Potential Infectious Disease Threats

1
Potential Infectious Disease Threats

• S. Scott Sutton, Pharm.D., BCPS
• Associate Clinical Professor
• University of South Carolina
• South Carolina College of Pharmacy

2
Objectives

• Characterize avian influenza virus
• Compare/Contrast avian influenza versus influenza
• List signs and symptoms of avian influenza
• Discuss treatment and risk to humans from avian
  influenza, SARS, and West Nile Virus

3
Patient CaseEmerging Infectious Diseases
200410(7)1321-1324

• A 39 year-old woman with no underlying disease
  was transferred to our hospital with rapidly
  progressive pneumonia. She reported fever for one
  week, diarrhea, nausea, and vomiting, with no
  early respiratory symptoms. All cultures were
  negative. She was prescribed a fluroquinolone
  antibiotic. On hospital day 5, cough and
  shortness of breath developed. Her antibiotics
  were changed to ceftazidime and amikacin.

4
Patient CaseEmerging Infectious Diseases
200410(7)1321-1324

• The patient and five family members live together
  in central Thailand.
• Her family reported that she was exposed to
  several dead chickens in her neighborhood.

5
Epidemic influenza remains the last great
uncontrolled plague of mankind.
F.M. Davenport
6
DefinitionsCenters for Disease Control
(www.cdc.gov)

• Endemic
• Occurring frequently in a region or population
• Epidemic
• Seasonal outbreak caused by subtypes already in
  existence
• Pandemic
• Global outbreak of disease that occurs
• New influenza A virus appears
• Causes serious illness
• Spreads easily from person to person worldwide
• Influenza
• Highly contagious viral infection that affects
  the respiratory system.

7
InfluenzaNEJM 20053521839-1842

• Typical year
• 30,000 50,000 deaths in United States
• Globally 20- 30 times higher
• 10 pandemics of Influenza A over 300 years
• Subtypes
• A
• B
• C

8
DefinitionsEmerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• There are many subtypes of flu viruses
• Based upon surface proteins
• Hemagglutinin (HA) H1-H15
• Neuraminidase (NA) N1-N9
• Antigenic Drifts
• Minor changes to surface proteins
• Associated with localized outbreaks
• Antigenic Shifts
• Major changes to surface proteins
• Associated with epidemics pandemics

9
InfluenzaEmerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• Influenza A virus that infects humans
• Hemagglutinins
• H1, H2, H3
• Neuraminidases
• N1, N2
• Influenza B virus
• Low propensity for antigenic changes
• Influenza C virus
• Mild illness
• CDC WHO track influenza virus

10
Influenza Pandemicswww.cdc.gov

• 1918-19 Spanish flu or swine influenza
• A (H1N1)
• Highest mortality
• gt 500,000 in United States
• Up to 50 million worldwide
• 50 were young, health adults
• Killed more people than the bubonic plague
• Influenza A (H1N1) circulates today after being
  introduced again in 1970

11
Influenza Pandemicswww.cdc.gov

• 1957-58 Asian Flu
• A (H2N2)
• 70,000 deaths in United States
• First identified in China 02/57
• Spread to U.S. by 06/57
• 1968-69 Hong Kong flu
• A (H3N2)
• 34,000 deaths in United States
• Still circulates today
• 1972-92
• 420,000 deaths in the United States

12
Avian InfluenzaEmerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• Three influenza pandemics during past century
• 1918, 1957, 1968
• Each has been caused by a novel virus of human
  avian origin
• Avian Influenza
• Hong Kong 1997 H5N1
• 18 cases during poultry outbreak
• 9 patients admitted to the intensive care unit
• 11 patients developed pneumonia
• 6 patients died
• All virus genes were of avian origin
• H5 seroprevalence rate up to 10 in poultry
  workers in Hong Kong

13
Avian Influenza H5N1Emerging Infectious
Diseases 200410(7)1321-1324 NEJM
20043501179-88, www.cdc.gov

• H5N1
• Avian influenza transmitted to
• 88 humans in 2004-05
• Prompted concern that the next pandemic is
  imminent
• Striking features
• Predominance of children young adults
• Majority of patients were less than 25 years of
  age
• High mortality rates 68
• H5N1 now endemic in poultry in Asia

14
Avian Influenza Emerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• H9N2
• 1999 20003 in Hong Kong
• Isolated from children
• Mild self-limiting respiratory infections
• Contained internal genes of H5N1
• Endemic in poultry in Asia

15
Avian Influenza Emerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• H7
• Responsible for occasional human disease
• Extensive outbreaks in poultry in 2003
• 87 workers developed conjunctivitis
• 2 cases of respiratory illness
• All genes were avian in origin

16
Avian Influenza Emerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• Human to Human transmission
• Family cluster of three patients in Thailand of
  H5N1
• Evidence of human to human transmission of H7N7

17
Avian Influenza Emerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• Clinical features
• Mild to severe symptoms
• Fever (100)
• Upper respiratory symptoms (67)
• Pneumonia (58)
• Gastrointestinal symptoms (50)
• Other
• Malaise, myalgia, sore throat, cough, rhinitis

18
Patient CaseEmerging Infectious Diseases
200410(7)1321-1324

• A 39 year-old woman with no underlying disease
  was transferred to our hospital with rapidly
  progressive pneumonia. She reported fever for one
  week, diarrhea, nausea, and vomiting, with no
  early respiratory symptoms. All cultures were
  negative. She was prescribed a fluroquinolone
  antibiotic. On hospital day 5, cough and
  shortness of breath developed. Her antibiotics
  were changed to ceftazidime and amikacin.

