May 18, 2021

Leptospirosis in India: Understanding the epidemiology and diagnosis of a silent epidemic

Leptospirosis is a zoonotic disease more prevalent in countries associated with poor sanitation and hygiene. It is a highly communicable disease of the tropical world passing on from the animals (primarily rodents and bovines), which are the reservoirs of the pathogen, to humans. The disease is caused by bacteria, specifically a Spirochaete, which was later named Leptospira. The etiological organism for the disease is Leptospira interrogans, a tiny (0.1µm x 6 -20µm) and highly motile organism with hooks. Due to its bending coil-like structure, the name Leptospirosis was conceived (in Greek leptos, meaning “fine,” and speira, meaning “a coil”). Since Adolf Weil first reported it, hence also called Weil’s Disease. Currently, 23 serogroups and more than 200 serovars of Leptospira are known to cause the disease globally.

The pathogen enters the body mainly from an infected animal through the bloodstream or mucosa or from a pregnant female to young ones, and the incubation period ranges from 5-14 days. It has a complex antigenic makeup with a genus-specific somatic antigen and a serovar-specific surface antigen made of polysaccharides. The most pathogenic of all is the outer membrane antigen, which attaches to the host cell. The immune response begins with phagocytosis. IgM is produced in primary response, which persists in high titer for the first two months of infection. Incidentally, IgA is a better serological marker compared to IgG antibodies produced in secondary response. IgA usually appears from the fifth day of infection and remains in the system for up to nine months.

In India, Leptospirosis has been neglected for a long time, and seldom has any study been done to map the extent of this disease. Recent outbreaks and endemics in the last decade have gained some attention among the health fraternity. Few studies have suggested its prevalence mostly in wet forest and coastal regions of the country, with the mean age group of the affected population be between 42 years. The fatality rate due to Leptospirosis has been reported to be around 3.5%. Clinically, the severity of Leptospirosis is highly erratic and can vary from mild illness to life-threatening complications as in multi-organ failure followed by death. Mild symptoms include high fever with bouts of Nausea and vomiting and occasional headache and chills. There can be few rashes in the body and muscle pain along with abdominal cramps. In severe infections, the symptoms would include hearing loss, meningitis, extreme fatigue, and deep breathing. The clinical manifestations can become complicated with the appearance of renal and liver failure. This condition is known as Weil Syndrome.

Considering the recent outbreaks, the Government has published guidelines for prevention from Leptospirosis, and the mitigation of resources in case of vast pockets are affected. L interrogans are difficult to isolate in pure cultures as most of the patients report in with some prior use of medication. Hence, serological tests form the benchmark for timely identification and diagnosis of the disease. The use of Rapid Cards, followed by more specific ELISA and PCR, are the standard Diagnostic techniques in practice.

J Mitra & Co. has been pivotal in providing state-of-the-art Diagnostic kits for Leptospirosis both in the form of Rapid Cards and ELISA kits. The Advantage Leptospira IgM IgG Card helps detect the disease with the spontaneous inference on the stage of antibody production. Also, a more precise test is that of the Lepto IgM ELISA with high sensitivity and specificity. The kits provided by J Mitra & Co. serve as a cornerstone in affordable and reliable diagnosis for this highly contagious disease.

, , , , , ,
Join Our Mailing List