What is Leptospira?

Leptospira is a bacterium that exists around the world but is most prevalent in hot, wet climates.

“Leptospirosis is a bacterial infection caused by certain members of the genus Leptospira. Most people who develop a leptospirosis infection only get mild symptoms, but a bit more serious influenza-like symptoms are also quite common. In a minority of infected persons, leptospirosis develops into the dreaded Weill’s disease. Weill’s disease is a serious condition that can involve liver failure, kidney failure, meningitis and sepsis. Weill’s disease can be lethal.

Urine and blood from a leptospirosis infected person or animal can contain a sufficient amount of bacteria to spread the disease. A common transmission route for humans is getting urine or blood from an infected animal on damaged skin. Even a tiny skin abrasion can be enough for the bacteria to get into the body. Leptospira bacteria can also enter the body through mucous membranes, e.g. those found in the eyes, nose, mouth and genitals.

When infected blood or urine gets into water or soil, the bacteria can survive there for several months. Contract with contaminated water or soil can be enough to catch leptospirosis, e.g. if you have a small abrasion on your skin or get water/soil onto a mucous membrane. Also keep in mind that water and soil can contaminate food, and food can also be directly contaminated by urine and blood.”



The size of Leptospira bacteria

Leptospira are incredibly small – they can pass through the pores in water filters, even those that claim to remove bacteria. They will pass easily through filters with a pore size of more than 0.2 micron, including membrane and charcoal types. High-pressure laboratory filters with a pore size of less than 0.1 micron will block them, but the typical hand-held water filters used by hikers, pool filters and the fitted canisters used in some domestic kitchen appliances are useless at removing leptospires – they are often used to separate leptospires from other bacteria when preparing samples for research, as the leptospires pass through but other bacteria don’t!

“The bacteria are in general about 0.1µm in diameter and 10-20µm in length. In comparison, a red blood cell is about 7µm in diameter, so despite being quite long, the very small width of leptospires makes them difficult to see under optical microscopes unless a contrast-enhancing technique such as dark-field is used.”



Why is the micron size of Leptospira important?

A “micron” is an abbreviated term for “micrometer”, or a millionth of a meter (1/1,000,000 meters). This is about .00004 inches. For Size comparison, a human red blood cell is about 5 microns across. A human hair is about 75 microns across (depending on the person).” **

Working down to a smaller scale 1 micron = 1,000 nanometers and .1 micron = 100 nanometers

The Black Berkey® purification elements can reduce viruses down to the nanometer scale, in the tested range of 24-26 nanometers:

24-26 nanometers is .024 to .026 microns…in other words, much smaller than the Leptospira being found in water.

What additional precautions should be taken if I suspect  Leptospira is in my water?

The Berkey water purification systems can efficiently purify raw untreated pond, lake and river water. However, always use the cleanest and clearest water possible. As an additional precaution, if using a source of water that you believe might contain extreme viral and bacteriological contamination, it is recommended by the CDC, EPA and other organizations that approximately sixteen drops of plain bleach (sodium hypochlorite) or iodine per gallon be added to treat the source water before purifying. This should kill minute pathogens such as viruses, within 30 minutes. The disinfectant will be removed from the treated water entirely with the Berkey system, including any odor or taste.

For more information about disinfecting water, please reference the following links. cdc.gov or  water.epa.gov

The fact that Black Berkey® purification elements have been tested to remove viruses to the nanometer range suggests that contaminants much larger in size, such as Leptospira should also be removed. Nonetheless, since actual testing of Leptospira has not yet been conducted, NMCL can’t officially make that claim.