Case of a Coughing KidAnna Chollet, MD/MPHMarch 6, 2013

Intermittent forceful coughing attacks for 2+ weeks, "like the child is going to die"

Especially at night or in car seat

Coughs up "thick saliva"

Sometimes vomits only when coughing.

19 mo F presents w/cough

More history

Low grade fevers

One episode of diarrhea

Decreased appetite

Lives with mom and another family including 4 other children; no known sick contacts

Physical Exam

HR 145, Temp 98.5, Oxygen sat % 92

HEENT: "Congested nares"; otherwise wnl

CV: regular rhythm, no murmursPULM: Clear to ausc bilaterallyAB: soft, NT, ND, normal bowel soundsEXT: no cyanosisNEURO: interactive, playful, occas

cough

Next steps?

What else do you want to know?

What is on your differential?

What tests would you order?

Lab

Bordatella pertussis culture:

POSITIVE!

B. pertussis or whooping coughTos Ferina o Tos

Convulsiva3 Stages:

1. Catarrhal: 7-10 days. Coryza, low fever, mild cough

2. Paroxysmal: 1-6 weeks, up to 10 weeks. Paroxysms of coughs, thick mucus expulsion, inspiratory "whoop", cyanosis, vomiting

3. Convalescent: 7-21 days. Gradual recovery, decreasing paroxysms, may recur

Characteristics

Paroxysmal cough

Inspiratory "whoop"

Prolonged cough (2+ weeks)

PathogenesisInfection by respiratory droplets

Bacteria target cilia of respiratory mucosa

Bacteria produce toxins which immobilize cilia, damage respiratory epithelium, induce mucus release, inflammation of resp tract

Incubation period: usually 7-10 days

Most contagious during catarrhal period (1-2 weeks) and first 2 weeks of paroxysmal phase

Epidemiology

Worldwide annual incidence in children < 1 yo is 10 million

400,000 deaths per year worldwide

Incidence has increased since 1980s in US:

- more sensitive tests - increased awareness - improve reporting- whole cell > acellular vaccine

EpidemiologyMost affected: Infants too young to be fully

immunized, less than 6 months old

Hospitalized infants: Apnea 50%, PNA 20%, 1% SZ, 1% death

~50% reported cases in adolescents and adults

Usually contracted from family member, especially parents!

Clinical Case Definition

If outbreak, cough >= 2 weeks

If endemic or sporadic case, cough >=2 wks

plus 1+ of the following:- paroxysms of cough- inspiratory "whoop"- post-tussive vomiting- no other apparent cause

Diagnosis

Acute cough with positive culture

Positive PCR with clinical case definition

Clinical case definition and known exposure to patient with positive culture or PCR

TestingGold std: nasopharyngeal swab

culture BUT low sensitivity (30-60%-->1-3%

by 3 weeks)

PCR: nasopharyngeal sample. More sensitive, rapid results BUT no inter-lab std, more false positives

WBC < 9,400 to rule out

Testing continued

Some evidence that PCR + serology is most sensitive for ruling out in exposed pts (level 2)

CDC does not accept serology for diagnosis

ComplicationsPneumonia, pneumothorax, pulmonary

hypertension, apnea, respiratory failure, syncope

Seizure, encephalopathy, cerebral hypoxia

FTT from vomiting, incontinence

Inguinal hernia, rectal prolapse, rib fx

But she was vaccinated!

Vaccine does not eliminate risk for infection

Increased cases in 2012 nationwide

Waning immunity?

Drift in bacterial strains?

When and why antibiotics?

Start if pt >1 yo within 3 wks of cough onset

if pt <1 yo within 6 wks of cough onset

Reduce transmission to others

Unlikely to improve dz course

Prophylaxis in exposed persons

Post-exposure prophylaxisSame dosage as for treatment

Within 3 weeks of exposure of close contact:

- close proximity to symptomatic pt >1 hr

- direct contact with secretions of symp pt

- face to face exposure w/in 3 ft of symp pt

High risk pts:< 1 yo, 3rd trim,

immunocompromised, underlying lung disease

Vaccines: safest prevention DTaP: 2, 4, 6 mos, then 15-18 mos, then 4-6 yrs

Close contact < 7 yo --> complete series

Close contact <7 yo: if 3rd dose >6 mo prior to exposure --> give 4th dose

Tdap for 10-64 yo post-exposure not eval'd

Infection 6x more likely in unvaccinated

At least 2 doses needed for protection. 5-6 yrs of protection

Treatment

Azithromycin< 6 mo 10 mg/kg/day x 5 days>= 6 mo 10 mg/kg/day on day 1 then 5 mg/kg/day for day 2-5Adult (or adult size?) 500 mg day 1, then 250 mg day 2-5

TMP-SMX in pts >2 months old and macrolide ineffective/not tolerated

Treatment SettingHome care if uncomplicated dz

No school/work for 5 days after starting abxIf no Rx, no school until 21 days of cough

No exclusions for asymptomatic contacts

Hospitalize if apnea, hypoxia, pneumonia, resp distress, need for supp O2, extreme leukocytosis, poor feeding

Droplet precautions until 5 days of abx

Take Home

Stay vigilant for pertussis in cough > 2 wks!

Vaccinate!

Treat contacts, if possible

Azithro easier to use than erythro

Advise parents on expected time course

Referenceshttp://www.cdc.gov/pertussis/clinical/features.html

Brown, M. Pertussis outbreaks on the decline, but immunization gaps still exist. AAFP News Now 1/31/2013 www.aafp.org/online/en/home/publications/news/news-now/health-of-the-public/20130131pertussisdown.html

Via DynaMed "Pertussis":Wood, N, McIntyre P. Pertussis: review of epidemiology, diagnosis, management and

prevention. Paediatric Respiratory Review. 2008 Sep;9(3): 201-11.

Cornia PB, Hersh AL, Lipsky BA, Newman TB, Gonzalez R. Does this coughing adolescent or adult parent have pertussis? JAMA. 2010 Aug 25;304(8): 890-6

Heininger U. Update on pertussis in children. Expert Rev Anti Infect Ther. 2010 Feb; 8(2): 163-173

MMWR Recomm Rep 2005 Dec 9;54 (RR-14):1 full-text

Wkly Epidemiol Rec 2010 Oct 1;85(40): 385

JAMA 2000 Dec 27;284(24): 3145