SARS Severe Acute Respiratory Syndrome

Document Sample
SARS Severe Acute Respiratory Syndrome Powered By Docstoc
					         Noroviruses



      Niv Seerpi & Mark Sears
Green River District Health Department
Introducing the artiste formerly
known as NLV
 Noroviruses (genus Noroviruses, family
  Caliciviridae) are a group of related RNA
  viruses that cause acute gastroenteritis in
  humans
 These viruses were formerly known as
  “Norwalk-like viruses”
 Were also referred to as Caliciviruses, and as
  Small Round Structured Viruses, or SRSVs
Noroviruses

   Named after the original strain which caused
    an outbreak of gastroenteritis in a school in
    Norwalk, Ohio, in 1968

   Currently, there are atleast five norovirus
    genogroups (GI, GII, GIII, GIV & GV) which in
    turn are divided into at least 31 genetic
    clusters
Clinical Presentation
 Incubation period – 24 to 48 hrs, can be as
  short as 12 hrs
 Acute onset vomiting, watery non-bloody
  diarrhea, abdominal cramps, nausea, low-
  grade fever
 Symptoms usually short-lived, 24-60 hours
 Complete recovery with no long-term
  sequelae
Transmission

 Fecal-oral route, either by consumption of
  fecally contaminated food or water or direct
  person-to-person spread
 Environmental & fomite transmission
 Aerosolization of vomitus results in droplets
  that contaminate surfaces or may enter the
  oral mucosa
Immunity
 Highly contagious
 Shedding usually begins with onset of
  symptoms and may continue for 2 weeks
  after
 Immunity is strain-specific and lasts only a
  few months
 Due to genetic variability of noroviruses,
  individuals are likely to be repeatedly infected
  throughout their life-times
Disease Burden

   CDC estimates that 23 million cases of
    acute gastroenteritis that occur annually
    are due to norovirus infection

   At least 50% of all food-borne outbreaks
    can be attributed to noroviruses
Outbreaks
 Contamination of food by a food handler
  immediately before it’s consumption
 Usually associated with consumption of cold
  foods like salads, sandwiches, and bakery
  products
 Other foods implicated include oysters, and
  produce like raspberries
 Sewage contamination of wells & recreational
  water have led to community outbreaks
Diagnosis

 Use of Reverse Transcriptase Polymerase
  Chain Reaction
 Identification of virus from stool specimens
  taken 48-72 hours after onset
 Older methods include electron microscopy,
  and detection of four-fold increase of specific
  antibodies in acute & convalescent phase
  blood samples
Diagnosis

 Sequencing of noroviruses helps by
  linking cases to each other in Epi
  investigations
 Sequences are entered into CaliciNet –
  a database used to store the different
  sequences of noroviruses
    Management

   Symptomatic therapy to replace fluid
    loss & correct electrolyte disturbances
    through oral and IV fluid administration
Noroviruses in congregate settings

   Noroviruses can spread rapidly in
    congregate living conditions
-   Nursing Homes
-   Schools
-   Cruise ships
In the Green River District

   4 outbreaks of Norovirus in nursing
    homes in the past 4 months

   1 outbreak on a steamboat cruise on
    the Ohio River
What is the Health Departments role
in an outbreak?
 Confirm existence of an outbreak
 Define case
 Data collection
 Coordinate collection of lab specimens & their
  submission
 Institute disease control & prevention measures
 Active surveillance measures
 Determine when an outbreak is over
 Enhanced surveillance post-outbreak
 Data analysis
   Communicate findings
It all began….on a Friday afternoon

   On Friday October 20, 2006, at 3.00 pm the GRDHD
    Epidemiologist was contacted by the ICN at
    Henderson Methodist Hospital

   She relayed information that a steamboat with sick
    passengers was docking at Henderson later that day

   The hospital was asked to prepare to treat these
    patients

   Details about the numbers and the nature of illness
    were not available
Conference Call
   A few minutes later, Dr Thoroughman called to ask
    us to participate in a conference call pertaining to
    illness on board the Mississippi Queen

   The Mississippi Queen had started this cruise on
    October 18 in Cincinnati, OH, and was scheduled to
    dock at Louisville, Henderson, Paducah, Cape
    Girardeau, MO, and conclude in St. Louis, MO on the
    October 25.

