All You Need To Know About Whooping Cough (Pertusis)

Whooping-cough is an acute infectious disease with the droplet mechanism of transmission, is characterized by the cyclic prolonged duration and presence of paroxysmal cough attacks, absence of intoxication.

Etiology:  gram negative bacterium Bordetella pertussis

Epidemiology:

Humans are the sole reservoir of B. Pertussis (from the last days of the latent period up to 30 days, the disease has begun.

Infection is spread by way of droplets (droplet mechanism, air-droplet way of transmission) produced by the coughing of infected persons.

Pertussis is highly contagious. More than 90 % of susceptible house hold contacts become infected. More often occurs in infants (who were not vaccinated).

Pathogenesis      

Entrance gate  is URT mucus membrane;

Due to several surface adhesions B. Pertussis attach to the respiratory epithelium of trachea;

colonization on a cylinder epithelium, toxin production;

local inflammatory processes, necrosis (catarrhal period);

The organism rarely invades tissues but produces the characteristic disease by Pertussis toxin systemic effects at distant sites in CNS (respiratory center, vascular center):

violation of breathing rhythm , hypoxemia, hypoxia;

vascular disorders + hypoxia = encephalopathy.

formation of stagnant excitation focus in the brain.

prolonged clinical disease.

Clinical presentation.

Incubation period typically is 7 to 10 days, but may be as short as 3 days, or as long as 20 days.

Catarrhal (prodromal) 7-14 days period: Whooping cough begins as an undifferentiated, typically subfebrile, upper respiratory tract infection with corryza and dry cough, more in the nighttime (with its gradual intensification). Toxic syndrome is absent.

Paroxysmal stage (4 -6 weeks) appears during the second week.

Paroxysmal cough should always alert the physical to the diagnosis. These paroxysms occur at variable intervals, and between episodes the patient usually appears comfortable, without signs of severe illness.

In young infants coughing may be accompanied by an inspiratory whoop. In the end of the cough – discharge much of transparent viscous phlegm. Vomiting, cyanosis, face swelling, apnea or respiratory arrest may complicate paroxysms of coughing. After severe paroxysms the patient may perspire profusely and appear exhausted. Subconjunctival hemorrhages, petechia, or epistaxis may result from severe spasmodic coughing.

The severing and frequency of these paroxysms of cough usually peak during the second or third week of the illness, but coughing can persist for 3 months or longer.

Hemorrhages in sclera, nose-bleeds, petechia on face are typical for this period.

Ulcer on the tongue frenula (Filatov’s sign) is Whooping cough characteristic sign.

Changes in other systems and organs: 

whooping cough lung (hard breathing, emphysema, intensification of pulmonary picture), bronchitis, bronchiolitis, pneumonia, athelectasis;

high blood pressure, tachycardia;

encephalopathy (anxiety or apathy, tremor, bad sleeping, seizures);

diarrhea (in infants).

Recovery period for 2 – 4 weeks

a cough loses spasmodic character, becomes easier, more rare;

vomiting disappears;

Asthenia for long period.

Typical Whooping cough severity

Signs		Mild	moderate	Severe
Prodromal period		9 – 14 days	6 – 9 days	3 – 5 days
Paroxysmal		4 – 5 weeks	5-6 weeks	6 – 8 weeks
Coughing number (per day)		Up to 15	16 - 25	> 25
Whoops number		3 – 5	10	> 10
Coughing number (between two woops)		3 – 5	6 – 9	10 – 12
Coughing paroxysm duration		Short	Prolonged	Very long with vomiting, hemorrhages, urination or defecation in the end
Apnea		Absent	Absent	Present
Complications		Absent	May be present	Typical
General condition		satisfactory	disorders of sleep, excitation, irritates	malaise, lowering of appetite, violation of sleep
Vomiting		Rare	Often	Often repeating
Cyanosis	In the rest	perinasal	perinasal	Perinasal, acrocyanosis
	During cough	Increased	Face	Face
Edema		Face, eyelids after the paroxysm	Constantly	Constantly
Hemorrhages		rare	often	Very often
Lungs symptoms		emphysema	Emphysema, single wheezes, rales	Emphysema, pneumonia
CNS symptoms		-	-	encephalopathy

Complications:

pneumonia (specific, caused by B.pertussis or secondary, caused by other bacteria);

encephalopathy;

apnea;

hemorrhages into sclera, skin, brain, inner organs, nasal bleeding;

umbilical or inguinal hernia;

prolapsed rectum mucous membrane;

pneumomediastinum or pneumothorax;

ulcer under the tongue.

Peculiarities of the pertussis in young infants:

Incubation and catarrhal periods are shorter (few days).

Paroxysmal period is longer (60-90 days).

Whoops are absent.

Apnea occurs often.

Paroxysms of sneezing.

Often pneumonia, encephalopathy may develop.

Laboratory Tests

A culture of nasopharyngeal secretions for B. pertussis may confirm the diagnosis.

Direct fluorescent antibody staining of nasopharyngeal secretions.

Serologic tests (AR, PHAR): antibody to pertussis toxin measured by enzyme-linked immunosorbent assay.

WBC count may be elevated above 15 000/ mm³ with 70 % or more lymphocytes.

PCR positive for B. pertussis from the nasopharyngeal mucus.

Diagnosis example:

Whooping cough, typical form, paroxysmal period, severe degree, complicated by apnea and encephalopathy

Whooping cough, typical form, paroxysmal period, moderate degree, complicated by the leftside lobar pneumonia with cardiovascular syndrome, cardiac insufficiency 1^st degree.

