Thein Shwe, MPH, MS, MBBSVPD & IBD Epidemiologist

Hot Topics Training11/17/2010

Division of Infectious Disease EpidemiologyOffice of Epidemiology & Prevention Services

Bureau for Public HealthWest Virginia Dept. of Health & Human Resources

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Objectives To describe clinical description, diagnosis and

epidemiology of pertussis

To understand Investigation of a case of pertussis and outbreak of

pertussis

To review a pertussis case study

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Disease DescriptionPertussis, a cough illness commonly known as whooping

cough (100 Day Cough), is caused by the bacterium Bordetella pertussis.

Prolonged paroxysmal cough often accompanied by an inspiratory whoop.

Varies with age and history of previous exposure or vaccination.

Neither infection nor immunization provides lifelong immunity

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Other Bordetella speciesThree other Bordetella species:

B. parapertussis, B. holmesii, and B. bronchiseptica.

B. pertussis and B. parapertussis coinfection is not unusual.

Disease with Bordetella species other than B. pertussis is not reportable.

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Clinical Description of Pertussis

StagesStages

(6-10 wks.)(6-10 wks.)

CatarrhalCatarrhal

(1-3 wks.)(1-3 wks.)

ParoxysmalParoxysmal

(1-2 wks.)(1-2 wks.)

ConvalescentConvalescent

(up to 3 mths.)(up to 3 mths.)

SymptomsSymptoms mild URT mild URT symptoms, symptoms, intermittent intermittent dry coughdry cough

coughing coughing spasmsspasmsinspiratory inspiratory whoop whoop Post-tussive Post-tussive vomitingvomiting

Infants <6 Infants <6 mths. mths.

Gagging, Gagging, gasping or gasping or apneaapnea

No whoopNo whoop ProlongedProlonged

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SOUND OF PERTUSSIS

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Epidemiology of Pertussis

Mode of transmission

Person to person viaAerosolized droplets from cough or sneezeDirect contact with secretions from respiratory tract of

infectious person

80% - secondary attack rate

Older children and adults are important sources of disease for infants and young children

Infants <12 months of age greatest risk for complications and death

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Epidemiology of Pertussis cont.

Reservoir - HumansIncubation period: 7-10 days (5-21 days).Infectious period: Most contagious during the

catarrhal stage (3 weeks before cough) and the first 2 weeks after cough onsetcough onset

Duration of illness:Children: 6-10 wks.~ ½ of Adolescents: 10 wks or longer

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Pertussis ComplicationsSyncope (temporary loss of consciousness/faint)Sleep disturbanceIncontinenceRib fracturesComplications among infants

Pneumonia (22%)Seizures (2%)Encephalopathy (<0.5%)

DeathInfants, particularly those who have not received a primary

vaccination series, are at risk for complications and mortality.

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Pertussis Laboratory Diagnosis

WV OLS offers pertussis PCR and Culture for free of charge

304-558-3530

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Pertussis Laboratory TestingCulture PCR DFA Serology

Specimen NP Swabs or aspirates

NP Swabs or aspirates

NP Swab Blood

Advantages •Gold standard•100% Specific

Results available quickly

Rapid results

Disadvantages •Relatively insensitive•Difficult to isolate•Most successful during the catarrhal stage•Takes 7-10 days to get the result

•Sensitivity & specificity varies

•Calcium alginate swabs cannot be used to collect NP swabs for PCR

•Not confirmatory

•No use for surveillance

•No standardized test available

•No use for Surveillance

Comments Use with culture Use with culture and/or PCR

Use with culture and/or PCR

NP swab=nasopharyngeal swabs, PCR-Polymerase chain reaction, DFA-direct florescent antibody

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Proper Technique for Obtaining a Nasopharyngeal Specimen for Isolation of B pertussis

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http://www.nejm.org/doi/full/10.1056/NEJMe0903992

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& Outbreak Investigation

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CDC/CSTE (2010)http://www.cdc.gov/ncphi/disss/nndss/casedef/pertussis_current.htm

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Pertussis Probable Case Definition

- In the absence of a more likely diagnosis, a cough illness lasting ≥2 weeks, with at least one of the following symptoms: paroxysms of coughing; OR inspiratory "whoop”; OR post-tussive vomiting; AND

absence of laboratory confirmation; AND no epidemiologic linkage to a laboratory-

confirmed (PCR or culture) case of pertussis

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Pertussis Confirmed Case Definition

Option 1 Acute cough illness of any duration with isolation (culture) of B. pertussis from a clinical specimen

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Pertussis Confirmed Case DefinitionOption 2

Cough illness lasting ≥2 weeks, with at least one of the following symptoms:

paroxysms of coughing; inspiratory "whoop"; or post-tussive vomiting

AND

polymerase chain reaction (PCR) positive for pertussis;

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Pertussis Confirmed Case Definition

Option 3Illness lasting ≥2 weeks, with at least one of the

following symptoms:

paroxysms of coughing; inspiratory "whoop"; or post-tussive vomiting;

AND, contact with a laboratory-confirmed (PCR or culture) case of pertussis.

