The Black Death - Modern Nightmare?

Credit AIDS Virus

We are all familiar with the dangers of emerging viral diseases: they stand starkly before us. HIV was probably born some million years ago and then mutated to its current form around 1930. Hunters were exposed to infected blood while killing and dressing chimpanzees in west central Africa. The changed socioeconomic conditions in Africa meant that HIV began to spread widely by sexual intercourse after 1960. The origins of the disease have been forgotten and it is now regarded as a deadly infectious disease of humans. Some 40 million people worldwide are living with HIV/AIDS.

SARS is another recent emergent disease that appeared early in 2003, having jumped across the species barrier from a cat-like animal called the masked palm civet to infect humans. The meat of the civet is prized as a delicacy in Guangdong province. The SARS epidemic was very minor, with only 2392 cases and 87 deaths but there are important lessons to be learnt. The disease rapidly spread worldwide, courtesy of air travel, and caused much panic including the prediction of staggering losses by the international airlines and the suggestion of the possibility of the collapse of the world economy.

Where on earth had the Black Death originally emerged?

To answer this question we have to go back to the cradle for human evolution in the Great Rift Valley in modern Kenya and Ethiopia where man and his hominid ancestors were living the longest in close association with animals.

Credit - Christopher Duncan and Susan Scott This image suggests the origins of haemorrhagic plague in the Great Rift Valley

A number of writings from the 5th century BC have traced plagues back to Ethiopia and they tell how epidemics spread by caravan traffic from there to Sudan and then to Egypt and North Africa. We can trace sporadic epidemics of haemorrhagic plague which occurred widely over the eastern Mediterranean area during a very long time-span, from the earliest writings. Presumably, the plague was active in the Nile valley, albeit unrecorded, well before these times:

1. Haemorrhagic fevers in the Nile valley in Pharaonic Egypt, 1500-1350 BC.

2. Haemorrhagic fevers in Mesopotamia, 700-450 BC and about 250 BC.

3. Plague of Athens, 430-427 BC. Thucydides left a detailed description of the symptoms of the disease which correspond closely with accounts of the Black Death.

4. Plague of Justinian, originated in Ethiopia, moved down the Nile Valley in AD 541 and thence to Asia Minor and Africa, arriving in Constantinople in AD 542. Procopius described the symptoms and there are striking similarities, both with the Plague of Athens and the Black Death. The Plague of Justinian continued until AD 700, with epidemics flaring up repeatedly.

5. The plagues of the early Islamic empire (AD 627-744).

6. The Black Death, 1347-1670.