Colliding epidemics

Amid Covid-19 and rising PM2.5 levels, a surge in the seasonal respiratory syncytial virus is cause for concern especially for infants and young children

After surfacing in Thailand in September this year, the respiratory syncytial virus (RSV) epidemic has claimed one life so far -- a 10-month-old infant from Chaiyaphum province -- as well caused the hospitalisation of scores of children under the age of six. Symptoms of the virus, for which there is no vaccine to date, include fever, dry/wet cough, sneezing, a runny nose, loss of appetite, and breathing difficulty and/or wheezing.

Medical news reports in Thailand claim that the seasonal virus, which lasts between August to November, is the source of 50% to 90% of hospitalisations related to bronchiolitis, 5% to 40% of hospitalisations for pneumonia, and 10% to 30% of hospitalisations for croup (laryngotracheobronchitis), a respiratory infection leading to swelling inside the trachea which then subsequently interferes with normal breathing.

Due to the highly contagious nature of RSV, the Department of Disease Control recently urged the public to take extra precautions in protecting their loved ones from the infection which can spread quickly through the respiratory droplets of an infected person as they sneeze or cough.

Although there are no statistics about the number of deaths annually from RSV in Thailand, global reports suggest that each year approximately 33.8 million children under the age of five are infected, of which 160,000 die as a result.

In Thailand, severe cases of RSV have been reported in hospitals not just in Bangkok but across multiple provinces such as Udon Thani, Ubon Ratchathani and Chaiyaphum.

To gauge how doctors in Bangkok are coping with a surge of the infection, Life spoke with paediatric pulmonologist Dr Issaranee Vareesunthorn, who says 80% of her patients are RSV cases.

"My patients are mostly pre-schoolers and infants between six months to two years of age. In fact, many older students contract the virus from their younger counterparts. This is why I would like to encourage parents to immediately take their children to the hospital even if they display mild symptoms such as fever, cough, the presence of mucus, breathlessness and wheezing," Issaranee said.

"RSV is highly contagious and those most at risk are infants and children under the age of six. So, if your child displays any symptoms, please do not allow them to go to school. Currently, there is no vaccine for RSV which is why prevention is the best option available.

"For infants, breastfeeding is also highly encouraged because it bolsters immunity naturally. Parents are also encouraged to follow the same precautionary measures as they do for Covid-19. This means avoid taking your children to crowded venues, wash hands properly, wear a mask, and practise social distancing. Additionally, as the weather gets cooler, make sure your children stay warm."

Furthermore, those who are most vulnerable and likely to experience a severe case of RSV are children born prematurely, those that have underlying heart and lung diseases such as congestive heart failure, chronic obstructive pulmonary disease, and/or bacterial infection complications, according to Issaranee.

"RSV can easily infect the lungs and respiratory tract of young children whose lungs have not adequately developed and whose immune systems are not as efficient as those of adults. The infection is also more common in young infants who are about two years old."

Shedding light on the time frame of the symptoms, Issaranee remarked that typically symptoms surface within four to six days after infection. Moreover, infection and the resulting inflammation of the respiratory tract and lungs can lead to complications such as laryngitis, bronchitis, bronchiolitis, and pneumonia in severe cases.

"Patients with severe symptoms may need to be admitted to the hospital to receive special treatment such as a bronchodilator to relax the lung muscle and widen the airway.

"However, most mild cases do not require treatment and will naturally clear up on their own within five to seven days. In moderate cases, patients are usually infected in the lower respiratory tract or have a chronic cough with mucus and may need percussion and postural drainage to empty mucus out of the respiratory tract. In such cases, symptoms may take around two to three weeks to subside."

Testing for RSV can be accomplished using a handful of methods, Issaranee said, including rapid antigen detection tests (RADTs) which are popular due to their ease of use, quick turnaround time, and acceptable sensitivity and specificity in infants and young children.

Direct fluorescent antibody (DFA) testing is also a reliable method for use in infants and young children, however, its sensitivity in adults and older children is poor due to a lower rate of viral shedding. Yet, since the DFA is more cost-effective than molecular testing (eg PCR), it is favoured over RADTs among infants and young children.

While an accurate and timely diagnosis of RSV infections facilitates appropriate management of the illness, should adults be looking to get themselves tested as well?

According Dr Issaranee, although RSV generally does not cause complications in healthy people, it can lead to increased morbidity and mortality rate in high-risk patients.

Among symptomatic patients, RSV testing is most warranted in young children but also among adults above the age of 65 who have underlying heart and lung conditions such as chronic obstructive pulmonary disease.

Issaranee also cautioned the public to take mask-wearing seriously, stressing the need to cover the entire nose and have both sides of your face covered to prevent the entry of any foreign particles. This is an important precaution, not just for Covid-19 but also RSV.

Also, if you need to have a conversation without your mask, remember to stand at least 2m apart.

The best-case scenario is to avoid being outdoors for a long period of time with your child.

Moreover, the increasing presence of PM2.5 has exacerbated health hazards for patients, admitted the paediatric pulmonologist.

"I would say the presence of PM2.5 dust particles in the air makes it worse for patients who are already suffering respiratory health issues because it makes their lungs and respiratory tract work harder.

"Prevention is better than the cure, so I would like to suggest the public build up their immunity by taking care of their overall health. Eat healthily, practise good sleeping habits, exercise daily, and also look after your emotional health."

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Respiratory syncytial virus (RSV) was first discovered in 1955 after an unknown respiratory illness spread in a colony of chimpanzees in a medical laboratory. The illness was named "chimpanzee coryza agent". However, it was later discovered that the source of the infection was actually human caretakers of the chimpanzees. In 1963, Robert Chanock and his colleagues isolated and characterised the virus. The name respiratory syncytial virus was given as a descriptive term related to pathological changes of the airway epithelium as a result of the infection, which until today is causing annual outbreaks among all age groups.

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