Whooping cough, typical form, catarrhal period

Differential diagnosis

Pertussis in catarrhal period may be confused with upper respiratory tract infections.

In paroxysmal period – with pneumonia caused by Chlamydia trachomatis, RS – virus, parapertussis.

In older children – with sinusitis, cystic fibrosis, aspirated foreign body, or tuberculosis.

Whooping Cough Differential Diagnosis

Signs	Whooping cough	Measles (not complicated)	URT viral infection,bronchitis	Acute pneumonia	Cystic fibrosis
beginning	acute	acute	acute	Subacute, acute, after URT viral infection	slow (from the neonatal period)
Epidemiological history	Contact with patient who had the same disease	Contact with patient who had the same disease	Contact with patient who had the same disease	super cooling, previous URT viral infection	Not complicated, Complicated obstetric, Genetic anamnesis
Main syndromes	Gradually intensified cough,that becomes paroxysmal,	Gradually intensifiedcatarrhal syndrome, rashes,intoxication	catarrhal syndrome, intoxication	Local changes in the lungs	Local, diffuse changes in the lungs,progressing respiratory insufficiency,intestinal problems,salt sweat
Cough character	Dry, moist Increase, become paroxysmal  With whoops	Dry, barking	Dry, moist, barking in case of laryngitis	Dry or moist,	Obtrusive, Exhausting
Toxic syndrome	Not typical	typical	typical	May be present	Not typical
Pulmonary percussion	Tympanic sound	normal	normal (Tympanic sound in case of obstruction)	Local dullness	Local dullness (in case of exacerbation)
Pulmonary auscultation	Hard breathing	Hard breathing,wheezing	Hard breathing,wheezing, moist rales, change their localization after the cough	Local breathing weakening Local small moist rales, crepitating, do not change their localization after the cough	Local breathing weakening diffuse middle, small moist rales, stable changes
Respiratory insufficiency	In severe degree	Not typical	In case of obstruction	typical	Expressed, progressing (in case of exacerbation)
Inspection	Perinasal cyanosis, facial swelling	catarrhal syndrome, rashes appear on3 – 4th day,	catarrhal syndrome	In respiratoryinsufficiency –acrocyanosis, in obstruction –involvement of intercostal spaces…	malnutrition,marasmus, chest deformation, clubbing fingers
Dyspeptic sign	Vomit in the end of cough paroxysm	Not typical	May be in infants	May be in infants	grey, ointment-like, in large volume
Diagnosis substantiation	Positive throat culture	ELISA test,serology (CBR)	Virusological test from pharyngeal smears	X-ray	Sweat-test

Treatment:

If etiotrope therapy is begun in the catarrhal stage – the duration of illness is shortened. Etiotrope therapy is prescribed to all patients, if the disease duration is not longer than 3 wks.

The erythromycin regimen is 40-to-50 mg/kg/day in four divided doses (or another macrolides) for 14 days. If azythromycin is given its’ dose is 10 mg/kg/ for the 1^st day, and 5 mg/kg/day for next days (the course is 5 days).

Alternative medicine (in case of hypersensitivity to macrolides) is trimethoprim/sulfomethoxasolum in average doses or ampicillin (100-200 mg/kg/day) for 14 days.

If the disease course is longer than 3 wks prescription of etiotrope therapy is discussed individually.

Pathogenetical therapy:

quiet and comfort; often ventilation, in mild and moderate cases – prolonged walks on fresh air

diet: usual daily food volume with increased numbers of feeding

therapy to decrease the cough center irritation (synecod)

In severe cases also:

therapy to decrease the cough center irritation (aminazin 1-2.5 mg/kg/day in 2-3 injections before going to sleep) or lytic suspension

novocain 0.25% 4 ml, +

aminazin 2.5% 1 ml, +

pipolphen 2.5% 1 ml (0.1 ml/kg of prepared solution).

intubation and ventilator support – in cause of apnea;

euphyllin 5-10 mg/ kg/day;

bronchial secretolytics (ambroxol, acetylcystein etc.), suctioning of secretions;

parenteral detoxication (5% glucose, physiologic sodium chloride solution);

Corticosteroids - 1-2 mg/kg/day prednisone or its equivalents for 3-5 days.

Prevention:

Isolation of the ill person on 30 days from the beginning of the disease.

Isolation of the contact persons younger 7 years old on 14 days.

Their throat culture (2 times), if negative – may attend preschool, school

Specific vaccination by DTP vaccine from 3 months of old 3 times with 30 days interval, revaccination in 18 months by DTaP vaccine.

References:

Main:

1.     Current therapy in pediatric infectious diseases – 2 edited by John D. Nelson, M. D. – B.C. Decker  inc. Toronto, Philadelphia, 1988, - P. 134-138, 285.

2.     Ambulatory pediatric care (edited by Robert A. Derchewitz; - 2 nd ed. – Lippincot – Raven, 1992. – P. 570-574; 255.          

3.     Principles and Practice of Pediatric Infectious Diseases. / Edited by Saran S. Long, Larry K. Pickering, Charles G. Prober, Philadelphia, Pa: Churchill Livingstone; 1997. – 1921 p.

Additional:

1.     Textbook of Pediatric Nursing.  Dorothy R. Marlow; R. N., Ed. D. –London, 1989.-661p.

2.     Pediatrics ( 2^nd edition, editor – Paul H.Dworkin, M.D.) – 1992. – 550 pp.