MULTIDRUG RESISTANT PATHOGEN EMERGING DISEASE AND MULTIDRUG RESISTANT PATHOGEN Lyme disease

What is an emerging disease ? An emerging disease is the one which has evoked suddenly among the population for the first time or that may have existed previously but is rapidly increasing in incidence or geographic range. These infectious diseases are continuing danger to everyone. e.g. SARS, West Nile virus, Lyme disease, AIDS, etc.

What is multiple drug resistance ? Multiple drug resistance or multidrug resistance is resistance to many structurally unrelated chemotherapy agents in cells that have developed natural resistance to a single cytotoxic compound. It is the property of a disease causing micro organism to withstand the drug therapy. This situation is more likely if the drug is not taken properly, or not prescribed properly.

What is Lyme disease ? Lyme disease or Lyme borreliosis is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Lyme disease is the most common tick-borne disease in the northern hemisphere. Borrelia is transmitted to humans by the bite of infected ticks belonging to a few species of the genus Ixodes ("hard ticks").

History of Lyme disease : This Lyme disease is named after the village, Lyme of Connecticut in USA, where a number of cases were identified in the year 1975. In 1978 Allen Steere realized that the Lyme disease is a tick- borne disease, but still the cause of the disease was unknown until 1982, when borrelia burgdorferi was identified by Willy Burgdorfer.

Location Borrelia burgdorferi sensu lato is the main cause of Lyme disease in the United States, whereas borrelia afzelii and Borrelia garinii cause most European cases.

Stages in Lyme disease THERE ARE THREE STAGES IN LYME DISEASE : Early localized infection Early disseminated infection Late persistent infection

Stage 1 : Early localized infection The classical sign of an early local infection in the case of Lyme is a circular, red colored rash known as erythema chronicum migrans (also erythema migrans or EM), which occurs at the site of the tick bite, in about 3 to 30 days after the tick bite.

Stage 2 : Early disseminated infection After the onset of local infection, the borrelia bacteria may begin to spread through the bloodstream. Erythema chronicum migrans may develop at sites across the body that bears no relation to the original tick bite. Other symptoms include migrating pain in muscles, joint, and tendons, and heart palpitations and dizziness caused by changes in heartbeat.

Stage 3 : late persistent infection If this Lyme disease if left untreated for several months the patient may face serious conditions and chronic symptoms that may affect many parts of the body including brain, nerves, eyes, joints and heart. Chronic neurologic symptoms occur in up to 5% of untreated patients. A polyneuropathy that involves severe pains, numbness and tingling in the hands or feet may also occur.

Causative agents Lyme disease is caused by Gram-negative spirochetal bacteria from the genus Borrelia. The group Borrelia burgdorferi sensu lato is made up of three closely-related species that are probably responsible for the large majority of cases: B. burgdorferi sensu stricto (predominant in North America, but also present in Europe), B. afzelii, and B. garinii (both predominant in Eurasia).

Images of bacteria borrelia

Transmission The Lyme disease bacterium, Borrelia burgdorferi, is transmitted among animals – and to humans – through the bites of certain species of ticks. Blacklegged (or deer) ticks can transmit several tick-borne diseases including anaplasmosis, babesiosis and Lyme disease.

Images of the tick bite

Ticks Ticks have evolved to become one of the most important groups of arthropod vectors of human pathogens. Ticks attach to skin of the host by using their hypostome as an anchor and create a feeding lesion to ingest blood or tissue fluids. Disease-causing organisms may be ingested or expelled during feeding.

Symptoms and signs Lyme disease affects different areas of the body. The site that the tick bites the body is where the bacteria enter through the skin. The infection causes an expanding reddish rash that is often associated with "flu-like" symptoms. Later, it can produce abnormalities in the joints, heart, and nervous system.

Laboratory testing The first step uses an ELISA or IFA test. If the ELISA or IFA is negative, it is highly unlikely that the person has Lyme disease, and no further testing is recommended.  If the ELISA or IFA is positive or indeterminate a second step should be performed to confirm the results.

The second step is a Western blot test The second step is a Western blot test. This test is designed to be "specific," meaning that it will usually be positive only if a person has been truly infected. If the Western blot is negative, it suggests that the first test was a false positive, which can occur for several reasons. 

Diagnosis In early Lyme disease, doctors make diagnosis simply by finding the classic red rash in people who have recently been in regions in which Lyme disease is common. The doctor might review the patient's history and examine the patient in order to exclude diseases with similar findings in the joints, heart, and nervous system.

Vaccination INTRAMUSCULAR is a vaccine used to provide protection against Lyme disease. This vaccine is not a treatment for Lyme disease. Researches are going on about the vaccines for Lyme disease.

Medical treatment Mostly Lyme disease is curable with antibiotics. The type of antibiotic depends on the stage of the disease and the areas of the body are affected. Early illness is usually treated with medicines taken by mouth, for example, doxycycline, amoxicillin, or cefuroxime axetil. Later illness such as nervous-system disease might require intravenous drugs; examples are ceftriaxone (Rocephin) and penicillin G.

Drugs Which Are Resistant to Borrelia Erythromycin Gentamicin Cefuroxime Doxycycline Amoxicillin Streptomycin

Prevention Avoid areas with lot ticks. Ticks can also be removed with tweezers. Check your skin and clothes with areas of ticks. Wearing long clothing can prevent the skin from bite of ticks.

Conclusion Thus the Lyme, which is an emerging infectious disease, can be treated by using antibiotics or alternative therapies in the earlier stages. But when it is left untreated for longer days or if the antibiotics are not properly given it would become multiple drugs resistant. Ticks that transmit B. burgdorferi to humans can also carry and transmit several other parasites such as Theileria microti and anaplasma phagocytophilum, which cause the diseases babesiosis and human granulocytic anaplasmosis, respectively. Hence awareness about these diseases should also be created.

S.NARMADA AND R.VIJAYALAKSHMI By S.NARMADA AND R.VIJAYALAKSHMI