HEALTH: LEPTOSPIROSIS: THE FLOOD-BORNE LEGACY

With antibiotics available all year round, deaths caused by leptospirosis can be avoided.  But unfortunately, Filipinos still die of it.

In the past years, leptospirosis has been a health problem with an average of 76 cases every year.  In 2009, 1,887 cases were rerported that resulted to 138 deaths.  Last July 5, the Department of Health declared an outbreak in various barangays in seven cities in Metro Manila.

Forewarned is forearmed, so goes a popular saying.  This must be the reason why the health department advised the public not to wade in floodwaters or to wear rubber boats when walking in flooded waters.

“Leptospirosis is an infection commonly transmitted to humans from water that has been contaminated by animal urine, and comes in contact with lesions in the skin, eyes, or with the mucous membranes,” commented Dr. Enrique Ona when he was still the head of the health department.

Aside from floodwaters, a person can also get leptospirosis by contact with fresh water, damp soil, or vegetation contaminated by the urine of infected animals, especially rodents and dogs.  People who swim in contaminated swimming pools, rivers, lakes, and streams can also get leptospirosis.  Farmers, particularly those who work in contaminated rice fields, are also prone to the disease.

The disease was first described by Adolf Weil in 1886.  Leptospira interrogans, a corkscrew-shape bacterium that caused the disease, was first observed in 1907 but it was the following year that it was declared as the cause of it.  In October 2010 British rower Andy Holmes died after contracting the disease.

The leptospirosis-causing bacteria are common around the world, but more so in tropical countries with heavy rainfall.  “Leptospirosis occurs in many wild and domestic animals,” explains The Merck Manual of Medical Information.  “Some animals act as carriers and pass the bacteria in their urine; others become ill and die.  People acquire these infections through contact with infected animals, their urine, or soil and water contaminated by infected urine.”

Aside from getting in contact with contaminated water and other media, leptospirosis bacteria also enter the body when a person swallows contaminated food or water, including during water sports.  Once in the bloodstream, the bacteria can reach all parts of the body and cause signs and symptoms of illness.

“Because mild leptospirosis typically causes vague, flu-like symptoms, many infections probably go unreported,” the Merck manual states.

Studies have shown that leptospirosis causes mild disease in about 90 percent of infected people, whereas 10 percent have severe, potentially fatal, disease that affects many organs.

There are two phases of leptospirosis.  “The first phase starts two to 20 days after infection with Leptospira,” the Merck manual informs.  “Symptoms begin abruptly with a fever, headache, severe muscle aches, and chills.  The eyes usually become red on the third or fourth day.  Nausea and vomiting are common.”

Symptoms involving the lungs (including coughing up of blood) occur in 10 to 15 percent of infected people, studies reveal.  Episodes of chills and fever, which often reaches 102 degrees Fahrenheit, continue for four to nine days.

The fever clears for a few days, marking the beginning of the second phase.  “During the second phase,” the Merck manual informs, “the body’s immune reaction against the bacteria causes inflammation, producing many symptoms.  The fever returns, and there is often inflammation of the tissues covering the brain (meningitis), causing a stiff neck, headache, and sometimes stupor and coma.

“In severe form of the infection, people may also have inflammation of the liver, kidneys, and lungs, resulting in jaundice, kidney failure, and bloody cough.  Sometimes the heart is inflamed, causing palpitations and dangerously low blood pressure (shock).  A pregnant woman who develops leptospirosis may miscarry.”

The severe form of leptospirosis is called Weil’s disease, which causes a continuous fever, stupor, and a reduction in the blood’s ability to clot leading to bleeding within tissues.  “By the third to sixth day, signs of kidney damage and liver injury appear,” the Merck manual says.  “Kidney abnormalities may cause blood in the urine and painful urination.  Liver injury tends to be mild and usually heals completely.”

Only a doctor can confirm the diagnosis of leptospirosis.  The doctor does this by identifying Leptospira in cultures of blood, urine, or cerebrospinal fluid samples or, more commonly, by detecting antibodies against the bacteria in the blood.

With the advent of modern-day science, medical devices like rapid immunochromatographic tests, or “rapid tests” as it is called, can readily be substituted to laboratory procedures that are lengthy in preparations and tardy in results.

Rapid tests are like pregnancy test kits that can be bought in pharmacies. It works by detecting a specific antigen which would normally be present in an infected individual thus confirming the diagnosis of a disease.

One rapid test that exists to detect leptospirosis is Leptocheck.  Several studies have found it to be 100 percent sensitive and specific to Leptospira antibodies, which can confirm the diagnosis of leptospirosis and the results are at par with the sophisticated laboratory testing procedures.

According to Zephyr, the manufacturer of Leptocheck, the product works by getting a drop of serum or whole blood of the patient to the sample port. With the aid of a running buffer, results are readily available in 15 minutes.

And just like a pregnancy kit, if two color band or “sticks” appears at the control window, the result is positive. Otherwise, the patient is negative for leptospirosis.  Again, as stated earlier, only physicians can confirm the diagnosis, although anybody can do rapid testing.

According to Merck manual, infected people who do not develop jaundice (yellowing of the skin and white of the eyes) usually recover.  Jaundice indicates liver damage and increases the death rate to 10 percent or higher in people older than 60.

Doxycycline, an antibiotic, can prevent the disease and is given to people who were exposed to the same source as an infected person.  Penicillin, ampicillin, or similar antibiotics are given to treat the disease.  In severe infections, antibiotics may be given intravenously.

In MedicineNet.com, Dr. John P. Cunha reported that a vaccine for leptospirosis is available and used in some countries in Europe and Asia.  “It must be given every year like a flu shot,” he said.  “A longer-acting vaccine is currently being investigated in Cuba.”

Leptospirosis is not a contagious disease.  “People with the disease do not have to be isolated, but care must be taken when handling and disposing of their urine,” the Merck manual points out.