Everything You Need To Know About Francisella Tularensis

Francisella Tularensis is usually considered to be a serious bioterrorism threat due to it being one of the most dangerously infectious pathogenic forms of bacteria.

As little as ten organisms can cause disease in human beings and thus, it has a vast capacity to cause death and serious illness.

For this reason, this bacterium has been developed into a bio-weapon by a number of countries over the years.

Tularemia can naturally occur as a zoonotic disease that derives from the bacteria known as Francisella Tularensis.

This organism is tough and is capable of surviving in most conditions including within very low temperatures and in water. It also tends to accumulate in the decaying carcasses of animals.

Everything You Need To Know About Francisella Tularensis

There are four subspecies of Francisella Tularensis. The first of these (Type A) is commonly found in North America and is strongly virulent amongst animals and humans.

Type B is far less virulent, however, it is responsible for human infection within Asia and Europe. There are two further less virulent forms that are found world-wide. 

Mammals that are natural habitats for Francisella Tularensis include squirrels, rabbits, voles and mice as they can accumulate this bacteria from flea bites, mosquitoes and through contact with environments that are contaminated with this bacteria.

Human infection can also take place via bites and contact with animals. Ingesting contaminated water supplies can also cause disease through the inhalation of aerosolized forms of bacteria. Human infection tends to occur more frequently within rural environments. 

Francisella Tularensis is incredibly infectious and thus, merely opening a laboratory culture plate without wearing the correct equipment could lead to human infection. 

Can Tularemia Be Used As A Biological Weapon?

Francisella Tularensis is deemed to be a serious biochemical threat as it is one of the most highly infectious forms of pathogenic bacteria.

Inhaling as little as ten organisms will cause considerable disease and it also has the capacity to cause death. This bacterium was specifically developed into a bioweapon by several countries for this reason. 

The dissemination of Francisella Tularensis within a highly populated area would result in a large number of acute cases and nonspecific respiratory illnesses that will occur 3-5 days after infection.

The World Health Organization stated that if 50kg of Francisella Tularensis was dispersed across a metropolitan area of five million people, there would be approximately 250,000 casualties resulting in 19,000 deaths. 

What Are The Control Measures For Francisella Tularensis?

As Francisella Tularensis does not spread between each person, it is not necessary to isolate those who have been diagnosed with tularemia. 

The symptoms of tularemia will depend on the level of virulence within the strain and the route of infection. However, symptoms usually include headache, body aches, malaise, and fevers.

Whilst symptoms will usually show 3-5 days after infection, the incubation period can be up to 14 days. 

Tularemia that naturally occurs will take on several forms. Pneumonic tularemia is the type that is more likely to cause pneumonia-like symptoms.

Diagnosis of tularemia requires laboratory testing. Children who are suspected to have tularemia need to obtain blood quickly and alert the relevant laboratory in order to specifically diagnose the tularemia and implement the relevant procedures. 

Francisella Tularensis can be identified via thorough, direct examination of exudates, secretions or biopsy specimens. This process involves using gram stains, immunohistochemical stains, or fluorescent antibodies.

It can also be grown from sputum specimens, pharyngeal washings and gastric aspirates. Francisella Tularensis is very rarely isolated from the blood and rapid testing is not widely available.

Therefore, it requires ancillary confirmatory testing via a microscopic demonstration of Francisella Tularensis that uses fluorescent-labeled antibodies in a procedure that is performed at designated laboratories.

The results of these tests will become available within hours whenever a laboratory is alerted. 


To conclude, Francisella Tularensis is commonly considered to be a bioweapon due to the devastating impact that it can have on animals and human beings.

Symptoms of tularemia will typically arrive 3-5 days after infection, however, the incubation period can be up to 14 days. 

The growth of Francisella Tularensis within society would lead to a definitive means of diagnostic confirmation that would arrive 48 hours after testing.

Francisella Tularensis is undoubtedly a highly toxic form of bacteria that has been developed by many countries as a form of bioweapon.

Jennifer Dawkins

Leave a Comment

Your email address will not be published. Required fields are marked *