Plague

Plague is a bacterial infection caused by Yersinia pestis and is spread by rodents, especially rats. Exposure to rats, rabbits and squirrels increases the risk.

Types of Plague

Bubonic plague: is an infection of the lymph nodes. Symptoms of Bubonic plague symptoms include chills and high fever along with headache and swollen lymph glands (bubo).

Pneumonic plague: is an infection of the lungs. Symptoms of Pneumonic plague include severe cough, blood in sputum and difficulty in breathing.

Septicemic plague: is an infection of the blood. Symptoms of Septicemic plague include diarrhea, fever, low blood pressure, abdominal pain, bleeding and organ failure.

Diagnostic tests that are prescribed for plague are blood and sputum culture. Fluid from a lymph node is often examined. Antibiotics (streptomycin, gentamicin, doxycycline, or ciprofloxacin) are the first line of treatment. Pneumonic plague is infectious. If left untreated, plague can lead to meningitis or later death.

Lymphogranuloma Venereum

Lymphogranuloma Venereum or LGV is caused by the Chlamydia trachomatis bacteria. This is caused most often by sexual contact but it can also occur due to other reasons. Lymphogranuloma Venereum is a sexually transmitted disease (STD) that is more prevalent in the tropical areas. Lymphogranuloma Venereum affects the lymph nodes and causes scarring and destruction of tissue. In the initial stage, Lymphogranuloma Venereum remains as a painless blister. When the disease lasts for a few months, it can spread to the lymph nodes. This may lead to lymphatic obstruction, chronic edema and fibrosis. Left untreated, it can lead to Genital elephantiasis.

Lymphogranuloma Venereum manifests as a small painless ulcer on the male or female genitalia. Swelling and tenderness is experienced in the surrounding lymph nodes. A patient suffering from Lymphogranuloma Venereum may have fever and loss of appetite. There may be drainage from the inguinal lymph nodes and redness and swelling. Women might notice abdominal pain and fistulas.

Multiple sexual partners is a leading cause for Lymphogranuloma Venereum. A blood test can confirm lymphogranuloma venereum based on antibodies against Chlamydia trachomatis. Biopsy of the lymph node or serology test for LGV are also conducted to help diagnose the condition. Antibiotic therapy can cure Lymphogranuloma venereum. Medications such as Tetracycline, Doxycycline, Erythromycin are prescribed.

Lymphoscintigraphy

Lymphoscintigraphy is a special type of nuclear medicine imaging study; it provides images of the lymphatic system. A radio tracer is used to obtain the images. The images are known as scintigrams. Lymph nodes act like a filter for foreign bodies such as viruses, pollen and germs. Lymphoscintigraphy is used as an imaging study in people suffering from any of the following - breast cancer, malignant melanoma (stage 1&2), head, neck gastric, thyroid, vulvar, and penile cancers. The procedure is carried out by a certified nuclear imaging technician. Lymphoscintigraphy is performed to

• Identify the sentinel lymph node i.e. the first node that drains a tumor.
  
• Identify the number of sentinel nodes.
  
• Mark the sentinel node over the skin for biopsy.
  
• Locate the sentinel in unexpected locations.
  
• Differentiate sentinel node from other subsequent nodes.
  
• Plan a or surgery that helps assess the stage of cancer so as to plan treatment.
  
• Identify points of blockage in the lymphatic system.

The study of the sentinel node is highly significant for the following reasons:

• It is the first node to receive metastatic deposits in a malignancy.
  
• A radio active channel leads to this node.
  
• It is the node close to the primary lesion.
  
• It is the first node to be visible during the lymphoscintigraphy study.

Lymphoscintigraphy became much sought after, after it was used to identify and study the breast sentinel nodes. This procedure is an important procedure because if the sentinel node is free of metastasis, then the subsequent nodes are also most likely to be disease free. This procedure permits the patient to skip axillary clearance surgery if the sentinel node shows negative for metastatic disease. This procedure becomes very useful for scores of people suffering from breast cancer across the world as it avoids a painful surgical procedure.

The patient is injected with the radioactive material; this radioactive material gives off gamma rays that are picked by the gamma camera. Pictures are taken for 1 hour to show the flow of the material through the lymph nodes. Anesthesia is not required, the patient is made to lie on a table and the gamma camera is positioned accordingly. As the gamma camera moves, it follows the radiation being emitted which in turn is mapped into a series of images. The doctor marks the skin at the sentinel node sites and these marks are later used during the surgery. The body passes out the small levels of radioactive material naturally.