Communicable Diseases: Definition

1
Communicable 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

2
CD- 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)

3
Importance 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

4
Communicable 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.

5
Communicable Disease Burden Varies Widely Among
Continents
6
Communicable disease burden in Europe
7
Causes of Death Vary Greatly by Country Income
Level
8
CDs 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

9
CDs 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

10
International 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

11
Human 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

13
Tuberculosis 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.

14
Global Prevalence of TB cases (WHO)
15
Tuberculosis
16
(No Transcript)
17
Tuberculosis 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

18
Malaria

• 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

19
Annual Reported Malaria Cases by Country (WHO
2003)
20
Global malaria prevalence
21
Malaria 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

22
HIV/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.

23
HIV 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

24
Global HIV Burden
25
HIV/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)

26
Avian 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.

27
Avian 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

28
Confirmed human cases of H5N1
29
Migratory pathway for birds and Avian influenza
30
Neglected 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

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Communicable Disease and Human Security

• Part 2 - Mounting an Effective Global Response

32
Approaches 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

33
Personal 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.

34
Utilitarian 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.

35
Regulations 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.

36
Regulation 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)

37
Partnerships 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.

38
Isnt 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
39
A 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.

40
Global Mismatch Between Disease Burden and Health
Spending
41
Global Mismatch Between Disease Burden and Health
Spending
42
Future Population Growth Will be in LICs and MICs
43
Key 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

44
World 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

45
World 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

46
Sources of Development Assistance for Health
Source Michaud 2006
47
Emerging 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.

52
Global 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
53
Geographic 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
54
WNV In USA
WNV is spreading rapidly throughout the
country
12/11/02
55
WNV 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
56
West 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

57
Severe Acute Respiratory Syndrome (SARS)
58
Severe 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
59
Severe 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
60
Severe 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

61
Severe 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
62
Severe 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
64
Severe 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
65
Severe 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
66
Severe 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
67
Severe 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
68
Severe 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
71
Severe 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

72
Severe 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

73
Hantavirus 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.

74
Influenza
75
Influenza

• 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
76

http//www.cdc.gov/nip/Flu/Public.htmFacts
77
Flu 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
78
Influenza 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
79
Prevention 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
81
Tuberculosis
82
Tuberculosis (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
83
Tuberculosis (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
84
Tuberculosis 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

85
PathogenesisLatent 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

86
PathogenesisActive M. tuberculosis Infection

• Active disease state
• Symptoms present
  
• Cough
  
• Fever
  
• Chills
  
• Night sweats
• May be infectious
• Disease both treatable preventable

87
Diagnosis
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

88
Administering 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

89
Reading the Tuberculin Skin Test

• Read reaction
• 48-72 hours
  after injection
• Measure only induration!
• Record reaction in
  millimeters

90
Dental 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
91
Risk 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
92
TB 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
93
TB 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
94
TB 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
95
Emergency 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
  

96
Tuberculosis

• 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

97
CDC/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