Common pathogens causing "tropical fevers", "seasonal fevers" "endemic /epidemic /outbreak fever", "monsoon fever":
- Malaria
- Respiratory Viruses (with mild sore throat and cough).
- If rash or exanthem is present without drug exposure (rule out drug allergy), consider mononucleosis syndrome (EBV, CMV, HIV) or an exanthematous viral illness (measles, rubella, etc).
- Primary or secondary dengue may be accompanied by maculo-papular rash or polyarthralgia.
- Scrub typhus or murine typhus may present with skin eschar, regional lymphadenopathy, and maculopapular rash.
- Leptospirosis can present with conjunctival suffusion, muscle tenderness and jaundice (ask for flood water or sewage exposure).
- Typhoid should be suspected in the presence of continuous fever, gastro intestinal symptoms and splenomegaly.
- Community acquired secondary bacteremia: Primary source may be occult. In most instances, it is either from underlying pneumonia, intra-abdominal infection or urosepsis. Symptoms related to these systems may not be manifest, especially in the elderly.
- Hepatitis A or E can cause fever that usually subsides with the onset of jaundice.
- Chikungunya presents with fever and polyarthralgia /polyarthritis.
- Consider rheumatic fever caused by Group A beta hemolytic streptococci if there is migratory arthritis with preceding significant sore throat.
- Tuberculosis should be considered in any patient with prolonged undifferentiated fever, especially if there is weight loss.