Leptospirosis: is there a cure? Understand symptoms and transmission

You have probably heard about leptospirosis.

The disease is known to be transmitted by the rat pee during floods and in soda cans (the latter much more difficult than the first case).

It is a serious disease and, therefore, it is important to be careful, avoiding becoming infected.


What is leptospirosis?

Leptospirosis is a disease caused by the leptospira bacteria. It is a zoonosis, that is, it is transmitted by animals.

This bacterium is usually present in the urine of rodents and is usually transmitted to humans or other animals when it comes in contact with the mucosa (eyes, mouth, nose) or small wounds during floods, for example, but it can also be present in lakes.

The bacteria lodges in the renal channels, but can be found in other parts of the body in the most serious cases.

Most leptospirosis infections are not dangerous, but around 10% of cases can cause death.

The mechanisms by which the bacteria act and cause the disease are unknown, but it is known that it can cause serious problems.

Although there is no human vaccine for leptospirosis, the canine version exists and serves to protect domestic dogs from the disease.

The leptospirosis code in the tenth edition of the International Register of Diseases, the ICD-10 , is A27 .

What are the types of leptospirosis?

Although it can be caused by more than 15 different types of bacteria from the same family, the disease is usually classified into only two types, one with few symptoms and the other extremely dangerous. Are they:

Anicteric leptospirosis

Anicteric leptospirosis is a mild form of the disease and the vast majority of patients carry this version. Symptoms are usually mild or, in some cases, not even present.

Approximately 90% of patients have this version of the disease. It gets its name as opposed to the icteric version, which causes jaundice (yellowing of the skin and eyes) and is much more dangerous.

Jaundice leptospirosis

Jaundice leptospirosis affects the liver so that it cannot metabolize bilirubin (a pigment), thus causing jaundice, which is the yellowing of the skin and eyes as a result of the accumulation of yellowish pigment.

This is also the most dangerous version of the disease, which can be called Adolf Weil’s Disease or Weil’s Disease . This variety of infection can kill due to bleeding complications that affect the lungs, for example, or other damage.

Causes: what is the etiologic agent of leptospirosis?

Leptospirosis is caused by a bacterium called Leptospira interrogans , which is often present in the urine of the rat. The bacterium has a spiral shape and, under the microscope, resembles a question mark. Infected humans are accidental hosts and do not transmit the disease.

The agent is found mainly in rodents, but it can also affect several other animals such as dogs and cattle, which can also transmit the bacteria through urine.

In addition, it can also live in water for up to 3 months .

Humans, although they can be infected, do not have the bacteria in the urine and therefore do not contribute to the Leptospira transmission cycle .

Transmission of leptospirosis

The transmission of leptospirosis occurs, in most cases, during contact with contaminated water, especially in floods.

Rats urinate on the streets and sewers, and floods carry the bacteria present in the urine to people in the flooded areas. In addition to the floods, it is also possible to contract the disease by swimming in a lake or river where contaminated animals urinate.

Although these are the most common modes of contamination, it is not the only one. Other animals, if infected, can also transmit leptospirosis through urine.

Dogs, for example, if they get the disease, have this ability. They can also transmit to other dogs through mating, since in them the bacteria is also present in the reproductive tract.

But water is not the only means of transmission since the bacteria can survive on land and mud for some time. Stepping barefoot on land where an infected animal has urinated can allow Leptospira to penetrate the body if there is a cut in the skin.

Even without cuts, it is still possible to have infection of the organism if the contact is prolonged.

Professionals who deal with animals, such as veterinarians and keepers, must protect themselves with gloves to avoid contact with the bacteria, which may be present in animals.

What are the risk factors for leptospirosis?

Anyone is liable to be infected by the leptospirosis bacteria, but some factors increase the risks. Are they:


Floods are the main and most famous risk factor for leptospirosis.

