Toxoplasmosis

Often pregnant mothers are warned to keep away from cats for fear of Toxoplasmosis, which spreads to human through cat feces. This can lead to severe health issues for the unborn baby. As a cat ingests an infected small animal such as a rodent, the protozoa invade cells of the cat's intestine. The parasite undergoes several developmental changes to become infective and gets released into the environment in cat feces. This parasite can invade another animal or human, as it buries into skeletal muscles, heart muscles and the brain. It forms cysts, and can stay there throughout her entire life. It is quite rare for humans to get Toxoplasmosis as house cats are not allowed outside and do not carry this parasite; wild cats or those that live outside and hunt are most likely to host toxoplasmosis parasite.

How does Toxoplasmosis spread ?

Toxoplasmosis can spread through:

Food, especially uncooked meats, pork, lamb which may carry toxo cysts.

• Directly from cat feces
  
  
• From contaminated water, from soil or water with toxo from kitty litter or feces - feral cats or trash disposal may be responsible.
  
  
• Blood transfusion
  
  
• Organ transplantation
  
  
• Mother-to-child transmission, congenital infections
  

Though the parasite is not infectious until 1 to 5 days after being excreted by an infected cat, it can survive in the environment or litter box for over a year.

Symptoms of Toxoplasmosis

Most infected with the parasite toxoplasmosis show no signs or symptoms. Approximately 10 to 20% of patients will develop flu-like symptoms that can last several weeks or more. Some develop swollen glands, such as in the neck - cervical lymph nodes. Confusion, lack of coordination, seizures, trouble breathing and blurred vision are some other signs of toxoplasmosis. These symptoms can last for a month or more and resolve on their own. Those with weakened immune system are at a risk of developing:

• Brain inflammation, causing headaches, seizures, confusion and coma
  
  
• Lung infection, which can cause cough, fever, shortness of breath

An infected fetus may exhibit symptoms mild or quite serious. It can lead to miscarriage, stillbirth or birth abnormalities including enlargement or smallness of head. Toxoplasmosis in an unborn baby can be life threatening for the baby soon after birth. It can also infect the baby's eyes and lead to temporary or permanent loss. While most newborns with congenital toxoplasmosis appear normal at birth, it can develop signs and symptoms as they age. Hence, it is important to check the baby's brain and eyes.

Causes

The parasite causing Toxoplasmosis is Toxoplasma gondii (T.gondii), which survives in contaminated meat that is raw or not thoroughly cooked. Drinking contaminated water, or in some rare cases, blood transfusion or a transplanted organ can cause toxoplasmosis. The parasite exists in feces and mostly found in feces of cat. This means, it can be found in some unwashed produce contaminated with manure. Wash your produce thoroughly to prevent toxoplasmosis.

The Role of Toxoplasma gondii in behavioral change: Even when the immune system combined with anthelmintic drugs fight off the parasites, they can remain dormant in the brain in some cases. According to an evolutionary biologist Jaroslav Flegr, these dormant parasites can affect the neuron connectivity in the brain resulting in strange behaviors which include increased suicidal tendencies. Another effect is lowered reaction time, increase in irritation which combine to increase the rate of road accidents. Rats infected with the parasite exhibit poor self preservation as they appear fearless against their predator - cats, an effect dubbed as fatal feline attraction. It affects men in a negative way while having no similar effects in women. Further research is needed to know the exact mechanism of how the parasite affects the brain cells.

In the US, although the parasite is found in nearly all warm-blooded animals, cats are the only hosts. The parasite's eggs only reproduce sexually in cats. And interestingly, cats do not show any symptoms of Toxoplasmosis, though they are hosts. Those humans who ingest the parasite become infected with toxoplasmosis. This happens, most likely, when cleaning out a litter box without washing hands properly afterward. Pregnant woman are at an increased risk of passing toxoplasmosis to their unborn child and hence, it is important to ask someone else to take care of cat litter box during pregnancy. Protect hands with gloves and change cat litter box daily. And remember, the parasite is not infectious until one to five days, after it is shed.

