Virus: distinguishing agent, transmission and prevention

The viral family brings together very different infections. Influenza and measles are associated with the respiratory tract; hepatitis B and HIV are associated with certain exposures to blood or sex; dengue is associated with a vector. The word "virus" therefore does not allow for a single protective measure.

The distinctions that change reading

Agent and disease

The same group of agents can produce different tables. Look for the exact name and source of the file.

Targeted prevention

Compare exposure routes before choosing a guide: air, blood, food, contacts or vectors.

Vaccines and treatments

Their availability varies depending on the infection. A vaccine recommendation does not automatically translate into another disease.

Practical issues

Is an antibiotic a general protection against viruses?

No. Antibiotics target bacteria; a possible associated bacterial infection is a separate diagnosis.

Why several ways for a single file?

A fact sheet can describe several established contexts. Their importance depends on the location, activity and agent.

Before interpreting a sheet

Find the agent's name, the indicated routes and the primary source. Then check the date and territory of this source. A section helps to compare; it does not determine a person's medical conduct.

Composition, provenance and limitations of data →

Documented agents and contexts — no estimate of individual risk
Sickness or syndrome	Agent indicated	Pathways and context	Deepening
Seasonal influenza	Influenza A and B viruses	Respiratory	Fact sheet · WHO Reference
Measles	Measles virus	Respiratory	Fact sheet · WHO Reference
COVID-19	SARS-CoV-2	Respiratory	Fact sheet · WHO Reference
Mpox	Virus monkeypox	Close contact Animal / zoonosis Mother and child transmission	Fact sheet · WHO Reference
Dengue	Dengue virus	Vector	Fact sheet · WHO Reference
Rabies	Lyssavirus	Animal / zoonosis Close contact	Fact sheet · WHO Reference
Hepatitis B	Hepatitis B virus	Blood and fluids Sexual use Mother and child transmission	Fact sheet · WHO Reference
HIV infection	Human immunodeficiency virus	Blood and fluids Sexual use Mother and child transmission	Fact sheet · WHO Reference
Hepatitis A	Hepatitis A virus	Water and food Close contact	Fact sheet · WHO Reference
Hepatitis C	Hepatitis C virus	Blood and fluids Mother and child transmission	Fact sheet · WHO Reference
Hepatitis E	Hepatitis E virus	Water and food Animal / zoonosis	Fact sheet · WHO Reference
Yellow fever	Yellow fever virus	Vector	Fact sheet · WHO Reference
Poliomyelitis	Poliovirus	Water and food Close contact	Fact sheet · WHO Reference
Ebola virus disease	Orthoebolavirus spp.	Close contact Animal / zoonosis	Fact sheet · WHO Reference
Marburg virus disease	Orthomarburgvirus marburgense	Animal / zoonosis Close contact	Fact sheet · WHO Reference
Lassa fever	Mammarenavirus of Lassa	Animal / zoonosis Close contact	Fact sheet · WHO Reference
MERS	MERS-CoV	Respiratory Animal / zoonosis Close contact	Fact sheet · WHO Reference
Respiratory syncytial virus (RSV) infection	Respiratory syncytial virus	Respiratory Close contact	Fact sheet · WHO Reference
Zika virus infection	Zika virus	Vector Sexual use Mother and child transmission	Fact sheet · WHO Reference
Chikungunya	Virus chikungunya	Vector	Fact sheet · WHO Reference
West Nile Virus Infection	West Nile virus	Vector	Fact sheet · WHO Reference
Japanese encephalitis	Japanese encephalitis virus	Vector	Fact sheet · WHO Reference
Norovirus	Norovirus	Water and food Close contact	Fact sheet · CDC Reference
Rotavirus infection	Rotavirus	Water and food Close contact	Fact sheet · WHO Reference
Hepatitis D	Hepatitis D virus	Blood and fluids	Fact sheet · WHO Reference
Hantavirus infection	Orthohantavirus spp.	Animal / zoonosis Environment	Fact sheet · WHO Reference
Mumps	Urinary virus	Respiratory Close contact	Fact sheet · CDC Reference
Rubella	Rubella virus	Respiratory Mother and child transmission	Fact sheet · WHO Reference
Chickenpox	Varicella zoster virus	Respiratory Close contact Mother and child transmission	Fact sheet · CDC Reference
Smallpox	Variolic virus	Respiratory Close contact	Fact sheet · WHO Reference
Crimean-Congo haemorrhagic fever	Crimea-Congo Orthonairovirus	Vector Animal / zoonosis Close contact	Fact sheet · WHO Reference
Rift Valley fever	Phlebovirus of the Rift Valley	Animal / zoonosis Vector	Fact sheet · WHO Reference
Nipah Virus Infection	Henipavirus nipahense	Animal / zoonosis Water and food Close contact	Fact sheet · WHO Reference
Zoonotic avian influenza	Avian influenza virus	Animal / zoonosis Close contact	Fact sheet · WHO Reference
Cytomegalovirus infection	Human Cytomegalovirus	Close contact Blood and fluids Mother and child transmission	Fact sheet · CDC Reference
Infectious mononucleosis	Epstein-Barr Virus	Close contact	Fact sheet · CDC Reference
Infection with parvovirus B19	Parvovirus B19	Respiratory Blood and fluids Mother and child transmission	Fact sheet · CDC Reference
Hand, foot and mouth disease	Enterovirus, including coxsackievirus	Close contact Respiratory Water and food	Fact sheet · CDC Reference
Enterovirus D68 infection	Enterovirus D68	Respiratory Close contact	Fact sheet · CDC Reference
Adenovirus infection	Human adenoviruses	Respiratory Close contact Water and food	Fact sheet · CDC Reference
Human metapneumovirus infection	Human Metapneumovirus	Respiratory Close contact	Fact sheet · CDC Reference
Oropouche virus disease	Oropouche virus	Vector	Fact sheet · WHO Reference
Tick-borne encephalitis	Tick-borne encephalitis virus	Vector Water and food	Fact sheet · ECDC Reference
Powassan Encephalitis	Virus Powassan	Vector	Fact sheet · CDC Reference
Eastern equine encephalitis	Eastern equine encephalitis virus	Vector	Fact sheet · CDC Reference
Lymphocytic choriomeningitis	Lymphocyte choriomeningitis virus	Animal / zoonosis Environment	Fact sheet · CDC Reference

Documented agents and contexts — no estimate of individual risk

Sickness or syndrome

Agent indicated

Pathways and context

Deepening

Seasonal influenza

Influenza A and B viruses