   Staff from the Kentucky DPH, Cincinnati DPH, West
    Virginia DPH, CDC & FDA participated in the call
Conference Call (cont)
   A clearer picture of the symptomology was
    presented; although details about numbers affected
    were sketchy

   It was then decided that Niv Seerpi, Epidemiologist
    and Mark Sears, Environmental Director would meet
    the boat at the Henderson riverfront and accompany
    the boat from Henderson to Paducah, which was
    their next stop

   A six member CDC team was to join us in Paducah
CDC Involvement

   Later that evening we were contacted by
    Anandi Sheth, MD, the CDC officer who was
    heading the investigation

   She faxed the Passenger Questionnaire - the
    survey instrument that was to be
    administered to all passengers & crew on
    board
    Mississippi Queen

 We boarded the boat at 8:30 pm that evening
 We spoke with the crew members and made
  arrangements for the questionnaires to be
  handed out
 We also made preliminary recommendations
  regarding infection control & disinfection
 We also examined the vessel’s
  gastrointestinal illness log
    And we are on our way….

   The boat was to depart for Paducah at noon
    on the 21st of October

   A representative of the US Food & Drug
    Administration joined us at the Henderson
    riverfront and accompanied us on the trip
    from Henderson to Paducah
Passengers
   On October 20-21, 34 passengers were treated at
    Methodist Hospital in Henderson for symptoms of
    nausea, diarrhea and dehydration

   Stool specimens were collected from 8 hospitalized
    passengers

   Three passengers were treated at Owensboro
    Medical Health System

   Other passengers who were not ill but wished to
    leave the boat were provided lodging at a hotel in
    Evansville, IN
    Measures

   Outbreak control measures observed:
    – Hand sanitizers were strategically placed
    – All sheets were washed in water >180 degrees F
    – All blankets were replaced with new, all
      bedspreads were removed for dry-cleaning
    – A private cleaning contractor was brought on
      board to wipe down all hard surfaces using
      phenolic-based cleaner
    – Public restrooms were closed
    – No self-service at the luncheon/dinner buffets
Inspection
   During the trip from Henderson to Paducah, the
    GRDHD and FDA Staff checked the water supply,
    food handling practices, general sanitation
    procedures and disease control procedures aboard
    the boat

   In addition, we gathered information from the
    passengers and crew to try to pinpoint a common
    source of contamination

   We obtained completed surveys from 390 of 512
    (76%) passengers and crew onboard
CDC Team arrives…

   The investigation was turned over to the CDC Epi
    Investigation Team and the staff of the Purchase
    District Health Department at the Paducah Riverfront

   As some of the ill passengers were taken to an area
    hospital as well as local hotels, the Purchase District
    Health Department checked for secondary cases and
    educated hotel staff on disease control precautions

   Similar practices were instituted at the hotels in
    Evansville, IN
Cruise discontinued
   This cruise was cancelled at its Cape Girardeau, MO
    stop and all remaining passengers were transported
    by bus to the final destination of St. Louis, MO due to
    continued illness onboard

   A total of 156 passengers (42%) and 16 crew (11%)
    reported illness on this cruise

   CDC Labs confirmed the presence of GII Noroviruses
    in stool specimens that were collected at different
    stops along the way – Henderson, Paducah & Cape
    Girardeau
                             No. of cases




                             10
                                  20
                                       30
                                            40
                                                 50




                         0
                10
                   /15
                10
                   /16
                10
                   /17
                10
                   /18
                10
                   /19
                10
                   /20
                10
                   /21
                10
                                                      Epi Curve-MQ




                   /22
Date of onset   10
                   /23
                10
                   /24
                10
                   /25
                10
                   /26
                10
                   /27
Investigation continues

   Despite a thorough cleaning and sanitization
    supervised by the CDC and the FDA, another
    outbreak occurred on the next cruise, and this
    cruise was discontinued after only 3 days

   The CDC and the FDA continue to investigate
    these outbreaks of noroviruses aboard the
    Mississippi Queen
   Questions??
THANK YOU!!!