Risk factors

Toxoplasmosis, though can infect anybody, is more severe in people whose immune systems are weakened, such as those with HIV. The infection can particularly be worrisome in pregnant woman.

Diagnosis

To diagnose Toxoplasmosis clinically could be difficult. A swollen lymph node may be the key to diagnosis, and diagnosis can be made if blood sample is sent specifically for toxoplasmosis. The blood test looks for antibodies against Toxoplasmosis and this specific antibody can help clinicians estimate when the infection occurred. Other diagnosis, though less common, includes microscopic examination of tissues or body fluids for presence of this parasite. Toxoplasma DNA in amniotic fluid is used to determine if the fetus is infected.

Treatment

Most healthy people recover without any treatment. Pregnant women and infants are usually treated with drugs – a combination of pyrimethamine (Daraprim) and sulfadiazine. Pyrimethamine is also used to treat malaria. Sulfadiazine is an antibiotic. Alternate regimens are available for those with drug allergies. If the disease is persistent, and it involves the eyes or internal organs, or the patient is suffering from HIV or AIDS, they need to continue these medications for life.

Treatment for pregnant mothers

During pregnancy, the treatment is somewhat different. The course of treatment depends upon whether the unborn child is infected and if so, the severity of the infection. Most likely, an antibiotic is prescribed depending upon how far she is in pregnancy and to reduce the likelihood of transmission to the fetus. A combination of drugs is generally used during second or third trimesters. If her unborn baby has toxoplasmosis, then pyrimethamine and sulfadiazine may be considered as a treatment. However, these drugs do have significant side effects on the mother and fetus and are used only as a last resort. Potential side effects include bone marrow that helps produce blood cells and liver toxicity.

Prevention tips

• Washing fresh produce of fruits and vegetables before consumption.
  
  
• Making sure that meat is properly cooked by following safe kitchen practices especially when cooking meat - 70 degrees Celsius for 10 minutes to kill the parasite.
  
  
• Washing utensils that are used to handle raw meat
  
  
• Washing hands after cleaning cat litter.
  
  
• Wearing gloves when gardening to avoid contact with feces in the soil.
  
  
• Keeping outdoor sand boxes covered to keep out infected cats.
  
  
• Avoid drinks that include un-pasteurized goat's milk and raw eggs.
  
  
• Pregnant women should stay away from cat litter box and preferably can ask someone else to do the cleaning.

Cat Scratch Disease

Cat scratch disease (CSD), also called Cat Scratch Fever, is a bacterial infection passed on to people from cats that are infected with Bartonella henselae bacteria, one of the most common bacteria in the world. The Bartonella genus encompasses at least 11 species out of which 4 cause infections in human. They are responsbile for diseases such as bacillary Angiomatosis.

When the cat infected with Bartonella henselae bacteria scratches or bites the person or saliva of an infected cat enters an open sore or wound of the person, the bacteria gets transmitted causing cat scratch disease. Cats are believed to contract these bacteria from infected fleas and nearly 40 percent of cats carry the bacteria at some time in their life span. When compared to adult cats, kittens are more prone to carry the bacteria and transmit the disease. Cat's sharp teeth result in deep puncture wounds which can get serious infections if left untreated.

Symptoms

The first symptoms of cat scratch disease surface after three to 14 days of coming into contact with the infected cat. Cat scratch disease can cause serious symptoms in people with impaired immune system such as cancer patients and HIV patients. The infection may be fatal and lead to inflammation of brain, spleen, liver, lungs, and bone marrow. Hence such cases require immediate medical attention and early treatment in case of suspicion.

• Papular lesion of the skin, at the site of the injury
  
• Swelling of lymph nodes near the bite. Most often lymph nodes located under arms, groin or neck are affected.
  
