WHO Mbewe
39A paradigm shift - Enlightened Self interest
- Communicable diseases have no borders.
- Predominantly affect the poor, and poor countries
- Also affect richer households and countries.
- Interventions are non-rival, non-exclusive and
have positive externalities. - Elimination and control of certain communicable
diseases increases global health security. - Limited financial incentives for the market to
drive needed innovation in research and drug
development - Mismatch between global health need and health
spending - Global health security is therefore inextricably
tied to the effective control of CDs in
developing world.
40Global Mismatch Between Disease Burden and Health
Spending
41Global Mismatch Between Disease Burden and Health
Spending
42Future Population Growth Will be in LICs and MICs
43Key principles of an Effective Global Response
- Respect for the value of each life
- Behind every statistic is an individual
- Understanding of the social context that govern
individual decision making - Disease Surveillance and reporting
- Management and containment of outbreaks
- Strong legal and regulatory framework
- Sustained and predictable financing
- Building national health systems
44World Banks involvement
- Relevance to our mandate
- CDs disproportionately affect the poor and LICs
and MICs - Enormous economic consequences
- Major constraint to achieving the MDGs
- Major source of financing for poor countries
- This position is rapidly changing with the
entrance of newer players in DAH such as Gates
foundation, Bilaterals, multilaterals. - Call for innovative financing schemes
45World Bank
- 430 million committed to malaria booster
projects in Africa - By 2008, 21 million bed nets and 42 million ACT
doses would have been distributed. - As of June 2007, the World Bank had approved
financing of 377 million for 40 projects in 45
countries in all six geographic regions to combat
Avian influenza - Cumulative WB commitment to HIV/AIDS is over 2.5
billion
46Sources of Development Assistance for Health
Source Michaud 2006
47Emerging viral diseases what are the threats and
how should we respond? Professor John Mackenzie
Professor of Tropical Infectious Diseases Curtin
University of Technology, Perth
Emerging viral diseases what are the threats and
how should we respond? Tuesday 4 September 2007
48(No Transcript)
49- Emerging diseases on rise
Date 21/02/2008 - An international research team has provided the
first scientific evidence that deadly emerging
diseases have risen steeply across the world, and
has mapped the outbreaks' main sources. They say
new diseases originating from wild animals in
poor nations are the greatest threat to humans.
Expansion of humans into shrinking pockets of
biodiversity and resulting contacts with wildlife
are the reason, they say. Meanwhile, richer
nations are nursing other outbreaks, including
multidrug-resistant pathogen strains, through
overuse of antibiotics, centralised food
processing and other technologies. The study
appears in the Feb. 21 issue of the leading
scientific journal Nature. Emerging
diseases-defined as newly identified pathogens,
or old ones moving to new regions--have caused
devastating outbreaks already. The HIV/AIDS
pandemic, thought to have started from human
contact with chimps, has led to over 65 million
infections recent outbreaks of SARS originating
in Chinese bats have cost up to 100 billion.
Outbreaks like the exotic African Ebola virus
have been small, but deadly. - Despite three decades of research, previous
attempts to explain these seemingly random
emergences were unsuccessful. In the new study,
researchers from four institutions analysed 335
emerging diseases from 1940 to 2004, then
converted the results into maps correlated with
human population density, population changes,
latitude, rainfall and wildlife biodiversity.
They showed that disease emergences have roughly
quadrupled over the past 50 years. Some 60 of
the diseases travelled from animals to humans
(such diseases are called zoonoses) and the
majority of those came from wild creatures. With
data corrected for lesser surveillance done in
poorer countries, "hot spots" jump out in areas
spanning sub-Saharan Africa, India and China
smaller spots appear in Europe, and North and
South America.
50- Emerging diseases on rise
Date 21/02/2008 - "We are crowding wildlife into ever-smaller
areas, and human population is increasing," said
coauthor Marc Levy, a global-change expert at the
Center for International Earth Science
Information Network (CIESIN), an affiliate of
Columbia University's Earth Institute. "The
meeting of these two things is a recipe for
something crossing over." The main sources are
mammals. Some pathogens may be picked up by
hunting or accidental contact others, such as
Malaysia's Nipah virus, go from wildlife to
livestock, then to people. Humans have evolved no
resistance to zoonoses, so the diseases can be
extraordinarily lethal. The scientists say that
the more wild species in an area, the more
pathogen varieties they may harbour. Kate E.
