From the Guidelines
Astrovirus infection is a common cause of gastroenteritis, particularly in young children, the elderly, and immunocompromised individuals, characterized by symptoms such as diarrhea, vomiting, fever, abdominal pain, and malaise. The virus spreads through the fecal-oral route, contaminated food or water, and contact with infected surfaces 1. According to the most recent evidence, astrovirus infections can lead to significant morbidity, especially in vulnerable populations, and can cause outbreaks in institutional settings such as schools, nursing homes, and hospitals 1.
Key Characteristics of Astrovirus Infection
- The virus primarily affects children less than 7 years of age, although adults can also be infected and may suffer from mild disease 1.
- Symptoms of astrovirus infection typically last about 2-3 days in healthy individuals but can persist longer in vulnerable populations.
- Treatment is supportive, focusing on preventing dehydration through oral rehydration solutions or, in severe cases, intravenous fluids.
- No specific antiviral medications exist for astrovirus infections.
- Prevention involves proper handwashing with soap and water, disinfecting contaminated surfaces with bleach-based cleaners, and avoiding potentially contaminated food and water.
Prevention and Control Measures
- Improved hand hygiene and surface disinfection can lead to lower rates of gastroenteritis, as demonstrated in an intervention study in elementary schools 1.
- Institutional settings, such as child care centers, schools, and nursing homes, are at risk for astrovirus outbreaks due to the lack of immunity to these viruses in young populations and the potential for person-to-person transmission 1.
- Proper infection control measures, including hand hygiene and surface disinfection, are crucial in preventing and controlling astrovirus outbreaks in these settings.
From the Research
Definition and Characteristics of Astrovirus Infection
- Astroviruses are positive-sense single-stranded RNA viruses that were discovered in 1975 2.
- They belong to the Astroviridae family, which shows a high diversity and zoonotic potential 2.
- There are three divergent groups of human astroviruses (HAstVs): the classic (MAstV 1), HAstV-MLB (MAstV 6), and HAstV-VA/HMO (MAstV 8 and MAstV 9) groups 2.
Transmission and Infection
- Classic HAstVs contain 8 serotypes and account for 2 to 9% of all acute nonbacterial gastroenteritis in children worldwide 2.
- Infections are usually self-limiting but can also spread systemically and cause severe infections in immunocompromised patients 2, 3.
- Novel astroviruses, such as HAstV-MLB and HAstV-VA/HMO, have been identified in humans and are phylogenetically more related to animal astroviruses, suggesting cross-species transmission 3.
Immune Response and Pathogenesis
- The immune response to astrovirus infection is not fully understood, but clinical observations and human volunteer studies have indicated a role for the humoral response and suggest neutralizing antibodies are important in limiting infection 4, 5.
- Cellular immunity, specifically CD4(+) T-cells, may also be involved in the anti-astrovirus response 4.
- The innate immune system may also play a role in controlling infections, as suggested by animal models 4, 5.
- Severe infections affect mainly immunocompromised patients, and novel astroviruses should be considered in the differential diagnosis of immunocompromised patients with meningitis or encephalitis of unknown origin 3.