Estimation of True Malaria Burden in India

Malaria imposes great socio-economic burden on humanity and with six other diseases like diarrhoea, HIV/AIDS, tuberculosis, measles, hepatitis B and pneumonia account for 85% of Global infectious disease burden. About 36% of the world population, i.e. 2020 million is exposed to the risk of contracting malaria in ~ 90 countries. World Health Organization estimates 300–500 million malaria cases annually and 90% of this burden is in Africa alone. In addition, the estimated annual mortality attributed to malaria ranges from 700,000 and 2.7 million globally and over 75% of them are African children and expectant mothers. Doubts have been expressed about reliability of these estimates as most of the hyperand holoendemic countries, especially in Africa lack credible diagnostic facilities and reporting system. In the south-east Asian Region of WHO, out of about 1.4 billion people living in 11 countries (land area 8,466,600 km, i.e. 6% of global area), 1.2 billion are exposed to the risk of malaria and most of whom live in India (Kondrachine 1992). However, the southeast Asia contributed only 2.5 million cases to the global burden of malaria. Of this, India alone contributed 76% of the total cases. Taking into account clinical episodes, it has now been estimated with the help of epidemiological models, geographical and demographic data that P. falciparum estimates outside Africa, especially in south-east Asia are 200% higher than that reported by the World Health Organization, i.e. 118.94 million out of global estimates of 515 million cases (Snow et al 2005). In addition to this, burden of P. vivax malaria in the world has been calculated at 71–80 million cases of which south-east Asia and western pacific countries contributed 42 million cases (Mendis et al 2001).