COQUELUCHOID SYNDROME: DIAGNOSIS, SYMPTOMS, TREATMENT - MEDICINE - 2025

The coqueluchoid syndrome is the name for a series of respiratory signs and symptoms similar to those presented in whooping cough, but where the presence of Bordetella pertussis cannot be demonstrated. Like whooping cough, the natural history of this pathology affects the respiratory system. But, various types of bacteria or viruses can cause it.

In some cases, pertussis produced, in effect, by Bordetella pertussis, may be called coqueluchoid syndrome, just due to the fact that we do not have the necessary diagnostic methods to isolate the microorganism.

Three species of Bordetella are known: B. pertussis, B. parapertussis, and B. bronchiseptic. Cross immunity has not been demonstrated between these three species. This means that you can have “whooping cough” more than once.

The mode of transmission is by direct contact, from person to person, through droplets of saliva.

Etiology of Coqueluchoid syndrome

The syndrome can be caused by several types of bacteria other than Bordetella pertussis and Bordetella parafertussis. Among them are H. influenzae, M. catarrhalis, and M. pneumoniae.

Similarly, it can be caused by some viruses that have already been isolated from similar clinics, such as adenovirus, influenza virus, parainfluenza 1-4, respiratory syncytial virus (RSV), cytomegalovirus, and Epstein Barr virus.

Of the latter, respiratory syncytial virus is the cause of almost 80% of the clinical pictures called “coqueluchoid syndrome”. For this reason, this very similar clinical picture can occur several times throughout a person's life.

There is evidence of a symbiotic relationship between B. pertussis and adenovirus. This indicates that infection by one of the microorganisms predisposes infection by the other.

Symptoms

In short, the symptoms are the same as those of whooping cough. For this reason, it is important to differentiate them by isolating the microorganism in order to give the diagnosis a name.

The symptomatic picture is divided into three phases or clinical stages that differ slightly, depending on the age of the patient.

Catarrhal phase

In this phase the symptoms are nonspecific, and are similar to a clearly upper respiratory infection.

It occurs with rhinorrhea, congestion, conjunctivitis, epiphora, and low-grade fever. This phase lasts for approximately 1 to 2 weeks. When the symptoms begin to disappear, the next phase begins.

Paroxysmal phase

Irritating and intermittent dry cough marks the beginning of this phase. Later, it evolves to inevitable paroxysms, which is the main characteristic of the pathology.

The patient will cough continuously. The neck and thoracic cavity will be hyperextended. In addition, he will present a protruding tongue, wide, watery eyes, and slight perioral cyanosis.

The cough is flushing and, at times, emetic. This period is exacerbated, reaching more than one episode per hour. This phase lasts between 2 and 6 weeks, when the intensity and frequency of symptoms begin to decrease.

Convalescence phase

This phase lasts approximately 2 weeks. At this time, the symptoms begin to diminish until they disappear completely.

In infants, the catarrhal stage does not manifest itself almost at all. Any stimulus considered normal can trigger suffocation with facial flushing. After the paroxysmal cough episode, there may be cyanosis or apnea.

The convalescent stage in infants is prolonged. Coughing and stridor are louder at this stage.

In adults and adolescents, a loss of immunity acquired by vaccines usually occurs. It usually takes 5-10 years after the last dose is received.

Therefore, in these cases, the symptoms may vary or be milder. The cough can last for more than two weeks, and have no systemic symptoms.

Diagnosis

Usually the diagnosis is clinical, epidemiological and paraclinical.

Clinically, the Atlanta CDC and the WHO establish as a confirmed clinical diagnosis: cough lasting more than two weeks accompanied by paroxysms, stridor or inspiratory rooster, resulting in emetic episodes.

Epidemiologically, it is diagnosed in infants who are not yet old enough to receive all the doses of the vaccine, or who have not received at least the first 3 doses.

Similarly, it is performed in adolescents and adults whose immunity induced by the vaccine is attenuated, making them susceptible to infection.

