Can dogs bite cause TB

Tuberculosis

When tuberculosis (TB) germs survive and multiply in the lungs, it is called a TB infection. A TB infection may be in one of three stages. Symptoms are different in each stage.

Primary TB infection. The first stage is called the primary infection. Immune system cells find and capture the germs. The immune system may completely destroy the germs. But some captured germs may still survive and multiply.

Most people don't have symptoms during a primary infection. Some people may get flu-like symptoms, such as:

• Low fever.
• Tiredness.
• Cough.

Latent TB infection. Primary infection is usually followed by the stage called latent TB infection. Immune system cells build a wall around lung tissue with TB germs. The germs can't do any more harm if the immune system keeps them under control. But the germs survive. There are no symptoms during latent TB infection.

Active TB disease. Active TB disease happens when the immune system can't control an infection. Germs cause disease throughout the lungs or other parts of the body. Active TB disease may happen right after primary infection. But it usually happens after months or years of latent TB infection.

Symptoms of active TB disease in the lungs usually begin gradually and worsen over a few weeks. They may include:

• Cough.
• Coughing up blood or mucus.
• Chest pain.
• Pain with breathing or coughing.
• Fever.
• Chills.
• Night sweats.
• Weight loss.
• Not wanting to eat.
• Tiredness.
• Not feeling well in general.

Active TB disease outside the lungs. TB infection can spread from the lungs to other parts of the body. This is called extrapulmonary tuberculosis. Symptoms vary depending on what part of the body is infected. Common symptoms may include:

• Fever.
• Chills.
• Night sweats.
• Weight loss.
• Not wanting to eat.
• Tiredness.
• Not feeling well in general.
• Pain near the site of infection.

Active TB disease in the voice box is outside the lungs, but it has symptoms more like disease in the lungs.

Common sites of active TB disease outside the lungs include:

• Kidneys.
• Liver.
• Fluid surrounding the brain and spinal cord.
• Heart muscles.
• Genitals.
• Lymph nodes.
• Bones and joints.
• Skin.
• Walls of blood vessels.
• Voice box, also called larynx.

Active TB disease in children. Symptoms of active TB disease in children vary. Typically, symptoms by age may include the following:

• Teenagers. Symptoms are similar to adult symptoms.
• 1- to 12-year-olds. Younger children may have a fever that won't go away and weight loss.
• Infants.The baby doesn't grow or gain weight as expected. Also, a baby may have symptoms from swelling in the fluid around the brain or spinal cord, including:
  • Being sluggish or not active.
  • Unusually fussy.
  • Vomiting.
  • Poor feeding.
  • Bulging soft spot on the head.
  • Poor reflexes.

Tuberculosis in Dogs

Tuberculosis is an infectious disease caused by bacteria of the genus Mycobacterium. The disease affects practically all species of vertebrates, and, before control measures were adopted, was a major disease of people and domestic animals. Signs and lesions are generally similar in the various species. Although commonly defined as a longterm, debilitating disease, tuberculosis occasionally has a sudden, rapidly progressive course.

There are several species of bacteria that cause tuberculosis. Each type is mainly found in one host species but may produce infection in other host species. The types that affect dogs include Mycobacterium tuberculosis, Mycobacterium bovis, and occasionally Mycobacterium avium complex and Mycobacterium fortuitum.

The breathing in of infected droplets expelled from the lungs of an infected person or animal is the usualthough not the onlyroute of infection. Ingestion, particularly via contaminated food or milk, may also be a common source of infection.

Most infected dogs do not have any signs, as the canine immune system actively suppresses the bacteria. When disease does occur, signs generally include chronic coughing with difficulty breathing or quick, shallow breaths. Other generalized signs include progressive emaciation, lethargy, weakness, poor appetite, and a low-grade, fluctuating fever.

The disease is easily transmitted to humans and other animals and represents a public health risk. Therefore, treatment of tuberculosis in dogs should be discussed with your veterinarian. If a dog is suspected of having advanced tuberculous lesions, it must be reported to the appropriate public health authorities, and the dog should be euthanized.

Also see professional content regarding tuberculosis in dogs.

What happens if a dog bite gets infected?

If a dog bite pierces the skin, bacteria can get into the body, which can cause an infection. This can cause symptoms, such as pain, swelling, and drainage from the wound.

Washing the wound thoroughly can remove the bacteria from the body and help prevent infection. If the bacteria stay in the body, they can cause an infection, such as tetanus, rabies, or sepsis.

In some cases, an infection can spread to other parts of the body. People will need antibiotics or vaccinations to treat these types of infection.

Symptoms of a dog bite infection can include:

• swelling and redness around the wound
• pain that lasts longer than 24 hours
• drainage from the wound
• difficulty moving the affected part of the body
• a warm feeling around the wound

Signs that the infection may have spread to other parts of the body include:

To help prevent infection from a dog bite, people should wash the wound as soon as possible. People can treat minor wounds by:

• washing the wound with soap and warm water, making sure to clean the area thoroughly
• running the wound under lukewarm water to flush out bacteria
• applying antibiotic cream to the wound and then wrapping a clean bandage around it

People should deal with deeper, more serious wounds by:

• pressing a dry, clean cloth firmly against the wound to stop the bleeding
• seeking medical attention straight away
• calling 911 or getting emergency help if the bleeding is uncontrollable or the person feels faint

People may be able to use at-home treatments to prevent a dog bite from becoming infected. Cleaning minor wounds immediately is often sufficient. However, people should see a doctor for more serious wounds.

