A 24-year-old college student Ruman Ghosh died in Kolkata last week. According to news reports, doctors at a Salt Lake hospital found that Ghosh had had a platelet transfusion at a nursing home where he had been previously admitted with dengue. The doctors fund that the student suffered blood infection and acute lung injury that led to septic shock and multi-organ failure. They also said that his platelet count had not dropped enough to warrant the transfusion of 18 units of blood that he received at the nursing home.

With dengue rife across the country in the monsoon season, patients in many cities face this threat.

In Mumbai for instance, the health department has similarly found that unindicated platelet transfusions are causing immune-based disorders that worsen the symptoms of dengue patients and in some cases even lead to death. The city corporation was forced to issue a circular last year asking blood banks and physicians to not offer platelet transfusions to any patient who has dengue. Their efforts seem to be paying off. A review by the Mumbai District AIDS Control Society, which governs blood banks in the city, found that the use of platelets dropped by 12% in 2015 following their circular.

“The drop in the platelet usage shows that unnecessary platelet transfusions were taking place, which stopped after our circular,” said Dr Shreekala Acharya from Mumbai District AIDS Control Society.

Acharya and collaborators from the Brihanmumbai Municipal Corporation last week organised another meeting to review the situation and urged blood banks and doctors to continue the judicious use of platelets.

Why dengue causes platelet drops

According to the National Vector Borne Disease Control Program, 15,099 people have contracted dengue and 26 others have died of the disease between January and July this year. Kerala has recorded the highest morbidity among states. Between January and June this year, the state has recorded 4,060 cases with five people dying of the mosquito-borne infection. Public health experts have declared said that these official numbers are just a tip of a morbid iceberg since several cases and deaths go unreported.

Dengue is a mosquito-borne infection spread by the Aedes aegypti species. A patient bitten by a mosquito infected with the dengue virus can develop the infection which has no specific treatment. The dengue virus causes suppression of bone marrow, which manufactures blood cells. So a dengue infections leads to fewer blood cells being produced that in turn leads to a fall in the number of platelets in the body. The normal platelet count of a health human being is 1,50,000 to 4,50,000 per microlitre of blood. Since platelets are also responsible for clotting, a very low count of below 20,000 causes bleeding complications and this is when doctors usually prescribe transfusions.

Platelets versus platelet

Since 2010, Mumbai has recorded 42 dengue-related deaths and the civic body has started analysing the factors that could have caused these deaths.

During the meetings of the committee, infectious disease expert, Dr Om Shrivastav highlighted the excessive use of platelets in treating dengue patients. “Each time a patient is given a platelet transfusion, the patient’s own body starts making platelet antibodies,” he said. “Hence, when the patient actually needs platelets and is administered with it, the body’s immune system gets to work. The additional platelets are chewed up by the body’s immune system which only worsens the patient’s condition.”

Shrivastav said that doctors often given platelet transfusion to patients when they don’t really need them leading to the consumption of close to 3 lakh units of platelets in Mumbai in 2015. Mumbai. “Owing to this practice, the transfusions don’t work, when the patient actually need it,” he added.

A study by doctors at the Bangalore Medical College and Research Institute also highlights the unnecessary use of blood platelets. The study published in the International Journal of Clinical Cases and Investigations concluded that platelet transfusion does not appear to be necessary in all patients with dengue, even those with severe thrombocytopenia – a condition where there is bleeding in the tissues.

To make sure that the new guidelines are followed, Mumbai’s civic body asked doctors to maintain records of patients to whom they prescribe platelet transfusions and the reason for the prescription. Blood banks have also been asked to alert the health department if they receive too many requests of platelets from a specific doctor. Civic officials claim that this system that has been in place since last year has helped them to control dengue mortality.

This year, so far, no dengue-related death has been recorded in Mumbai, according to the health department.