Viral diseases
virusAn ultramicroscopic infectious non-cellular organism that can replicate inside the cells of living hosts, with negative consequences. are not alive because they do not complete all of the seven life processes, which are:
- movement
- respiration
- sensitivity
- nutrition
- excretion
- reproduction
- growth
We say 'strains' of virus and not species. Strains are made of a relatively short length of genetic material (DNADeoxyribonucleic acid. The material inside the nucleus of cells, carrying the genetic information of a living being.) which is surrounded by a protein coatThe proteins that surround the DNA of a virus..
Viral infections cannot be treated by antibioticsSubstances that control the spread of bacteria in the body by killing them or stopping them reproducing..
HIV/AIDS
HIVHuman Immunodeficiency Virus, a disease which damages cells in the immune system. stands for human immunodeficiency virus. This infection is transmitted by body fluids, often during unprotected sex, but also through cuts and injecting drugs using unsterilized needles. Immediately after infection, people often suffer mild flu-like symptoms. These pass and for a period of time infected people might not know they are infected.
AIDSAcquired Immune Deficiency Syndrome 鈥 a disease of the human immune system caused by infection with Human Immunodeficiency Virus (HIV). stands for acquired immune deficiency syndrome. Months or years after the infection by HIV, the virus becomes active and attacks the patient's white blood cells. HIV at this point has resulted in AIDS.
There is no cure for HIV/AIDS although scientists are trying to find one. Currently, infected people are given antiviralsDrugs that prevent viruses replicating., which can significantly slow the development of AIDS.
Ebola
In 2015 an outbreak of EbolaOften fatal disease caused by a virus which originated in Africa. occurred in West Africa. Between 50% and 90% of Ebola cases are fatal. Early symptoms of Ebola include:
- fever and headache
- joint and muscle pain
- muscle weakness
Patients then develop diarrhoea, vomiting, stomach pain and internal bleeding.
The virus is transmitted in body fluids. It is possible to catch it from a dead person several days after they have died. It is also possible to catch it from the clothes or possessions of a dead person, having sex with an infected person or from unsterilized needles shared with an infected person.
There is currently no licensed treatment for Ebola.