Brucellosis is a bacterial infection caused in human beings by exposure to infected animals or infected animal products or air particles released by infected animals. The animals in question have bacteria that come from the Brucella genus. Sometimes, the bacteria is carried by the animal without the animal itself being made sick but most often the bacteria live in the reproductive organs of the animal and cause sterility in males and abortions in females.
The name for a disease that human beings can “catch” from animals is zoonosis, and Brucellosis is a zoonosis. Although seven known strands exist, there are currently four strands of the Brucella species that human beings are known to become sick with - one carried by pigs (Brucella suis), one carried by Yaks, camels, buffalo and cows (Brucella abortus), one carried by goats, sheep and camels (Brucella melitencis), and one carried by canines (Brucella canis).
The United States thought of bacteria from the Brucella genus as potential biological weapons because the bacteria were spread through the air so easily. Attempts by the U.S. were made as early as 1942 to research the bacteria for the purpose of biological warfare. In the 1950’s Brucellosis bacteria were used to make the first biological weapon of the United States, and bombs with air particles from the bacteria were created by the U.S. Brucella bacteria were not used in biological weapons after 1967, and all biological warfare weapons were banned by the United States in 1969.
Brucellosis has been brought under control in the United States by enforcing pasteurization processes for milk, vaccinations of animals, and the inspection of livestock by federal authorities with usually no more than one hundred cases per year being reported in the U.S. currently. However, a renewed interest in the disease has occurred because of international tourism and the migration of large numbers of people from Mexico, and also because of the possibility of the bacteria being used as a biological weapon by terrorists.
World wide, brucellosis has approximately five hundred thousand cases per year. It is more of a problem in peoples who rely on farming and in countries with less stringent standards of hygiene for the handling of animals and animal products being prepared for consumption by human beings.
Because of the risk of biological warfare, physicians should familiarize themselves with the symptoms of Brucellosis. Brucellae gain access to the body through breaks in the skin, the eyes, and the gastro intestinal tract. Sexual intercourse has not been proven to transmit the disease.
Symptoms of Brucellosis include fever, chills, weight loss, bone and joint problems, neurological symptoms, coughing, gastrointestinal symptoms, and neuropsychiatric symptoms such as headache. Diagnosis is usually done through medical history and blood tests. In the United States, cases tend to occur individually, and hence a number of cases close together should raise a flag for the possibility of a biological weapon's having caused the outbreak.
Sources
Al-Nassir, Wafa, MD, Lisgaris, Michael, MD and Salata, Michael A., MD, “Brucellosis,” eMedicine Article last updated July 18th, 2006
Most E Coli bacteria are relatively harmless.In fact, E Coli is often grown in laboratories for educational and didactic purposes because of its lesser potential for harm when compared to other bacteria.
However, one strand of E Coli known as Escherichia coli: 0157:H7 has been known to cause serious illness in human beings since 1982.At that time a serious outbreak of severe diarrhea occurred in the United States with the diarrhea frequently involving bloody stools.Researchers who investigated the problem diarrhea found that it was connected to eating under cooked hamburger meat.Subsequent attacks of this strand of E Coli have also most frequently been associated with the consumption of hamburger meat as well.The most recent of these attacks resulted in the massive recall of Topps Meat hamburger patties in September of 2007, and in October of 2007, the closing of the sixty seven year old business which could not recoup under the weight of the loss and subsequent bad publicity.
There are several ways of getting Escherichia coli: 0157:H7 besides eating rare hamburger meat.Other foods that might contain the bacteria are milk or juice that is not pasteurized, alfalfa and bean sprouts, unwashed fruit, spinach and lettuce.Petting zoos are known to harbor the bacteria, and infection might be spread on the ground or through contact on the handrails.Insufficient hygiene when changing baby diapers of children sick with diarrhea from Escherichia coli: 0157:H7 could also spread the disease.Swimming in or drinking water from water sources with sewage drainage can also cause the spread of this form of E Coli.
The usual symptoms of the 0157:H7 strand of E Coli are severe and bloody diarrhea along with stomach cramps.A complication of the illness most frequently seen in children under five and older persons is hemolytic uremic syndrome (hus).Hemolytic uremic syndrome (hus) can cause acute kidney failure.It destroys the red blood cells as well as causing the kidneys to fail.
The presence of E Coli can be determined by laboratory tests of stool specimen.At the present time, the identity of this particular bacteria is not always tested for without a specific request in many laboratories.The presence of blood in diarrhea is enough evidence to request further pinpointing of the E Coli, according to the Centers for Disease Control and Prevention website.(http://www.cdc.gov/echoli)
To avoid developing anti-biotic resistant forms of this E Coli strand, treatment does not involve antibiotics.If the disease is complicated by hus, supportive measures such as dialysis and treatment in an intensive care unit may be required.The death rate for hus when it is treated is estimated as being between three percent and five percent at this time.
