BLACK DEATH

The Black Death was one of the most devastating pandemics in human history, resulting in the deaths of an estimated 75 to 200 million people and peaking in Europe in the years 1346–1353.Although there were several competing theories as to the etiology of the black death, analysis of DNA from victims in northern and southern Europe published in 2010 and 2011 indicates that the pathogen responsible was the Yersinia pestis bacterium, probably causing several forms of plague.

Origins of the disease

The Black Death is thought to have originated in the arid plains of Central Asia, where it then travelled along the Silk Road, reaching the Crimea by 1343.From there, it was most likely carried by Oriental rat fleas living on the black rats that were regular passengers on merchant ships. Spreading throughout the Mediterranean and Europe, the Black Death is estimated to have killed 30 to 60% of Europe's total population.In total, the plague reduced the world population from an estimated 450 million down to 350–375 million in the 14th century.

Symptoms

Contemporary accounts of the plague are often varied or imprecise. The most commonly noted symptom was the appearance of buboes or gavocciolos in the groin, the neck and armpits,which oozed pus and bled when opened.


A hand showing how acral gangrene of the fingers due to bubonic plague causes the skin and flesh to die and turn black.

Chikungunya (Malaysia)

Chikungunya fever is a viral disease transmitted to humans by the bite of infected mosquitoes. Chikungunya virus is a member of the alphavirus genus, in the family Togaviridae. Chikungunya fever is diagnosed based on symptoms, physical findings, laboratory testing, and the possibility of exposure to infected mosquitoes.

Symptoms

Chikungunya virus infection can cause a debilitating illness, most often characterized by fever, headache, fatigue, nausea, vomiting, muscle pain, rash, and joint pain. The term ‘chikungunya’ means ‘that which bends up’ in the Kimakonde language of Mozambique.

Can Chikungunya cause death?

In Malaysia, Chikungunya has never been reported as causing haemorrhage bleeding or death. However, some patients experience prolonged symptoms. Aged patients could suffer from recurrent joint aches ranging from several months to a year.

Vaccine

Currently, no approved vaccines are available. A phase-II vaccine trial used a live, attenuated virus, to develop viral resistance in 98% of those tested after 28 days and 85% still showed resistance after one year.However, 8% of people reported transient joint pain,and attenuation was found to be due to only two mutations in the E2 glycoprotein.Alternative vaccine strategies have been developed, and show efficacy in mouse models, but have so far not reached clinical trials.