Ranchi, Aug. 21: Malaria without fever, its most obvious symptom, is baffling patients and healthcare experts in Jharkhand alike, Rajendra Institute of Medical Sciences (RIMS) doctors have reported.

Cases of dormant malaria without any of its known symptoms are occurring in the southern belt of the state. Some 200 patients from districts like Khunti, Simdega, Gumla and West Singhbhum in one year, complaining of repeated diarrhoea, leg cramps and even jaundice were diagnosed with malaria despite their not exhibiting classic symptoms of high fever and chills.

“In June 2012, over 50 jawans who had been engaged in Naxalite combat in Saranda came to us. They didn’t have fever but complained of unease, headache and nausea. Initial pathological tests did not reveal much. As symptoms did not subside, a series of clinical tests confirmed malaria,” RIMS director Tulsi Mahto told The Telegraph.

Usually, malarial symptoms flare up between 10 days and four weeks of the infection. But not always. Mahto stressed the malarial parasite can stay dormant inside the human liver for four years without showing symptoms.

“Ever since we treated the Saranda jawans, the RIMS administration has been given standing instructions to check the presence of the vector-borne parasite among patients from Jharkhand’s southern districts,” he added.

Recently, the Khunti double tragedy was a copybook case of malaria with suppressed symptoms. This April, the deaths of two minor trafficked girls from Khunti — Jaymani Gudia and Jyoti Mariam Horo — caused a sensation when even their autopsy reports could not clarify the reason. Finally, forensic reports divulged both girls were suffering from malaria.

State malaria officer P. Baskey explained how malaria could occur without fever.

“A person’s immune system may sometimes suppress the full-blown symptoms of the disease. In some cases, parasites Plasmodium vivax and Plasmodium ovale can remain dormant in the liver for several months up to about four years after a person is bitten by an infected mosquito. When parasites emerge from hibernation and invade red blood cells, we term it relapse,” he said.

Baskey said that those in malaria-prone areas reporting cramps in legs, headache, minor cold and cough or even dizziness should go for proper clinical investigations.

“If it is malaria and is undetected for a long time for lack of proper diagnosis, it causes much internal harm to the patient,” he added.

Last year, the London School of Hygiene and Tropical Medicines, UK, in association with National Institute of Malaria Research, New Delhi, started a study in Gumla and Simdega on malaria among pregnant women.

Researchers confirmed they came across no less than 30 women who exhibited no malarial symptoms. Amazingly, the women never complained of ill health. “But, they tested positive for the malaria parasite after series of clinical tests,” said a research fellow.

Neena Valecha, the director of the New Delhi institute, and Irene Kuepfer, her London-based counterpart, told The Telegraph that the research would continue for three years.

“We can comment on the findings only after the full tenure,” Valecha said.