The CDC website indicated that changing the way cattle meat is processed significantly decreased the amount of this form of E Coli found currently in the market – at least until recently.
Some suggestions by the CDC for lowering the risk of Escherichia coli: 0157:H7 include thoroughly cooking ground hamburger meat, sending a hamburger back to be cooked more thoroughly if given a rare hamburger in a restaurant, keeping cooked meat in a separate plate from that the raw hamburger patties were on, washing all utensils involved in preparing raw meat, drinking only pasteurized juices and milk, running water thoroughly over raw fruits and vegetables, avoiding swallowing water when swimming, drink only chlorinated municipal drinking water, and washing of hands after changing baby diapers.
Source
“Escherichia coli: 0157:H7” article on CDC website
Tuberculosis has been around for a long time. It was the subject of a famous novel - Thomas Mann's The Magic Mountain. Many more literary people dealt personally with tuberculosis including the poets John Keats, Elizabeth Barrett Browning, and Edgar Allen Poe.
There was a time in United States history when tuberculosis was thought to be under control but more recently with the advent of AIDS making its victims more susceptible to tuberculosis and the development of anti-bacterial resistant strands of tuberculosis, the disease has returned with a vengence.
Mycobacterium tuberculosis is the name of the bacteria causing tuberculosis. The mere presence of the bacteria in a person's body is not considered active tuberculosis. In order to get active tuberculosis, one does have to have the bacteria enter her body, but she also has to develop the tuberculosis disease in her body.
The initial active site of the disease is usually the lungs, and this primary infection developed there usually does so within six weeks of the person's having been exposed to the tuberculosis bacteria. A person with a good immune system and not very young and not very old can usually fight off the initial disease, and build up a wall surrounding the initial infection. When the initial infection is sealed off by a good immune system, the disease goes into latency, and develops only if and when the person's immune system breaks down for some reason or other. Ninety percent of the people who have the primary infection never get active tuberculosis.
There is a vaccine for tuberculosis. It has been around for awhile. The name of the vaccine is Bacillus Camille Geurin (BCG) vaccine. The success rate of the BCG fluctuates, and the vaccine is not recommended for people in the United States except for people in high risk categories. The BCG has had a better success rate reported for children than for adults.
There are also skin tests for tuberculosis. The Tuberculin skin test has been available for approximately a hundred years. One of the drawbacks to the Tuberculin skin test is that the person being examined has to be seen by medical personnel twice – the first time when the test takes place and the second time a few days later when the site of the test must be evaluated by qualified personnel to determine the evaluation of the test—i.e., whether the person has the tuberculosis bacteria in her body. Another weakness of the Tuberculin skin test is that an individual who has had the BCG vaccine will also show a positive reaction to the test even though the person does not have the actual tuberculosis infection.
More recently, a new test has been developed. This test is called the QuantiFeron TB Gold test (QFT-Gold), requires only one reading, and cost about $15.00 for a kit. Since the cost of the personnel is usually an additional $10 per reading, and no second reading is involved, in the United States at least, the QFT-Gold test is comparable in price to the Tuberculin skin test. Another advantage to the QFT-Gold test is that it is not as likely to give false positives to people who have had the BCG vaccine as is the Tuberculin skin test. The QFT-Gold has been approved by the FDA since May of 2005.
Treatment of tuberculosis depends on whether the person has active tuberculosis or just the primary infection. One medication is usually sufficient for people with good immune systems who have just the primary infection. Isoniazid is usually administered for six months for these patients. A more complex combination of medications is given to people who have the active disease or a weakened immune system.
People with a high risk for tuberculosis should be screened as soon as possible once the risk is identified. High risk patients include alcoholics, homeless people, prisoners, personnel at jails, homeless shelters and hospitals, people with diabetes, those with AIDS, etc.
Instructions need to be provided to a person with tuberculosis as to proper precautions such as covering her mouth with a handkerchief when coughing or sneezing. A person with active tuberculosis should be isolated from other patients in an hospital. Proper ventilation should provided in prisons, homeless shelters, and hospitals.
Severe Acute Respiratory Syndrome (SARS) is a virus caused by a coronavirus. A coronavirus has a large RNA structure. The coronavirus is responsible for many illnesses in mammals. The SARS disease reached epidemic proportions, and caused seven hundred and seventy four deaths between November of 2002 and July of 2003 with eight thousand and ninety six known cases of the viral infection during that time.