Jones, an evolutionary biologist at the
Zoological Society of London and first author of
the study, said the work urgently highlights the
need to prevent further intrusion into areas of
high biodiversity. "It turns out that
conservation may be an important means of
preventing new diseases," she said. - About 20 percent of known emergences are
multidrug-resistant strains of previously known
pathogens, including tuberculosis. Richer
nations' increasing reliance on modern
antibiotics has helped breed such dangerous
strains, said Peter Daszak, an emerging-diseases
biologist with the Consortium for Conservation
Medicine at the Wildlife Trust, another Earth
Institute affiliate, who directed the study.
Daszak said that some strains, such as lethal
variants of the common bacteria e. coli, now
spread widely with great speed because products
like raw vegetables are processed in huge,
centralised facilities. "Disease can be a cost of
development," he said.
51- Emerging diseases on rise
Date 21/02/2008 - The group's analyses showed also that more
diseases emerged in the 1980s than any other
decade-likely due to the HIV/AIDS pandemic, which
led to other new diseases in immune-compromised
victims. In the 1990s, insect-transmitted
diseases saw a peak, possibly in reaction to
rapid climate changes that started taking hold
then. Team members soon hope to study this
possibility and its future implications. - Daszak says the study has immediate uses. "The
world's public-health resources are
misallocated," he said. "Most are focused on
richer countries that can afford surveillance,
but most of the hotspots are in developing
countries. If you look at the high-impact
diseases of the future, we're missing the point."
Team members say nations must share more
technology and resources in hot-spots to reduce
risk. "We need to start finding pathogens before
they emerge," said Daszak.
52Global Distribution of Relative Risk of an EID
Event
Caption Global
distribution of relative risk of an EID event.
Maps are derived for EID events caused by a,
zoonotic pathogens from wildlife, b, zoonotic
pathogens from nonwildlife, c, drug-resistant
pathogens and d, vector-borne pathogens. The
relative risk is calculated from regression
coefficients and variable values in Table 1
(omitting the variable measuring reporting
effort), categorized by standard deviations from
the mean and mapped on a linear scale from green
(lower values) to red (higher values). Credit Jon
es et. al., Nature Usage Restrictions Please
credit Jones et. al., Nature
A
B
C
D
53Geographic Origins of EID events from 1940 to 2004
Caption Global richness map of the geographic
origins of EID events from 1940 to 2004. The map
is derived for EID events caused by all pathogen
types. Circles represent one degree grid cells,
and the area of the circle is proportional to the
number of events in the cell. Credit Jones et.
al., Nature
54WNV In USA
WNV is spreading rapidly throughout the
country
12/11/02
55WNV in USA 12/31/2002
- In 2002, 5 States Il, MI, OH, LA and IN accounted
for - 62.2 of WNV cases
- 70.5 of deaths
www.cdc.gov/od/oc/media/wncount.htm
56West Nile Virus
Clinical Presentation
- Incubation period 3 - 14 days
- 20 develop West Nile fever
- 1 in 150 develop meningoencephalitis
- Advanced age primary risk factor for severe
neurological disease and death - Mild dengue-like illness of sudden onset
- Duration 3 - 6 days
- Fever, lymphadenopathy, headache, abdominal pain,
vomiting, rash, conjunctivitis, eye pain,
anorexia - Symptoms of West Nile fever in contemporary
outbreaks not fully studied
57Severe Acute Respiratory Syndrome (SARS)
58Severe Acute Respiratory Syndrome (SARS)
- The Initial Epidemic
- Outbreak of atypical pneumonia in Hong Kong in
March 2003 - Between 03/11/03 and 03/25/03 156 patients were
hospitalized with SARS - 138 were identified as secondary or tertiary
cases as a result of exposure to index case(s) - 112 secondary cases
- 26 tertiary cases
- Includes 69 HCWs
- 20 MDs
- 34 Nurses
- 15 Allied HCWs
- 54 patients on ward or visitors
- 16 medical students
- 32 of the 138 patients (23.2) had severe
respiratory failure - 5 patients died (3.6)
- All had been hospitalized with a major medical
condition
Lee N et al. NEJM April 7, 2003. www.nejm.org
59Severe Acute Respiratory Syndrome (SARS)
- The Clinical Presentation- Initial 138 Cases
- Incubation period was 2-10 days from initial
exposure to onset of fever - Median incubation period was 6 days
- The most common clinical symptoms were
- Fever (100) gt 100.50
