Dengue, Typhoid or Malaria: Sorting Out a Fever in India
A fever lasting more than two or three days in India raises a short list of likely causes, and the three that dominate are dengue, typhoid and malaria. They overlap enough that they cannot be reliably separated by symptoms alone, which is why testing matters, but the pattern of illness does give useful clues.
Dengue
Spread by the Aedes mosquito, which bites during the day, breeds in clean stagnant water in coolers, flower pots, tyres and overhead tanks, and is an urban mosquito.
Pattern. Abrupt high fever, often 39 to 40 degrees, with severe headache, pain behind the eyes, intense muscle and joint pain that earned it the name breakbone fever, nausea, vomiting and a flushed appearance. A rash often appears around day three to five, sometimes described as islands of white in a sea of red.
The critical phase. Here is the point most people miss: the dangerous phase of dengue begins as the fever falls, usually days four to six. Plasma leaks from blood vessels and platelets drop. Feeling relieved that the fever has broken is exactly when to be most watchful.
Warning signs needing immediate hospital assessment:
- Severe abdominal pain or tenderness
- Persistent vomiting
- Bleeding from gums or nose, blood in vomit, stool or urine
- Black tarry stools
- Lethargy, restlessness or irritability
- Cold clammy skin, rapid weak pulse
- Reduced urine output
- Sudden drop in temperature with worsening condition
- Rapid breathing
Testing. NS1 antigen is positive in the first five days. IgM antibodies appear from around day five. Serial complete blood counts tracking platelets and haematocrit matter more than a single result.
Treatment. Supportive. Paracetamol for fever and pain, generous oral fluids including ORS, rest, and monitoring. Avoid aspirin, ibuprofen and other NSAIDs entirely, as they increase bleeding risk. Platelet transfusion is not given on the basis of a low count alone, but for active bleeding or on specialist advice. Papaya leaf extract and similar remedies have no reliable evidence and must never replace monitoring.
Typhoid
Spread by contaminated food and water carrying Salmonella typhi. It is a faecal-oral infection, not mosquito-borne.
Pattern. Gradual onset, unlike dengue. Fever climbs in a stepwise fashion over several days and becomes persistent, often with a relative slowing of the pulse compared with the temperature. Headache, abdominal discomfort, loss of appetite, and constipation more often than diarrhoea in adults, while children more often have diarrhoea. The abdomen may be distended and the spleen enlarged. Rose spots, faint pink lesions on the trunk, are classical but uncommon.
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Testing. Blood culture is the definitive test and is most useful in the first week, before antibiotics are started. The Widal test is widely used and widely misleading: it is frequently positive from previous infection or vaccination, and a single Widal result should not drive a diagnosis.
Treatment. Antibiotics chosen according to local resistance patterns, which have shifted substantially. The full course must be completed; stopping when the fever settles causes relapse and carrier states. Complications, which usually appear in the third week, include intestinal perforation and bleeding, and present as sudden severe abdominal pain.
Prevention. Safe water, thorough hand washing, avoiding raw salads, cut fruit and ice from uncertain sources, and typhoid vaccination.
Malaria
Spread by the Anopheles mosquito, which bites from dusk to dawn and breeds in both clean and dirty water depending on species.
Pattern. Classic paroxysms of chills and rigors, followed by high fever, followed by drenching sweats and exhaustion, sometimes on alternate days. In practice, especially early, fever is often continuous and the classic pattern is absent. Headache, body aches, nausea and an enlarged spleen are common. Anaemia and jaundice can develop.
Plasmodium falciparum malaria can progress rapidly to cerebral malaria, kidney failure, severe anaemia and shock. Plasmodium vivax relapses from dormant liver forms months later unless specifically treated.
Testing. A peripheral blood smear, ideally taken during fever, and rapid diagnostic antigen tests. A single negative smear does not exclude malaria; repeat testing is often needed.
Treatment. Depends on the species and local resistance, with artemisinin-based combination therapy standard for falciparum. Vivax additionally requires primaquine to clear liver forms, which needs a G6PD test first to avoid causing haemolysis.
Features that point one way or another
- Sudden very high fever with severe eye pain and body ache: suggests dengue
- Gradual stepwise fever over a week with abdominal symptoms: suggests typhoid
- Distinct chills and rigors with sweating episodes: suggests malaria
- Falling platelets with rising haematocrit: dengue
- Very low white cell count: common in both dengue and typhoid
- Jaundice with anaemia: consider malaria, or hepatitis
None of these is reliable alone, and co-infection happens. Chikungunya, scrub typhus, leptospirosis, urinary infection, COVID-19 and influenza all belong on the list too, particularly scrub typhus, which is treatable with doxycycline and frequently missed.
What to do with any fever lasting more than 48 hours
See a doctor rather than self-medicating. Take paracetamol for fever, not NSAIDs, until dengue is excluded. Maintain fluid intake and monitor urine output. Do not take leftover antibiotics, which can render a blood culture useless and delay the correct diagnosis.
Go to hospital immediately for breathlessness, chest pain, bleeding, persistent vomiting, severe abdominal pain, drowsiness or confusion, seizures, a rash that does not fade on pressure, reduced urine output, or inability to keep fluids down.
Prevention
Remove standing water weekly, cover stored water, use mosquito repellent and nets, wear covering clothes at dawn and dusk, screen windows, drink safe water, wash hands before eating, and keep typhoid and other vaccinations up to date.
This is general information. Fever in India has many causes, some of which deteriorate quickly; a doctor’s assessment and the right test are what separate them.