What is the difference between flu and a cold?

Flu symptoms come on suddenly and are more severe than a cold. Flu typically causes high fever (100-104°F), body aches, extreme fatigue, and dry cough. Colds develop gradually with milder symptoms like runny nose, sneezing, and sore throat. Flu is also more likely to cause serious complications requiring hospitalization.

How does the flu spread?

Flu spreads primarily through respiratory droplets when infected people cough, sneeze, or talk. You can also get flu by touching contaminated surfaces and then touching your face. People with flu are most contagious in the first 3-4 days after illness begins, but can spread the virus 1 day before symptoms start.

How effective is the flu vaccine?

Flu vaccine effectiveness varies by season (typically 40-60% effective) based on how well the vaccine matches circulating strains. Even when not perfectly matched, the vaccine reduces illness severity, hospitalizations by 40-60%, and deaths. It takes about 2 weeks after vaccination for antibodies to develop.

What are flu complications to watch for?

Serious complications include pneumonia, bronchitis, sinus infections, ear infections, myocarditis (heart inflammation), and encephalitis (brain inflammation). Warning signs requiring immediate care: difficulty breathing, chest pain, persistent vomiting, confusion, severe weakness, fever returning after improvement, or worsening of chronic conditions.

When should I take antiviral medications?

Antiviral medications (oseltamivir/Tamiflu, zanamivir/Relenza) work best when started within 48 hours of symptom onset. They're recommended for people at high risk of complications, those with severe illness, or hospitalized patients. Antivirals can shorten illness duration by 1-2 days and reduce complications.

Where is flu activity highest right now?

Flu season typically peaks between December and February in the Northern Hemisphere, but can occur year-round in some regions. Check the live outbreak data above for current flu activity levels, dominant strains, and geographic hotspots.

Virginia

Influenza in Virginia

Influenza (flu) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness and can lead to hospitalization or death, particularly in high-risk populations.

Track Influenza activity in Virginia in real time.

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¿Qué es Influenza?

Influenza is a seasonal respiratory virus that affects millions of people worldwide each year. Unlike the common cold, flu comes on suddenly and can cause serious complications like pneumonia, especially in children, elderly, pregnant women, and those with chronic conditions. Annual flu vaccination is the best prevention method.

Síntomas

Sudden onset of high fever (100-104°F)
Dry cough
Severe body aches and muscle pain
Extreme fatigue and weakness
Headache
Sore throat
Runny or stuffy nose
Sometimes nausea, vomiting, diarrhea (more common in children)

Transmisión

Flu spreads through respiratory droplets when infected people cough, sneeze, or talk. It can also spread by touching contaminated surfaces and then touching the mouth, nose, or eyes. The virus can survive on surfaces for 24-48 hours.

Período de Contagio: 1 day before symptoms appear through 5-7 days after becoming sick (children and immunocompromised may be contagious longer)

Prevención

Annual flu vaccination (recommended for everyone 6 months and older)
Frequent handwashing with soap and water for 20 seconds
Avoid touching face (eyes, nose, mouth)
Stay home when sick (at least 24 hours after fever resolves)
Cover coughs and sneezes with tissue or elbow
Clean and disinfect frequently touched surfaces
Avoid close contact with sick people
Consider wearing a mask in crowded indoor settings during flu season

Virginia Recursos de Salud

Información del departamento de salud local y orientación de prevención específica del estado

Estamos Monitoreando Virginia

Nuestra vigilancia impulsada por IA monitorea continuamente la actividad de Influenza en todo Virginia. Rastreamos datos de departamentos de salud estatales, hospitales locales, informes del CDC y más de 50 fuentes de salud globales para proporcionar advertencia temprana de amenazas emergentes.

Reciba notificaciones instantáneas cuando la actividad de Influenza aumenta en Virginia o en su condado específico.

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Virginia Departamento de Salud

Para alertas oficiales de salud del estado, ubicaciones de vacunación y orientación de salud pública específica de Virginia, visite el sitio web del departamento de salud de su estado.

→ Virginia Departamento de Salud → CDC Influenza Information → CDC Health Topics

Understanding Influenza: Key Questions

Ya sea que viva en Virginia or are traveling there, knowing the symptoms, timeline, and when to seek care helps you act quickly if exposure occurs.

Cuándo Buscar Atención Médica

Seek care if you experience severe dehydration, bloody stools, high fever, or symptoms lasting more than 3 days. Children under 5, adults over 65, and immunocompromised individuals should seek care earlier.

Síntomas de emergencia: Severe dehydration, inability to keep fluids down for 12 or more hours, or neurological symptoms require emergency care.

Recursos Expertos y Referencias

Información confiable de las principales organizaciones de salud

CDC

Orientación oficial de los Centros para el Control y la Prevención de Enfermedades de EE. UU.

Ver Recursos del CDC →

WHO

Vigilancia global de enfermedades y directrices de la Organización Mundial de la Salud

Ver Recursos de la OMS →

Investigación

Últimas investigaciones revisadas por pares y estudios clínicos

Ver Investigación →

Contenido Revisado Médicamente

La información sobre enfermedades en Virus Watcher es revisada por nuestro Epidemiólogo Jefe, ex analista principal del CDC para el pronóstico FluSight. Los datos de brotes se agregan de fuentes verificadas incluyendo BEACON, ProMED, OMS, CDC y más de 50 agencias nacionales de salud. Esta información es con fines educativos y no debe reemplazar el asesoramiento médico profesional.

Última revisión: 2026-08-13

Preguntas Frecuentes

Preguntas frecuentes sobre Influenza respondidas por nuestro equipo de epidemiología

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Obtenga Influenza Alertas para Virginia

Reciba notificaciones instantáneas cuando la actividad de Influenza aumenta en Virginia o sus destinos de viaje. Rastree más de 200 enfermedades con alertas basadas en ubicación. Utilizado por sistemas de salud, servicios de emergencias médicas, escuelas y viajeros de todo el mundo.