- Chills, rigors or both (73.2)
- Myalgia (60.9)
- Cough (57.3)
- Headache (55.8)
- Dizziness (42.8)
- Less common symptoms included
- Sore throat, sputum production, coryza, nausea,
vomiting, and diarrhea
Lee N et al. NEJM April 7, 2003. www.nejm.org
60Severe Acute Respiratory Syndrome (SARS)
- Routes of Transmission
- The principal way SARS appears to be spread is
through droplet transmission1,2 - Namely, when a SARS patient coughs or sneezes
droplets into the air and someone else breathes
them in. - It is possible that SARS can be transmitted
through the air or from objects that have become
contaminated.1,2 - People at risk 1,2
- Direct close contact with an infected person
- Sharing a household with a SARS patient
- HCWs who did not use infection control procedures
while caring for a SARS patient. - In the United States, there is no indication of
community transmission at this time.1,2
- CDC. April 4, 2003. http//www.cdc.gov/ncidod/sars
/faq.htm. - http//www.ada.org/prof/prac/issues/topics/sars.ht
ml
61Severe Acute Respiratory Syndrome (SARS)
- Respiratory illness of viral etiology with onset
since February 1, 2003, and
the following criteria - Measured temperature gt 100.5F (gt38 C)
AND - One or more clinical findings of respiratory
illness - Cough
- Shortness of breath
- Difficulty breathing
- Hypoxia
- Radiographic findings of either pneumonia or
acute respiratory distress syndrome - AND
http//www.cdc.gov/ncidod/sars/casedefinition.htm
62Severe Acute Respiratory Syndrome (SARS)
- Travel within 10 days of onset of symptoms to an
area with documented or suspected community
transmission of SARS - Peoples' Republic of China
- Mainland China
- Hong Kong Special Administrative Region
- Hanoi, Vietnam
- Singapore
- Toronto, Canada (04/21/03)
- OR
http//www.cdc.gov/ncidod/sars/casedefinition.htm
63 Severe Acute Respiratory Syndrome (SARS)
- Close contact within 10 days of onset of symptoms
with either a person with a respiratory illness
who traveled to a SARS area or a person known to
be a suspect SARS case. - Close contact is defined as having
- Cared for
- Lived with
- Direct contact with respiratory secretions and/or
body fluids of a patient known to be suspect SARS
case.
http//www.cdc.gov/ncidod/sars/casedefinition.htm
64Severe Acute Respiratory Syndrome (SARS)Case
Definition 04/20/03
- Suspected Case
- Travel within 10 days of onset of symptoms to an
area with documented or suspected community
transmission of SARS - Excludes areas with secondary cases limited to
healthcare workers or direct household contacts) - Travel includes transit in an airport in an area
with documented or suspected community
transmission of SARS. Areas with documented or
suspected community transmission of SARS - People's Republic of China
- Mainland China
- Hong Kong Special Administrative Region
- Hanoi, Vietnam
- Singapore
- Toronto, Canada.
http//www.cdc.gov/ncidod/sars/casedefinition.htm
65Severe Acute Respiratory Syndrome (SARS)Case
Definition 04/20/03
- Suspected Case
- Close contact within 10 days of onset of symptoms
with a person
known to be a suspect SARS case. - Close contact is defined as having cared for,
having lived with, or having direct contact with
respiratory secretions and/or body fluids of a
patient known to be suspect SARS case. - Probable Case
- A suspected case with one of the following
- Radiographic evidence of pneumonia or
respiratory
distress syndrome - Autopsy findings consistent with respiratory
distress
syndrome without an identifiable cause
http//www.cdc.gov/ncidod/sars/casedefinition.htm
66Severe Acute Respiratory Syndrome (SARS)
- Cause of SARS
- Scientists at CDC and other laboratories have
detected a
previously unrecognized coronavirus in
patients with SARS.1-4 - Confirmed as causative agent by WHO on 04/16/03
- Virus a member of the coronavirus family, never
before seen in humans
1. http//www.cdc.gov/ncidod/sars/casedefinition.h
tm 2. Peiris J et al, Lancet 2003
http//image.thelancet.com/extras/03art3477web.pdf
3. Drosten C et al. NEJM 2003 www.nejm.org 4.
Ksiazek T et al. NEJM 2003 www.nejm.org
67Severe Acute Respiratory Syndrome (SARS)
- Cause of SARS
- Coronaviruses are a group of viruses
that have a halo or crown-like (corona)
appearance when
viewed under a microscope. - These viruses are a common cause of mild to
moderate upper-respiratory illness in humans and
are associated with respiratory,
gastrointestinal, liver and neurologic disease in
animals. - Coronaviruses can survive in the environment for
as long as three to four hours.