Cities are the habitat of rats, the main vectors of the disease, and they can urinate on the streets, inside the sewage or rainwater galleries, and when a flood occurs, the urine mixes with the water.

This facilitates the contact of the bacteria with anyone who is currently on the street, which, depending on the size of the city, can mean thousands of people.

Any wound can be a gateway to the microbe and even if there are no wounds, if it comes into contact with the mouth, nose or eyes, contamination is possible.

Finding yourself in a flood does not necessarily mean that you will be contaminated, but the chances increase a lot, so it is recommended to avoid street water.

Walk barefoot

In rural regions, this is one of the most common methods of contamination.

When a contaminated animal – be it a dog, mouse or any other person – urinates on the floor and a person steps in that barefoot place, a small, even tiny, wound is enough for the bacteria to be able to enter.

It is always important to wear shoes to avoid the disease.

Non-existent or inefficient basic sanitation

The lack of basic sanitation results in human waste in the open in many cases.

This means that contact with human urine – which can also transmit leptospirosis if the person is ill – can also cause the infection.

If there is no drainage of rainwater, there is also the facilitation of floods and the difficulty in cleaning the urine of animals, which creates an environment conducive to the proliferation of the bacteria that causes leptospirosis.

Inadequate garbage collection

If garbage collection in a region is not carried out or is inadequate, contaminated animals can be attracted to the tailings. This facilitates contamination in the region as several animals with the bacteria can be gathered in a small space.

What are the symptoms of leptospirosis?

The two versions of leptospirosis have similar symptoms, but they are more intense in the icteric version, which manifests them more intensely than those of the anicteric one. These symptoms can take 1 to 30 days after exposure to appear, but the most common is that this happens between the 7th and the 14th day.

The most common symptoms are:


fever is a mechanism of the immune system used to fight infections such as leptospirosis.

The symptom may indicate the presence of the infection, which, in the case of the disease, is usually high (above 38 degrees) and can be a dangerous symptom.


The headache is one of the most common symptoms of leptospirosis. About 75% of infected patients experience headache at some level, even in the weakest cases.

Muscle aches

Like headaches, the infection can cause muscle pain even in the weakest cases. The intensity of the pain is low in these cases, but it can be quite uncomfortable when the disease is jaundiced.

Vomiting and diarrhea

Approximately half of the patients experience vomiting and diarrhea . It is especially important that, in these cases, the patient is well hydrated as these symptoms cause high water loss from the body.


Jaundice in leptospirosis is a sign that it is the most serious version of the disease, which bears the name icterus due to this symptom.

The condition is the yellowing of the skin and the whites of the eyes due to the accumulation of bilirubin , a pigment naturally produced by the body.

Normally, bilirubin is metabolized by the liver and deposited in the gallbladder, forming part of the bile. In turn, bile is used to dissolve fats that reach the intestine and, therefore, bilirubin leaves the body through the stool.

When the liver is unable to metabolize bilirubin, the pigment remains in the bloodstream and accumulates in tissues such as the skin and eyes, causing it to turn yellow.

If there is jaundice in leptospirosis, it means that the bacteria is infecting the liver in addition to the kidneys. It can also be in other parts of the body.

Dark urine and light stools

When bilirubin stays in the blood instead of being processed by the liver, it is eliminated in the urine. This causes the urine to be dark yellowish in color, very strong.

On the other hand, since the pigment is being eliminated by the urine and not by the feces, they are clear, since it is the bilirubin that gives the typical color of the fecal cake.


The hepatomegaly is the enlargement of the liver , which can be caused by infection by leptospirosis. The condition can also cause reduced liver function, resulting in several problems in the body.


The splenomegaly is the enlargement of the spleen. Infection with leptospira bacteria can affect the organ and cause it to enlarge, as well as the liver.

Renal insufficiency

Leptospirosis can cause kidney failure in different intensities and in different ways, since this disease affects, above all, the kidneys.

