Whooping cough is endemic in the EU/EEA and worldwide. Outbreaks are expected every three to five years, even where vaccination rates are high. More than 25,000 cases of pertussis were reported in 2023 and more than 32,000 between January and March 2024. Similar figures were observed in 2016 (41,026) and 2019 (34,468). Most deaths occurred in infants. In temperate zones, incidence is increased in autumn and winter. (***, 2024)

Recently, Romania has seen an increase in whooping cough cases. In the following you will learn all the necessary information about this disease: what it is, the causes of its occurrence, how it is transmitted, how it is diagnosed, what complications may occur, how to treat it and most importantly, how to prevent infection.

What is whooping cough?

Whooping cough (pertussis) is a highly contagious infection that affects the airways and lungs, manifested by violent bouts of uncontrollable coughing that makes breathing difficult. At the end of the coughing fit, deep inspiration causes a sound similar to a donkey’s roar, which is why it is also popularly called “donkey cough” (***, 2022)
. Keeping in mind that coughing episodes can last for more than 10 weeks, the disease is also known as the “100-day cough” (Zingman, Brennan, & Wojcik, ***) (Zingman, Brennan, & Wojcik, ***).

Causes of whooping cough

It is caused by bacteria of the genus Bordetella (B. Pertussis, rarely B. parapertussis). They cause inflammation of the respiratory mucosa and destruction of hair cells in the tracheobronchial tree by releasing toxins (pertussis toxin, dermonecrotic toxin, adenylate cyclase and tracheal cytotoxin) (***, 2024) (***, 2024).

How is it transmitted.

It is transmitted directly, airborne (through droplets of saliva expelled during coughing or sneezing), during the catarrhal and convulsive period of the disease. Infected people are contagious before the first symptoms appear(incubation period is 5 to 10 days, maximum 21 days) and for up to 3 weeks after the onset of coughing. However, if the infected person is given an appropriate antibiotic, they will usually stop spreading the bacteria after 5 days of treatment (***, 2023) Whooping cough can also be spread by a person who is asymptomatic or who has mild symptoms.

Transmission can also be spread indirectly through recently contaminated objects.

Who is most at risk of infection?

Anyone can become ill regardless of age, but certain population groups are at higher risk (***, 2024):

• High risk for unimmunized or partially immunized infants younger than 6 months of age (the group with the highest morbidity and mortality).
• Moderate risk for non-immunized or partially immunized infants older than 6 months and children up to 15 years of age and low risk if fully immunized according to the national immunization schedule.
• Moderate risk for adolescents older than 16 years and adults up to 64 years of age, respectively lowrisk if they have recently received a booster dose.
• Moderate risk for adults ≥65 years of age and people of any age with comorbidities (asthma, chronic obstructive pulmonary disease – COPD, immunosuppression), a moderate risk of infection and moderate impact (a higher likelihood of experiencing severe disease than people in the younger age group).

Also, great care should be taken by women in the third trimester of pregnancy (may expose the newborn to pertussis), people living in the home with a sick person, those working in healthcare or caring for people at increased risk of illness (infants, children, pregnant women), unvaccinated people (***, Whooping cough, ***).

What are the signs and symptoms?

The disease begins with symptoms similar to other common upper respiratory tract infections(catarrhal phase): tiredness, rhinorrhea, stuffy nose, mild cough that gradually increases in intensity and frequency, mild fever, redness of the conjunctiva, apnea (in infants). May last about 1-2 weeks. (***, 2024)

Then follows the paroxysmal (manifestation) phase , characterized by numerous, violent and rapid attacks of coughing, followed by a noisy and prolonged inspiration (due to accumulation of mucus inside the airways). The cough is frequently triggered by cold, loud noises and often occurs during the night (on average 15 attacks/24 hours, gradually decreasing after 2-3 weeks). It can lead to cyanosis of the integuments (especially in babies and children), post-cough vomiting, shortness of breath. Diaphoresis (profuse sweating) and exhaustion also occur. (***, 2024)

Some people may not show that characteristic wheezing, and infants may not even cough at all.