1. http//www.cdc.gov/ncidod/sars/casedefinition.h
tm 2. Peiris J et al, Lancet 2003
http//image.thelancet.com/extras/03art3477web.pdf
3. Drosten C et al. NEJM 2003 www.nejm.org 4.
Ksiazek T et al. NEJM 2003 www.nejm.org
68Severe Acute Respiratory Syndrome (SARS)Dental
School, University of Maryland
- Precautions for Dental Patients Who
May Have
Been Exposed to SARS - While taking initial medical histories and at
periodic updates, all dental patients at the
Dental School will routinely be asked about - Recent travel of patient or immediate family
members to areas where SARS is endemic - Peoples' Republic of China
- Mainland China
- Hong Kong Special Administrative Region
- Hanoi, Vietnam
- Singapore
- Toronto, Canada
DePaola L, 2003, University of Maryland Baltimore
69 Severe Acute Respiratory Syndrome (SARS)Dental
School, University of Maryland
- Precautions for Dental Patients Who May Have
Been Exposed to SARS - Recent respiratory illness
- Cough
- Shortness of breath
- Difficulty breathing
- Hypoxia
- Radiographic findings of either pneumonia or
acute respiratory distress syndrome - Close contact with anyone suspected of being
infected with SARS - While taking initial medical histories and at
periodic updates, all dental patients at the
Dental School will routinely be asked whether
they have a history of and/or S S suggestive
of SARS
DePaola L, 2003, University of Maryland Baltimore
70 Severe Acute Respiratory Syndrome (SARS)Dental
School, University of Maryland
- Precautions for Dental Patients Who May Have Been
Exposed to SARS - Patients with a medical history or signs and
symptoms of SARS will be immediately referred to
the University of Maryland Medical System, or
their private physician for medical evaluation
for possible infectiousness. - Such patients should not remain in the Dental
School any longer than required to arrange the
referral. - Elective dental treatment will be deferred until
a physician confirms that the patient does not
have SARS.
DePaola L, 2003, University of Maryland Baltimore
71Severe Acute Respiratory Syndrome (SARS)
- Infection Control Procedures Suspected Cases1-3
- Isolate patients in a separate waiting area
- Give patients a surgical mask to wear
- Instruct patients to cover mouth when coughing or
sneezing - HCWS utilize surgical mask
- Healthcare personnel should apply
- Standard precautions
- Hand hygiene
- Soap and water or alcohol-based hand rub
- Contact precautions when aerosol-generating
procedures
are being performed on patients who may have
SARS. - Gloves, gown, and eyewear
- Airborne precautions
- Respiratory protective devices with a filter
efficiency of greater than or equal to 95 - Recommended with confirmed SARS patients
- http//www.cdc.gov/ncidod/sars/infectioncontrol.ht
m. - http//www.ada.org/prof/prac/issues/topics/sars.ht
ml - DePaola L, 2003, University of Maryland Baltimore
72Severe Acute Respiratory Syndrome (SARS)
- Infection Control Procedures
- For known SARS patients
- Due to rapid development of symptoms it is
unlikely
that SARS will be seen in
the dental office - HCWS utilize NIOSH respirators appropriate for
TB - Defer all elective treatment until patient has
been evaluated - Refer patients for urgent/emergency care to
locations equipped with TB Isolation Areas, i.e.
local hospitals - Follow the Guidelines for Preventing the
Transmission of Mycobacterium tuberculosis in
Health-Care Facilities http//www.cdc.gov/mmwr/pre
view/mmwrhtml/00035909.htm - In summary, healthcare personnel should apply
- Standard precautions
- Contact precautions
- Airborne precautions
- http//www.cdc.gov/ncidod/sars/infectioncontrol.ht
m. - http//www.ada.org/prof/prac/issues/topics/sars.ht
ml - DePaola L, 2003, University of Maryland Baltimore
73Hantavirus Pulmonary Syndrome (HPS)
- An outbreak of unexplained illness occurred in
May 1993 an area of the Southwest shared by NM,
AZ, CO, and UT (Four Corners). - A number of previously healthy young adults
suddenly developed acute respiratory symptoms
about half soon died. - A hantavirus, which is transmitted by rodents,
was suspected. - The virus named Sin Nombre virus (SNV) and its
principal carrier, the deer mouse were positively
identified. - A "bumper crop" of rodents there,
due to heavy rains during
the spring
of 1993. - Determined that person to person
transmission of SNV was unlikely. - SNV had actually been present, but
unrecognized, at least as early as 1959. - Since the discovery in 1993, hantavirus
pulmonary syndrome (HPS) has been
identified in over half of the states
of the U.S.