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PERTUSSIS CASE INVESTIGATION

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Importance of Rapid Case Identification

Early diagnosis and treatment to limit disease spread

Identify and provide prophylaxis to close contacts pending laboratory confirmation

When suspicion of pertussis is low, investigation

can be delayed pending laboratory confirmation Exception: prophylaxis of infants and their household

contacts should NOT be delayed

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What is the next step in a case investigation?

Refer to Pertussis Protocol

Use Pertussis WVEDSS form

Begin your case ascertainment

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Resources Needed for Case Investigation

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Resources Needed for Case Investigation cont.

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Resources Needed for Case Investigation cont.

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Resources Needed for Case Investigation cont.

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How do you ascertain a case?

Three pieces of information needed to determine if you have a pertussis case

1. Clinical information

2. Laboratory report(s)

3. Epidemiological information

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Verify the diagnosis

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Epidemiologic Information

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Management of Close Contact(s)

Identify close contactsPrevent secondary transmissionCollect nasopharyngeal swab (if not done so) for PCR

and culture testing at OLSTreat the patient with recommended antibioticsIsolate the patient for 5 days (after the beginning of

antibiotics) or 21 days (if no A/b treatment received)

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Contact TracingClose contact definition

Direct face-to-face contact for a period (not defined) with a case-patient who is symptomatic during the catarrhal and early paroxysmal stages of infection. All residents of the same household; Daycare and baby-sitting contacts; and Close friends, regardless of immunization

status.

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Contact TracingClose contact definition (cont.)

Shared confined space in close proximity for a prolonged period of time, such as >1 hours, with a symptomatic case-patient: or

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Contact TracingClose contact definition (cont.)

Direct contact with respiratory, oral, or nasal secretions from a symptomatic case-patient – example:an explosive cough or sneeze in the face, sharing food, sharing eating utensils during a

meal, kissing, mouth-to mouth resuscitation, or performing s full medical exam including

examination of the nose and throat.

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Contact Tracing of a Pertussis Case

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Management for Exposed persons

Type of ContactType of Contact Evaluate Evaluate & Lab & Lab

VaccinateVaccinate Prophylaxis/Prophylaxis/

treatmenttreatment

AsymptomaticAsymptomatic

Within 3 weeksWithin 3 weeks

NoNo YesYes YesYes

AsymptomaticAsymptomatic

> 3 weeks> 3 weeks

NoNo YesYes Consider for Consider for households with high-households with high-risk contacts (infants, risk contacts (infants, pregnant women, pregnant women, people who have people who have contact with infants)contact with infants)

SymptomaticSymptomatic YesYes

Collect Collect NP NP swabswab

YesYes YesYes

Postexposure Prophylaxis for Pertussis in Infants, Children, Adolescents, and Adults

Source: Red Book 2009 AAP – pg. 507

Age Azithromycin(Recommended)

ErythromycinRecommended

Clarithromycin(Recommended)

TMP-SMX(alternative)

<1mo 10mg/kg/day as a single dose for 5 days

40mg/kg/day in 4 divided dosesx14days

Not recommended CI at <2 mo of age

1-5 mo See above See above 15mg/kg/day in 2 divided doses x 7 days

≥2mo of age:TMP,8mg/kg/day;SMX,40mg/kg/day in 2 doses x 14 days

≥6 mo or older & children

10mg/kg/day as a single dose on day 1(maximum 500 mg); then 5 mg/kg/day as a single dose on days 2-5(maximum 250 mg/day)

40 mg/kg/day in 4 divided doses for 14 days (maximum 2g/day)

15mg/kg/day in 2 divided doses x 7 days(maximum 1 g/day)

See above

Adolescents & adults

500 mg as a single dose on day 1, then 250 mg as a single dose on days 2-5

2g/day in 4 divided doses for 14 days

1g/day in 2 divided doses for 7 days

TMP, 200 mg/day; SMX,1600 mg/day in 2 divided doses x 14 days

TMP- trimethoprin; SMX-sulfamethoxazole; CI - contraindication36

Once the investigation is completed..

