The study by Indian and Canadian researchers indicated that malaria kills about 205,000 people in India each year, a figure 200-fold higher than the health ministry’s count, and 18 times the WHO estimate, as reported in The Telegraph today.
A senior WHO official said the methodology of verbal autopsies used by the study to assign the causes of deaths was inappropriate to assess malaria deaths. “(The) WHO has serious doubts about the high estimate of (205,000) malaria deaths in India,” said Nata Menabde, the WHO representative-designate to India.
The study authors said such a reaction was expected. “We would expect a natural reluctance to revise numbers based on just one study,” said Prabhat Jha of the University of Toronto, the lead author of the study published today in the journal Lancet.
The WHO has itself in the past hailed the relevance of verbal autopsies. “The reality is that for poor, often rural populations… (the) verbal autopsy for all its shortcomings remains the only practical option for measuring levels and trends in specific causes (of deaths),” a WHO document had said.
In verbal autopsies, fieldworkers question family members of the dead and document the symptoms that obtained in the days or weeks before the deaths. Independent doctors then scrutinise the documents and attribute specific causes to the deaths. The methodology carries the inherent imperfection that family members may unintentionally provide misleading information.
“In this method, deaths due to fever from any cause are likely to be misinterpreted as malaria in areas of high incidence,” said Menabde. “In areas of low malaria incidence, the symptoms are difficult to distinguish and would result in overestimates of malaria deaths.”
But Jha and his colleagues said most of the malaria deaths they had observed did not occur in areas where dengue, meningitis or typhoid — diseases with similar symptoms — were common. The deaths overlapped with areas of high malaria transmission.
Jha said the WHO should use peer-reviewed, scientifically valid data to criticise the study. “But the WHO itself relies on Indian government data to arrive at its estimates,” said study co-author Vinod Sharma, former director of the Malaria Research Centre, New Delhi.