• Tired feeling
  
• Headaches
  
• Low-grade fever
  
• Loss of appetite
  
• Weight loss

Diagnosis

It is difficult to establish the diagnosis of cat scratch disease as causative bacteria cannot be easily cultured from human lymph node samples. Therefore diagnosis is done based on the history of contact with a cat and the presence of a scratch or primary lesion of the skin, eye or mucous membrane. Serological test and epidemiological, histological findings are taken into consideration before conforming the diagnosis.

Treatment

Cat scratch disease is self limiting and usually regresses over few weeks. The condition does not require antibiotic treatment unless the patient is suffering from weakened immune system. Analgesics along with local heat application are recommended to relieve the pain of enlarged lymph nodes.

Prevention

Cat scratch disease is not contagious from person to person. The bacteria is transmitted only by the scratch or bite of an infected cat, most often kitten. Keep your pet cats free of fleas. Avoid rough play with the cats. Scratches from cat, if any, should be washed immediately and cats should not be allowed to lick open wounds.

Cat Behavior

Cats are solitary predators unlike dogs which are pack or herd animals.In consequence, Cats don't treat humans as authority figures in the same manner the dogs do. A cat's visual cortex contains more neurons than the equivalent area of a human brain. Typically a cat's brain weighs about 30 gm which is just under 1 percent of its total body weight. Compare this to a human brain which is 2 % of the body weight or to a dog which is 1.2 %. However, the cortex of the cat's brain has high Cortical folding which significantly increases the amount of the cerebral cortex. As a result, a cat has a well developed area of the brain responsible for interpreting sensory information. It can use its paws almost like humans. Cat's night vision is exceptional and their binocular vision is attuned to see in depth and to judge distances accurately. Their night vision is further enhanced by a layer behind the retina called as tapetum lucidum which is the reason why a cat's eyes shine bright golden or green disk when struck by a light. Their eyes detect motion better than actual sharp details. With large eyes it takes more time to focus sharp.

Most cat bites occur because of fear on the cat’s part or a phenomenon known as petting-induced aggression. Petting induced aggression is a behavior in which a cat - usually younger cats that has been apparently enjoying contact with a human suddenly turns on the human and bites. In elderly cats, the aggression may have been induced by pain due to pressure on arthritic joints.

Inflammation is probably the most common sign of infection from an animal bite. The skin around the wound may turn red and warm and over a period of time the wound may exude pus. Nearby lymph glands may become swollen. If not treated in time, complications may arise when the infection spreads deep or to the blood stream. Live disease causing bacteria within the bloodstream or in the tissues may cause major complications further away from the wound site. Such complications include meningitis, brain abscesses, pneumonia, lung abscesses and heart infections which can be fatal at times.

Cat scratch disease is caused by Bartonella Henselae), previously known as Rochalimaeaquintana, a type of bacteria in cat saliva. Infection may occur with a bite or a scratch. As per CDC, in USA alone there are 22000 reported cases. The Cat scratch disease is not normally severe in people with healthy immune systems. However, it can become sever in immunocompromised individuals - acquired immune deficiency syndrome (AIDS) or those undergoing chemotherapy.

Prevention: Cat bites can easily be avoided by learning about a cat’s body language and recognizing the signs of impending aggression. Look out for signs such as:

• dilating pupils
• a low growl
  
• stiffening of the body
  
• wagging/flicking tail - increasing frequency denotes increasing anger
  
• twitching of the tail
  
• flattening the ears backward against the head
  

Warning Stance: When a cat stands with his rump raised or back arched, it feels threatened and it is a warning that it is about to strike/attack. Sometimes the hair on its body may also be raised. A cat's tail is probably the most significant signal:

A healthy cat tends to be friendly. An ailing cat can be aggressive or scratch you unintentionally.
Vital signs of Cats

• body temperature : 100.5 - 102.5°F (38 - 39°C).
  
• Pulse rate: 110 - 180 beats per minute
  
• Respirations : 20 - 30 per minute
  
• Time for gum to regain pink color after being blanched by gentle pressure with finger(Capillary refill time): < 2 seconds