A doctor may use a syringe to apply water and a cleaning solution to the wound. Doing this helps flush out bacteria from the wound. The doctor may then prescribe antibiotics to fight off any bacteria that have entered the body and prevent infection.

A doctor will also be able to examine the wound to look for any damage to structures in the body, such as nerves or bones.

If the person has not had a tetanus vaccine in the last 5 years, they may need to have one to reduce the risk of tetanus.

According to the American Academy of Pediatrics, people with a dirty wound should have a booster tetanus vaccine if more than 5 years have passed since their last shot. For a clean wound, people should have a booster vaccine if it has been more than 10 years since their last shot.

In cases of severe or facial wounds, people may need stitches to close the wound. If the person does not know the dogs history of rabies vaccination, they will need a postexposure rabies vaccine to protect them from the possibility of rabies.

Bites on the hands or feet carry a higher risk of infection. Certain infections from dog bites can be very serious and lead to complications. Without treatment, these infections can be fatal.

Capnocytophaga

If people have a Capnocytophaga infection from a dog bite, they may have the following symptoms:

• blistering around the wound
• redness, swelling, and pain around the wound
• oozing from the wound
• fever
• vomiting and diarrhea
• headaches
• joint pain

Symptoms can appear between 1 and 14 days after a dog bite. The following factors can increase a persons risk of infection:

• excessive alcohol use
• not having a spleen
• the presence of health conditions that affect the immune system
• taking medications that can damage cells, such as chemotherapy

Without treatment, complications of Capnocytophaga infection can include:

A doctor will prescribe antibiotics to treat a Capnocytophaga infection.

Sepsis

Untreated animal bites can sometimes lead to sepsis. Sepsis is a severe reaction to infection, and it can be life threatening. Signs of sepsis include:

• high or low body temperature
• confusion
• extreme daytime sleepiness
• severe pain or discomfort

If a person suspects that they have sepsis, they should seek immediate medical attention. A doctor will treat sepsis with antibiotics and intravenous fluids.

Rabies

People can get rabies if a dog that has rabies bites them. The first symptoms of rabies are:

• a headache, fever, and other flu-like symptoms
• weakness
• an itching or prickling feeling around the bite

Rabies is fatal if a person does not receive treatment. People should see their doctor straight away if they think that the dog that bit them might have rabies. Postexposure rabies vaccination can treat the infection.

Tetanus

A dog bite can cause tetanus bacteria to enter the body. Symptoms of tetanus include:

• cramping in the jaw
• muscle spasms, usually in the stomach
• difficulty swallowing
• muscle stiffness

Tetanus is a serious infection. People with any symptoms of tetanus need immediate medical attention. They will require medications, such as antibiotics, as well as a tetanus vaccine.

People should seek emergency medical attention for a dog bite if they have:

• uncontrollable bleeding from the wound
• a fever
• a red, swollen, or painful wound
• a wound that feels warm
• a deep wound and have not had their tetanus shot within the last 5 years

If a person thinks that a dog bite has resulted in damage to the nerves or bones, they should seek emergency treatment. Emergency treatment is also necessary if an infection has spread to other parts of the body.

People should also seek medical attention if the dog that bit them was acting strangely, or they are unsure whether the dog has received a vaccine against rabies.

People may be able to avoid getting an infection from a dog bite if they wash the wound straight away. They can hold the wound under running water or use soap and water to wash it thoroughly before covering the wound with a bandage to keep it clean.

For deeper wounds, the person should see a doctor, who will wash out the wound with a saline solution and apply a dressing.

People should see their doctor straight away if they have any symptoms of infection around the wound, such as:

• redness
• worsening pain
• warmth around the wound
• swelling
• oozing from the wound

If the person is at risk of developing an infection from a dog bite, a doctor may prescribe antibiotics to fight the infection. In some cases, people may need a tetanus or rabies vaccine to prevent these types of infection.

How animals can give you tuberculosis

Editors Note: Vital Signs is a monthly program bringing viewers health stories from around the world.

Story highlights

Cattle infected with bovine tuberculosis are spreading infections to humans

Eating unpasteurized milk products form infected herds is a prime source of infection

Living and working in close proximity to infected animals also puts humans at risk

CNN

In 2014, an estimated 9.6 million people were infected by tuberculosis, according to the World Health Organization. Potentially fatal 1.5 million died from it the same year it is a disease known to be spread from human to human. But a subset of those contracting the disease today are getting it from infected animals.

Unbeknownst to many, tuberculosis can spread through your food, as well as the air, via infected animals.

The most common culprits? Infected cattle. The most common source? Their infected food products, such as milk and cheese.

