Using sunlight to treat neonatal jaundice in resource poor areas

Some 60% of newborns become clinically jaundiced during their first week of life. Jaundice is usually a harmless condition which causes yellowing of skin and the white part of our eyes. It is usually due to the build-up of bilirubin (a waste product from the destruction of red blood cells) in the blood. However, very high levels of bilirubin can damage the central nervous system, known as kernicterus, leading to neurodevelopment problems, disability, and even death.

Kernicterus is preventable. Conventional phototherapy is the standard treatment, whereby an affected baby is placed under an electric lamp-generated blue light. The light changes the shape and structure of bilirubin, making it easier for the body to excrete. This appears to be a pretty simple form of treatment for a condition that is responsible for a large amount of neonatal morbidity and mortality in the world.

However, how can affected babies be treated in parts of the world that don’t have access to reliable sources of electrical power?

Luckily, Dr Tina Slusher and her colleagues decided to investigate whether babies could actually be treated with filtered sunlight phototherapy, and if it could be as good as conventional phototherapy in treating neonatal jaundice.  Worldwide, approximately 481,000 term and near term babies annually have high bilirubin levels. Of these, roughly 24% die and approximately 63,000 survive with moderate to severe morbidity. 75% of these 481,000 babies live in sub-Saharan Africa and India – areas of the world where electrical power problems are very common.

The use of sunlight to decrease bilirubin levels dates back to 1958, and led to the production of fluorescent blue light tubes used in phototherapy. However, these lights are expensive, require irradiance measurements, and require specific knowledge in order for the light to be used in the most optimal way. If not used appropriately, babies do not get treated. Despite sunlight being effective, there have always been concerns about sun rays containing ultraviolet radiation which can damage human skin, and infrared rays which can lead to a rise in body temperature. This is particularly dangerous for babies, who still have immature homeostasis mechanisms. Nonetheless, if ultraviolet and infrared rays are filtered out, sunlight is a natural, cheap, sustainable way of providing phototherapy to millions of babies in the developing world, and who are ultimately dying from something so preventable.

Back in 2015, Dr Slusher and her team conducted a randomized control trial in Nigeria, comparing the effectiveness of sunlight phototherapy with conventional phototherapy. 224 infants received sunlight phototherapy and were placed under a canopy that transmitted blue light. 223 infants were given conventional phototherapy. They found that filtered sunlight phototherapy was effective in managing neonatal jaundice, and no infant developed sunburn or dehydration. In comparison to conventional phototherapy, filtered sunlight was not inferior. However, in order to spot any complications of the treatment, stringent monitoring of body temperature, vital signs, and general well-being were required, particularly as sunlight cannot be measured or controlled. Therefore, a greater amount of human resources would be required in order to monitor babies if this was scaled up. This method cannot be implemented unless the manpower is available, or these countries have access to advanced body monitoring technology. There is also the issue about the provision of therapy at night. Some babies with high levels of bilirubin require treatment overnight, and so this highlights the need for conventional phototherapy units at night, when no sunlight is present.

Despite these technical issues, the team are unrelenting and continue to iterate, in order to provide treatment to babies in countries where disease burden is the highest, and where low cost innovative technology can have the biggest impact.

By Shreya Patel

Photo credit: Max Pixel