In milder cases, it is possible that it causes proteinuria, a simpler condition in which some proteins are eliminated in the urine (which should not happen since the kidney must filter these proteins).

However, in the most severe cases, it can cause severe kidney failure, which causes the body to maintain various toxins that should be eliminated by urine.

Insufficiency can happen by several means ranging from the direct toxicity of the bacteria to the kidneys to the presence of bilirubin because of jaundice.

The kidneys are not prepared to deal with the pigment and, over time, can be damaged by it.

High digestive bleeding

Hemorrhagic symptoms are signs that leptospirosis is in a serious condition and it is essential that medical attention is sought when this is the case. Upper gastrointestinal bleeding is bleeding from the upper gastrointestinal tract .

The upper gastrointestinal tract is composed of the pharynx, esophagus, stomach and duodenum. When there is bleeding from any of these structures, upper gastrointestinal bleeding is characterized.

In such cases, the patient may spit or vomit blood.

In addition, the blood that flows into the intestine can make the stools look extremely dark – black – and change their odor.

It can also cause difficulty in swallowing, pressure drop, fainting and weakness due to blood loss.

Pulmonary hemorrhage

Pulmonary hemorrhage is another extremely severe symptom of icteric leptospirosis and is a major cause of death.

In these cases, the bacterium causes bleeding in the lungs, which damages the organ, making it difficult or even impeding breathing, in addition to other symptoms related to blood loss.

The symptom usually arises only in advanced cases of severe leptospirosis, but it is what kills the most. Approximately 50% of patients who develop this symptom die.

How is leptospirosis diagnosed?

Leptospirosis is a disease caused by bacteria. There are some ways to make the diagnosis when the disease is suspected, which due to the symptoms, can be confused with dengue , hemorrhagic fever, malaria or viral hepatitis, among others.

Who makes this diagnosis can be a general practitioner or an infectious disease .

Blood test

The blood test is used to identify some signs that may indicate leptospirosis. For example, it is possible to identify the presence of bilirubin at high levels, which can indicate liver problems.

Enzyme-linked immunosorbent assay (ELISA-IgM)

The ELISA-IgM test is a test that seeks to find out whether there are antigens (substances that make the body produce antibodies) of leptospirosis.

Through chemical reactions, these antibodies and antigens are identified. Depending on the reaction to which substances and antibodies, it is possible to know which bacteria are present in the sample.

Thus, the diagnosis of leptospirosis and several other infections can be carried out accurately.

Is leptospirosis curable?

-Yeah . Often leptospirosis, when it is anicteric (lighter version), is cured without medical intervention by the patient’s own immune system.

For this reason, in several cases the person does not even know that he has been infected.

However, in cases where the symptoms appear, especially when they are strong and related to the jaundiced version (with jaundice), it is important that there is medical treatment for the elimination of bacteria.

The use of antibiotic medications is essential in this case for a cure to be achieved.

What is the treatment of leptospirosis?

The treatment of leptospirosis involves the use of antibiotics to eliminate the bacteria, in addition to rest and treatment of symptoms.

It is possible for the patient to rest at home, but in the most severe cases – such as jaundice – they may require the patient’s hospitalization in order for the disease to be cured.

How long does leptospirosis treatment take?

Treatment can last from 5 to 7 days with antibiotics to eliminate the bacteria.

It is extremely important that the medicines are used during the time recommended by the doctor and at the times indicated.

If antibiotics are used improperly, some bacteria can survive the treatment and multiply, developing resistance to it.

The result is that the disease comes back, but the treatment may not be as effective.

Medicines for leptospirosis

The main drugs used to treat leptospirosis are antibiotics. In addition, antipyretic drugs and pain relievers can be used to reduce the symptoms of the disease.

It is important to remember that leptospirosis can cause bleeding. Therefore, any medication that can thin the blood, such as those with Acetylsalicylic Acid (ASA) in its composition, is contraindicated .

