A four year-old boy with invasive meningococcal disease is hospitalized in an Adelaide hospital.

According to health authorities of South Australia, the boy who comes from Adelaide, has been in contact with 28 people, seven of them will be tested and will be receiving antibiotics as a preventative measure.

Just this year, this case is the eighth reported one in Australia, as compared to six cases reported around the same time, the previous year.

In 2009, the total cases of meningococcal infection were 22.