In the World Health Organization reports, the SARS cases were broken down by countries, and the five countries with the highest number of cases (in descending order) were the People's Republic of China, Hong Kong, Canada, Tawain, and Singapore. No cases have been reported since 2004 when some research workers—two in Singapore and one in Taiwan were thought to have contracted the disease through improper handling of specimens of the SARS virus.
The symptoms of SARS are similar to symptoms of the flu – e.g. fever, stomach problems, sore throat, cough, tiredness, etc. with shortness of breath often appearing in the later stages of the illness. Initial symptoms usually appear within two or three days after exposure to the virus.
The World Health Organization divides SARS cases into suspected, probable and known with progressive inclusion of criteria across the three levels of certainty of the illness. A suspected case of SARS occurred when a person had a temperature above 38 degrees Centigrade, and had either recently visited an area where the SARS breakout occurred or had come into close contact with someone with a SARS diagnosis within the previous ten days. A probable case of SARS was indicated when the individual had the same symptoms as that of a suspected case of SARS, and in addition, had a chest xRay with indications of pneumonia that was not typical or which indicated some other respiratory distress. Once the laboratory tests were developed to confirm diagnosis of SARS, a person with a confirmed laboratory diagnosis was considered a known case of SARS.
The mortality rate associated with SARS approached ten percent.
Since SARS is a viral infection, antibiotics do not help with the disease. Supportive therapy and the implementation of quarantines and travel advisory to prevent spreading were the main treatments used when the epidemic was raging. Currently, vaccines have been developed for the illness should it recur.Research has also been done into the treatment of the illness with weapons used to fight other diseases such as AIDS, influenza, and hepatitis.
The countries with the heaviest caseload of SARS received economic setbacks from the presence of SARS in their countries. In the western world, the city of Toronto, Canada was the most heavily hit economically with travel advisories being issued against flying to Toronto as well as to the People's Republic of China where the disease was thought to have originated and to other far eastern countries which had a large number of victims. Chinatowns throughout the United State but particularly in New York City experienced a lowering of clientele as a result of the epidemic.
Sources
Centers for Disease Control and Prevention website information on SARS
Histoplasmosis is a dimorphic fungus infection caused by bird and bat droppings in the soil. (Dimorphic meaning two forms indicates that the fungus depending on the temperature at which it is grown can take the form of either a yeast like fungus in the body of a mammal or a mycelial fungus in the surrounding environment.) Histoplasmosis is endemic to midwestern and east central states in the United State in regions near the Mississippi River Valley and the Ohio River Valley.
According to an eMedicine article by Ryan C. Chang, MD (http://www.emedicine.com/MED/topic1021.htm),birds can not actually get or transmit the fungus but their droppings contribute to the richness of the soil for mycelial growth of the fungus, and make the ambient form of the disease more likely. Bats, on the other hand, can become infected with histoplasmosis, and pass on the fungus to the surrounding soil in their droppings.
The Center for Disease Control and Prevention reported on its website
People contract the illness by breathing the spores of the fungus when the soil is contaminated and then disturbed for some reason (e.g., digging). Histoplasmosis is not passed from person to person. Human beings who do not have AIDS or other immunological disorders and who are neither very young nor elderly are usually able to fight off histoplasmosis without its becoming disseminated – i.e., spreading to the lymph nodes and affecting body organs besides the lungs. However, in persons with insufficient immune systems the disseminated form of the disease can result in damage to the spleen, central nervous system, liver, eye and/or blood system, according to Chang's article. The disease can also take on the rheumatologic system, the article stated. People with emphysema are less likely to resist the fungus and more likely to develop chronic pulmonary histoplasmosis, it was noted in the article.
Although ninety percent of persons with histoplasmosis do not develop symptoms of the illness, the symptoms will appear in three days to two weeks if they are going to occur at all, stated both the CDC article and the Chang article. Common symptoms of the acute form of pulmonary histoplasmosis are chills and fever, headache, myalgia and stomach pains. Less common symptoms include joint pain, skin lesions, enlarged lymph nodes, shortness of breath, cough, pericarditis and/or chest pain.
According to the Chang article no treatment is needed for people with acute pulmonary histoplasmosis who do not show symptoms of histoplasmosis, but monitoring is necessary for those with mild symptoms, and medical treatment should be initiated for those with moderate to severe symptoms. Chronic pulmonary histoplasmosis should be treated in persons with impaired immune systems regardless of whether clinical symptoms are present. Treatment is to be initiated immediately for all cases of progressive disseminated histoplasmosis and those cases involving meningitis.
Sources
Center for Disease Control and Prevention website article on histoplasmosis
