The world Malaria Report 2008 released on Thursday dramatically halved the global estimates of malaria cases from 500 million in 2004 to 247 million in 2006. Almost all of the fall is attributable to updated surveillance data from Asia, particularly in India, where the numbers fell from over 82 million in 2004 to 10.6 million in 2006.
The World Health Organisation (WHO), which brings out the report, attributes the revision to more accurate data collection methods.
Much of the Asian data, used in the 2005 report to predict regions with malaria-carrying mosquitoes and greater disease was 40 years old, says Mac Otten, coordinator of the surveillance, monitoring and evaluation unit at the WHO's Global Malaria Programme.
“With urbanisation, deforestation and then malaria control, the data is just out of date. Malaria zones in Asia, especially India, where much of the revision took place, have become patchy,” Otten told mediapersons.
Health ministry officials in India say they're not surprised. “The WHO has always gone by estimates but we go by reported cases, which is 1.6 million malaria cases every year and about 1,000 deaths. I admit the cases may be more as some cases treated in the private sector may not be reported. Still, the discrepancy in numbers will not be as phenomenal as claimed,” says G.P. Dhillon, director, national vector-borne disease control programme (NVBDCP).
This is the second big fall in global estimates for a disease. In 2007, the UN body had slashed global HIV/AIDS estimates from nearly 40 million to 33 million. The numbers in India registered the most dramatic drop-from 5.7 million in 2005 to 2.5 million in 2006.
The WHO admits that it overestimated the number and improved data collection methods show that malaria is not quite as common as feared in Asia.
The number of estimated global malaria deaths also fell slightly, from over one million in 2004 to 881,000 in 2006.