Whooping Cough (Pertussis)

Pertussis also called whooping cough (kaalee khaansee, kukurakhaansee) . It is a highly infectious respiratory disease caused by the Bordetella pertussis bacterium (Gram-negative).

Pertussis can cause violent and rapid coughing. This infection known for uncontrollable, violent coughing that often makes hard to breathe.

Whooping cough or pertussis is a higly contagious disease, it can be deadly for babies. It spreads from person to person, usually by coughing or sneezing of infected individuals.

Pertussis can affect all age groups of people, but can be very serious and even deadly for babies less than a year old.

The best way to prevent pertussis infection is by getting vaccinated.

Epidemiological Triad

Agent – The causative agent of whooping cough (pertussis) is Bordetella pertussis, gram-negative bacteria.

This causative agent is present in the nasopharyngeal, broncheal secretions of whooping cough patient’s and also present in the object which are freshly contaminated.

Whooping cough is most infectious during catarrhal (initial) phase stage.

Pertussis or whooping cough,is a human disease. No animal or insect source or vector of whooping cough is known to exist.

Host factor- Whooping cough mostly occurs in infants and pre-school children highly incidence is seen in children below 5 years of age.

Environmental factor-  Most occurs during winter and spring seasons, Overcrowding places.

Low socio-economic status also one of factors of the environment.

Modes of Transmission

Pertussis or whooping cough is highly communicable infection.  Transmission most commonly occurs by the respiratory route-

1. Droplet infection

2. Droplet nuclei

3. Personal contact

4. Contact with airborne droplets of case of respiratory secretions.

5. Contact with freshly contaminated articles of an infected person, this transmission occurs is less frequently.

Persons with whooping cough are most infectious during the initial (catarrhal) period and the first 2 weeks after cough onset.

 Incubation Period

The incubation period of pertussis is commonly 7–14 days, with a range of 4–21 days.

Pertussis (whooping cough) can cause serious and contagious illness in babies, children, teens, and adults.

Symptoms of whooping cough usually develop within 5 to 10 days after the exposure of infection.

The period of communicability of whooping cough is considered  as one week after the exposure to about 3 weeks after the onset of paroxysmal stage (paroxysmal stage of whooping cough is characterized by recurring and intense episodes of coughing; coughing fits, whooping sounds produced).

 Pathophysiology of Pertussis

1. Bacteria attach to cilia of the respiratory epithelial cells

2. Produce toxins that paralyze the cilia

3.  Librates numbers of antigen and toxins

4. Inflammatory response to mucosa (nasopharynx to bronchioles)   and secretion appear

5. Cause inflammation of respiratory tract, damage of local epithelium which interfere with the clearing of pulmonary secretions and symptoms occurs.

Clinical Features – Sign and Symptoms of Pertussis

Whooping cough has three stages-

1. Catarrhal stage – Duration; 1-2 weeks

Characterized by –  

The onset of coryza (runny nose , nasal congestion, sneezing) 

Low – grade fever, occasional cough within about 10 days

The cough gradually becomes more severe, and after 1–2 weeks, the second, or paroxysmal stage, begins.

2.  Paroxysmal cough stage  – Duration; 1-6 weeks

Characterized by –

Rapid coughs and Paroxysmal attacks

Difficulty expelling thick mucus from the tracheobronchial tree

Long inspiratory effort usually accompanied by a characteristic high-pitched “whoop” at the end of the paroxysms.

During paroxysmal attacks, the patient may become cyanotic (turn blue).

Children and young infants appear very ill, sick and distressed.

Vomiting and exhaustion due to the episode

Increase in frequency during the first 1-2 weeks, remain at the same frequency for 2-4 weeks, and then gradually decrease.

3. Convalescent stage – Duration; weeks to months

Characterized by –

Recovery is gradual

Persistent cough becomes less paroxysmal and disappears in 2 to 3 weeks

Early symptoms can last for 1 to 2 weeks and usually include-

1. Runny nose

2. Low-grade fever

3. Mild, occasional cough

4. Apnea – a pause in breathing (in babies)

Later-stage Symptoms – After 1 to 2 weeks and as the disease progresses, the symptoms of pertussis may appear and include –

1. Paroxysms attack (fits) of many, rapid coughs followed by a high-pitched “whoop” sound

2. Vomiting during or after coughing fits

3. Exhaustion (very tired) after coughing fits

Laboratory Diagnosis

Laboratory tests –

1. Bacterial culture – nasopharyngeal (NP) swab or nasal aspirate

2. Polymerase chain reaction (PCR) test to detects genetic material (e.g., DNA) from the bacteria – taken nasopharyngeal (NP) swab or nasal aspirate sample

3. Serology – Blood test for antibodies (IgA, IgG, IgM)

Prevention of Pertussis

1. Vaccine

Pertussis vaccine protects against whooping cough (pertussis).These vaccines are also provide protection against tetanus and diphtheria.

Pertussis vaccine are two main types: whole-cell vaccines and acellular vaccines. 

1. Whole-cell pertussis vaccine

Vaccines of this type, prepared from suspensions of inactivated Bordetella pertussis bacterial cells.

(DTwP)

2. Acellular pertussis vaccines

Vaccines of this type, contain purified, inactivated components (toxins) of B. pertussis cells.

Infants and children younger than 7 years old receive DTaP  (Diphtheria, Tetanus, Acellular Pertussis), while older children,  adults and pregnant women receive Tdap (Tetanus, diphtheria and Acellular pertussis).

Single dose of Tdap recommends for healthcare personnel who have not previously received Tdap and who have direct patient contact.

2. Immunisation

1. Combined vaccine 

 DPT is given intramuscularly in three primary doses – at 2, 4, and 6 months; at an interval of 1 months.

Two Booster dose of DPT is administered at age of 18-24 months  and 4 through 6 years. This combined vaccine protects the infant against diphtheria, whooping cough and tetanus.

2. Single vaccine

0.5ml I/M given in 3 doses, at interval of 6-8 weeks.

Note – It should not given to individuals with epilepsy, convulsions, febrile conditions, allergy to triple vaccine DPT or any person having CN S disorder.

Control of Whooping Cough

1. Early diagnosis

2. Isolation

3. Treatment – Antibiotic treatment; Erythromycin, Ampicillin, Septran, Tetracycline

Clinical Complications of Pertussis

In Babies and Children

1. Pneumonia (lung infection)

2. Convulsions (violent, uncontrolled shaking)

3.  Apnea (slowed or stopped breathing)

4. Seizures and Encephalopathy (disease of the brain) – more common among infants

5. Hypoxia (reduction of oxygen supply) from coughing or toxin

6. Otitis media

7. Urinary incontinence

8. Anorexia

More severe complications can include-

1. Dehydration.

2. Pneumothorax (collapsed lung)

3. Epistaxis – (nosebleeding) 

4. Subdural hematomas

5. Hernias

6.  Rectal prolapsed (rectum protrudes from the anus) 

In Adolescents and Adults

1. Weight loss

2. Loss of bladder – Urinary incontinence

3. Rib fractures from severe coughing

4.Syncope