The final stage is the convalescence (recovery) stage which can last from several weeks to several months. It is manifested by a residual cough, not as pronounced, which disappears in 2 to 3 weeks. May recur with a subsequent respiratory infection. (***, 2024)

All symptoms are much more pronounced in unvaccinated infants and children, and the convalescence phase is longer in their case, atypical symptoms may occur such as: apnea or tachypnea, exacerbated coughing at night, wheezing, convulsions, seizures, epistaxis, cyanosis, episodic bradycardia, occasionally febrile conditions. Some people have moderate symptoms, especially if they have been vaccinated. (***, 2024)

When to go to the doctor?

When the cough lasts more than a week, significant shortness of breath (dyspnea or apnea) and characteristic wheezing, cyanosis, vomiting, convulsions, signs of dehydration (dry mouth, excessive thirst, fatigue, less urination, muscle weakness, headache, dizziness), you should go to the doctor urgently for a correct diagnosis (***, 2024)
. In younger children, the signs of dehydration are: dry and sticky mouth, few or no tears when crying, drowsiness and tiredness, thirst, reduced urination (less wet diapers than usual), muscle weakness, headache, dizziness (feeling “light headed”) (Durani, 2023) (Durani, 2023)

What investigations are needed to make the diagnosis?

Early diagnosis helps prevent the spread of infection and worsening of symptoms to complications. It is established on the basis of anamnesis and laboratory examinations (nasopharyngeal culture and PCR) (Lauria & Zabbo, 2022) . Differential diagnosis is made with influenza, paragyriasis, adenoviritis and RS-virus infection. (***, 2021)

Complications of whooping cough

Complications include: anorexia, dehydration, difficulty sleeping, epistaxis, hernia, otitis media, syncope, weight loss, urinary incontinence. In severe cases, apnea, encephalopathy, pneumonia, pneumothorax, rectal prolapse, refractory pulmonary hypertension (in infants), rib fractures, seizures, subdural hematomas and even death may occur. (***, 2024)

The most frequent pathogens that can lead to bacterial superinfection are Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, Staphylococcus aureus, but also Respiratory syncytial virus, Cytomegalovirus and Adenovirus. (Lauria & Zabbo, 2022)

Treatment of whooping cough

If the infection is diagnosed early, antibiotics are of real help, greatly reducing symptoms, especially the cough. It also prevents further transmission of the infection. Consult your doctor to get the correct treatment.

Cough suppressants or expectorants should be avoided (they don’t help and may cause side effects, especially in infants and young children), and if the cough is so bad that you can’t hydrate sufficiently, dehydration may occur. In this case, contact your doctor urgently as intravenous fluids will most likely be needed.

Get plenty of rest, adopt a healthy, vitamin-rich diet, eat small, frequent meals (to prevent vomiting), hydrate sufficiently (plain water, juices, teas, etc.), keep the air in your home clean and moist (to alleviate and avoid coughing fits caused by dust, smoke or other irritants) and avoid smoking (Mitchell, 2024). For sick babies who are breastfed, breastfeeding should not be interrupted and should be done on demand to keep them hydrated. Also continue to give formula to those who are formula-fed.

Only give antipyretics such as paracetamol or ibuprofen on doctor’s advice to lower the temperature and never aspirin to children under 16.

Babies may need to aspirate mucus from their nose. Almost a third of babies under 1 year of age need to be admitted to hospital (where they can receive intravenous treatment and oxygen if needed).

How do we prevent illness?

Immunization is the main prevention method. In Romania, according to the national immunization plan for children, 3 doses of hexavalent vaccine (DTPa-VPI-Hib-Hep B at 2, 4 and 11 months of age) are administered free of charge by the family doctor. They protect against diphtheria, tetanus, whooping cough, poliomyelitis, Haemophilus influenzae type B and viral hepatitis type B. A dose of tetravalent vaccine (DTaP-IPV) is given at 6 years of age and the trivalent diphtheria-tetanus-pertussis acellular vaccine (dTpa) for adults at 14 years of age. (National Institute of Public Health, 2024)

