Leptospira IgG + IgM rapid diagnosis by ICT card test

Why is it Important : Leptospirosis as a disease has so much in common with regards to sign and symptoms in relation to common infections like Malaria, Typhoid, Influenza, Viral Hepatitis, Japanese Encephalitis, Scrub Typhus etc that it is easy to skip this disease consideration yet it itself is endemic in India.

The Disease :

Leptospirosis or Weil's Disease is a zoonotic disease in Humans caused by a Bacteria known as Leptospira - a gram negative spiral shaped bacteria classified as "spirochetes " in accordance to its microscopic look. It has the potential to cause disease in both Humans and Animals.

In Humans Leptospira can cause an wide variety of symptoms with or without fever and jaundice, and mimics many of the symptoms found in common with viral, bacterial and protozoal infections. Surprisingly sometimes patients can remain asymptomatic.

Untreated, Leptospirosis can lead to kidney damage, meningitis (inflammation of the membrane around the brain and spinal cord), liver failure, respiratory distress, and even death.

Spiral shaped Leptospira, a spirochete

Is it a common Infection :

Contrary to our believe leptospirosis not a rare disease and is Endemic in India more so in Southern Peninsula. However this disease is one of the under reported and under diagnosed entity due to a magnitude of reasons including lack of awareness, lack of adequate diagnostic facilities, its similarities to some other common infections and antibiotic abuse.

How It Spreads :

The bacteria that cause leptospirosis are spread through the urine of infected animals, which can get into water or soil and can survive there for weeks to months.

Few examples includes :

• Rodents like rats and mice

• Domestic and wild Dogs and cats

• Pigs, cattle's and Horses

• Other wild animals

Once Infected animals may remain asymptomatic and continue to excrete the bacteria into the environment continuously or every once in a while for a few months, even up to several years and the disease is passed on to Humans by

• Contact with urine (or other body fluids, except saliva) from infected animals.

• Contact with water, soil, or food contaminated with the urine of infected animals.

The bacteria can enter the body through skin or mucous membranes (eyes, nose, or mouth), especially if the skin is broken from a cut or scratch. Drinking contaminated water can also cause infection. Outbreaks of leptospirosis are usually caused by exposure to contaminated water, such as floodwaters. Person to person transmission is rare.

Signs and Symptoms

In humans, Leptospirosis can cause a wide range of symptoms, including:

• High fever

• Headache

• Chills

• Muscle aches

• Vomiting

• Jaundice (yellow skin and eyes)

• Red eyes

• Abdominal pain

• Diarrhea

• Rash

• Fatigue

• Disorientation

The time interval between a person’s exposure to a source of infection and developing symptoms can vary from 2 days to 4 weeks, which usually begins with abrupt fever and other symptoms. Leptospirosis may occur in two phases: ( Biphasic pattern)

• After the first phase (with fever, chills, headache, muscle aches, vomiting, or diarrhea) the patient may recover for a time only to become sick again.

• If a second phase occurs, it may be more severe and complications may develop in vital organs and functions like kidney , liver failure or meningitis.

The course of illness may last from a few days to 3 weeks or longer and without treatment, recovery may take several months.

Laboratory Diagnosis :

It is important to exclude other common infections that are common to a particular location in a particular season or in regards to other conditions.

Weil Felix test used to be done in past and lacks specificity and is discontinued.

Dark-Field Microscopy is often described as a useful diagnostic method but its significance is doubtful.

MAT test : Leptospiral Microscopic Agglutination Test with live antigen using dark field microscopy, Needs infrastructure

Culture

Culture of Leptospira is a difficult and relatively insensitive process; it is laborious and can take up to three months. In the acute phase, which lasts for about 10 days, the Leptospira can often be cultured from blood or cerebrospinal fluid (CSF). When specific antibody response is detected (at approx. 10 days), Leptospira tends to disappear from the blood. During the second phase, which may last up to several months, bacteriuria is often intermittent.

Antibody detection by Serology :

Antibodies may be detected in the blood within 5–7 days of symptom onset. Evidences of seroconversion between acute and convalescent-phase serum (Paired sera) specimens confirm the diagnosis of leptospirosis which can be demonstrated by microscopic agglutination test (MAT).

Serological test by Other serological methods

• ELISA test to detect IgG and IgM antibodies

• Rapid card test by Immunochromatographic method for IgG and IgM antibodies is simple fast and handy in areas with very good infrastructure.

Molecular Methods

Polymerase Chain Reaction (PCR) assay can be used on clinical samples such as CSF, urine, or blood to detect the presence of leptospiral genetic material. This needs good resources and Infrastructure.

The test we do :

• Rapid card test by Immunochromatographic method for IgG and IgM antibodies is simple fast and handy in areas with very good infrastructure.

Ordering Information :

Leptospira IgG + IgM or Leptospira antibody

When to order : Like all antibody tests antibody develops only few days after infection. Hence serological tests are best done after few days of symptom and repeated after few days again or by testing a convalescent sample.