TB Strains Confirmed from Ancient DNA of Marine Mammals and Humans in Peru During Pre-Colonial Period

Tuberculosis (TB) strains linked with marine mammals were found in the ancient DNA of humans living far from coastal Peru during the pre-colonial period in South America, according to a new study.

The new discovery highlights the complex transmission of TB between animals and humans in Peru.

From Marine Mammals to Humans

The most evident and common tuberculosis symptoms are coughing with blood or mucus for several weeks. Some TB symptoms also include chest pain and pain associated with breathing.

These symptoms can range from moderate to severe and can lead to death if left untreated.

Scientists have been reportedly divided on the origin of ancient tuberculosis genomes but a new study finally answers the origin of TB's animal to human transmission in Peru.

The disease can be transmitted through air, yet it was unprecedented that was a product of indirect transmission from marine mammals to humans.

In a new study published in the journal Nature Communications on Monday, March 7, researchers proved that the spread of TB from seals and sea lions to humans was a case of complex indirect animal to human transmission during pre-colonial South America.

The new study highlights those ancient marine mammals did not directly transmit TB to humans.

It is rather tuberculosis had to travel far distances from Peru's coastal waters to the mainland in South America during the pre-colonial period.

Zoonotic Tuberculosis

This rationale was confirmed by researchers from the new study when they found TB variants from the ancient DNA of people living far from the coastal areas of Peru.

In fact, the research team showed that inland inhabitants of Peru at that time had no direct contact with marine mammals.

The new study had its roots from the discovery back in 2014 when scientists found that the origin of tuberculosis in Peru came from marine mammals.

Since the recent study has shown the absence of contact between the two species, it opened the grounds that other living organisms carried out the transmission.

The integration of these two studies shows that zoonotic tuberculosis in pre-colonial Peru involved a series of natural events, which allowed the TB pathogen M. pinnipedii to jump indirectly from the marine mammals to humans via unknown animals or other living species.

TB Vaccine

According to the Centers for Disease Control and Prevention (CDC), the Bacille Calmette-Guerin (BCG) vaccine does not always guarantee that people will be protected from acquiring the TB disease.

Despite the widespread production of the BCG vaccine, it is mostly given to children and infants in countries where TB is common.

Despite the production and usage of the BCG vaccine worldwide, a lot of people still die from tuberculosis disease each year and across the world.

Deaths are most common for unvaccinated individuals and for people who failed to seek medical checkups of their existing or worsening TB symptoms.

According to the World Health Organization (WHO) TB is the second cause of death worldwide after COVID-19 among infectious pathogens.

Additionally, TB is the 13th leading cause of death on the planet.

The WHO reported that the disease had killed a total of 1.5 million people worldwide in 2020.