Question

Given below are two statements:
Statement (I) : When the animals are infected with a host adapted serovar of Leptospira spp., they are called as reservoir hosts.
Statement (II) : The Leptospira spp. infection show a short kindley phase in the maintenance host.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true
• B. Both Statement (I) and Statement (II) are false
• C. Statement (I) is true but Statement (II) is false
• D. Statement (I) is false but Statement (II) is true

Hint:

In reservoir (maintenance) hosts, the renal phase of Leptospirosis is always prolonged and chronic, leading to long-term shedding in urine.
This chronic shedding is what makes them effective reservoirs for infecting other animals and humans.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Leptospirosis is a widespread, zoonotic bacterial disease caused by spirochetes of the genus *Leptospira*.
The epidemiology of leptospirosis involves a complex relationship between the host species and specific bacterial serovars, classified as either maintenance (reservoir) hosts or accidental (incidental) hosts.

Step 2: Detailed Explanation:
Let us analyze both statements.
Statement (I) is correct. When an animal species is infected with a host-adapted serovar of *Leptospira* (such as serovar Hardjo in cattle, serovar Canicola in dogs, or serovar Bratislava in pigs), the species acts as a maintenance or reservoir host.
In these hosts, the infection is highly adapted, often causing mild or subclinical disease, but allowing the bacteria to persist and spread efficiently within the population.
Statement (II) is incorrect. In maintenance (reservoir) hosts, *Leptospira* bacteria migrate to the kidneys and colonize the proximal renal tubules.
Because the host-adapted serovar does not trigger a strong inflammatory response in the kidneys, the bacteria can persist and multiply there for months, years, or even the lifetime of the animal.
This results in a prolonged (chronic) renal phase with continuous or intermittent shedding of leptospires in the urine (leptospiruria), which maintains the infection in the environment.
A short renal phase is characteristic of accidental hosts, where the infection is acute and is either cleared quickly or leads to severe, fatal renal failure.
Therefore, Statement (I) is true but Statement (II) is false.

Step 3: Final Answer:
The correct option is (C).