Arboviral Diseases

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Arboviral Diseases
Presented by Kathi Rose Malloy, RN, BSN
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• Information courtesy of
• Department of Health and Human Service Centers
  for Disease Control and Prevention

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Background Arthropod-borne Viruses (Arbovirus)

• Viruses spread via the bite of an arthropod, most
  commonly a tick or mosquito
• Approximately 80 arboviruses known to cause human
  disease
• In the Eastern region of the United States the
  two most important types of arboviruses include
  Eastern Equine Encephalitis (EEE) West Nile Virus
  (WNV)

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Background Eastern Equine Encephalitis

• EEE first isolated in the US in 1933
• Most commonly found in North America, Central and
  South America, and the Carribean
• In the US, most cases reported from the eastern
  seaboard states, the Gulf Coast, and some inland
  midwestern states

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Background West Nile Virus

• West Nile virus was first recognized in the US in
  1999 in metropolitan New York City
• More commonly found in Africa, West and Central
  Asia, and the Middle East
• It is unknown how the virus arrived in the US

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EEE in the United States
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Spread of West Nile virusby state, 1999-2002.
West Nile Virus Activity in the U.S. in Birds,
Horses, Mosquitoes, Animals, or Humans.
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West Nile Virus in the United States as of
October 15, 2003
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Maryland's Arbovirus Surveillance Testing
Results 2003(Updated 01/08/04)

• Avian
• West Nile virus was established as endemic in
  Maryland in 2002. Therefore, the Maryland
  Department of Health and Mental Hygiene (DHMH)
  discontinued pickup and testing of dead birds in
  2003.

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Maryland's Arbovirus Surveillance Testing
Results 2003(Updated 01/08/04)

• Equine
• One-hundred and eighty (180) Maryland horses
  tested positive for West Nile Virus (WNV)
  infection in 20 jurisdictions in 2003.
• Sixty-six (66) of the 180 horse cases were
  fatal.

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Maryland Jurisdictions with WNV in horses - 2003

• Anne Arundel 16
• Baltimore 6
• Calvert 3
• Caroline 10
• Carroll 40
• Cecil 2
• Charles 8
• Dorchester 2
• Frederick 24
• Harford 5

• Howard 8
• Kent 4
• Montgomery 14
• Prince Georges 9
• Queen Annes 10
• St. Marys 7
• Somerset 1
• Talbot 7
• Washington 3
• Worcester 1

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Maryland's Arbovirus Surveillance Testing
Results 2003(Updated 01/08/04)

• Mosquitoes
• Over 195,000 mosquitoes were tested in Maryland
  between June 1 and October 31, 2003. A total of
  62 mosquito pools in 13 jurisdictions tested
  positive for West Nile Virus during that time.
  One pool of Culiseta melanura mosquitoes
  collected in Worcester County tested positive for
  both WNV and EEE.

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Maryland Jurisdictions with WNV in mosquitoes -
2003

• Alleghany 1
• Anne Arundel 10
• Baltimore Co 15
• Caroline 1
• Carroll 3
• Charles 1
• Dorchester 5

• Frederick 3
• Prince Georges 3
• Somerset 3
• Talbot 1
• Wicomico 2
• Worcester 11
• Baltimore City 3

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Maryland's Arbovirus Surveillance Testing
Results 2003(Updated 01/08/04)

• Humans
• Seventy-three (73) human WNV cases (63 confirmed,
  10 probable) have been reported this year in 13
  jurisdictions.
• Five (5) WNV related fatalities have been
  reported to date.

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Maryland Jurisdictions with WNV in humans- 2003

• Anne Arundel 7
• Baltimore City 14
• Baltimore Co 17
• Caroline 1
• Carroll 2
• Charles 1
• Frederick 3

• Harford 2
• Howard 3
• Montgomery 10
• Prince Georges 4
• Queen Annes 5
• Washington 4
• Total 73

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Eastern Equine Encephalitis Surveillance in MD,
2003

• Mosquitoes - Ten (10) pools of Culiseta melanura
  mosquitoes in two jurisdictions (Wicomico and
  Worcester Counties) have tested positive for EEE
  in Maryland. A single pool of C. melanura
  mosquitoes collected in Worcester County tested
  positive for both WNV and EEE.
• Horses - Three horses in Worcester County have
  tested positive for EEE. All three were fatal
  cases. None of the horses had received the EEE
  vaccine.
• Ratites (Flightless birds) - One (1) emu in
  Wicomico County has tested positive for EEE.

