Towards the end of the 19th century and early parts of the 20th century, and as more and more countries were colonized Africans experienced an increase in famine and disease. Prior to colonialism, many African states had mastered their environment and the spread of diseases was relatively under control. The agricultural skills they had acquired up to this point ensured that famines were never an issue and diseases could be controlled. Africans had cultural norms that placed a great deal of value on the environment and animal species. Early contact with European soldiers, traders and missionaries introduced diseases that devastated local African tribes.
In the 1880s, Italian traders introduced the cattle disease rinderpest which devastated areas in Tanzania, Kenya, Malawi, Zambia and South Africa in the early 1890s. Up to 90 percent of the cattle in parts of central and eastern Africa were killed by this disease. This devastation occurred at the same time that Europeans were colonizing Africa leaving them weak and unable to resist the early occupation by white settlers.
The introduction of the slave trade in East Africa produced new patterns of settlement; more people began to live in close proximity for security reasons. More people began living in close proximity and previously inhabited areas became large forests that were a breeding ground for tsetse flies especially in central and eastern Africa. As a result, some 200,000 people died of sleeping sickness around the Lake Victoria area. When the disease spread in the Congo, to Lake Tanganyika and eventually Zambia it had disastrous consequences for the local populations.
More contact with European slave traders and settlers led to the introduction of small pox and jiggers (a sand flea from South America which is painful and can lead to loss of limbs). In addition, Europeans also introduced cholera, yellow fever and meningitis. Some believe that these diseases were deliberately introduced by Europeans to make it easier to subdue the local people.
Arabs in Uganda were believed to have introduced sexually transmitted diseases including a particular strain of syphilis. Also, the introduction of gonorrhea in the equatorial region of Africa led to low birth rates in the early twentieth century.
Other more deliberate attempts in the effort to colonize Africa had very devastating effects on the land and people. Colonial warfare often involved scotched earth tactics which led to large scale destruction of villages and famines. In the German effort to suppress the Herero in Namibia for example, it is estimated that about 80,000 were killed and only 15,000 survived. As a consequence of the breakdown of traditional agricultural methods and economic systems, the regions of Ethiopia, Sudan and Kenya experienced famine in the 1880s and 1890s.
Ironically, Europeans viewed this process as necessary for civilizing Africans and hunger and disease became dominant stereotypes in the European mindset. African population dropped dramatically between the late 1800s and early 1900s. For example in the Belgian Congo, population dropped about 50 percent between 1880 and 1920. This left many Africans weak and vulnerable.