The drugs used to treat leptospirosis can be:


  • Doxycycline Hydrochloride ( Vibramycin );
  • Amoxicillin ( Amoxil ).

Analgesics and antipyretics

  • Dipyrone Monohydrate ( Novalgine );
  • Paracetamol (Tylenol).

Read more: Can pregnant women take dipyrone? Does it harm the baby?


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained in this website is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.

What is the prognosis?

The prognosis of leptospirosis varies from person to person and the type of the disease. In most cases, it is positive as the immune system itself is able to cope with the disease.

However, when it is the severe form of (jaundiced) leptospirosis, treatment is necessary, but not always enough to save the patient, especially when the disease is advanced.

Approximately 10% to 50% of patients who contract leptospirosis die, and the type of the disease – jaundiced or not – changes the chances.

A patient with the severe version, the icterus, is in much greater danger. Therefore, it is essential that, if there are signs of the disease, see a doctor.

Complications of leptospirosis

Leptospirosis is a serious disease that can cause some complications. Between them:

Renal insufficiency

The bacteria that causes leptospirosis directly affects the kidneys. In addition to its direct toxicity, it also causes other symptoms, such as jaundice, which can damage the organs.

Due to these damages, kidney failure can appear, being one of the most common complications.


Hemorrhages are the most serious consequences of the disease, as blood loss can be fatal.

Pulmonary hemorrhage is the complication that most kills leptospirosis patients and, therefore, when the disease is in the icteric form, it is essential that the person is taken to the hospital.


The bacteria that causes leptospirosis can affect the meninges (layers that protect the brain), causing meningitis .

This disease is serious, can cause death and leave neurological sequelae in patients. So it requires urgent treatment.


Myocarditis is the inflammation of the walls of the heart. It can happen due to the action of the Leptospira bacteria in the heart, leading to a dangerous inflammatory process.


Jaundice leptospirosis can result in anemia , which is a reduction in the amount of red blood cells in the blood. This often happens because of a lack of iron in the diet, but other conditions, such as leptospirosis, can trigger it.

Read more: Foods for anemia that help in healing and prevention


When the leptospirosis-causing bacteria affects the pancreas, it can lead to pancreatitis as a complication. It is the inflammation of the organ. It is also a complication related to the icteric form of the disease.


Leptospiral infection can cause death. So it is very important that the disease is prevented and that people are prevented. When it is contracted, medical treatment is essential to prevent the patient’s death.

How to do prevention?

Leptospirosis can be a very dangerous disease, but there are ways to reduce the chances of contamination by the bacteria that cause it. Some of these ways are:

Don’t walk barefoot

Walking barefoot in places where animals may have urinated increases your chances of coming into contact with leptospirosis bacteria, which can infect very small cuts in your body. Wearing shoes avoids this contact and can protect you.

Do not enter flood water

Flooding is the most common contamination method for leptospirosis. Rat urine tends to stay on the ground and in sewers, but floods have the ability to carry the bacteria present in that urine to the surface, in addition to transporting them to meet people.

Do not let children or animals play in flood water, and if you work in an area that requires direct contact with flood water or feel that you cannot avoid it, wearing boots and gloves can reduce the risks.

Avoid mice

The bacterium is present in several animals, but rodents are the main vector of the disease. Avoiding contact with them reduces your chance of being infected.

To do this, keep the land and residence clean, without accumulated garbage or exposed food that may attract them.

Clean your water tank

Leptospirosis can be transmitted through contact with contaminated water and, therefore, an exposed water tank or in a place that rats can access is a way of contaminating an entire house.

Clean your water tank frequently to prevent this and other microorganisms from multiplying in your water.

The bleach is effective for removing various bacteria including Leptospira . You can use it to disinfect water reservoirs that may have come in contact with bacteria or floods.

Use 1 liter of bleach for every 1000 liters of water in your reservoir, this will be enough to prevent contamination of the residents.