74Influenza
75Influenza
- Acute, febrile illness, usually self limited
- Headache, malaise, myalgias
- Fever - 104oF-106oF (days 1-3)
- URI symptoms
- Nasal discharge, sore throat, cough (days 2-7)
- Cervical adenopathy (children gt adults) and
rhonchi - Attack rate 10 - 40
- Viral shedding
- One day before - until 10 days after symptom
onset - Peak day 3-4
- Shedding is prolonged in young children
- Transmission
- Person to person via small particle aerosols
- Virus is relatively stable and favors low
humidity and cool
temperatures
www.cdc.gov/ncidod/diseases/flu/fluvirus.htm
76http//www.cdc.gov/nip/Flu/Public.htmFacts
77Flu Facts
- Influenza (flu) is a serious disease
- Flu is not a cold!
- It is far more dangerous than a bad cold
- The virus infects the lungs.
- It can lead to pneumonia/other sequellae.
- Every year in the USA approximately
- 114,000 people are hospitalized
- 20,000 people die because of the flu.
- Most who die are over 65 years old. But small
children less than 2 years old are as likely as
those over 65 to have to go to the hospital
because of the flu.
http//www.cdc.gov/nip/Flu/Public.htmFacts
78Influenza Vaccine
- Type Inactivated split or whole virus
- Route/schedule 0.5 IM annually
- Efficacy 70-90
- Indications
- Age gt 65
- Health care or day care workers
- Nursing home/chronic care residents
- Adults and children with pulmonary and
cardiovascular disorders, chronic metabolic
disease (diabetes mellitus),
renal dysfunction, immunosuppression - Teenagers and children on ASA
- Women in the 2nd and 3rd trimester of pregnancy
- Contraindications Anaphylaxis to eggs
- Side effects
- Local pain, occasional myalgias and rare allergic
reactions
www.cdc.gov/ncidod/diseases/flu/fluvirus.htm
79Prevention and Control of InfluenzaRecommendatio
ns of the Advisory Committee on Immunization
Practices (ACIP)
- The 2002 recommendations include five principal
changes or updates - The optimal time to receive influenza vaccine is
during Oct. and Nov. - However, because of vaccine distribution delays
during the past 2 years, ACIP recommends that
vaccination efforts in Oct. focus on persons at
greatest risk for influenza-related complications
and health-care workers and that vaccination of
other groups begin in November. - Vaccination efforts for all groups should
continue into Dec. and later,
for as long as vaccine is available.
- Because young, otherwise healthy children are at
increased risk for flu-related hospitalization,
influenza vaccination of healthy children aged
6--23 months is encouraged when feasible. - Vaccination of children aged gt6 months who have
certain medical conditions continues to be
strongly recommended. - The 2002--2003 trivalent vaccine virus strains
are A/Moscow/10/99 (H3N2)-like, A/New
Caledonia/20/99 (H1N1)-like, and B/Hong
Kong/330/2001-like strains. - A limited amount of influenza vaccine with
reduced thimerosal content will be available for
the 2002--2003 influenza season.
MMWR. April 12, 2002 / 51(RR03)1-31
80 - The 2002--2003 trivalent vaccine virus strains
are - A/Moscow/10/99 (H3N2)-like
- A/New Caledonia/20/99 (H1N1)-like
- B/Hong Kong/330/2001-like strains
http//www.cdc.gov/mmwr/preview/mmwrhtml/rr5103a1.
htm
81Tuberculosis
82Tuberculosis (TB)
The number one single infectious disease killer
- TB is not on the decline.
