Which of the following is the primary reservoir host for pathogenic Leptospira interrogans?

Explanation

## Leptospira Reservoir Hosts **Key Point:** Rodents (particularly rats and mice) are the primary natural reservoir hosts for pathogenic Leptospira interrogans. These animals shed the organism in urine chronically without developing clinical disease. **High-Yield:** The most common serovars (Icterohaemorrhagiae, Copenhageni) are maintained in rodent populations. Humans acquire infection through contact with contaminated urine in water, soil, or food. ### Reservoir Characteristics | Host | Role | Clinical Status | Shedding Pattern | | --- | --- | --- | --- | | Rodents | Primary reservoir | Asymptomatic carriers | Chronic urinary shedding | | Cattle, buffalo | Secondary reservoir | May show clinical signs | Intermittent shedding | | Dogs, pigs | Accidental hosts | Can develop disease | Variable shedding | | Humans | Dead-end host | Symptomatic infection | No transmission to others | **Clinical Pearl:** Occupational exposure (farmers, veterinarians, sewer workers, rice field workers in India) increases risk due to contact with rodent-contaminated water and soil. **Mnemonic:** **RAT** = **R**odents **A**re **T**he primary reservoir