contagious infectious diseases
The boundary between contagious and non-contagious infectious diseases is not perfectly drawn, as illustrated classically by tuberculosis, which is clearly transmissible from person to person, but was not classically considered a contagious disease.he non-contagious category of infections usually require a special mode of transmission between persons or hosts. These include need for intermediate vector species (mosquitoes that cause malaria) or by non-casual transfer of bodily fluid (such as transfusions, needle sharing or sexual contact).