- One third of the world's population is
infected with TB - In 1999 TB caused 8,000 deaths/day
- The most deaths from TB in history
- 7- 8 million people become infected with TB/year
- 5-10 of these people will develop active TB
- Between 1993 and 1996, TB increased 13
- TB accounts for more than 1/4 of all preventable
adult deaths the developing world.
nfid.org/factsheets
83Tuberculosis (TB)
The number one single infectious disease killer
- Someone is newly infected with TB
every second ! - TB is the leading killer of women
- TB outranks all causes of maternal mortality
- TB creates more orphans than
any other infectious disease - TB is the leading cause of death
among HIV-positive individuals
nfid.org/factsheets
84Tuberculosis Transmission
- Caused by Mycobacterium tuberculosis
- Spread by
- Airborne route
- Droplet nuclei - Affected by
- Infectiousness of
patient -
Environmental conditions
- Duration of exposure - Most persons exposed do not become infected
85PathogenesisLatent M.tuberculosis Infection
- Inhaled droplet nuclei with M. tuberculosis
- - Reach alveoli
- - Are taken up by alveolar macrophages
- - Reach regional lymph nodes
- - Enter bloodstream and disseminate
- Chest radiograph may have transient abnormalities
- Specific cell-mediated immune response controls
further spread
86PathogenesisActive M. tuberculosis Infection
- Active disease state
- Symptoms present
- Cough
- Fever
- Chills
- Night sweats
- May be infectious
- Disease both treatable preventable
87Diagnosis
of Active TB
- History and epidemiologic clues
- Think TB!!!
- Chest X-ray
- Tuberculin skin test
- AFB smear
- AFB culture
- Nucleic acid amplification
- Fast but sensitivity poor in smear neg.
- Empiric treatment trial
88Administering the Tuberculin Skin Test
- Inject intra-dermally
- 0.1 ml of 5 TU PPD tuberculin
- Produce wheal
- 6 mm to 10 mm in diameter
- Do not recap, bend,
or break needles,
or remove needles
from syringes - Follow universal
precautions for
infection
control
89Reading the Tuberculin Skin Test
- Read reaction
- 48-72 hours
after injection - Measure only induration!
- Record reaction in
millimeters
90Dental Offices
- .No specific dental procedure
has been
classified as cough inducing.
In light of these
observations
the following additional
considerations appear
prudent in dental settings
Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in Health-Care Facilities,
MMWR October 28, 1994 / 43(RR13)1-132
91Risk of Occupational
TB Transmission
Private Dental Offices
- Considered minimal
- Follow CDC/ADA
guidelines - No OSHA regulations
(to date)
Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in
Health-Care Facilities, MMWR October 28, 1994 /
43(RR13)1-132
92TB Guidelines
- During initial medical history and periodic
updates DHCW should - Routinely ask all patients
about a history of TB - And signs and
symptoms
suggestive of TB
Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in Health-Care
Facilities, MMWR October 28, 1994 /
43(RR13)1-132
93TB Guidelines
- All elective dental care should be
deferred until a physician determines - That the patient doesnt have TB
or - Anti-TB therapy has
been rendered and
the patient is no
longer infectious!
Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in Health-Care
Facilities, MMWR October 28, 1994 /
43(RR13)1-132
94TB Guidelines
- If urgent care must be provided for
a patient with active TB or signs symptoms
suggestive of TB, - TB isolation practices
should be implemented - DHCW should use appropriate respiratory
protection while performing procedures on these
patients
Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in Health-Care Facilities, MMWR October
28, 1994 / 43(RR13)1-132
95Emergency Dental Treatment
for TB Patients
- Perform treatment in facilities with TB isolation
capability - Use recommended respiratory protection
- Fit tested HEPA filter mask
- Select least invasive treatment options
- Accomplish definitive care after patient is no
longer infectious - Sputum Negative for Acid Fast Bacillus (AFB)
- Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in Health-Care
Facilities, MMWR October 28, 1994 /
43(RR13)1-132
96Tuberculosis
- Dental-care in high risk facilities
- Use engineering controls similar to those in
general use areas of medical facilities with
similar risk profile. - Evaluation of Dental HCW TB symptoms
- Evaluate promptly
- Do not return to clinic until
- TB Diagnosis is ruled out or
- DHCW is on therapy and non-infectious
Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in
Health-Care Facilities, MMWR October 28, 1994 /
43(RR13)1-132
97CDC/ADA Dental Office
TB Recommendations
Written Plan Should Include
- Protocol for referring TB patients
to dental isolation facility - Protocol for identifying and referring
patients for medical evaluation for TB - DHCW education, training, counseling
and screening - Periodic risk assessment and updates
Guidelines for Preventing the Transmission of
Mycobacterium tuberculosis
in
Health-Care Facilities, MMWR October 28, 1994 /
43(RR13)1-132