Influenza is a viral infection that primarily affects the nose, throat, bronchi, and occasionally the lungs. The infection usually lasts for a week and is characterized by the sudden onset of high fever, muscle pain, headache, marked general malaise, dry cough, sore throat, and rhinitis. The virus is easily transmitted from one person to another through droplets and small particles expelled when coughing or sneezing. Influenza usually spreads rapidly during seasonal epidemics. Most affected people recover within a week or two without requiring medical treatment. However, in young children, older adults, and people with other serious medical conditions, infection can cause serious complications of underlying medical conditions, lead to pneumonia, or lead to death.
SARS-CoV-2 is the virus that causes the infectious disease called COVID-19. Most people infected with the virus develop mild to moderate respiratory illness and recover without special treatment. However, some people become seriously ill and require medical attention. Older adults and people with underlying medical conditions such as cardiovascular disease, diabetes, chronic respiratory disease, or cancer are more likely to develop severe illness. The virus can be spread from an infected person’s mouth or nose through small liquid particles when the infected person coughs, sneezes, talks, sings or breathes. Anyone of any age can get COVID-19 and become seriously ill or die.
Respiratory syncytial virus (RSV) is a common respiratory virus that usually causes mild cold-like symptoms. Most people recover within one to two weeks, but RSV can be serious. Infants and older adults are more likely to develop severe respiratory syncytial virus and require hospitalization. Vaccine protects older adults from severe RSV infection. Monoclonal antibody products protect infants and young children against severe RSV infection.
key data
People of any age can be affected, although some are more at risk than others.
- People at higher risk for serious illness or complications are pregnant women, people younger than 59 months, older adults, and people with chronic disease (cardiac, pulmonary, renal, metabolic, neurodevelopmental, hepatic, or hematologic) or immunosuppression (caused by patients caused by HIV/AIDS, chemotherapy, corticosteroid therapy, or malignancy).
- Healthcare professionals are at high risk for contracting and spreading the influenza virus due to contact with patients, especially to vulnerable populations.
Seasonal flu spreads easily and quickly in places like schools and nursing homes. When coughing or sneezing, an infected person spreads infectious droplets (containing the virus) into the air up to 1 meter away, infecting people nearby who inhale these droplets. The virus can also be spread through contaminated hands. To prevent spread, wash your hands frequently and cover your mouth and nose with a tissue when coughing. In temperate climates, seasonal epidemics mainly occur in winter, while in tropical areas, seasonal epidemics can occur throughout the year, resulting in more irregular epidemics.
The incubation period (the time from infection to the onset of disease) is approximately 2 days, but can range from 1 to 4 days.
Pan American Health Organization’s response
PAHO supports countries in the region in the surveillance, prevention, preparedness and control of epidemics and epidemic-prone diseases by developing evidence-based strategies to predict, prevent, detect and respond to infectious disease threats. It also ensures regional monitoring of functions related to these threats.
Main lines of action:
- Epidemics and epidemic-prone diseases: Influenza, MERS, hemorrhagic fevers and hantaviruses, yellow fever and emerging arboviruses, leptospirosis and meningococcemia.
- Expert networks and monitoring and response interventions: Epidemiology and modeling, laboratory, clinical management, and infection control and prevention.