Here you’ll find 14 Viruses that start with A, organized from “Adeno-associated virus (AAV)” to “Avian influenza (avian influenza virus)”. Many entries are human pathogens, animal viruses, or research tools used in diagnostics and gene therapy.

Viruses that start with A are viruses whose accepted names begin with the letter A. They include notable human pathogens and research examples like Adeno-associated virus (AAV).

Below you’ll find the table with Name, Classification, Affects humans?, Common symptoms, and Transmission.

Name: The commonly used virus name, so you can identify each entry quickly and match it to literature and clinical reports.

Classification: Shows family, genus, or species per ICTV so you understand relationships and find related viruses.

Affects humans?: Indicates “Yes” or “No” with a short qualifier so you can see zoonotic or opportunistic risk at a glance.

Common symptoms: Lists typical presentations in five to ten words so you can recognize usual clinical features quickly.

Transmission: States principal routes of spread succinctly so you understand how infection commonly occurs.

Viruses that start with A

NameClassificationAffects humans?Transmission
AdenovirusAdenoviridae / MastadenovirusYes — common human pathogensRespiratory droplets; fecal–oral; contact
Adeno-associated virus (AAV)Parvoviridae / DependoparvovirusNo — nonpathogenic, research-useNot typically human‑to‑human (vector delivery)
Aichi virusPicornaviridae / KobuvirusYes — human gastroenteritisFecal–oral
Astrovirus (human)Astroviridae / MamastrovirusYes — pediatric gastroenteritisFecal–oral; close contact
Anellovirus (e.g., Torque teno)Anelloviridae / AlphatorquevirusYes — ubiquitous, usually asymptomaticBlood; body fluids (routes unclear)
Alkhurma hemorrhagic fever virusFlaviviridae / FlavivirusYes — zoonotic, human diseaseTick‑borne; contact with livestock
Andes virusHantaviridae / OrthohantavirusYes — zoonoticRodent excreta inhalation; rare person‑to‑person
Australian bat lyssavirusRhabdoviridae / LyssavirusYes — zoonoticBat bite or scratch
African swine fever virusAsfarviridae / AsfivirusNo — swine onlyDirect contact; ticks; fomites (pigs)
African horse sickness virusReoviridae / OrbivirusNo — equids onlyVector‑borne — Culicoides midges
Amapari virusArenaviridae / MammarenavirusNo — rodent-associatedRodent contact/excreta
Akabane virusPeribunyaviridae / OrthobunyavirusNo — livestock virusVector‑borne — midges (Culicoides)
Aino virusPeribunyaviridae / OrthobunyavirusNo — primarily animals; rare human exposureVector‑borne — biting midges
Avian influenza (avian influenza virus)Orthomyxoviridae / AlphainfluenzavirusYes — zoonotic potentialRespiratory droplets; bird‑to‑human contact

Descriptions

Adenovirus
Causes respiratory illness, conjunctivitis, sometimes gastroenteritis (fever, cough, redness, diarrhea); usually mild but can be severe in infants/immunocompromised (CDC 2023) Last updated 2026-03-09
Adeno-associated virus (AAV)
Small dependoparvovirus used in gene therapy; typically asymptomatic in humans, nonpathogenic and widespread in nature (ICTV 2023) Last updated 2026-03-09
Aichi virus
Causes acute gastroenteritis (diarrhea, vomiting, abdominal pain); generally self-limited in children and adults (ICTV 2023) Last updated 2026-03-09
Astrovirus (human)
Often causes watery diarrhea, vomiting, low-grade fever; mostly mild in children, elderly can be more affected (CDC 2022) Last updated 2026-03-09
Anellovirus (e.g., Torque teno)
Highly prevalent, usually asymptomatic; detected in blood and tissues with uncertain disease role, common in healthy people (ICTV 2023) Last updated 2026-03-09
Alkhurma hemorrhagic fever virus
Causes fever, hemorrhage, sometimes encephalitis; can be severe and occasionally fatal after tick exposure (WHO 2020) Last updated 2026-03-09
Andes virus
Leads to hantavirus pulmonary syndrome: fever, cough, rapid respiratory failure; high case fatality in severe cases (CDC 2020) Last updated 2026-03-09
Australian bat lyssavirus
Causes rabies-like encephalitis following bat exposure; nearly always fatal without prompt post‑exposure prophylaxis (WHO 2021) Last updated 2026-03-09
African swine fever virus
Causes severe hemorrhagic disease in domestic and wild pigs with high mortality; major agricultural impact, not a human pathogen (OIE 2022) Last updated 2026-03-09
African horse sickness virus
Produces severe respiratory and circulatory disease in horses (fever, edema, respiratory distress); high mortality in susceptible equids (OIE 2021) Last updated 2026-03-09
Amapari virus
A mammarenavirus identified in rodents; limited human evidence and not a recognized common human pathogen (ICTV 2023) Last updated 2026-03-09
Akabane virus
Infects ruminants causing congenital defects and abortions; rare or no human disease reported (ICTV 2023) Last updated 2026-03-09
Aino virus
Primarily infects livestock; human seropositivity reported but clinical disease in humans is rare or undocumented (ICTV 2023) Last updated 2026-03-09
Avian influenza (avian influenza virus)
Bird-origin influenza viruses that can infect humans (fever, cough, pneumonia); some subtypes cause severe disease and pandemics risk (WHO 2023) Last updated 2026-03-09
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