ELISA test

ELISA is an abbreviation for 'enzyme-linked immunosorbent assay'. ELISA tests are relatively accurate tests, highly sensitive and specific. They compare favorably with other methods used to detect substances in the body such as Radio immune assay (RIA) tests. ELISA tests have an added advantage in that there is no need for radioisotopes or costly radiation counter. An HIV ELISA test is also called HIV enzyme immunoassay (EIA). It is the first and basic test to determine if an individual is positive for a selected pathogen such as HIV. The test is performed in a plastic plate of 8 cm x 12 cm which contains 8 x 12 matrix of 96 wells, each of which is about 1 cm high and 0.7 cm in diameter.

A patient's serum contains certain antibodies. If the patient is HIV positive, then the serum will contain antibodies to HIV. Those antibodies will bind to the HIV antigens on the plate. Sometimes, even in some individuals not infected with HIV antibodies, positive result is given in HIV ELISA. This is called false positive. One reason for false positive is that in women who have had multiple pregnancies, may possess the antibodies directed against human leukocyte antigens (HLA) which are present in host cells used to propagate HIV. As HIV buds from the surface of the host cell, it incorporates some of the host cell HLA into its envelope. False negatives can also occur during the window between infection and an antibody response to the virus called seroconversion. A person will be retested if the serum gives positive result. If the ELISA retests are also positive, then the patient will be retested by western blot analysis.

Lyme Disease

Lyme Disease is a bacterial infection transmitted by deer ticks. Typically this disease is noticed in the Northeast, northern California and upper Midwest in the U.S. Lyme disease is also noticed in Europe, Asia and Australia. Ticks latch on to the person and transmit the disease-producing bacteria such as Borrelia burgdorferi. The bacteria passes through the bloodstream and produces symptoms that may resemble fibromyalgia or chronic fatigue syndrome or joint disorder.

Symptoms of Lyme Disease include a rash that can be noticed at the site of the tick bite. The red bumps are warm and tender to the touch. The rashes resemble a bull's eye. Patient suffering from Lyme Disease is likely to suffer flu-like symptoms along with the rashes. There is severe joint pain. Other symptoms of Lyme Disease include difficulty in concentration and remembering. The disease progressively affects the heart and central nervous system.

The ELISA test is used to detect Lyme disease. Other diagnostic tests include Western Blot test and Polymerase chain reaction test. Oral antibiotics such as doxycycline or amoxicillin are used to treat Lyme disease in the early stage. If the disease has progressed, intravenous antibiotic treatment may be required. Persons in tick-infected areas must cover themselves completely with long sleeves and pants. They must check for any attached ticks after going out. Remove any tick with a pair of tweezers and then disinfect the site of the bite. Use of repellant may help.