There whooping cough it's a infectious disease of the respiratory tract caused by Gram negative bacillus Bordetella Pertussis. In the past it was called "whooping cough" or "canine cough" or "donkey cough" due to the characteristics of coughing fits. The bacterium Bordetella parapertusissis belongs to the same family, is less common, and causes a similar but milder disease than that caused by B.pertussis.
Before the vaccine pertussis was available was the leading cause of death from communicable disease aged <14 years, after the introduction of the vaccine the number of cases has drastically reduced.
Whooping cough is extremely contagious, man represents the only reservoir of the bacterium and the infection is easily transmitted through drops of saliva and secretions produced by the cough of infected subjects. Neither natural disease nor vaccination ensures complete or lifelong immunity against reinfection or disease.
The incubation period of the disease can last 3-12 days. Then there are 3 phases: catarrhal, paroxysmal and of convalescence, each lasting 1-2 weeks. The catarrhal phase is characterized by symptoms such as nasal congestion, rhinorrhea, sneezing, some lines of fever and is indistinguishable from other more common respiratory infections. This is the phase of greatest contagiousness. Whooping cough then remains transmissible for up to 3 weeks after the onset of the cough.
In paroxysmal phase you have sudden fits of cough lasting a few minutes. During coughing fits the face becomes purplish, the tongue protrudes forward until the cough stops and at the end a cry may follow due to the passage of air through the narrowed airways. There may also be vomiting after coughing. The number and severity of coughing fits increase over a week and then remain stable. During the convalescence phase, the number, severity and duration of the episodes decrease.
In younger children (<3-6 months) the various stages do not occur but the fits of cough can be so severe as to lead to semi-suffocation, a purplish face (cyanosis), vomiting; you may have episodes of apnea which can sometimes be the only symptom and can lead to death.
Even adults and adolescents may not present the three distinct phases but may report a feeling of suffocation followed by uninterrupted cough, headache and then vomiting; fits of cough are interspersed with well-being.
The complications more serious are made up of apneas, bacterial superinfections, which can lead to ear infections, pneumonia, bronchitis or even neurological diseases (seizures, encephalitis); pneumothorax.
All 'physical examination there are no specific manifestations, there is usually no fever and chest auscultation may be negative, conjunctival hemorrhages and petechiae may be present in the upper body.
There diagnosis requires the isolation of B.pertussis bacterium in culture on throat swab or nasopharyngeal aspirate. PCR (polymerase chain reaction) may also be performed on nasopharyngeal aspirate samples but this test may not be available in laboratories. Such investigations are frequently negative in subjects previously vaccinated or who have already been treated with antibiotic therapy.
The search for antibodies against B.pertussis in the acute or convalescent phase appears to be a more sensitive test in vaccinated subjects, in these subjects an increase in pertussis anti-toxin IgG antibodies must be observed. In laboratory tests it is typical to observe an increase in lymphocytes in the catarrhal stage. Chest x-rays may only be abnormal in some cases, for example in infants, and can detect complications. The aim of therapy is to limit the number and severity of coughing fits and limit the spread of the disease.
There therapy medical treatment consists in the use of antibiotics, the most suitable are those belonging to the family of macrolides (azithromycin, clarithromycin). With regard to infants less than 3-6 months of age, hospitalization is indicated to monitor the progress of the disease and the patient, prevent and treat any complications and provide respiratory support if necessary. Patients with heart, lung, muscle or neurological diseases are also at high risk for severe disease.
Patients with suspected pertussis should be placed in isolation and the isolation maintained for 5 days after initiation of antibiotic therapy. It is also recommended to perform a prophylaxis of close contacts (e.g. family members) with the same drugs at doses appropriate for age and weight. Given the high contagiousness of the disease and the high risk of severe disease or complications, especially in younger children, it is essential to prevent the infection that occurs through vaccination.
The vaccine pertussis is administered as part of the hexavalent vaccination (Diphtheria, Tetanus, Pertussis, Hepatitis B, Haemophilus i., Poliovirus).
The current Italian vaccination schedule provides for the use of the hexavalent vaccine with the following scheme: the first dose at the 3rd month of life, the second dose at the 5th month of life, the third dose at the 11th-13th month of life. A fourth dose (1st booster diphtheria-tetanus-pertussis) is given at 5-6 years of age to give continued protection in the first years of school; a fifth dose (2nd booster) is finally given at 14-15 years. Mild localized reactions such as swelling, redness at the injection site and even fever may occur following the vaccine, usually in the first 24 to 48 hours after the vaccine. More serious reactions are represented by allergic reactions which are however extremely rare.Tags: Children Infectious diseases Virus