1.1 Definition of Leptospirosis

1.1 Definition of Leptospirosis

Leptospirosis is an example of zoonotic disease (spread from animals to humans) for which globalization and social variation have different epidemiological patterns for the poor and rich community. According to the Malaysia Ministry of Health (KKM) official website, the other names for this disease are Weil’s disease, Icterohemorrhagic fever, Swineherd’s disease, Rice-field fever, Cane-cutter fever, Swamp fever, and others. This disease is a significant health problem in developing countries especially for the poor rural society (Bharti, 2003). It has been reported that this disease commonly occurs in tropical and subtropical countries that are suitable for the bacteria's growth and it can reach more than 1 million cases per year globally. Malaysia is one of the Southeast Asia countries that has a significant increase in disease outbreaks and reported cases in recent years (Garba, Bahaman, Khairani-Bejo, Zakaria, & Mutalib, 2017). Until now, Malaysia is endemic for Leptospirosis with increasing cases recorded over the years.

Leptospira Bacteria is a photograph by Kateryna Kon/science Photo Library which was uploaded on October 1st, 2018.

Electronic image of Leptospira interorgans

Leptospirosis disease is caused by the spirochetes bacteria belonging to the genus Leptospira. These bacteria are gram-negative and aerobic bacteria. The common size of bacteria is 20 micrometers long and it has a right-handed helical (Karpagam & Ganesh, 2020). Sixty-six different species of Leptospira have been discovered and it has been divided into 2 clades and 4 subclades (P1, P2, S1, S2) according to their genomic sequence. 8 of 19 species from the P1 (L. borgpetersenii, L. alexanderi, L. interrogans, L. mayottensis, L. kirschneri, L. noguchii, L. weilii, & L. santarosai) can cause severe disease and 21 species from P2 were believed could cause mild disease in human. Other 26 species belong to the S1 and S2. They are saprophytes that undergo saprotrophic nutrition (Caimi & Ruybal, 2020). Rodents, cattle, dogs, horses, sheep, swine and wild animals are believed to be the reservoir hosts of the bacteria (Ellis, 2015).