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Transmitting WNV infection
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Additional Transmission

• Blood Transfusions
• Additional evidence shows WNV can be spread via
  blood transfusions
• CDC, FDA, HRSA, State and local Health
  Departments have ongoing investigations
• A blood screening test has been developed
• Breast milk
• Health benefits of breastfeeding are well
  established
• Risk of WNV transmission via breast milk unknown
• No suggested changes in breast feeding
  recommendations

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Symptoms EEE

• Most people have no symptoms
• Central Nervous system symptoms develop 4-10 days
  after being bitten
• Sudden onset of fever, muscle aches, headache
• May progress to more severe symptoms such as
  seizure and coma (encephalitis)
• 30 to 50 of patients with encephalitis die of
  the disease

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Symptoms West Nile virus

• Most people do not develop symptoms
• An estimated 20 become ill 3-15 days after being
  bitten
• Mild illness fever, headache, body aches, and
  sometimes skin rash and swollen glands
• An estimated 1 in 150 persons infected develop a
  more severe form of the disease
• West Nile encephalitis inflammation of the
  brain, high fever, stiff neck, stupor,
  disorientation, coma, tremors, convulsions,
  muscle weakness, and paralysis few cases have
  been fatal

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Geographic Risks

• People are only at risk when EEE and West Nile
  Viruses are circulating in nature
• Northern states at risk during summer
• Southern states at risk year round
• Marylands Eastern Shore is in a moderate climate
  and therefore at risk until the first killing
  frost
• Killing frost is defined as 27-28?? Fahrenheit
  for at least 4 hours

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High Risk Persons

• Risk of arboviral encephalitis is higher for the
  youngest and oldest (50) segments of the
  population
• People living in an area where the disease is
  common
• People who work outside or participate in outdoor
  activities in areas where disease is common

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Human Illness

• EEE fewer than 5 cases are reported in most
  years. Last human death in Maryland was in 1989
  (Dorchester County)
• WNV in the most affected areas of New York City
  only 2.6 population infected

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Treatment

• No specific therapy for infection of EEE or West
  Nile viruses
• Arboviral encephalitis treated by
  hospitalization, intravenous fluids, respiratory
  support, prevention of secondary infections, and
  good nursing care

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Vaccine

• Not available for humans
• Horse vaccine is available generally
  recommended annually in March, may booster
  mid-late summer in years where disease activity
  present

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Prevention and ControlFIGHT THE BITE !

• AVOID MOSQUITO BITES
• Apply insect repellent to exposed skin when
  outdoors. The most effective contain DEET.
  Higher concentrations equals longer protection.
  Over 50 does not increase length of protection.
• Use care in applying repellent to children dont
  put repellent on their hands and avoid their
  mouths and eyes. Products containing 10 DEET or
  less recommended for children 2-12.
• When possible, wear protective clothing while
  outdoors

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• Spray clothing with repellents
• Consider staying indoors between dusk and dawn to
  avoid peak mosquito biting time
• Avoid areas where mosquitoes are prevalent
• Fix or install window or door screens to keep
  mosquitoes out of buildings

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• AVOID CREATING MOSQUITO BREEDING AREAS DRAIN
  STANDING WATER WHERE POSSIBLE
• MOSQUITO SPRAYING
• Community based
• Public Health Emergency

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Summary

• EEE and West Nile encephalitis are NOT
  transmitted person to person
• There is no evidence that a person can get the
  virus from handling live or dead infected birds.
  However, persons should avoid bare-handed contact
  when handling any dead animals and use gloves or
  double plastic bags to place the carcass in a
  garbage can.
• There is no evidence that the virus can be
  transmitted to humans through consuming infected
  birds or animals, but procedures for fully
  cooking meat should always be used.
• Although the vast majority of infections have
  been in birds horses, and other mammals may be
  infected
• If you think you are infected and display any of
  the symptoms, contact your health care provider
  or doctor immediately.

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Additional Info

• Websites
• Worcester County Health Department
  www.worcesterhealth.org
• Department of Health and Mental Hygiene Disease
  control
• www.edcp.org
• Centers for Disease Control
• www.cdc.gov
• Maryland Department of Agriculture
• www.mda.state.md.us

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Reporting concerns

• Standing Water Reports Worcester County Dept of
  Development _at_ 410-632-1200
• Mosquito Spraying Worcester County Mosquito
  Control _at_ 410-632-3767
• Dead bird Disposal State Health Topics Hotline
  _at_ 1-866-866-2769