Leptospirosis, often called rat fever, is a bacterial disease linked to rodent urine and flood water. Surat has a documented history of it after the 2006 floods. This page collects the figures we could trace to a named published source, with their dates and limits stated plainly.
By Nirav Thakkar, Universal Pest Control Service, Surat (operating since 1998). Published 2 October 2026.
Key findings at a glance
- 112 leptospirosis cases were studied during the post-flood outbreak in Surat in August–September 2006 (Source: Prasad et al., National Journal of Community Medicine, 2010).
- A 2012 death audit across Surat and Navsari recorded 61 confirmed cases and 13 deaths, a case fatality of 21.3% (Source: National Journal of Community Medicine, 2013).
- All 13 deaths in that audit were men, and 11 of 13 had a recorded exposure in the previous 15 days (Source: same audit).
- Surat Municipal Corporation’s 2018 vector-borne disease report records 22,524 rodent traps laid, 5,048 rodents collected and 30,953 rat burrows treated (Source: SMC VBDC Annual Report 2018).
- A 2023 review pooling Indian studies estimated combined mortality at 11% (Source: Choudhary et al., 2023).
On this page
- What leptospirosis is and how rodents are involved
- Surat after the 2006 floods
- The 2012 death audit: Surat and Navsari
- What Surat Municipal Corporation recorded on rodents
- The wider Indian picture
- What this means for households and businesses
- Methodology and sources
What leptospirosis is and how rodents are involved
Leptospirosis is a zoonotic disease, meaning it passes from animals to people. A 2023 review of Indian data lists the animal groups in which infection was found most often: buffalo (45.75%), rodents (40%), dogs (26%), cows (24.26%), goats (19.42%) and pigs (15.8%) (Source: Choudhary et al., Journal of Pure and Applied Microbiology, 2023). Rodents are therefore one important reservoir, not the only one.
The same review identifies monsoon rainfall as a key risk factor, which is why cases tend to follow flooding.
Surat after the 2006 floods
| Item | Figure | Period |
|---|---|---|
| Leptospirosis cases studied, post-flood outbreak | 112 | August–September 2006 |
(Source: Prasad R, Srivastava V, Bansal R, Pawar A, Desai V, Desai K, Jain M. National Journal of Community Medicine, 2010.)
The authors concluded that early detection of cases in an epidemic, preventive treatment for exposed people, and prompt referral with strong intensive-care support are needed to reduce deaths.
The 2012 death audit: Surat and Navsari
| Measure | Figure |
|---|---|
| Confirmed cases (15 June – 31 October 2012) | 61 |
| Deaths | 13 |
| Case fatality | 21.3% |
| Deaths in men | 13 of 13 |
| Deaths aged 20–45 / 45–60 | 10 / 3 |
| Deceased who were farm workers or farmers | 9 and 2 |
| Deceased with exposure in the previous 15 days | 11 |
| Average days from first symptoms to first consultation | 3.1 |
| Average days from first symptoms to first antibiotic dose | 4.5 |
| Average days from first symptoms to death | 8.4 |
| Reduced urine output (oliguria) among deceased | 12 of 13 |
(Source: Death Audit of Leptospirosis Cases in Surat and Navsari District of South Gujarat, National Journal of Community Medicine, March 2013.)
The gap between first symptoms and first antibiotic dose, 4.5 days on average, is the detail that stands out. Leptospirosis can look like an ordinary monsoon fever, which is a medical point and not a pest-control one: anyone with fever after wading through flood water should tell their doctor about the exposure.
What Surat Municipal Corporation recorded on rodents
| 2018 rodent-control activity (plague surveillance) | Figure |
|---|---|
| Traps laid | 22,524 |
| Rodents collected | 5,048 |
| Rat burrows treated | 30,953 |
| General flea index | 0.50 |
(Source: Surat Municipal Corporation, Vector Borne Diseases Control Department, Annual Report 2018.)
Dividing rodents collected by traps laid gives roughly 22 per 100 traps (our own calculation from the two figures above). The report is a plague-surveillance record. It does not report leptospirosis cases, and it should not be read as a measure of how many rodents live in Surat.
The wider Indian picture
| Place and period | Reported figure |
|---|---|
| Maharashtra, 2005 monsoon floods | 2,355 cases and 167 deaths |
| Karnataka, 2004 / 2005 | 152 cases, 11 deaths / 224 cases, 19 deaths |
| Kerala, 2018 post-flood outbreak | about 70 lives lost |
| India, pooled studies 2005–2023 | 9.47% of 4,394 human samples positive (416) |
| Combined mortality across studies | estimated 11% |
(Source: Choudhary et al., Journal of Pure and Applied Microbiology, published 30 November 2023.)
These come from different places, years and study designs, so they should not be compared with one another as if they were a single series.
What this means for households and businesses
Rodent control is one part of lowering risk, alongside drainage, waste handling, protective footwear in flood water and prompt medical care. It reduces exposure; it does not remove the disease risk, and no pest-control treatment can promise that.
In practice the sensible steps are the plain ones: find where rodents are getting in or feeding, close those gaps, keep food and waste covered, and treat burrows and runs where they are active. After flooding, avoid wading through standing water where you can, and see a doctor early if a fever follows exposure.
If you are seeing rodents at a home, shop, godown or society in Surat, our rodent control service in Surat page explains how we inspect and what a realistic plan looks like.
Methodology and sources
Every figure was read from a source opened while preparing this page. Where a figure could not be traced to a named source it was left out. This includes a 2008 news report of a Surat outbreak, which we did not use because it gave no official count. We do not present estimates of current Surat cases because none were available to us.
- Prasad R et al. Post-Flood Profile of Leptospirosis Cases at Teaching Hospital of Municipal Medical College in Surat City. National Journal of Community Medicine, 2010.
- Death Audit of Leptospirosis Cases in Surat and Navsari District of South Gujarat. National Journal of Community Medicine, 2013.
- Surat Municipal Corporation, Vector Borne Diseases Control Department. Annual Report 2018.
- Choudhary et al. Epidemiological Status of Leptospirosis in India. Journal of Pure and Applied Microbiology, 30 November 2023.