The World Health Organization (WHO) has significantly lowered its previous estimate of the number of people who contract malaria each year. This decrease is attributed to rapid urbanization in Asia, which has led to the destruction of the forest habitats of mosquitoes that spread the disease. According to a report released by the WHO, in 2006, 247 million people worldwide were infected with malaria, a significant decrease from the previous estimate of 350 million to 500 million. The global death toll from malaria has also been reduced by about 10 percent compared to the WHO's previous report issued three years ago, primarily due to improvements in calculation methods. The World Health Organization stated that it is unclear whether cases and deaths decreased between 2004 and 2006. A report revealed that 881,000 people died from malaria in 2006, which was lower than previous estimates of over 1 million annual deaths from the disease, which primarily affects infants, children, and pregnant women. Malaria has received significant amounts of public funding in recent years, with organizations such as the WHO, the Global Fund to Fight AIDS, Tuberculosis and Malaria, the Bill & Melinda Gates Foundation, and the Clinton Foundation channeling funds towards prevention and treatment efforts. The Roll Back Malaria Partnership of the WHO has called for an increase in funding for malaria to $3.4 billion annually, up from $1.2 billion, in order to improve access to artemisinin-based drugs and insecticide-treated bed nets to prevent infection. Estimating the global burden of disease is a challenging task, and public health experts often need to make significant adjustments to their estimates. Last year, the World Health Organization (WHO) reduced its estimate of AIDS virus infections to 33 million from 40 million due to new data from India. The U.S. Centers for Disease Control and Prevention also increased its estimate of yearly HIV cases in Americans by 40 percent by using more accurate reporting methods. WHO Director-General Margaret Chan stated that less than one-third of the WHO's member states have reliable disease monitoring systems, making it difficult to accurately document diseases like malaria, which has symptoms similar to the flu. Chan announced that the malaria report will now be issued annually to provide decision-makers with current information on the disease, emphasizing the importance of reliable information and analysis due to increased funding efforts to reduce the malaria burden. Novartis AG's drug Coartem is used to treat malaria, and other pharmaceutical companies like Austria's Intercell are also working on developing malaria vaccines, but it will be some years before any are available on the market. Malaria is most commonly found in Africa, where the World Health Organization (WHO) uses climate data on heat and humidity to estimate the number of cases, taking into account mosquito breeding patterns and sample surveys. In 2006, Nigeria, the Democratic Republic of Congo, Uganda, Ethiopia, and Tanzania had the highest number of malaria deaths according to the WHO. Outside of Africa, countries most affected included India, Myanmar, Bangladesh, and Indonesia.