What microorganism causes this disease?
The microorganism responsible for this disease is any of the three species of bacteria from the genus Borrelia that consists of about eleven members (Talaro & Chess, 2011). The three are B. burgdorferi sensu stricto which is mostly found in the United States of America, B. afzelii and B. garinii that are mostly found in Europe; collectively, they are known as Borrelia Burgdorferi sensu lato collectively (Willey.Sherwood and Woolverton, 2007). Other members of this genus suspected to cause an infection similar to the one this woman was experiencing include B. bissettii and B. valaisiana. Collectively, members of this genus are gram-negative spirochetes.
What is your best diagnosis of this case?
The best diagnosis for this case is Lyme’s disease.
What features are critical to your diagnosis?
The most outstanding symptom of Lyme disease is the circular rash with a central red spot, which makes it appear like a bull’s eye. This is the unique symptom of the disease in spite of the fact that some people with the disease do not develop it (Willey, Sherwood & Woolverton, 2007). The other factor that aided in this diagnosis is the fact that the patient went to work in the bush infested with numerous insects including ticks. The vectors of this disease, ticks, as well as the reservoirs of the disease are widely found in such areas. Fatigue and tender joints are other strong indicators that the patient was suffering from Lyme’s disease (Cowan, 2011).
What further steps should be taken to clear up the problem?
To begin with, laboratory tests should be taken to ascertain the presence of the disease in the patient. This is preferably done by use of Enzyme Linked Immunosorbent Assay tests (ELISA). Early stages of the disease, like the one this patient is probably in, is successfully treated throuh chemotherapy for between two and three weeks. The disease is treated by use of antibiotics such as doxycycline for adults, amoxicillin for children, erythromycin for expectant women, and ceftriaxone. In late stages of the disease, these drugs are administered orally and intravenously and in addition, minocycline is used for infections that have reached the brain (Strasheim, 2009).
How is this disease transmitted?
The disease is transmitted through the bite of infected ticks of the genus ixode. It is considered a form of zoonosis whereby the bacteria is found naturally in a reservoir and is only transmitted to human beings through ticks that feed on both the reservoir and human beings. Ticks of the genus ixode are responsible for the spread of this disease especially during their nymphal stage of development whereby due to their small size, they are able to attach and feed off the host for prolonged periods without being noticed (Willey.Sherwood and Woolverton, 2007). In addition, the tick pumps some secretions into the bite, which numbs any feelings in the area, and therefore the host may not notice its presence. However, the tick must e attached to the host for at least a day for infection to occur.
The bacterium is introduced into the body from the bite of an infected tick of the genus Ixode. Its entrance into the body is aided by the saliva that the tick pumps into the bite wound which interferes with the immune response at the location of the bite and consequently creates an environment that promotes the proliferation of the bacteria (Willey.Sherwood and Woolverton, 2007).
The bacteria grow, multiply, and migrate to the outer region of the skin, the dermis. At this point, the hosts’ immune response to the presence of the bacteria on the skin causes the characteristic red lesion with a bull’s eye in the centre (Cowan, 2011).
In a few days or weeks, the bacteria spread to the rest of the body; aided by the bloodstream (Strasheim, 20009). They move to organs such as the heart, other parts of the skin, the nervous system, and even to the brain.
The parasites are able to evade the immune system of the host by minimizing the amount of surface antigens, which they express. As a result, even neutrophils, which would successfully eliminate them, are unable to do so (Talaro, and Chess, 2011).
What symptoms might the patient develop if the disease is not treated? What is the prognosis with treatment?
If the disease is not treated promptly, some of the early symptoms go away on their own, but the infection persists. The rash goes away on its own without treatment but within weeks or months of the initial infection, the effects of the disease start to be felt in the joints, circulatory system, and the nervous system including the brain (Willey, Sherwood & Woolverton, 2007).
Eventually, symptoms such as arrhythmia and even heart failure may be observed as a result of inflammation of the heart muscles. Prolonged infection in the nervous system results in paralysis of the facial muscles, which is known as Bell’s palsy, peripheral neuropathy, meningitis and confusion. Disorders in the musculo-skeletal system are observed in case of untreated infections in the end. These are manifested by arthritis, swellings, stiffness and pain; not all the joints will be affected but the knees are commonly affected (Cowan, 2011).
Early treatment is normally very effective in eliminating the parasite and the symptoms from the patient’s body. However, relief does not come as fast when treatment is started in the later stages of the disease. This may be further complicated by the low immunity of the patient or co-infection with another disease transmitted by ticks among other factors. Patients that begin treatment when the disease has already progressed may continue to experience fatigue and muscle pain even after the bacteria have been cleared from the body (Willey, Sherwood & Woolverton, 2007).