19
Patient CaseEmerging Infectious Diseases
200410(7)1321-1324

• A 39 year-old woman with no underlying disease
  was transferred to our hospital with rapidly
  progressive pneumonia. She reported fever for one
  week, diarrhea, nausea, and vomiting, with no
  early respiratory symptoms. All cultures were
  negative. She was prescribed a fluroquinolone
  antibiotic. On hospital day 5, cough and
  shortness of breath developed. Her antibiotics
  were changed to ceftazidime and amikacin.

20
Avain / Influenza / SARSNEJM 20043501179-88,
www.cdc.gov
21
Diagnosis Emerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• Clinical symptoms
• History of exposure to dead or ill poultry
• Traditional influenza A tests not beneficial
• HA specific reverse transcriptase polymerase
  chain reaction (RT-PCR)
• Viral culture - nasopharyngeal

22
Patient CaseEmerging Infectious Diseases
200410(7)1321-1324

• A 39 year-old woman with no underlying disease
  was transferred to our hospital with rapidly
  progressive pneumonia. She reported fever for one
  week, diarrhea, nausea, and vomiting, with no
  early respiratory symptoms. All cultures were
  negative. She was prescribed a fluroquinolone
  antibiotic. On hospital day 5, cough and
  shortness of breath developed. Her antibiotics
  were changed to ceftazidime and amikacin.
• Nasopharnygeal aspirates
• positive for Influenza A H5 strain by two RT-PCR

23
Patient CaseEmerging Infectious Diseases
200410(7)1321-1324 www.cdc.gov

• Treatment
• Patient Case
• Antiviral treatment was not administered
• Antiviral Medications
• Antiviral effects are unclear
• Amantadine rimantadine are resistant to H5N1.
• Zanamivir Oseltamavir are unclear
• May be beneficial to give
• Case Reports
• Potential benefit in treatment / prophylaxis
• Decrease viral shedding

24
TreatmentNEJM 20003431778-1787
25
Prevention Emerging Infectious Diseases
200410(7)1321-1324 NEJM 20043501179-88,
www.cdc.gov

• Vaccination
• Principal means of prevention
• No licensed vaccine against avian influenza
• Trials are underway
• Traditional methods not feasible
• Safety
• Antivirals
• Unsure of role
• Preparation

26
West Nile VirusCenters for Disease Control

• First isolated in 1937
• West Nile District of Uganda
• First Appearance in U.S.
• 1999

27
West Nile VirusCenters for Disease Control

• Transmission
• Bite of infected mosquito
• Mosquitoes become infected - feed on infected
  birds
• Salivary glands
• Mosquitoes bite
• Virus may be injected
• Additional transmission routes (small )
• Transplanted organs
• Blood transfusions
• Transplacental (mother child) one case
• Breastfeeding one case
• Laboratory workers two cases

28
West Nile VirusCenters for Disease Control

• Clinical features
• Incubation period
• 3 14 days
• Mild infections
• Often clinically unapparent
• 20 develop mild illness
• West Nile fever
• Symptoms generally last 3 6 days

29
West Nile VirusCenters for Disease Control

• West Nile Fever
• Febrile illness
• Sudden onset

• Symptoms
• Malaise
• Anorexia
• Nausea
• Vomiting
• Eye Pain
• Headache
• Myalgia
• Rash
• Lymphadenopathy

30
West Nile VirusCenters for Disease Control

• Severe Infection
• 1 / 150 infections will result in severe
  neurological disease
• Significant risk factor AGE
• Encephalitis is more common then meningitis

31
West Nile VirusCenters for Disease Control

• Severe Infection
• Fever
• Weakness
• Gastrointestinal symptoms
• Change in mental status
• Rash
• Severe muscle weakness and paralysis
• Neurological presentations
• Ataxia, extrapyramidal signs, cranial nerve
  abnormalities, seizures

32
West Nile VirusCenters for Disease Control

• Treatment
• Supportive
• Hospitalization (esp. for severe infection)
• Intravenous fluids
• Respiratory support
• Ribavirin interferon alpha
• in vitro activity
• No clinical studies

33
West Nile VirusCenters for Disease Control

• Prevention
• Protect from mosquito bites
• Apply insect repellent sparingly to exposed skin
• Heavy application is not necessary
• DEET
• N, N-diethyl-m-toluamide
• Concentration represents how long it protects
• 23.8 DEET provides 5 hours of protection
• 20 DEET provides 4 hours of protection
• 6.65 DEET provides 2 hours of protection
• 4.75 DEET provides 1.5 hours of protection

34
West Nile VirusCenters for Disease Control

• DEET
• gt 50 does not provide increased protection
• DEET Sunscreen
• Apply sunscreen first
• Do not reapply DEET as often as sunscreen
• Reapplication of DEET
• Reapply when being bitten
• Do not apply to cuts, wounds, irritated skin

35
West Nile VirusCenters for Disease Control

• DEET
• Do not apply directly to face
• Children DEET
• American Academy of Pediatrics
• 10 DEET appears to be safe
• Age cut off 2 months and 2 years
• Apply to hands and run onto child
• Avoid eyes, mouth, hands, and ears
• Spray clothing
• Wear long-sleeved shirts and long pants

36
West Nile VirusCenters for Disease Control

• Prevention
• Drain standing water
• Will reduce the number of mosquitoes that can lay
  eggs breed
• Empty water from flower pots, pet food dishes,
  swimming pool covers, buckets and barrels
• Check for clogged rain gutters
• Remove discarded tires
• Screens on windows and doors

37
Objectives

• Characterize avian influenza virus
• Compare/Contrast avian influenza versus influenza
• List signs and symptoms of avian influenza
• Discuss treatment and risk to humans from avian
  influenza, SARS, and West Nile Virus