Wednesday’s tale: Black Death and its Origin

Image by Christian Dorn from Pixabay

This wednesday’s tale, June 29th 2022, is about one of the worst pandemics in history, the Black Death! This pandemic of plague reached Europe in 1346 via the Mediterranean basin through ships carrying goods from the Black Sea. On board these ships, in addition to cargo and passengers, there were little stowaways: flea-infested black rats carrying the bubonic plague. And so, one of the most deadly pathogens was released at the ports of Europe. Rapid and fatal, the consequences were: disease, suffering and death on a cataclysmic scale. Up to 60% of the population of Europe, the Middle East and North Africa was killed in eight years by the Black Death.


First, in 1894, the pathogen responsible for the disease was discovered by bacteriologists Kitasato Shibasaburo and Alexandre Yersin. At the same time, they discovered the plague bacillus, an elongated “rod-shaped” bacterium. They named it Yersinia pestis, a bacterium carried by fleas proliferating on rats and other small rodents. The bacilli multiply in the flea’s intestine. When the flea bites its host, it regurgitates the bacilli into the host’s body and infects it. And normally, this happens in a closed cycle between fleas and rodents. The bacteria spreads at such a rate that it kills its rodent hosts. This forced the fleas to find new hosts, namely humans. The infection spread easily. Rats were attracted to human activity, especially to food stored in barns, mills and houses.


Then, the symptoms of the Black Death. The incubation period was very long, varying between 16-23 days before the first symptoms appeared. Three to five days later, the victim would die. It was too late to understand the cause of death and to be fully aware of the danger.

Nodules in the patients’ lymphatic system were affected, causing swelling in the groin and armpits. These initial symptoms were accompanied by vomiting, headaches and a very high fever that made the patients tremble.


First, the bubonic plague as the most common form of the Black Death. The lymph gland was inflamed and widely known as a bubo. This gave rise to the term bubonic plague.

Second was septicemic plague, as one of the other variants of the plague. It infected the victim’s blood, causing visibly black spots under the skin. This is probably what gave the Black Death its name.

Third, the pulmonary plague which affected the respiratory system, causing the victim to cough. This facilitated the infection by droplet projection. In the medieval period, septicemic and pneumonic plagues had a 100% mortality rate.


Finally, the origin of the Black Death pandemic. According to a study putting an end to nearly seven centuries of questioning, it would have emerged in Central Asia in Kyrgyzstan. Researchers were able to trace the source by extracting ancient human DNA from a 14th-century burial site in northern Kyrgyzstan. Of the more than 400 tombstones at this burial site, about 100 dated precisely between 1338-1339. With an epitaph mentioning “death by pestilence”, in ancient Syriac. Phil Slavin, one of the authors of the study and a professor at the University of Stirling, knew of the existence of two medieval burial sites. These burial sites located near the lake of Issyk Kul in Kyrgyzstan had been excavated at the end of the 19th century.

The researchers searched the dental DNA of seven skeletons to find the cause of death. One of the authors of the study, Maria Spyrou from the University of Tübingen in Germany, explains: “The dental pulp is a valuable source, because it is a highly vascularized area that gives a high chance of detecting pathogens in the blood”. The DNA was sequenced and compared to a database containing the genome of thousands of bacteria. The verdict: the bodies were infected by the bacterium Yersinia pestis, the bacillus responsible for the Black Death, transmitted to humans by rodent fleas.

This community had therefore been the victim of the same plague that struck Europe a few years later. Analyses of the Yersinia pestis genome also revealed that it was an ancestral strain of the bacterium. It was the one at the base of the “genetic tree” of the plague. This Christian community, ethnically diverse (Mongols, Uyghurs…) practiced long-distance trade. Phil Slavin argues, “Living in the heart of the Silk Roads, they must have traveled extensively, which played a role in the spread of the epidemic via the Black Sea.”

Can you imagine a pandemic without appropriate hygiene programs/guidelines, vaccines and hand sanitizers or surface disinfectants?

Sources and free translations of:

How to clean and dispose of a mask?

