For this week’s column I decided to do a sequel to last week’s column. Again my aim is to describe infectious diseases that you may have heard of, but aren’t necessarily familiar enough to know what they really are. Hopefully after these two columns you have a better understanding of these diseases.
Typhoid Fever This disease is caused by the ingestion of contaminated food, water, and milk usually among travelers. People who are malnourished or are immuno-suppressed are at a higher risk of developing the infection. When ingested the organism, Salmonella typhi, injects itself through the lining of the gut, and produces an ulceration there. It then spreads through the rest of the body. If it gets into the gallbladder, it can lead to a chronic carrier state, which occurs in 3-5% of patients. After about 10 days (it can be anywhere from 3 to 60 days), the symptoms start. These include headache, fatigue, poor appetite, fever, chills, muscle aches, and sometimes confusion. Patients can also develop crops of what are known as “rose spots” mainly on their upper abdomen. Typhoid is usually suspected with a good clinical history for it, and often can be diagnosed from physical examination. Definitive diagnosis is made when the organism is isolated either in a culture of the blood or stool. If left alone, typhoid fever will get better in about a month without treatment. Since complication rates can be high and life threatening, antibiotics should be given if the patient does not improve on his or her own. There is a vaccine for typhoid fever available to travelers, although it is controversial. It requires two injections, one month apart. The drawback is that it is associated with side effects, and only provides partial protection. There is an oral vaccine that is just as good as the injection, but doesn’t have any side effects. It is important that if you are traveling to areas where typhoid fever is a concern, like Pakistan, you should be vaccinated.
Diptheria
Diptheria is caused by the organism Corynebacterium diptheriae and is actually a rare disease in the United States. Infection is spread by droplets and usually occurs in the mouth. It can take anywhere from 1 to 8 days for the infection to manifest. Symptoms include low-grade fever and pain in the mouth and upper throat. What makes the diagnosis is that patients with diptheria develop a thick gray membrane that covers their tonsils and throat. It can even cause airway obstruction. If one tries to remove the membrane it usually causes bleeding. The toxin associated with diptheria, when released, can cause neurologic and cardiac side effects. It can also have a skin element to it, causing a rash all over the body. Treatment involves giving antitoxin as early as possible, and antibiotics. The good news is that there is an effective vaccine to prevent infection of diptheria. It is given at the following ages: 2, 4, 6, and at 12 - 18 months, and at age 5, and every 10 years after that.
Tetanus
You may have noticed that whenever you get a cut, the doctor asks you when was the last time you got a tetanus shot. The reason of that is that when you get a cut, depending on how it occurred, it may become contaminated with spores of Clostridium tetani. This organism produces a toxin that gets into the nervous system and interferes with the way it works. Its interference leads to muscle stiffness with symptoms usually beginning in 7 days. Infection starts off with lockjaw followed by difficulty experienced in swallowing, and stiff or painful neck, shoulder, and back muscles. This stiffness can also be complicated by violent muscle spasms and muscle rupture. Treatment is centered on eliminating the source of toxin, and neutralizing any toxin that is floating around in the patient’s body. Obviously this is done to prevent the muscle rigidity and spasms from occurring. Penicillin is given to treat the source of the toxin. Human tetanus immune globulin is given as soon as possible to neutralize the toxin. Muscle relaxants are given to treat the muscle spasms. Any other needs that may arise need to be addressed quickly, including the need to have a machine breath for the patient if problems occur with the muscles involved in breathing. Since patients do not develop immunity after infection with tetanus, they need to be actively immunized against it. Usually in the immunization regime the first and second doses are given 4 - 8 weeks apart, and the third dose is given 6 - 12 months after the second one. A booster shot has to be given every 10 years to keep up the immunity. Anyone who develops a wound should have his or her tetanus vaccination history examined, and if it is lacking, should be given the vaccine. For severe wounds sometimes a booster is given if it has been more than 5 years since the last booster was given. Those patients will usually get the human tetanus immune globulin as well. Tetanus can be a life threatening disease, so that is why it is always important to think of it when any injury that causes a wound to the skin occurs.
Mononucleosis (The Kissing Disease)
The Epstein-Barr virus causes this illness. The reason why it is known as the kissing disease is that it is primarily transmitted through saliva. The hallmark symptom is inflammation of the throat. Other major symptoms include extreme fatigue, fever, poor appetite, and sometimes a rash. Usually lymph nodes and the spleen are also enlarged. Due to the enlarged spleen, the patient should not do any contact sports for at least 6 weeks so that no injury to the spleen should occur. There is no specific treatment for it because the body will fight off the virus on its own. The sore throat should get better in about a week, but it can take longer for the other symptoms to resolve.