Detection of Whooping Cough (Bordetella pertussis) Respiratory Tract Infections from Throat Swabs by PCR Method

Whooping cough is caused by the Bordetella pertussis bacterium, which, when settled in the upper respiratory tract, releases toxins leading to symptoms typical of whooping cough. It is transmitted from an infected person through airborne droplets: when talking, sneezing, and especially coughing. The disease is often spread by adults who do not even know they have whooping cough, as their symptoms are milder, so whooping cough is often confused with other upper respiratory tract diseases.

A person with whooping cough spreads the disease for about 20 days, from the onset of the first symptoms to 2 weeks after the characteristic cough attacks appear. Whooping cough usually occurs during the cold season - late autumn, winter, or early spring. It most commonly affects children aged 1-5 years, but newborns and infants are also very susceptible to this disease.

In Lithuania, according to the preventive children's vaccination calendar, children are vaccinated against whooping cough at 2, 4, 6, and 18 months, and later at 6-7 years of age. Immunity lasts only about 10 years after vaccination and about 7 years after infection (depending on the immune system). Immunity to whooping cough begins to weaken gradually 2 years after vaccination or infection. Due to the relatively short duration of immunity and the belief that adults primarily spread whooping cough, many countries recommend revaccination for adolescents and adults, as well as pregnant women and their family members. In Lithuania, since 2015, 15-16-year-old adolescents have been revaccinated for free.

Revaccination is especially recommended for parents who have or plan to have young children, as well as other family members - teenagers and grandparents. Since most infants and young children (according to statistics, 80% of infants are infected with the highly dangerous whooping cough by adult family members) suffer from this infection with complications: dehydration; apnea (temporary cessation of breathing) - occurs in 61%; pneumonia - 23%; convulsions (strong uncontrolled seizures) - 1.1%; death - 1%.

S y m p t o m s :

1. For 1-2 weeks, whooping cough symptoms resemble many cold illnesses - the patient has a runny nose, sneezes, has a slight fever, and coughs a little. During this stage, whooping cough is often mistaken for a common cold.
2. As the disease progresses, a stage of whooping cough characteristic cough attacks begins, lasting 1-6 weeks but can extend up to 10 weeks. There may be several to dozens of attacks per day, which become more frequent and stronger at night. During an attack, the cough is dry, spasmodic, very intense, the patient may start to choke, vomit, become very tired, and frightened. However, since the immune system of teenagers and adults is stronger, they carry the disease more easily, the cough may be quite usual, and serious and very exhausting cough attacks may not occur.
3. Recovery from whooping cough takes a long time, the recovery stage lasts 2-6 weeks, sometimes several months. However, it can recur at any time, especially if a cold or respiratory tract infection is caught.

D i a g n o s i n g :

Tests for determining whooping cough:

1. CBC (increased lymphocyte count)
2. Bacteriological culture test from the nasopharynx
3. Bordetella pertussis antibodies IgA - appear only during the disease, 3-6 weeks from the onset of symptoms
4. Bordetella pertussis antibodies IgG - appear 4 weeks after the onset of symptoms and indicate current whooping cough infection or past vaccination. This test is recommended to be performed together with the IgA antibody test.

Determining whooping cough diagnosis:

1. In children - whooping cough can be suspected if frequent and very exhausting, intense cough attacks occur, especially at night.
2. In adults - the symptoms of the disease are not as obvious, but if coughing lasts for 2 weeks or more, tests should be performed.