Archive · 21 Aug 2026
Tripura Study Finds Severe Vivax Malaria Infections Turning Deadly
Malaria is an illness caused by tiny parasites spread by mosquitoes.
Doctors once thought the vivax type usually caused only milder sickness in Northeast India.
A study in Tripura found that some people with vivax malaria became severely ill.
Eleven of 223 vivax patients in the study had severe disease.
The vivax parasite made up about half of the malaria infections found.
A sensitive laboratory test found many infections that regular tests missed.
The parasite can also stay hidden in the body and cause illness again later.
Researchers say doctors may need better tests and closer treatment for vivax malaria.
ICMR-NIHR researchers identified 11 severe cases among 223 Tripura patients with Plasmodium vivax infections.
The 18-month study found severe disease in 5% of vivax infections, compared with 9% of falciparum infections.
Vivax malaria now represents about half of Northeast India’s infections, up from less than 10% five years ago.
PCR testing detected infections missed by both routine microscopy and rapid diagnostic tests.
Researchers say severe vivax disease and dormant relapses require improved diagnosis and patient management.
- Who
- Researchers from the Indian Council of Medical Research-National Institute of Health Research, with collaborators from Tripura and other institutions, studied malaria patients.
- What
- The study documented severe Plasmodium vivax malaria in Northeast India and found that routine tests missed many infections.
- When
- The findings came from an 18-month study; the article does not specify its exact dates.
- Where
- The research was conducted in a high-transmission area of Tripura, Northeast India.
- Why
- The study was conducted to understand local malaria patterns and showed that rising vivax infections and severe cases require improved diagnosis and management.
Earlier Medical View
Tripura Study Findings
Severity of vivax malaria
Earlier Medical View
Plasmodium vivax was generally considered more likely to cause fever, chills, and headache than severe disease, while severe malaria in India was primarily associated with Plasmodium falciparum.
Tripura Study Findings
The Tripura researchers found 11 severe vivax cases and said their observations challenge the idea that vivax malaria in the Northeast is mainly benign.
Clinical management
Earlier Medical View
Routine microscopy and rapid diagnostic testing have been used to identify malaria infections.
Tripura Study Findings
The researchers said PCR detected infections missed by standard methods, highlighting the need for expanded molecular diagnostics and improved patient management.
- Study location
- A high-transmission area of Tripura, India
- Malaria patients
- 444 total: 183 falciparum, 223 vivax, and 38 mixed infections
- Severe infections
- 32 patients overall, including 11 with vivax infections
- Severe-disease rates
- 9% of falciparum infections, 5% of vivax infections, and 13% of mixed infections
- Vivax share
- About half of Northeast India’s infections now, compared with less than 10% five years ago
- Tripura case trend
- About 22,000 cases in 2023, 9,000 in 2024, and 6,000 in 2025
- Diagnostic finding
- PCR identified 121 infections missed by both rapid testing and microscopy