Do not throw garbage on the street

Throwing garbage on the street is a way to increase the chances of flooding, as it can block the manholes and pipes into which rainwater should drain.

Floods, in turn, multiply the chances of leptospirosis being contracted by hundreds or even thousands of people.

Get your dog vaccinated

Although there is no vaccine against leptospirosis for humans, dogs have this option of protection. Vaccinating your pet prevents it from getting sick and also helps to prevent the disease from spreading further.

Leptospirosis in dogs

The canine leptospirosis can be particularly dangerous for the animals.

Normally, as in humans, it is not very intense, but when the animal has low immunity, the disease can present itself in a serious way, causing hemorrhages, pain and even death.

Dogs have a much higher risk than humans of contracting the disease since many live outside the home, where they can have contact with mice without the owner knowing.

Therefore, prevention is extremely important. Keeping the dog away from wild animals is essential when possible, but vaccinations are the best guarantee.

Canine vaccine for leptospirosis

There is no human vaccine for the disease, but canine does. It protects the animal from leptospirosis, which in addition to being fatal to the pet, can also help spread it.

The vaccine can cause allergy- related side effects , but they are rare.

This vaccination does not make the animal completely immune, but it increases the chances that the immune system will control the bacteria more easily, besides greatly reducing the possibility of leptospirosis to present itself in a serious way in dogs.

The vaccine should be repeated annually, especially in dogs that live in areas at risk, where floods are common or many rodents are nearby.

Common questions

Does every rat have leptospirosis?

No, not all mice transmit leptospirosis. It is necessary that the animal is infected by the bacteria that causes the disease, which is not always the case.

However, the disease is common in rats and taking care about contact with rodents reduces the risk of contamination.

Is leptospirosis contagious?

No . Leptospirosis is not transmitted from human to human, so there is no concern in contact with infected people.

What is the incubation period for leptospirosis?

The incubation period for leptospirosis is, on average, 7 to 14 days. It is the time it takes for the symptoms to begin to appear. However, in some cases, this time may be different, manifesting symptoms as early as the first day or taking up to 30 days to occur.

How long does it take for leptospirosis to appear?

The first symptoms can appear between 1 and 30 days after the contamination. After they are identified, it is essential to pay a visit to the doctor to prevent the disease from developing in a serious way.

Can I get leptospirosis by drinking soda or liquids in cans?

If a rat urinates in the can, it is theoretically possible. However, there are no recorded cases that some contamination happened in this way.

Leptospirosis can be contracted when drinking contaminated liquids, as the bacteria can pass through the lining of the mouth, but this is rare.

If there is contaminated rat urine on the can and someone drinks from it, the bacteria can contaminate the person, but it is more likely to go into the stomach and be destroyed by stomach acids.

The chances of contamination are greater if there are sores in the mouth.

In conclusion, the chances of this type of contamination are low, but still, cleaning the top of the cans is not a bad idea, whether you are a consumer or a seller, since several bacteria may be present in it.

What to do if I cannot avoid contaminated water?

If you have no way of avoiding water that may be contaminated, stay in contact with it for as little time as possible.

If your house is flooded, when cleaning, it is important to use bleach to prevent bacteria from getting on the floor or surfaces.

For hygiene, mix 400mL of bleach in a 20-liter bucket of water and let the mixture sit for 15 minutes in the region. Then rinse the area with clean water.

Food that comes in contact with water should be thrown away.

How long does the leptospirosis bacteria survive in the environment?

Depending on the conditions in the area, it can survive for months without a host. However, the bacteria is sensitive to common disinfectants and to direct sunlight.

Is leptospirosis contagious?

No . It is not possible to transmit the Leptospira bacteria between people. It is only transmitted through the contact of the microorganism in the urine of some mammals, among which the human being is not included. The bacteria is not present in human urine.

Leptospirosis is a dangerous disease, which spreads easily during floods and is caused by a bacterium that is often in the urine of the rat. Share this text with your friends!