Document public health action Check case classification Print the report for your files or per your

LHD policy & procedure Send lab report(s) to DIDE Submit completed WVEDSS report

electronically to your regional epidemiologist and DIDE

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Pertussis Outbreak Case Definition

Outbreak is defined as: Two or more cases Involving two or more households Clustered in time & space AND One case must be confirmed by

positive culture

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Pertussis Outbreak Line List Formhttp://www.wvidep.org/Portals/31/PDFs/IDEP/Pertussis/Pertussis%20Outbreak%20Linelisting

%20Form.pdf

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Outbreak Notification and Control

Notify your regional epidemiologist & DIDE immediately

Evaluate case status & manage close contacts

Obtain nasopharyngeal swabs for culture (confirmation) and PCR

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Outbreak Control in Any Settings

Treat/Prophylax with recommended antibiotic

Isolate 5 days after starting antibiotic treatment or 21 days from cough onset if no treatment

Bring immunizations up-to-dateAccelerated vaccination if cases are occurring young

infants

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Alert your providers and notify the parents…

Healthcare ProvidersSend Health alert letterProvider information sheet

Parent/GuardianSend notification letterPublic information sheet

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Exposures in Child CareExposed Children (especially incompletely

immunized) and childcare providers should beObserved for respiratory tract symptoms for 21 days

after contact with an infectious person has been terminated

Administer vaccine and antibiotics Exclude:

Symptomatic or confirmed pertussis until completion of 5 days of the recommended course of antimicrobial therapy or 21 days if untreated

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Follow up & ReportCheck the status of the outbreak control

Document and update your regional epidemiologist and DIDE when the outbreak is controlled completely

Forward report with lab results to DIDE

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Case StudyOn November 1, 2010, an Infection Preventionist (IP) of

CAMC called your health department to notify you about two 6-month old twins who presented to the ED with cough for 10 days since 10/22/10, apnea and paroxysmal cough, the labs are pending at this time, the ER doctor had high suspicion of pertussis,both babies were admitted to CAMC, andtreated with Azithromycin 10mg/kg/day for 5 days.

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What would you do as soon as you receive a call like this?

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What Information would you collect for contact tracing?

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Contact Tracing Information Six household members and a baby sitter were exposed to these twins

during the infectious period. A baby sitter and 5 of 6 household members have been coughing:

Amy, mother, 30 yo, cough started on 10/23, no vaccine Bob, father, 32 yo, cough started on 10/24, vaccine yes, # of dose -UK Ann, grandma, 67 yo, cough started on 10/16, no vaccine John, brother, 9 yo, no cough, had 4 doses of PCV Julie, sister, 6 yo, cough started on 10/22, had 4 doses of PCV Brad, brother, 4 yo, cough started on 10/24, had 4 doses of PCV Katie, baby sitter, 19 yo, cough started on 10/10, had 3 doses of PCV

3 siblings attend the same elementary school and have been attending school while coughing.

No lab done yet on any symptomatic cases as of 11/1/10None of them has received PEP yet as of 11/1/10

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What is your next step at this time?

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Do you have an outbreak at this time and why?

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On 11/2/10 and 11/8/10Lab results were faxed to your HD:

Name Specimen Source/Date

Type of Test Result Reference

Kevin Smith

NP swab11/1/10

DNA/PCRB pertussis B parapertussis

DetectedNot detected

Not detectedNot detected

Kevin Smith

NP swab11/1/10

CultureB pertussis B parapertussis

Not isolatedNot isolated

Not isolatedNot isolated

Marvin Smith

NP swab11/1/10

DNA/PCRB pertussis B parapertussis

DetectedNot detected

Not detectedNot detected

Marvin Smith

NP swab11/1/10

CultureB pertussis B parapertussis

IsolatedNot isolated

Not isolatedNot isolated

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Information about Close Contacts

All close contacts received PEP.

Nasopharyngeal swabs have been taken from all symptomatic contacts for lab confirmation and all were negative for B. pertussis for PCR and culture.

All symptomatic contacts had at least two weeks of cough.

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Case Ascertainment of Close Contacts

Name Clinical Criteria

Lab Criteria

Epi-linked Case Status?

Amy met negative yes

Bob Not met Negative yes

Ann Met Negative yes

John Met Negative Yes

Julie Met Negative Yes

Brad Not met Not done

Katie Yes Negative Yes

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Do you have an outbreak at this time and why?

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What is your next step at this time?

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SummaryDisease description including clinical characteristics,

laboratory diagnosis and epidemiology

Pertussis case investigation and outbreak investigationCase study

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Resources IDEP Pertussis site:http://www.wvdhhr.org/idep/a-z/a-z-pertussis.asp CDC Pertussis Surveillance Investigation:

http://www.cdc.gov/nip/publications/sur-manual/chpt08_pertussis.pdf

Guideline for Control of Pertussis Outbreak:http://www.cdc.gov/nip/publications/pertussis/gui

de.htm

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References

CDC VPD Surveillance Manual, 4th Edition, 2008 Pertussis: Chapter 10

Pertussis (Whooping Cough) Pg. 504-519, Red Book, 2009 Report of the Committee on Infectious Diseases – American Academy of Pediatrics, 28th Edition

http://www.cdc.gov/vaccines/recs/schedules/adult-schedule.htm

Pertussis Pg. 455-461, Control of Communicable Diseases Manual, APHA & WHO, 19th Edition, David Heymann, MD, Editor

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Questions?

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