Cows and many other animals can harbor bovine tuberculosis (TB), a disease caused by infection with Mycobacterium bovis a close relative of the bacteria that cause human tuberculosis. Risk of human disease rises when animal infections arent controlled.

The highest rates of bovine TB cases in the United States are found along the U.S.- Mexican border, according to Colleen Scott, Epidemic Intelligence Service Officer at the U.S. Centers for Disease Control and Prevention (CDC).

During a symposium at the 46th World Conference on Lung Health in Cape Town, South Africa, in early December, Scott presented new findings that showed that cases of bovine TB in the United States were found to be significantly higher among Hispanic communities. According to Scott, up to 44% of Hispanic people infected with TB were found to have the bovine form of the disease.

Read more: Victorian diseases like scurvy, TB rebound in UK

What were seeing is they are getting it from ingestion of unpasteurized milk products, she says.

Those products are unpasteurized milk itself, but also raw cheeses known as queso fresco that are made with milk from infected herds.

Scotts analysis investigated all reported cases of TB in the United States from 2006 to 2013 and found 1.5% of all cases in this time period to be infected with bovine TB. According to the CDC, up to 230 cases of TB in the United States each year are attributable to this form of the disease.

Globally, the rate is thought to be similar at 1.4%% with estimates of more than 120,000 cases of bovine TB in humans each year.

Raw milk and cheese

Forty per cent of milk and dairy products in Mexico are consumed unpasteurized, says Alejandro Pereira-Ortiz, from the U.S. Department of Agricultures base in Mexico, a country where unpasteurized cheese is prized for its flavor. I see infected cattle herds and people eating fresh cheese and drinking fresh milk, says Pereira-Ortiz, who also presented at the conference.

Programs are in place to control infections among commercial cattle exported to countries like the United States typically beef herds but controls are often not applied to smaller-scale dairy herds according to Pereira-Ortiz.

Research in Ecuador, also presented at the conference, found up to 65% of herds screened as part of the study to be infected with bovine TB.

Cattle found to be infected are typically slaughtered but in many low income countries there is no financial compensation for slaughtered cattle, so cases of Bovine TB are often not reported.

The existence of Bovine TB among animals and humans is not unique to the Americas. The disease is found globally, particularly in Africa and parts of Asia, and in a 2012 study by the International Livestock Research Institute, more than 7% of livestock screened globally tested positive for the disease.

[In India] people are very intimately associated with their cows we look after the cattle, men sleep in the area where cattle are tethered the proximity is very close, says Krishna Prasad Hanumanthappa from the All India Institute of Medical Sciences, New Delhi. Hanumanthappa has seen the presence of both regular and bovine TB cow milk in India. Here, however, he says ingestion is not the main concern.

The practice of boiling milk has been one of the greatest safeguards weve had on transmission, says Hanumanthappa. He instead worries about the disease spreading through other means.

[Bacteria] can be excreted through fecal matter, urine, coughs, and sneezes, he explains.

In most countries in Africa, bovine TB is endemic, but experts say regular milk pasteurization and slaughterhouse meat inspections are rare.

We used to see a lot of cattle slaughtered with TB lesions in the lungs of the animals and locals eat these products, says Simeon Cadmus, from the University of Ibadan, Nigeria. His recent study of a sample of livestock workers in Nigeria found 6-7% of traders and butchers to be infected with TB of some kind.

Cadmeus also worries about people rearing cattle who live closely with their cows. They eat, drink and stay all their lives with their cattle, says Cadmeus who adds that further studies of his among herds have found 40-60% of cattle infected. Because of poor animal health issues the pastoralists also get infected, he says.

Despite the name bovine TB, the bacteria behind the infection infect a wide range of animals, including deer, elk, meerkats and lions, making those animals reservoirs of the disease. We have found bovine TB in two dozen mammal species in South Africa and I would guess a form of TB could be found in every mammal, says Paul Van Helden, director of the MRC Center for TB research, in South Africa.

People didnt think it would spread, but it has, says Van Helden. His concern is the lack of routine screening for this form of the disease. Public health programs continue to screen mainly for Mycobacterium tuberculosis the human form of the disease. If we dont know how much we have, we dont know how to prioritize it, says Van Helden.

Tuberculosis is a complicated disease with the ability to infect not only the lungs, but other parts of the body known as extra pulmonary TB. This latter form of the disease is common among bovine TB infections and is harder to diagnose in humans as the most common tests which analyze a persons sputum cannot detect it.

Two thirds of the U.S. cases identified in Scotts data had the extra-pulmonary form of TB, which cannot be spread by coughs and sneezes. But researchers in the field are now concerned about the remaining third; they suspect the pulmonary form of bovine TB could spread between humans.

The question now is whether [this] can be transmitted through the airborne route, says Scott. If so, control measures will need to changed.

The World Health Organization launched its End TB strategy in 2015, setting a target to eliminate TB by 2035 just 20 years away. Though only a small percentage of people with TB are infected with the bovine form, researchers say they need to be factored in if TB is to be eliminated.

Once we have transmission through the pulmonary route, these people will travel and the bug will spread out, says Cadmeus. Thats why we must do something now.