PERTUSSIS or WHOOPING COUGH

Presented by – Mohamed Akmal Khan MBBS ( VII SEM) IIMS&R ,LUCKNOW

INDEXINTRODUCTIONEPIDEMIOLOGICAL DETERMINANTSINCUBATION PEROIDCLINICAL COURSECOMPLICATIONSTREATMENT AND CONTROL

INTRODUCTIONPertussis is also called as Whooping cough

is a highly contagious disease mainly of children caused by Bordetella pertussis.

It is characterized by severe uncontrollable coughing spells which can sometimes end in a “whoop” sound when person breathes in.

Also called as “100 day cough” by Chinese.

In 2012, 2.49 cases were reported by WHO globally when the DPT immunization was 83%.

In India after launch of immunization programme in 1987, the reported cases dropped from 1.63 lakh to only 36,661 cases in 2013 ( 77% decline)

Underlying malnutrition and other respiratory infections in children make then prone to this disease.

Recently the disease shows increase incidence in older children, adolescents and adults.(21% adults had pertussis after serological studies of adults with cough for more than 2 weeks)

Epidemiological DeterminantsAGENT FACTORS- Agent -Causative agent is Bordetella

pertussis. Also caused by B.parapertussis, Viruses(parainfluenzae,

adenovirus)

Source of infection- Only man is the known source of infection.

Pervious case of pertussis which may be mild, missed and unrecognised case is usually the source of infection.

No chronic carrier state existInfective material –Nasopharyngeal and

bronchial secretion. Fomites contaminated by such discharge

are also infective.

Infective period- Catarrhal stage most infective.

Extends from week after exposure to about 3 weeks after onset of paroxysmal stage.

Secondary attack rate- Average 90% in unimmunized people.

HOST FACTORS Age- Infants and pre-school (<5 years) - Developing countries (20-30 months) and developed countries (50 months) -Highest mortality below 6 months. Sex- More common among females. Immunity-Immunity develops after a case or

immunization. No cross immunity. Secondary attack occur in declining

immune person.

ENVIRONMENT More cases occur during winter and

spring. Lower socio-economic group more prone

than well to do groups due to overcrowding.

INCUBATION PEROIDUsually 7-14 days but not more than 3

weeks

CLINICAL COURSECauses local infection by multiplying in the

surface epithelium of respiratory mucosa.Leads to inflammation and necrosis of

mucosa.Occurs in 3 stages- 1. Catarrhal stage 2. Paroxysmal stage 3. Convalescent stage

1. Catarrhal stage- - Lasts for 10 days. - Characterized by: Insidious onset Lacrimation Sneezing Coryza Anorexia Malaise Hacking night cough that becomes

diurnal

2. Paroxysmal stage -Lasts for 2-4 weeks -Characterized by burst of rapid,

consecutive coughs followed by a deep, deep

pitched inspiration (whoop) - Followed by vomiting In infants- Causes cyanosis and apnoea In adults and adolescents-

Uncharacteristic,persistent cough

3. Convalescent stage- Lasts for 1-2 weeks Decrease in paroxysms of coughing

both in freq and severity Cessation of Vomiting

ComplicationsOccurs in 5-6% casesFrequent in infants aged less than 6 monthsMainly- Bronchitis - Bronchopneumonia (5.2%) -Bronchiectasis -Subconjuctival hemorrhage -Epistaxis -Heomptysis -Punctate cerebral hemorrhage -Coma and convulsions

Control of whooping coughCases and contacts- 1. Cases- Early diagnosis by

bacteriological exam. of nose and throat secretions (60% chances within 10-14 days from onset)

- Isolation of case - Treatment of case- Erythromycin 30-50 mg/kg for 10 days Septran , Ampicillin and Tetracycline can also be used.

Given during incubation or in early catarrhal stage to prevent or moderate clinical pertussis.During paroxysmal stage only eliminate bacteria from nasopharynx eliminating transmission

2.Contacts -Isolation of case -Prophylactic antibiotics (Erythromycin or

Ampicillin ) treatment for 10 days to prevent

establishment of case in exposed infants.

Active immunization- Covered under National Immunization

Programme -Combined as DPT, DTWP or DTaP vaccine. -Administered as 3 dose ( each dose 0.5 ml)

IM at 1 month interval starting at 6 weeks. -Booster dose at 18-24 months -Acellular vaccine for older children and

adults

Efficacy 85%Duration of protection 6-12 years following complete

dose+ boosterHIV positive individuals should also be immunizedAdverse reactions- Early vaccine caused screaming and collapse. -Give rise to local reactions at site of injection, mild fever and irritability -Rare vaccine reaction are-

Inconsolable screaming, seizures, hypotonic hypo- responsive episode, anaphylactic reaction and encephalopathy

Contraindications- Anaphylactic reactions, encephalopathy, history of epilepsy, convulsions or similar CNS disorders , any febrile episode and reaction to previous triple vaccine

• Passive immunization- Hyperimmune globulin is given but efficacy

no established yet.

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