Paraclinically, the WHO gold standard is the nasopharyngeal culture. This can be by aspiration or with a swab (dacron or calcium alginate), with a negative result for Bordetella pertussis, as well as a negative PCR.

If the culture is positive, it is no longer considered coqueluchoid syndrome, but the diagnosis of whooping cough is established.

Differentiation criteria

Two terms are differentiated, according to the criteria met by the patient:

• Probable case: clinical diagnosis without paraclinical diagnosis.
• Confirmed case of whooping cough:

1. Any respiratory symptoms, with a positive culture for Bordetella pertussis.
2. Clinical diagnostic criteria, with positive CRP.
3. Epidemiological criteria, with positive culture.

Treatment

The treatment will depend on the microorganism that is causing the infection. If the presence of a bacterial microorganism is paraclinically demonstrated, treatment will be based on antibiotic therapy.

In turn, antibiotic therapy is based on macrolides. Erythromycin is prescribed, as the first option, at a dose of 40-50 mg / kg / day every 6 hrs for 14 days, or Clarithromycin 15-20 mg / kg / day every 12 hrs for 7 days. Additionally, bronchodilators are prescribed.

If it is paraclinically demonstrated that the colonization was by a virus, the treatment will be symptomatic. In the case of infants, special attention will be paid.

Nasal washes with physiological solution and nebulotherapy with ipatropium bromide 1 drop / kg / dose up to 10kg (15 drops if older than 6 years and 20 drops older than 12 years) are carried out.

Also, a cycle of 3 nebulizations is performed, with intervals of 20 minutes each.

In very severe cases of respiratory distress, EV steroids can be used, such as hydrocortisone 10mg / kg / dose EV STAT and, subsequently, 5 mg / kg / dose EV every 6-8 hrs, if necessary.

Solumedrol can also be used, 3-5 mg / Kg / dose EV STAT, and a maintenance dose of 1-2 mg / Kg / dose EV every 8-12 hrs.

Recommendation

It is recommended to comply with the vaccination schedule suggested by the CDC, DTaP at 2, 4, 6, 15-18 months, and the 5th and last dose at 4-6 years.

Likewise, a dose of TDaP is recommended in children 11 or 12 years of age, or in adults who never received the vaccination.

Difference between whooping cough and coqueluchoid syndrome

The difference is only that in whooping cough, Bordetella pertussis can be isolated from nasopharyngeal culture.

This is because Bordetella pertussis is the only one that, despite sharing a high degree of homology with similar species, expresses the pertussis toxin or pertussis toxin. In contrast, the microorganisms that produce coqueluchoid syndrome do not express it.

In whooping cough, it is not bacteremia that causes the pathology, since the bacteria cannot cross the epithelial layers. It is the toxin that produces the local and systemic effects upon entering the bloodstream.

With respect to the clinical manifestations, the characteristic "rooster" of pertussis is not so clearly seen in coqueluchoid syndrome.

Children with the DTaP vaccine have a shortening of all phases in pertussis, but this is not the case in infections with the rest of the microorganisms.

References

1. Centers for Disease Control and Prevention. National Center for Immunization and Respiratory Diseases (NCIRD). 2017. Recovered from cdc.gov.
2. Treaty of Pediatrics. Elsevier Saunders. Volume I. 18th Edition. Sarah S. Long. Whooping cough. (Bordetella pertussis and Bordetella parapertussis) Chapter 194. Infectious Diseases, 1178-1182.
3. Centers for Disease Control and Prevention. Pertussis (Whooping Cough). Recovered from cdc.gov.
4. Cortese MM, Bisgard KM. Pertussis. In: Wallace RB, Kohatsu N, Kast JM, ed. Maxcy-Rosenau-Last Public Health & Preventive Medicine, Fifteenth Edition. The McGraw-Hill Companies, Inc.; 2008: 111–14.
5. Pabón, JH Clinical practice consultation - Medical. MedBook. Medical Editorial. 2nd Edition. (2014); 390-391.