Health and Disease

Leptospirosis: What Comes After Floods

Aside from drowning and physical injuries, one of the biggest hazards that come with flooding are infectious diseases. Leptospirosis, a zoonotic bacterial disease, is one such example, commonly reported after flash floods. With the ever-growing problem of climate change, possibly causing an increase in flooding occurrences globally, what exactly is the state of Leptospirosis internationally?


Leptospirosis is a zoonotic disease caused by the bacteria genus Leptospira, afflicting both humans and animals alike. The bacteria is spread by animal carriers (such as rodents, cattle, pigs, and more) through their urine, which can get into soil, mud, and water. Humans contract Leptospirosis when they get in contact with the urine of infected animals, or mediums such as food and water contaminated with the urine. The pathogenic bacterium enters the body through the nose, mouth, and open wounds.

Individuals most at risk of contracting the disease are those who work closely with possible carrier animals (like farmers) and those who frequently afflicted rivers or similar bodies of water. Outbreaks are especially common during the aftermath of intense flooding when people are most exposed to contaminated floodwaters.

Leptospirosis Worldwide

While leptospirosis occurs worldwide, it is more prevalent and usually endemic to tropical and humid regions, such as Southeast Asia, Africa, Central, and South America, Australia, and the Caribbean.

Over the years, numerous Leptospirosis outbreaks have been recorded. The recent onslaught of typhoons in the Philippines nearing the end of 2020 saw a small increase in Leptospirosis cases. Despite this increase, the total number of leptospirosis cases in the Philippines for 2020 (1,071) still decreased from 2019’s 3,140. Cases reported in certain regions of the country exceeded the epidemic threshold. There were reports that the National Kidney and Transplant Institutes lacked enough beds for Leptospirosis patients, in addition to the currently limited hospital facilities due to COVID-19 (Montemayor, 2020). Similarly, India reported an increase in Leptospirosis cases last 2020 compared to their 2019 record, counting 153 from their previous 83 (Suresh, 2020).

Because the majority of leptospirosis cases occur in developing countries, reports and details about these cases are often under-reported. However, there are still efforts to accurately determine global incidence rates and statistics about leptospirosis.

Symptoms, Signs, and Treatments

The incubation period of leptospirosis lasts 2-30 days, while signs and symptoms (illness) may be felt within five days to two weeks after exposure. However, some patients may be asymptomatic.

Some symptoms include high fever, chills, jaundice, head and muscle aches, abdominal pain, diarrhea, vomiting, and skin rashes. Milder cases of leptospirosis may be confused with the common flu. The illness may occur in two phases: (1) a case of fever, chills, body aches, vomiting, and diarrhea, after which the patient may feel better, and the second (2), which manifests more severely, triggering possible kidney, liver failure, or meningitis.

Doctors prescribe antibiotics such as doxycycline and penicillin to treat leptospirosis. However, the best way to prevent leptospirosis is to avoid contaminated waters. From a public health perspective, preventing leptospirosis outbreaks also means promoting access to clean water and better community sanitation and hygiene.

Conclusion: Current Issues and Possible Resolutions
According to Trott et al.’s study (2018), most Leptospira strains remain susceptible to doxycycline and other antimicrobial agents used for acute leptospirosis. In Chakraborty et al.’s research (2010), they were able to show that Leptospira strains were resistant to amphotericin B, 5-fluorouracil, fosfomycin, trimethoprim, sulfamethoxazole, neomycin, and vancomycin but susceptible to ampicillin, cefotaxime, ciprofloxacin, norfloxacin, doxycycline, erythromycin, and streptomycin.

Even with the current effectiveness of certain antimicrobial agents (such as doxycycline) for leptospirosis, antibiotic resistance remains a problem for the future of bacterial diseases. The misuse of these antibiotics can affect the future of leptospirosis treatment.

The prevalence of leptospirosis globally also remains a problem, given the increase in population and urban slums. Its manifestation poses more questions for the general state of public health, especially for developing countries. While leptospirosis is a very treatable disease, the overall prevention of it can be done through better identification of risk controls and addressing those. Policymakers can focus on imposing better occupational hygiene standards and protocols, water drainage, educational campaigns, national sanitation services, and vector control. National and local governments alike should strengthen sanitation measures.

With the inevitable coming of stronger typhoons and hurricanes because of climate change, flooding is inescapable as well. All health departments, especially for countries that are most affected by these natural disasters, should acknowledge the possible outbreaks and thus prepare accordingly.

As it is, developing countries remain the most vulnerable to leptospirosis outbreaks. Some may even argue that health issues of developing countries, not just leptospirosis, are largely brought about by deeply-rooted colonialism and imperialism. Notwithstanding, without the resources and financial capacity most advanced countries have, implementing effective sanitation measures— and thus, solving leptospirosis outbreaks, remains a distant dream.

Elmira Decena, Youth Medical Journal 2021


Montemayor, M. T. (2020). DOH notes drop on leptospirosis cases. Philippine News Agency Retrieved from:

CDC. (2019). Leptospirosis. Center for Disease Control and Prevention. Retrieved from:

Suresh, M. (2020). Dengue, leptospirosis cases. The New Indian Express. Retrieved from:

Trott, D. J., Abraham, S., & Adler, B. (2018). Antimicrobial Resistance in Leptospira, Brucella, and Other Rarely Investigated Veterinary and Zoonotic Pathogens. Microbiology Spectrum, 6(4). doi:10.1128/microbiolspec.arba-0029-2017

Chakraborty, A., Miyahara, S., Villanueva, S. Y. A. M., Gloriani, N. G., & Yoshida, S. -i. (2010). In Vitro Sensitivity and Resistance of 46 Leptospira Strains Isolated from Rats in the Philippines to 14 Antimicrobial Agents. Antimicrobial Agents and Chemotherapy, 54(12), 5403–5405. doi:10.1128/aac.00973-10


By Elmira Decena

Philippine Science High School student. Writer, dreamer, scientist. Protect our scientists. #SolusyongMedikalHindiMilitar

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