4. TYPHUS
In humans, several rickettsia species cause the disease known as epidemic typhus. Ticks, mites, fleas, or lice transmit the disease, with each agent having a unique epidemiology but all causing a disease with symptoms similar to a bad cold, including fever lasting one to several weeks, chills, headache, and muscle pains, as well as a body rash. A large painful sore appears at the site of the bite, and nearby lymph nodes are swollen and painful.
The four main types of typhus are as follows:
- Epidemic typhus
- Brill-Zinsser disease
- Endemic or murine typhus
- Scrub typhus
Epidemic typhus (European, classic, louse born)
Typhoid fever is a worldwide epidemic. The body louse transmits this acute disease from person to person. Although endemic epidemic typhus exists in highland populations in Africa and South America, tourists are unlikely to contract lice or the disease. Large outbreaks of typhus have occurred primarily in Africa since World War II, with the majority of reported cases coming from three countries: Burundi, Ethiopia, and Rwanda.
Rickettsia prowazekii, which is carried by the body louse Pediculus humanus corporis, causes epidemic typhus. When lice feed on a human, they may defecate at the same time. When the person scratches the bite, the bacteria-carrying faeces are scratched into the wound. Body lice are common in overcrowded, dirty areas where people have few opportunities to wash themselves or their clothing. As a result, this type of typhus affects a large number of people living in the same community at the same time.
Fever, headache, weakness, and muscle aches are all symptoms of epidemic typhus. It also produces a rash with both spots and bumps. The rash appears first on the back, chest, and abdomen before spreading to the arms and legs. The most serious complications include swelling in the heart muscle or the brain (encephalitis). This type of typhus can be fatal if not treated. The disease is distinguished by a high fever, an intractable headache, and a rash. Temperatures reach 104° F in a matter of days and remain high. The headache is widespread and severe. On the fifth to sixth day, a macular eruption (dark spot on the skin) appears, initially on the upper trunk. which then spreads to the entire body with the exception of the face, palms, and soles of the feet. Case fatalities range between 1% and 20%. Low blood pressure causes prostration, which may be followed by vascular collapse. Fatalities in children are uncommon; mortality increases with age.
Brill-Zinsser disease is caused by the reactivation of a previous infection with epidemic typhus. It affects people years after they have fully recovered from epidemic typhus due to immune system weakness. The bacteria can then retake control, resulting in extremely mild illness. Brill-Zinsser disease is relatively mild, with a week-long fever and a light rash similar to the original illness.
Tick Typhus
Tick typhus, a type of spotted fever, is common among travelers who spend time trekking or on safari in Africa or the Indian subcontinent. Cattle or wild-animal ticks may pose a risk to hikers in southern Africa.
Seek local advice on tick-infested areas, and always check your skin for ticks after walking in a high-risk area, such as a tropical forest. A strong insect repellent can help, and serious walkers in tick-infested areas should consider impregnating their boots and trousers with benzyl benzoate and dibutylphthalate.
Scrub Typhus( mite borne typhus)
Scrub typhus is primarily found on Pacific islands, as well as in Southeast and East Asia, and is spread by mites that feed on infected rodents. The incidence is highest in the spring and summer, when human activity brings them into contact with mites looking for animal hosts.
Rickettsia tsutsugamushi causes scrub typhus. Mites or chiggers carry this bacterium. The bacteria are deposited by the mites as they feed on humans. Scrub typhus is widely distributed in the southwest Pacific, Southeast Asia, and Japan. It is a common cause of illness for people who live in or visit these areas. It is more common during the rainy season.
Scrub typhus has a wide range of symptoms. Fever, headache, muscle aches and pains, cough, abdominal pain, nausea and vomiting, and diarrhea are the most common symptoms. Some patients only have these symptoms. Some patients experience a rash that can be flat or bumpy. Individual spots develop crusty black scabs over time. Other patients progress to a more serious disease that causes encephalitis, pneumonia, and swelling of the liver and spleen (hepatosplenomegaly). The onset is abrupt, with fever, chills, headache, and generalized lymph node swelling. A red lesion appears at the site of the bite when the fever begins. During the first week, a high fever of up to 104 °F develops, as does a severe headache. During the first week of fever, a cough is present, and pneumonia may develop. A rash appears on the torso, often spreading to the arms and legs.
MURINE TYPHUS (RAT, FLES TYPUS)
Murine typhus is a relatively common disease that is spread by fleas. Clinically, it is similar to epidemic typhus, but less severe. The most cases occur during the summer months, when rats and their fleas are most active and plentiful.
Fleas transmit the disease, which is also known as endemic typhus. When a flea lands on a person, it may defecate while feeding. When a person scratches the itchy spot where the flea was feeding, bacteria-laden faeces are scratched into the skin, resulting in infection. Rickettsia typhi is the bacterium that causes the disease. Endemism typhus is most common in warm, coastal areas. Southern Texas and southern California have the most cases in the United States.
Chills, headaches, and fever are among the symptoms of the disease, which lasts about 12 days. Rash and other symptoms resemble epidemic typhus.
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Diagnosis
A variety of tests are available to determine how antibodies (immune cells in the blood) react to the presence of specific viral and bacterial markers. When antibodies react in a specific way, it indicates the presence of a rickettsial infection. Because many tests take some time to process, practitioners will frequently begin treatment without first completing tests, relying solely on a patient's symptoms.
PREVENTION
The best tick typhus prevention is prompt removal of attached ticks and the use of repellents to prevent tick attachment. Laundering louse-infested clothing is the most effective way to prevent lice transmission and epidemic typhus. Tick and mite-borne typhus can be prevented by taking precautions when walking in rural areas and using insect repellents. Each of these types of typhus can be avoided by avoiding the insects that carry the causative bacteria. Other preventive measures include maintaining good hygiene and using insect repellents.
VACCCINATION
No country requires typhus vaccination as a prerequisite for entry. The treatment for all types of typhus is the same. The manufacture of typhus vaccine in the United States has ceased, and there are no plans to commercialize a new vaccine.
Treatment
Each form of typhus is treated with the antibiotics tetracycline or chloramphenicol. Fever is quickly resolved with chloramphenicol, doxycycline, or other forms of tetracycline, and relapses are uncommon. Regardless of the patient's age, a single dose of 200 mg doxycycline (two tablets) can be given.
Cleanliness is essential in the prevention of body louse infestations. For minor infestations, the simplest control method is to expose infested clothing to a minimum temperature of 70o C for at least one hour. Chemical control is generally required, which entails using a dusting technique to apply insecticides and treating clothing. Permethrin (0.5%), temephos (2%), propoxur (1%), and carbaryl (5%) are effective insecticide dusts for controlling body louse. One thorough insecticide treatment of infested clothing should suffice. Dusting is not advised for people who have dermatological problems or open wounds. When an infestation is known to be widespread, it is recommended that an insecticide be applied to all members of the community on a regular basis.
disease no 5
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Thank you so much for sharing all this wonderful info with the how-to's!!!! It is so appreciated!!!” “You always have good humor in your posts/blogs. So much fun and easy to read!
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