The vaccine can also be given to pregnant women during the third trimester without harming the fetus. DTaP is approved in the last 3 months of pregnancy to prevent sickness in infants under 2 months of age. (Lauria & Zabbo, 2022)

Acquiring antipertussis antibodies naturally (post-infection) or artificially (post-vaccination) does not confer long-lasting immunity, but can last from 4 to 20 years (post-infection) and 4-12 years (post-vaccination), depending on the individual’s body. (Wendelboe, Van Rie, Salmaso, & Englund, 2005) Because immunization through vaccination is not permanent, the National Institute of Public Health recommends booster every 10 years. (National Institute of Public Health, 2024)

Whooping cough vaccines work, but are not 100% effective. Some vaccinated people may get sick, but the symptoms will be milder.

As the community is where most illnesses occur, certain measures should be taken to ensure personal hygiene and hygiene of surfaces touched by sick people:

• Hand hygiene: hands should be washed frequently (minimum 20 seconds) and/or disinfected with alcohol-based solutions (before eating, after using the toilet, after coughing/sneezing and whenever necessary);
• Respiratory hygiene: sneeze/cough into a disposable tissue to be immediately disposed of in the trash, then wash/disinfect hands; if no tissue, sneeze/cough into bent elbow, not into palm;
• Room hygiene: rooms will be aired (at least 10 minutes) and surfaces cleaned and disinfected;
• Exchange of personal items and touching eyes, nose and mouth with dirty hands should be avoided;
• In case of illness, delayed re-entry to the school (usually 5 days after starting antibiotics and 3 weeks after the onset of symptoms if no antibiotics have been given)

Despite the availability of effective vaccines, pertussis remains a public health challenge. Knowledge of symptomatology, treatment and prevention strategies are essential to control and stop the spread of infection.

Bibliography

***. (Retrieved from https://www.healthdirect.gov.au/whooping-cough

***. (2021). Retrieved from https://bioclinica.ro/blog/boli-infectioase/tusea-convulsiva-pertussis-transmitere-simptome-diagnostic-tratament-vaccin#complicatii

***. (2022). Retrieved from https://www.mayoclinic.org/diseases-conditions/whooping-cough/symptoms-causes/syc-20378973

***. (2023). Retrieved from https://www.health.ny.gov/publications/2171/

***. (2024). Retrieved from https://www.cdc.gov/pertussis/hcp/clinical-overview/index.html

***. (2024). Retrieved from https://www.cdc.gov/pertussis/hcp/clinical-overview/index.html

***. (2024). Retrieved from https://www.nhsinform.scot/illnesses-and-conditions/infections-and-poisoning/whooping-cough/

***. (2024). Retrieved from chrome-extension://efaidnbmnnnnnibpcajpcglglclefindmkaj/https://www.ecdc.europa.eu/sites/default/files/documents/Increase%20in%20pertussis%20cases%20in%20the%20EU-EEA%20-%20May%202024%20FINAL.pdf

Durani, Y. (2023). Retrieved from https://kidshealth.org/en/parents/whooping-cough.html

National Institute of Public Health.(2024). Retrieved from chrome-extension://efaidnbmnnnnnibpcajpcglglclefindmkaj/https://insp.gov.ro/wp-content/uploads/2024/04/Calendar-National-VACCINARE-2024.pdf

National Institute of Public Health. (2024). Retrieved from https://insp.gov.ro/2024/05/14/comunicat-privind-cresterea-incidentei-tusei-convulsive-in-romania-si-recomandari-de-sanatate-publica/

Lauria, A. M., & Zabbo, C. P. (2022). Pertussis. StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK519008/

Mitchell, K. (2024). Retrieved from https://www.webmd.com/children/whooping-cough-symptoms-treatment

Wendelboe, A. M., Van Rie, A., Salmaso, S., & Englund, J. A. (2005). Duration of Immunity Against Pertussis After Natural Infection or Vaccination. The Pediatric Infectious Disease Journal. Retrieved from https://journals.lww.com/pidj/fulltext/2005/05001/duration_of_immunity_against_pertussis_after.11.as

Zingman, B., Brennan, D., & Wojcik, S. (***). Retrieved from https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=90&contentid=P02533