According to the data you provided (reccurent fever, normal complete blood count, normal results from X-ray, flu tests and strep tests and no other symptoms), it is possible that your son might be experiencing several episodes of viral infections.


It is not uncommon for children to be sick in that age (second year of their life), because it is the period when the child’s immune system meets the bacteria and viruses for the first time. Once the immune system develops its own immune response, the symptoms would be less severe when the body meets the same bacteria or the same virus the next time. However, if another bacteria or virus causes a new infection, the immune system would have to start all over again to create an adequate immune response. It explains why little children are susceptible to repetitive infections.


The immune system of a child develops approximately from the second till the fourth year and the repetitive infections are expected in that period, too.


In the first six months of the life, the baby is protected with the antibodies that originate from the mother and have entered the baby’s body via the umbilical cord during pregnancy. Afterwards, the antibodies levels decrease and the body needs to come in contact with the infective agents in order to develop adequate imune respoonses. Each different agent (bacteria or virus) devlops its own immune response and that is why so many infections might occur during childhood. The infections usually start when the child starts to be in contact with other children, for example, kindergarden.


You might want to take your child to a specialist for pediatric immunology that would make a physical examination and series of blood examinations to detect or rule out possible immune disorders.