QUESTION

Up to now how many people died of malaria?

Up to now how many people died of Hepatitis A?

Up to now how many people died of Cholera?

ANSWER

It is believed that malaria is singly responsible for the most deaths of humans in history. However, the exact number is impossible to know. Our modern concept of disease as caused by a particular organisms or pathogen is very new, having only really developed in the 19th century, though dating back to the work of Anton van Leeuwenhoek in the late 17th century (he has since been described as “the father of microbiology”).

As such, in the past, diseases were often mistaken for each other, and particularly since malaria has such general symptoms (fever, aches, chills—these are commonly seen in many other illnesses as well), it is hard to determine what people actually died from malaria and which died from other causes. Indeed, this difficulty remains today, making it hard to estimate accurately the number of people who die from malaria even now. The World Health Organisation currently estimates that approximately 700,000 people died last year of malaria, from close to 700 million cases – this actually represents a very low death rate, thanks is large part to global efforts to improve access to diagnosis and treatment.

Hepatitis A is far less common than malaria; there are an estimated 1.4 million cases per year. Most of these are asymptomatic or mild, with a low fatality rate (4 deaths per 1000 people infected in people under 50; that rises to 17.5 per 1000 for people over 50, as older people tend to have more severe manifestations of the disease and a greater risk of subsequent liver complications – note that these data are from the CDC back in 1991). There is a very safe and effective vaccine available against hepatitis A virus (HAV)—almost 100% of people given the vaccine develop antibodies against infection.

Cholera is slightly more common than HAV (3-5 million estimated cases each year, according to the World Health Organisation) but similarly, most cases are of mild severity. Less than 20% of patients develop “typical” cholera with severe, life-threatening dehydration. 100,000-120,000 people are estimated to die from cholera each year.