Human Leptospirosis outbreak in Puerto Rico over the past 5-10 years; the infectious Disease process and its complications


Human leptospirosis is a bacterial infection that is transmitted through contaminated water and open wounds. The spiral-shaped leptospira bacterium is found in the urine of rodents and several other animals. According to the World Health Organization, the bacterial infection tends to spread after floods through consumption of contaminated water or through infection of open wounds. The disease does not typically spread from person to person.  Leptospirosis can cause organ failure and eventually death in serious cases. Human leptospirosis is not uncommon in the tropics, especially after heavy rains or floodwaters. The bacteria contaminates water or soil and can survive there for several months.

Puerto Rico has been in the middle of a prolonged crisis since being struck by Hurricane Maria in September 2017.  Most parts of the island remain without electricity, water that is safe for consumption and limited gas. Additionally, the United States territory is facing a public health crisis which is due to the infectious illnesses that has been spread by the storm. Puerto Rico typically has 60 to 95 reported cases per year (Rettner, 2017). It is important to realize that the symptoms of this infection can be confused with those of other illnesses such as dengue.  It can also mimic the flu which makes it difficult to diagnose in the early stages, resulting in fatal consequences. The Centers for Disease Control and Prevention said that leptospirosis can be treated with antibiotics as long as the treatment is done as soon as possible to reduce severity and duration of the illness.

Background on Human Leptospirosis

Human Leptospirosis is a bacterial infection caused by spiral-shaped leptospira bacteria. Some individuals infected with this bacteria may fail to show any symptoms. If the symptoms do the show, they can begin as little as forty-eight hours later or take as long as one month after exposure to show. The symptoms vary widely. In one instance, a 61-year old bus driver by the name Jorge Morales stopped for a drink from a stream near his house in Canovanas a week after Hurricane Maria. Thereafter he developed a high fever, his skin turned yellow and seven days later he passed away in a hospital in Carolina. He was among five other patients who visited the hospital after consuming water from the streams in Canovanas and Loiza (Health, 2017). The most common symptoms are high fever, muscle pain, headache, and red eyes. Most of the Leptospirosis cases are mild with no complications but approximately 10% of the people who contact the illness develop severe cases.  In the case where the patient does not recover after the early stages of the infection, they have a high chance of developing liver or kidney failure, bleeding in the lungs or even meningitis during the more deadly second stage.

 The disease particularly affects the poor and those living in the tropical regions especially after flooding. Rodents are the most common source of infection to human beings. However, they are not the only culprits. Various wild and domestic animals such as unvaccinated dogs, horses, and pigs can harbor the bacteria. It is transmitted when open wounds or the mucous membrane of the eyes, nose, and mouth come in contact with water that is contaminated with the leptospirosis bacteria. There are some reports of the infection being transmitted through sex and lactation. In addition, the infection can be transmitted through the placenta leading to abortion or stillbirth (Hurtado, 2017).

Increased risk of infection

There were several factors that suggested that the leptospirosis cases were more prevalent in the U.S. territory. Scientific literature relating to post-hurricane infections is limited, however, a study done after the 1996 leptospirosis outbreak in Puerto Rico found that in 2017 the infection had affected four times as many people. Males were believed to be at a higher risk of getting the infection since the assisted in the relief work. According to the authorities, a quarter of the population did not have access to clean drinking water for months after the hurricane as the areas that did have clean water were not evenly distributed. The conditions in Puerto Rico were alarming. The destruction throughout the island had created a breeding ground for contamination. A disaster that led to the death of many.

The study suggested that floodwaters provide ideal conditions for the survival of the bacteria. Floods prevent animal urine from evaporating into the air or being absorbed into the soil. The leptospires are therefore passed directly into the surface waters or stay in the mud. Victims contract the bacteria either by ingesting the contaminated water or by swimming in the water with open sores (Bandino, 2015). According to Fox News, the lack of safe and clean drinking water is causing the residents of Puerto Rio to drink from whatever sources they can find (Hurtado, 2017). This approach, together with the presence of floodwater increased the risk of contamination. The government was urged to take preventative measures to curb the spread of the bacteria in the island after Hurricane Maria.

Challenges to human Leptospirosis Surveillance

The Puerto Rico Department has recorded many cases of leptospirosis over the last decade but the data does not show the true burden of the illness. A report previously released by the CDC suggest that sixty to ninety percent of deaths caused by leptospirosis in Puerto Rico are not reported. There are a number of reasons for this. First, according to the report, there is lack of timely diagnostics. This is mostly because the remote areas of Puerto Rico lack advanced laboratory services. The lack of proper medical infrastructure on the island results in the increased risk of spreading the disease. Secondly, due to the similarity in the symptom presentation as other illnesses such as dengue, many cases may be misdiagnosed (Hurtado, 2017). This particularly occurs in areas where dengue is an epidemic which is the case in Puerto Rico. This is so unfortunate because if leptospirosis is correctly diagnosed it is easily treatable with antibiotics (Health, 2017). Another reason why there is a challenge in leptospirosis surveillance is the number of asymptomatic cases. Sometimes people infected with the bacteria do not show symptoms and therefore those cases are not reported. However small the number is, it may contribute significantly to the growing risk of leptospirosis in Puerto Rico and other U.S. islands which are amidst of a prolonged health crisis.


Investigation shows that the spread of leptospirosis is preventable and easily treatable therefore lives do not have to be lost. There are several strategies that have been implemented in Puerto Rico to help contain the infectious disease. The most effective way is educating the residents on how they can protect themselves from the bacteria. Creating awareness is the first step towards successfully reducing the spread. Residents of Puerto Rico should be advised to either take bottled water or use the pills distributed by the health department and the U.S. military to purify their drinking water. They can also boil the water to make sure it is safe for human consumption. Additionally, it is important to teach people the importance of wearing protective footwear near water bodies that may be contaminated with animal urine as well as avoiding swimming in them. Metrological data has shown that disastrous floods are increasing in frequency and becoming more severe in the recent years. This is perhaps due to climate change, therefore, it is crucial to remain prepared.

Another preventative measure that was taken by the government was sending fliers with step by step instructions on how to disinfect water with pills to mayors for distribution with food suppliers in towns all over the island. Non-profits and other organizations have been providing filtration and purification devices to households and group homes in Puerto Rico. This project was called Operation Agua. Those who have access to the internet are advised to research about how to keep themselves free from leptospirosis. Adventure travelers or people with occupational risk are advised to consult a healthcare provider about preventative measures. There is currently no commercially available vaccine against leptospirosis for human beings but scientists are working on preventative antibiotics that will save many lives. These diseases are everywhere and there are ways to prevent them.


Bandino, J. (2015). The Infectious and Noninfectious Dermatological Consequencesof Flooding: A Feild Manual for the Responding Provider . American Journal of Clinical Dermatology, 399-424.

Health, C. (2017, October 12). Puerto Rico Investigates Post-hurricane Disease Outbreak. Retrieved from CBS News:

Hurtado, C. (2017, October 19). The Growing Risk of Leptospirosis in Puerto Rico. Retrieved from Outbreak Observatory:

Rettner, R. (2017, October 25). What is Leptospirosis? Dozens of Cases Suspected In Puerto Rico. Retrieved from Live Science: