Black Vomiting

There was a time when yellow fever was one of the most feared human diseases in the whole western world. Unfortunately, it is still around and we won’t eradicate it anytime soon. Here is why.

As they study their visa requirements, travellers to some of the less developed parts of the world will learn — perhaps with some surprise — that they must be vaccinated against yellow fever. It was one of the few remaining mandatory health protection measures before COVID-19 struck. Although the term “yellow fever” may trigger thoughts about celebrity gossip at first, it is a historically significant and much older health problem. Luckily, it lasts for a much shorter time than the addiction to following celebrity gossip, which can be lifelong for many people. Yellow fever is caused by a specific virus. Microbiologists classify it among viruses with ribonucleic acid (RNA), in the genus Flavivirus. Its presence in the body can only be confirmed by detecting the RNA molecule of the virus in the blood of a person who is unwell. This is accomplished by using a molecular-biological laboratory technique called polymerase chain reaction (PCR), which is used to detect a target DNA or RNA molecule in the body.

The presence of the yellow fever virus in the body leads to a reasonably short illness. It starts with fever, chills and headache. Loss of appetite, nausea and muscle pain often occur, especially in the back. Thus, the disease does not start differently from other mild viral infections, which attack the majority of people several times a year. Why was it called “yellow…