CLINICAL MEDICINE

Detailed explanation-1: -Some of those that do cause disease can only replicate inside the cells of the human body and are called obligate pathogens.

Detailed explanation-2: -Viruses need to enter a living cell (such as a human cell) to be able to reproduce, and once inside they take over all of the cellular machinery and force the cell to make new virus. Viruses cause diseases including the flu, herpes simplex virus, Ebola, Zika and the formidable common cold.

Detailed explanation-3: -A virus is an even smaller micro-organism that can only reproduce inside a host’s living cell. It is very difficult to kill a virus. That’s why some of the most serious communicable diseases known to medical science are viral in origin.

Detailed explanation-4: -Obligate pathogens require a host to fulfil their life cycle. All viruses are obligate pathogens as they are dependent on the cellular machinery of their host for their reproduction.