Introduction

Pertussis, commonly called whooping cough, is an extremely contagious respiratory infection which is caused by the bacterium Bordetella pertussis. It is an highly contagious droplet infection.
The initial symptoms begin to appear 7 to 10 days after infection. They include symptoms such as mild fever, runny nose and cough, which in typical cases gradually develops into a hacking cough followed by whooping (hence the common name of ‘whooping cough’). Pneumonia is a relatively common complication, and sometimes seizures and brain disease may occur.

It is important to be aware of the risk factors of breastfeeding when you have pertussis so you are able to take the necessary precautions to ensure that the infant isn’t exposed to this dangerous infection.

Importance of breastfeeding

Benefits for infant health

Breast milk is the best source of nutrition for most babies as it takes care of the babies dietary needs before they are able to begin consuming solid foods. It also has a protective property against some short- and long-term illnesses and diseases, therefore lowering the risks of conditions including asthma, obesity, type 1 diabetes, sudden infant death syndrome (SIDS), ear infections and stomach bugs.

Overview of immune benefits

Breast milk components such as non-immune and immune cells and bioactive molecules, namely, cytokines/chemokines, lipids, hormones, and enzymes, reportedly play many roles in breastfed newborns and in mothers by providing protection against diseases and shaping the immune system of the newborn.

Impact of breastfeeding on the risk of pertussis

Background on pertussis

Causative agent (Bordetella pertussis/parapertussis)

Bordetella pertussis and Bordetella parapertussis are gram negative cocci that cause pertussis in humans These do not cause bacteraemia.

Mode of transmission

The bacterium are transmitted through droplets which colonise exclusively on the ciliated cells of the respiratory mucosa.

Epidemiology and incidence rates

The natural home of B. pertussis and B. parapertussis is the human respiratory mucosa. Most of the time, transmission occurs directly between people. During the early, catarrhal stage (early stage where mucus builds up in the throat, leading to symptoms such as runny nose and cough) of the illness, patients are most contagious and stay so for roughly five weeks. For those who are not vaccinated against pertussis, it can be a common and potentially fatal childhood illness.

Complications associated with pertussis, especially in infants

Pertussis in infants is often severe, and infants are more likely than older children or adults to develop complications. The most common complication of pertussis is bacterial pneumonia. Rare complications include seizures, inflammation of the brain, and death.

The immune benefits of breastfeeding

Composition of breast milk

Human breast milk contains about 87%–88% water, and 124- g/L solid components as macronutrients, including about 7% (60–70 g/L) carbohydrates, 1% (8–10 g/L) protein, and 3.8% (35–40 g/L) fat. The composition may vary in different individuals due to  environmental factors such as maternal diet.

Antibodies (IgA, IgG)

Antibodies from the mother pass into the breast milk and give the baby a little protective booster via antibodies. For example IgA, an antibody that is found in breast milk, protects infants from infection by coating the baby’s oral mucosa, nasal cavity, eustachian tubes (tubes that drain the ears), and gastrointestinal tract. IgA then binds to bacteria and viruses at the surface, preventing them from entering the baby’s system.

Breastfeeding and Pertussis: Current Research

Breastfeeding duration and pertussis incidence

Epidemiological studies have consistently shown a correlation between the duration of breastfeeding and a reduced incidence of pertussis in infants. Research indicates that infants breastfed for at least six months exhibit lower rates of pertussis compared to those breastfed for shorter periods or not at all. This protective effect is attributed to the transfer of maternal antibodies and the overall enhancement of the infant's immune system through breastfeeding.

Comparison with formula-fed infants

When comparing breastfed infants to those who are formula-fed, studies reveal that formula-fed infants are more susceptible to pertussis. The absence of maternal antibodies in formula means these infants lack the immediate passive immunity provided by breast milk, making them more vulnerable to pertussis infections, especially in the first few months of life.

Analysis of maternal antibodies against pertussis

Clinical trials have demonstrated that maternal antibodies against pertussis, transferred through breast milk, play a crucial role in protecting infants. These antibodies provide passive immunity that helps guard against infections until the infant's immune system can respond more robustly to vaccinations and environmental exposures.

Studies on breast milk's effectiveness in preventing pertussis

Several clinical studies have focused on the components of breast milk, such as immunoglobulins and other immune factors, which contribute to its effectiveness in preventing pertussis. Findings indicate that breast milk not only provides passive immunity but also enhances the infant's own immune response, offering a dual layer of protection against pertussis.

Mechanisms of Protection Against Pertussis through Breastfeeding

Transfer of maternal antibodies to the infant

One of the primary mechanisms by which breastfeeding protects against pertussis is through the transfer of maternal antibodies. These antibodies provide immediate immunity to the infant, helping to protect against pertussis until the infant can be vaccinated and develop their own immune response.

Breast milk's role in modulating the infant's immune response

Breast milk contains various immunological components that not only protect against pathogens but also help modulate and mature the infant's immune system. This includes the enhancement of mucosal immunity, which is crucial in the defense against respiratory infections like pertussis.

Interaction with pertussis vaccination schedules

Timing of breastfeeding and vaccination

The timing of breastfeeding in relation to vaccination schedules can be crucial. Breastfeeding can help sustain the infant's immunity during the critical period before the full vaccination series is completed, ensuring continuous protection.

Synergistic effects of breastfeeding and immunisation

Research suggests that breastfeeding and vaccination have synergistic effects (working together to protect the baby). Vaccines often show better efficacy in breastfed infants, potentially due to the immune-boosting components of breast milk enhancing the infant's response to vaccines.

Challenges and Considerations

Barriers to breastfeeding

Socioeconomic factors

Socioeconomic factors, including lack of access to breastfeeding resources and support, can hinder breastfeeding efforts. Addressing these barriers through targeted interventions is essential for promoting breastfeeding.

Cultural and societal influences

Cultural and societal attitudes towards breastfeeding can also impact its prevalence. Public health efforts need to address misconceptions and cultural barriers to promote breastfeeding effectively.

Addressing misconceptions about breastfeeding and pertussis

There are several misconceptions about breastfeeding and its benefits. Public health initiatives should focus on providing accurate information to dispel myths and encourage breastfeeding as a means to prevent pertussis.

Support systems for breastfeeding parents

Providing robust support systems, including lactation consultants and peer support groups, can help parents successfully breastfeed. These support systems are crucial in overcoming challenges and ensuring that parents can breastfeed for the recommended duration.

Summary

Pertussis, also known as whooping cough, is a highly infectious respiratory disease often affecting those in childhood and leading to symptoms such as a cough (which may progress to a severe cough), fever and runny nose. In some cases, especially in young children and the unvaccinated, pertussis can lead to severe symptoms such as seizures, inflammation around the brain and pneumonia, and may be fatal. Breastfeeding is a key source of nutrition for infants, offering all the necessary nutrients for their dietary needs before they are able to move onto solid foods, and a useful source of nutrition alongside solid foods. Breast milk also provides various health and immune benefits to the baby, helping to protect them against diseases and develop their immune system through the transmission of antibodies and other bioactive components. In situations where a breastfeeding parent is infected with pertussis (whooping cough), the immune benefits provided by breastfeeding may help to protect infants against developing pertussis. Public health efforts should focus on promoting breastfeeding, good breastfeeding support and practices, and emphasising the benefits of breastfeeding for disease prevention; especially against fatal childhood illnesses such as pertussis.