Whooping cough, also called whooping cough or canine cough, is a highly contagious respiratory tract infection caused by the bacterium Bordetella pertussis. Other such bacteria Bordetella as Bordetella parapertussis and Bordetella holmesii, may, although rarely, cause similar but milder complaints. Whooping cough affects individuals of all ages but mostly children under the age of 5; infants less than 6 months old are more at risk of contracting a severe form of the disease, which can even lead to death. Unlike other childhood diseases, immunity acquired following natural infection or vaccination is not definitive, but decreases over time.
Pertussis is widespread all over the world but in countries where childhood vaccination was introduced the number of new cases has drastically reduced. Today, 90% of whooping cough cases appear in countries with low vaccination coverage (read the Bufala). However, even in countries where vaccination for pertussis is practiced there are cases of pertussis. It is hypothesized that this is due to the failure to carry out the appropriate booster doses, which resulted in the progressive loss of immunity conferred by the vaccine , or by characteristics of the circulating bacteria. Adequate antibiotic treatment allows healing in about fifteen days.Symptoms
The whooping cough bacterium causes respiratory tract infections that can be hard to recognize, but also extremely serious, especially if they affect a newborn. Whooping cough has an incubation period of 7-10 days. If there are no complications, the disease usually lasts 6-10 weeks and causes different disorders (symptoms) according to the different stages that characterize it.
The onset of the disease is manifested by ailments (symptoms) similar to those of a cold, such as runny nose, red and watery eyes, sore throat, mild cough accompanied by some line of fever; such disturbances (symptoms) last from 1 to 2 weeks. The coughing fit can cause the face to become very red and may cause slight bleeding under the skin or in the eyes. Young children, if they have difficulty breathing, may turn blue (cyanosis) for a short time. In children very small, cough may not be particularly noticeable, but short periods of not breathing (apnea) may occur.
Paroxysmal / convulsive stage
The cough becomes intense and uncontrollable (paroxysmal) and is associated with difficulty in breathing. In the absence of treatment, this phase usually lasts 1-6 weeks but can last for over 2 months. Absence of breathing, blue color and vomiting may also occur following coughing attacks. In this phase of the disease, the paroxysmal cough attacks end with a typical sound emitted to get air, the so-called inspiratory scream, and with the expulsion of very thick and viscous phlegm. They can be followed by retching. In very young children the inspiratory scream may be missing and in its place there may be absence of breathing, blue color and suffocation.
This phase usually begins within 4 weeks and is characterized by the alleviation of the disturbances (symptoms) and the improvement of the general condition.Causes
Whooping cough is caused by a bacterium called Bordetella pertussis. When an infected person coughs or sneezes, tiny droplets full of germs are dispersed into the air and anyone nearby can inhale and become infected.Diagnosis
Detecting (diagnosing) whooping cough in the early stages can be difficult because the signs and symptoms (symptoms) it causes are similar to those of other common respiratory diseases, such as colds, flu or bronchitis.
Medical tests may be required to ascertain this, including:
- bacterial culture: The doctor swabs or sucks up the phlegm found on the inside of the nose (nasopharynx) and places it in special culture media to check if the whooping cough bacterium is growing (Bordetella pertussis)
- polymerase chain reaction (PCR): it is a more sophisticated examination that can be performed on the same sample taken from the nasopharynx. The PCR test is faster and more sensitive than culture to detect the presence of the pertussis bacterium
- blood tests: a small amount of blood is taken and sent to a laboratory to do a blood count and check the number of white blood cells. White blood cells, in fact, increase in case of infections. This is a general test and not specific for the whooping cough
- chest x-ray: it may be needed to detect whether whooping cough has caused pneumonia
- serological tests: in doubtful cases, pertussis can be ascertained (diagnosed) two or three weeks after acute infection, by means of serological tests, ie by measuring the specific antibodies present in the blood. These tests can also be used to ascertain whooping cough in older children, adolescents and adults
The therapy is based on the use of antibiotics, usually erythromycin or antibiotics of the same class. The antibiotic treatment started before the phase in which the cough becomes intense and uncontrollable (paroxysmal phase) shortens the time of contagion and the duration of the disease, but complaints (symptoms) are not always reduced. In people treated with antibiotics, the infectious period ends about 5 days after starting therapy, while in untreated people the possibility of infecting others lasts up to 3 weeks. the disorders (symptoms), antitussive drugs, sedatives, and anti-spasm drugs may also be prescribed. In infants and young children, hospitalization is generally required because the complaints (symptoms) are more severe and the disease is more dangerous .
It is helpful to drink plenty of fluids; In infants and young children, it is important to look out for signs of dehydration, such as dry lips, tearless crying, and dry or low-pissing diapers. To prevent vomiting from appearing after a cough, it may be advisable to eat small and frequent meals. To prevent infection, you need to cover your mouth and wash your hands often; in the presence of other people, it is advisable to wear a mask.Prevention
The best way to prevent whooping cough is childhood vaccination.
The hexavalent vaccine is generally administered within the first year of life (read the Buffalo) and protects against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B (HB) and haemophilus influenzae type b (Hib) (read the Hoax). It is administered with an intramuscular injection according to a specific schedule:
- first dose at 3 months of age
- second dose at 5 months of age
- third dose at 11-12 months of age
The vaccination calendar in Italy provides for a mandatory recall for children of pre-school age (6 years) and for adolescents born from 2001 onwards.
As pertussis is more severe and can even be fatal in newborns and infants up to 6 months and typically in infants under 1 year, vaccination of the mother in the third trimester of pregnancy is recommended to protect the babies before complete the immunization cycle (read the Hoax). In fact, maternal antibodies pass to the unborn child through the placenta.
Prevention with antibiotics (prophylaxis)
If you have been in contact with people with whooping cough, your doctor may advise you to take antibiotics to protect yourself from infection in the following cases:
- unvaccinated child less than 12 months of age
- health at risk of serious illness or complications, for example in cases of weakened immune systems
Teens and adults often recover from whooping cough without any problems.
Complications can be due to coughing fits and consist of:
- cracked ribs
- abdominal hernias
- breaks in blood vessels in the skin or whites of the eyes
- nose bleeding
Because infants and young children have a higher risk of having complications from whooping cough, they are more likely to need hospitalization.
The most serious complications are bacterial superinfections which can lead to:
- ear infection
- neurological complications (seizures, encephalitis)
In newborns and infants under 1 year old, whooping cough can be even fatal.Impact on the population
Impact on the population
Whooping cough is always present (endemic) around the world and shows peaks in the number of cases every 3-5 years. Most of them occur in the summer-autumn period. According to estimates by the World Health Organization, the disease caused 63,000 deaths among children under the age of 5 in 2013. Most resided in developing countries, where vaccination is less common.
In Italy, the introduction of the pertussis vaccine has made it possible to significantly reduce the number of sick and deaths: the most recent data indicate that in 2017 vaccination coverage was 94.5% for 24-month-old children and 88.6% for children of 5-6 years; on the other hand, for adolescents aged 18 (born in 1999) the vaccination coverage was considerably lower (66.7%).Bibliography
Mayo Clinic. Whooping-cough (English)
NHS. Whooping-cough (English)
EpiCentro (ISS). Whooping cough
Ministry of Health. Vaccinations