Why should you know about parainfluenza during pregnancy?

Pregnant mothers are susceptible to various diseases and disorders throughout their pregnancy, and it’s normal to be worried that any illness, even a simple one, could harm you or your baby. Parainfluenza is somehow considered a simple illness, yet it can sometimes become serious and might lead to severe complications. Therefore, it’s critical that you have an idea about what could occur if you get infected with parainfluenza during your pregnancy and what you should do in order to protect yourself and your baby.

What is parainfluenza?

Parainfluenza is caused by Human Parainfluenza Viruses (HPIVs), which can lead to both upper and lower respiratory tract illnesses. There are four types of them, and they all could lead to similar clinical manifestations. HPIV infection could also differ in its effect according to your age.¹

Parainfluenza is different from influenza,  the virus that causes the flu. It is also different from Respiratory Syncytial Virus (RSV) and COVID-19, yet all the viruses can cause similar symptoms. This similarity can make it hard to know which virus you have without specific testing by your healthcare provider.

Symptoms of parainfluenza

The infection starts in your nose and oropharynx, and after that, it spreads to your lower respiratory system. Symptoms can vary depending on the age and other factors of the individual, but commonly include the following:²

• Otitis media, pharyngitis, and conjunctivitis, especially common in children
• Croup, which causes fever, hoarseness, cough, stridor, respiratory fatigue, hypoxia, and cyanosis. It’s characterised by the inflammation of your larynx and trachea, and is also known as laryngotracheitis. When the inflammation reaches your bronchi, it’s called laryngotracheobronchitis
• Bronchiolitis: It usually starts with a fever and nasal congestion 1-3 days before the beginning of the lower respiratory signs, which include cough, expiratory wheezing, tachypnea, rales, and chest wall retractions. Children with severe cases might suffer from other complications, such as apnea and respiratory failure, requiring mechanical ventilation
• Pneumonia (lower respiratory tract infection involving the lungs)
• Tracheobronchitis: It generally includes inflammation of your large airways, that is, the trachea and bronchi, in the absence of symptoms of croup and radiologic findings of pneumonia. You might also experience a productive cough, wheezing, and rhonchi, in addition to the usual upper respiratory tract symptoms and fever
• Neurological symptoms: These have been reported in children and adults, such as febrile seizures, ventriculitis, and encephalitis

How does parainfluenza affect pregnancy?

• A study was conducted to examine acute respiratory illnesses (ARI) and their impact on pregnant women. These illnesses include rhinoviruses, influenza viruses, parainfluenza (types 1, 2, and 3), respiratory syncytial virus, and human metapneumovirus. Some of these women were vaccinated against influenza before the study. The signs and symptoms that were observed include: cough, rhinorrhea, subjective fever, sore throat, headache, fatigue, shortness of breath, myalgias, prostration, and bronchopneumonia. However, the Centres for Disease Control and Prevention (CDC) strongly recommends that you avoid exposure to respiratory viruses by using non-pharmaceutical interventions, such as regular handwashing, avoiding close contact with ill people, and physical distancing and mask-wearing during epidemic periods³
• Until 2020, there had not been any confirmed cases of intrauterine transmission of parainfluenza virus to the foetus. Moreover, young infants have antibodies against HPIVs from their mothers, which are transferred to them through the placenta during the last trimester of pregnancy.  These antibodies are able to provide some protection during the first months of the infant’s life⁴
• Nevertheless, respiratory viral infections are the most recurrent infections during pregnancy. Unfortunately, there isn’t enough information about the effect of prenatal exposure to these infections on the health of your baby. Also, no previous systematic reviews have elaborated on the connection between maternal respiratory infections and normative developmental outcomes in childhood⁵

Complications of parainfluenza

Parainfluenza can, in some cases, lead to some serious complications, such as parotitis, central nervous system (CNS) infections and neurological symptoms, myocarditis and pericarditis, rhabdomyolysis, different febrile illnesses, viremia, and Kawasaki disease⁶.

Diagnosis of parainfluenza

There are several methods to diagnose parainfluenza:²

• Laboratory diagnosis: Most presentations of parainfluenza don’t have distinct features, apart from croup; therefore, the viral infection is more likely to be diagnosed on just clinical grounds. Laboratory testing can be done either by viral detection or host antibody response to the infection
• Sample collection: It’s known that, to detect the virus by any method, there must be an adequate sample. The type of sample depends on the age and immune condition of the patient, the stage and severity of the disease, and the timing of illness (early or late stages). The samples include nasopharyngeal swabs (NPS), combined nose and throat swabs, nasal washes, sputum, and bronchoalveolar lavage
• Viral culture: It has been considered the gold standard for diagnosing parainfluenza for many years. However, the traditional method takes significantly longer (5-14 days); therefore, new adjunctive methods have been developed to simplify the process
• Other diagnostic methods include fluorescent antibody assays, molecular assays, and serological diagnosis

Treatment of parainfluenza

There is no specific antiviral agent for parainfluenza. In general, treatment involves managing the symptoms in otherwise healthy patients:²

• Croup: This is the most common symptom of parainfluenza. The main treatment for it is corticosteroids, which have been effective in managing mild, moderate, and severe cases. They can be given orally or intramuscularly, as the inhaled form has not shown the same level of effectiveness as them²
• Most of the treatments depend on a combination of aerosolised or oral ribavirin, intravenous immunoglobulin (IVIG) and/or corticosteroids

Prevention of parainfluenza

Vaccines

Unfortunately, there are currently no approved vaccines for parainfluenza, and the reason is mostly because of the different virus types. Currently, efforts are directed at type 3 parainfluenza, as it is the primary cause of severe disease and pneumonia, especially in children and the elderly.²

Infection control

Parainfluenza is mostly transmitted through large particle aerosols and fomites via self-inoculation. Moreover, young children can excrete high quantities of virus, which may remain viable on porous surfaces for about 10 hours. Therefore, isolation- especially in huge pandemics- is extremely crucial to prevent the spread of the virus.²

Summary

Parainfluenza is a viral respiratory disease, and it’s different from influenza and other respiratory illnesses. It mostly affects children and the elderly, but it can affect adults as well. Parainfluenza can affect pregnant women, but in most cases, the symptoms are simple and the infection doesn’t harm the fetus. However, it’s recommended to protect yourself as much as possible because there isn’t enough information about how exactly this illness affects pregnant women and their babies.

FAQs

Is parainfluenza bad for babies?

In general, children are more affected by parainfluenza than adults, especially with type 3, which is the most serious one.

Is parainfluenza dangerous in pregnancy?

Parainfluenza can cause some symptoms in pregnant women, such as cough, rhinorrhea, subjective fever, sore throat, headache, fatigue, shortness of breath, myalgias, prostration, and bronchopneumonia. However, there aren’t enough studies that elaborate on the effect of parainfluenza on pregnancy.

Can parainfluenza be treated with antibiotics?

Parainfluenza is caused by a virus, and antibiotics are used for bacterial illnesses. Therefore, antibiotics can’t be used to treat parainfluenza.