Types of viral fever
Reading File
Finding Sources
Finding Sources
Searching the Web
types of viral fever classification symptoms
Reading File
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Reading File
I now have comprehensive information from Harrison's and other sources. Let me compile the full, well-structured answer.
Types of Viral Fever
Viral fever refers to any febrile illness caused by a virus, ranging from mild self-limiting infections to life-threatening systemic disease. They are best organized by the organ system affected, mode of transmission, or clinical syndrome.
1. Respiratory Viral Fevers
These infect the upper or lower respiratory tract and are the most common type.
| Virus | Disease | Key Features |
|---|---|---|
| Influenza A/B | Flu | Abrupt onset, high fever, chills, headache, dry cough, myalgia, lasting 3-7 days |
| SARS-CoV-2 | COVID-19 | Fever, cough, loss of smell/taste, fatigue; can cause severe pneumonia |
| Rhinovirus, coronavirus | Common cold | Mild fever, rhinorrhea, sore throat |
| RSV | Bronchiolitis/pneumonia | Mainly infants and elderly; fever + wheeze |
| Parainfluenza virus | Croup | Barking cough, stridor, low-grade fever |
| Adenovirus | Pharyngoconjunctival fever | Fever, sore throat, conjunctivitis |
Influenza typically presents as fever with constitutional symptoms (headache, malaise, myalgias) and respiratory symptoms; up to one-third of patients may not have fever. - Harrison's Principles of Internal Medicine 22E, p. 1718
2. Enteric (Gastrointestinal) Viral Fevers
Viruses infecting the GI tract cause fever alongside GI symptoms.
| Virus | Disease | Key Features |
|---|---|---|
| Norovirus | Viral gastroenteritis | Vomiting, watery diarrhoea, low-grade fever, 2-3 days |
| Rotavirus | Gastroenteritis (children) | High fever, vomiting, profuse diarrhoea |
| Hepatitis A, E | Viral hepatitis | Fever, jaundice, hepatomegaly |
| Enteroviruses (Coxsackie, ECHO) | Herpangina, hand-foot-mouth | Fever, oral ulcers, rash on palms/soles |
3. Exanthematous (Rash-Associated) Viral Fevers
Characterized by fever + rash.
| Virus | Disease | Key Features |
|---|---|---|
| Measles (Rubeola) | Measles | High fever, cough, coryza, Koplik's spots, maculopapular rash (head-to-toe) |
| Rubella | German measles | Mild fever, pink rash, lymphadenopathy |
| Varicella-zoster | Chickenpox | Fever + pruritic vesicular rash in crops |
| Human herpesvirus 6 | Roseola (exanthem subitum) | High fever for 3-4 days, then rash when fever breaks |
| Parvovirus B19 | Fifth disease (erythema infectiosum) | "Slapped cheek" rash, mild fever |
| Dengue virus | Dengue fever | High fever, severe joint/bone pain ("breakbone fever"), maculopapular rash, low platelets |
4. Arboviral Fevers (Arthropod-borne)
Transmitted by mosquitoes, ticks, sandflies.
| Virus | Vector | Disease | Key Features |
|---|---|---|---|
| Dengue virus (DENV 1-4) | Aedes mosquito | Dengue fever / DHF | Fever, thrombocytopenia, rash, hemorrhage in severe form |
| Chikungunya virus | Aedes mosquito | Chikungunya fever | Fever, incapacitating arthralgia |
| Zika virus | Aedes mosquito | Zika fever | Mild fever, rash, conjunctivitis; microcephaly in fetus |
| Yellow fever virus | Aedes mosquito | Yellow fever | Fever, jaundice, hemorrhage; liver is a primary target |
| West Nile virus | Culex mosquito | West Nile fever | Fever, meningitis/encephalitis in severe form |
| Sandfly fever virus | Sandfly | Phlebotomus fever | Short self-limiting fever, headache, myalgia |
5. Viral Hemorrhagic Fevers (VHF)
A specific, severe subset where widespread vascular dysfunction leads to bleeding tendency, shock, and multiorgan failure. They are classified by virus family. - Harrison's Principles of Internal Medicine 22E, p. 1717-1720
VHF syndrome shares a common pathophysiology: direct or indirect damage to the microvasculature causes increased permeability and actual disruption, leading to skin/mucous membrane hemorrhage, and circulatory dysfunction contributing to shock.