Wearing a mask has become our new habit during the pandemic situation. Therefore, let us explore how to clean and remove a mask or a face cover. In fact, there is more than one way to clean a mask including some additional precautions. So, let’s go over some methods!


First, according to Health Canada, if you plan to rewear a reusable (non-medical cloth) mask, we suggest cleaning it by putting it directly in the laundry. It can be washed with other items using a hot water cycle. As for the cleaning product to use, regular laundry soap should be fairly effective, according to the New York Times. In addition, according to Le Parisien, washing with hot water should be at least 60° C for 30 minutes.

Laundry machine


Second, following what was shared in the New York Times, experts have said that hand washing face covers in a sink works as well. You should lather the soap and rub the mask for 20 seconds. It’s a similar process to hand washing.

Hand laundry kit


Third, soak the mask in warm soapy water. This method comes from Professor Golemi-Kotra, an expert in molecular biology in Toronto York University. She said the best way to clean a cloth mask would be to soak it in hot, soapy water for at least an hour.


Afterwards, dry the mask completely in the dryer or by hanging it.

Drying masks


Finally, we dispose a mask that cannot be washed when it is wet, soiled or wrinkled. So just throw the mask properly in a lined trash can. It’s the same for a damaged reusable mask or a face cover at the end of its life span. Do not leave your mask lying anywhere else.

In short, these were ways to clean a face cover. Which method is right for you? Above all, do not forget to wash your hands properly before putting on a mask and also after removing it! Also, disinfect your surfaces as well!

Visit Lalema for masks and soaps!


COVID-19 and the preventive measures.

2019-nCoV is making the headlines these days. What is the 2019-nCoV and what are the preventive measures? Up to now, we don’t fully understand the pathogenic potential and transmission dynamics of this new 2019 coronavirus.

Young woman with respiratory mask

What is it?

In a nutshell, it is part of the coronavirus family. It presents “80% of similarities” with the SARS (Severe acute respiratory syndrome) which killed hundreds of people in 2003. This virus does not spread as well as influenza and doesn’t evolve very quickly. The symptoms are the same as most flu cases: fever, cough, muscle aches, shortness of breath and difficulty breathing.

Last December, the coronavirus appeared in Wuhan, a city in central China. The cities of Wuhan and Huanggang have been quarantined. So far, it has killed 490 people in China and thousands of people have been infected. The virus has also been detected in 23 other countries. In order to limit its spread, measures are being taken in several countries. The WHO (World Health Organization) has declared this virus as an international emergency.

Yellow Crane Tower in Wuhan

What are the preventive measures?

Brief, here are some preventive measures for 2019-nCoV. As suggested by the WHO, the following are strategies for health care-associated infection prevention and control when a case of nCoV is suspected:

  1. Early detection and source control
    – Encouraging health care workers and managers to have a high level of clinical suspicion
  2. Application of standard precautions for all patients
    – Ensure that respiratory hygiene measures are taken by providing a medical mask in case of suspected nCoV infection for those who can tolerate it
    – Cover your nose and mouth by coughing or sneezing into a tissue or bent elbow
    Wash hands after contact with respiratory secretions
    – Wear personal protective equipment
    – Follow environmental cleaning and disinfection procedures consistently and correctly
  3. The implementation of empirical additional precautions
    – Wear a particulate respirator at least as protective as a NIOSH N95, EU FFP2 certified respirator or equivalent
    – Wear eye protection (goggles or face shield)
    – Use clean, non-sterile long-sleeved coveralls
    – Wear gloves and avoid contact with eyes, nose or mouth with potentially contaminated hands
    – Use disposable equipment or dedicated equipment to be disinfected after each use
  4. Administrative controls
    – Ensure sustainable infection prevention and control infrastructure and activities are in place
    – Provide training and education to health care workers and patients
  5. Environmental and technical controls
    – Ensure adequate ventilation and proper cleaning of the environment

So, do not hesitate to contact us for your needs and questions about our products or hygiene training.

For more details on 2019-nCoV, see the following sources: