The Black Death
With the plague spreading at an alarming rate in Madagascar, it’s timely to look at what the disease actually is.
PETALING JAYA: The bubonic plague is also known as the Black Death and with good reason: it has ravaged populations since the Middle Ages.
In modern times, it is treatable with common antibiotics, said Sungai Buloh Hospital Infectious Disease head Datuk Dr Christopher Lee.
“The good news is that it is treatable. Without treatment, there is a high mortality rate and many people can die from the plague. But with the antibiotics we have, treatment is pretty successful,” he said, adding that the antibiotics used are fairly accessible, such as doxycycline and gentamicin.
As such, he said, the number of plague cases nowadays cannot compare to the high numbers suffered previously.
“I dare not say (the plague is eradicated) 100%. Even in the United States, there have been some cases every year. However, there are not many, maybe seven to 10 a year,” he said.
He compared the low mortality rate today to the high numbers killed in the 14th century, when society at that time did not understand the nature of the disease and how to properly treat it.
“They basically isolated people and left them to their own devices,” he said.
Dr Lee explained that the cause of the plague is a bacterium called Yersinia pestis, which is mainly transmitted by rodents.
“When fleas bite the rats, the fleas get infected, and then they bite human beings which results in a human infection,” he said.
According to Dr Lee, there are three broad versions of the plague: bubonic plague, pneumonic plague and septicaemic plague.
“The most common is the bubonic plague. The mortality risk is not so high but if the infection is not treated, the bacteria that is in the lymph nodes, or the buboes, can spread to the blood, making it much more dangerous.
“The type with the highest risk of death is the pneumonic plague because it spreads differently,” he said, adding that this type spreads through aerosol transmission.
“When the yersinia bacteria gets into the lungs, you get pneumonia, you would cough and each time you cough, the bacteria can come out as droplets, and the next person breathes it in,” he explained.
For the septicaemic plague, Dr Lee explained that it is not known why the Yersinia pestis bacteria spreads in the bloodstream in some people.
“Mortality is very high in such cases. Many septicaemic plague patients will have lung problems but they generally die of shock because their blood pressure drops.”
Dr Lee said the key to curing the plague is whether or not it is detected in time.
“The fear is that we misdiagnose, that we didn’t diagnose it as the bubonic plague because we didn’t think of it.
“The tests are not special, the organism can be cultured from blood or pus. However, if people come in late, we may not think of diagnosing it as the plague, we may miss it and we may delay the antibiotics, which may result in death.
“That’s probably what happened in Madagascar this year. People may have come in late to see the doctors, the rodent population may be high, people live in close contact, so it spreads,” he said.
However, the symptoms of the plague usually manifest early, according to Dr Lee.
“The risk of transmission is not so high because the incubation period is quite short. The period is less than a week – it varies between two days and six days. If you have the plague, you cannot remain asymptomatic for a long time,” he said.
Dr Lee said that the initial symptoms of the plague are nonspecific, including fever, headache, severe lethargy and swollen lymph nodes in the groin area.
If it’s the pneumonic plague, patients experience coughing, plenty of phlegm, shortness of breath and blood in the sputum.
He added that for septicaemic plague, victims will be very ill and are typically bedridden. Their blood pressure will drop and they may die very quickly.
At an advanced stage, Dr Lee said that patients can have bleeding disorders, as well as gangrene of the extremities, i.e. feet or hands.
Lumps and bruises also form easily, without any injury.
Dr Lee explained that environmental hygiene plays a huge role in the transmission of the plague.
“Overall environmental hygiene has improved so the rat population has also dropped. Here in our country, because the climate is temperate, rats are more linked to leptospirosis than the bubonic plague.”
To his knowledge, there has been no out break of the bubonic plague in Malaysia so far.
“But if somebody with the plague comes into our country and happens to come into close contact with rats, the fleas from the rats might bite that person and then jump off and bite somebody else, so the potential or risk is there,” he said.
If a case is suspected in Malaysia, Lee said that the protocol would be “pretty standard”. The individual would be isolated and his illness investigated to confirm whether it is the plague.
“If somebody comes back from Madagascar, for instance, with symptoms that suggest the plague – fever, feeling unwell, painful lymph nodes or pneumonia that seems quite bad, or they are coughing up blood – I would quickly isolate them and investigate straight away.
“But so far, the plague has been very localised in certain areas. I think Africa is the main continent but other big Asian countries like India and China, and some of the less developed countries, will certainly still have the plague,” he said.
Black Death in history
Arrived in Europe in October 1347 when sailors carrying the plague docked their ships at the Messina port;
The disease spread quickly: people who were perfectly healthy when they went to bed at night could be dead by morning;
Many people at that time believed that the Black Death was divine retribution;
Flagellants travelled from town to town and would beat themselves with heavy leather straps as penance; Physicians used crude and unsanitary techniques, like bloodletting and boillancing, to “cure” the disease; and Superstitious practices were also conducted, such as burning herbs and bathing in rosewater or vinegar.