Medical Articles
Why Does It Start to Spread in June, Even in a Country with Year-Round Summer Weather?!
31.05.2026
This is about “pharyngoconjunctival fever,” one of the three major summer colds that spread worldwide during the summer months.
This illness is also commonly known as “pool fever.” This name comes from two factors: that the infection can spread through swimming pools, and that outbreaks often coincide with the start of the swimming season. However, the cause of this “pool fever” is a virus called adenovirus. Swimming pools are only one of the transmission routes; it is primarily spread through respiratory droplets and direct contact.
Specifically, the virus enters the body through the mucous membranes of the mouth, nose, or throat, or through the conjunctiva (the lining of the eyes). Adenovirus is also shed in feces. Therefore, if an infected child uses the bathroom and enters the pool without maintaining proper hygiene, the virus can enter the bodies of others through the pool water. The incubation period is about 5 to 10 days, with symptoms including fever and a sore throat. This often leads to conjunctivitis (redness and pain in the eyes).
Infections typically begin to increase from June through July, but unfortunately, there is no medication that can fundamentally cure adenovirus itself. Consequently, there is no specific cure for “pool fever” either. Treatment is primarily symptomatic: pain relievers are prescribed for sore throats, and fever reducers for high fevers, while doctors monitor the patient’s condition and wait for the illness to resolve naturally. Prevention is therefore crucial. Be sure to wash your hands and gargle after swimming. Since infection through the eyes is common, you should also rinse your eyes. While many young children use pools in condominiums and other facilities, infection can be prevented with proper precautions. However, if you experience any symptoms that suggest you may have the illness, please visit a medical facility as soon as possible.
Author Bio
Dr. Vivien
Medical Director/Family Medicine Specialist
After completing medical school in Moscow, Dr. Vivien gained clinical experience at a general hospital in Penang, Malaysia. She later served as a full-time physician at Batu Gajah Hospital in Perak and at a clinic in Selangor.
Since 2018, she has been with Hibari Clinic, where she currently serves as Medical Director and is dedicated to providing care for the local community. She has a strong interest in pediatrics and psychosomatic medicine, and values patient-centered care that respects each individual’s needs.