By Virus Family:
Filoviridae
- Ebola virus disease - CFR up to 90% in some outbreaks; fever, diarrhoea, vomiting, hemorrhage
- Marburg virus disease - Similar to Ebola
Arenaviridae (Mammarenaviruses)
- Lassa fever - Endemic in West Africa; tens to hundreds of thousands of infections annually; ~20% develop full Lassa fever; treatable with ribavirin
- Junín virus (Argentinian hemorrhagic fever) - Thrombocytopenia, mucosal bleeding, CNS features (tremors, cerebellar signs); treated with convalescent plasma or ribavirin
- Machupo virus (Bolivian hemorrhagic fever)
- Guanarito virus (Venezuelan hemorrhagic fever)
Bunyaviricetes
- Crimean-Congo hemorrhagic fever (CCHF) - Tick-borne; widespread in Africa, Asia, Eastern Europe
- Hantavirus hemorrhagic fever with renal syndrome (HFRS) - Rodent-borne; kidneys are primary target; hemoconcentration is most marked
- Rift Valley fever (RVF) - Mosquito/contact-borne in Africa
- Severe fever with thrombocytopenia syndrome (SFTS) - Emerging; caused by SFTSV (phenuivirid)
Flaviviridae
- Yellow fever - Liver is primary target; vaccine-preventable
- Dengue hemorrhagic fever (DHF) / Dengue shock syndrome (DSS) - Urban; caused by DENV 1-4; hemoconcentration most marked in severe dengue
- Kyasanur Forest disease, Omsk hemorrhagic fever - Tick-borne
6. Neurotropic Viral Fevers
Virus has affinity for the nervous system.
| Virus | Disease | Key Features |
|---|---|---|
| Herpes simplex virus | HSV encephalitis | Fever + focal neurological signs |
| Rabies virus | Rabies | Fever, hydrophobia, encephalitis; invariably fatal once symptomatic |
| Poliovirus | Poliomyelitis | Fever, meningism, flaccid paralysis |
| Japanese encephalitis virus | JE | Fever, encephalitis; vaccine-preventable |
| Enterovirus 71 | Hand-foot-mouth / encephalitis | Rash + encephalitis in severe cases |
7. Glandular / Systemic Viral Fevers
| Virus | Disease | Key Features |
|---|---|---|
| EBV (Epstein-Barr virus) | Infectious mononucleosis | Fever, pharyngitis, lymphadenopathy, splenomegaly, atypical lymphocytes |
| CMV | CMV mononucleosis | Similar to EBV but pharyngitis less prominent |
| HIV | Acute retroviral syndrome | Fever, rash, lymphadenopathy, 2-4 weeks after exposure |
| Mumps virus | Mumps | Parotitis, fever; orchitis/oophoritis possible |
General Clinical Features of Viral Fever
- Fever (38-40°C or higher), often with rigors
- Myalgia, arthralgia, headache
- Fatigue and malaise
- Rhinitis, pharyngitis (respiratory types)
- Rash in many types
- Self-limiting in most cases (3-7 days)
Key Diagnostic Pointers
| Feature | Suggests |
|---|---|
| Travel history to endemic area | VHF, dengue, malaria |
| Rash + fever | Dengue, measles, chikungunya, exanthems |
| Hemorrhagic manifestations | VHF (Ebola, Lassa, CCHF, dengue) |
| Thrombocytopenia | Dengue, CCHF, Lassa, hantavirus |
| Jaundice + fever | Yellow fever, hepatitis A/E, Ebola |
| Lymphadenopathy + fever | EBV, CMV, HIV, rubella |
Sources:
- Harrison's Principles of Internal Medicine 22E (2025) - Viral Hemorrhagic Fever chapter
- Jawetz Melnick & Adelberg's Medical Microbiology 28E - Influenza
- CDC - About Viral Hemorrhagic Fevers
- Apollo Hospitals - Viral Fever Classification
This is a shared conversation. Sign in to Orris to start your own chat.