One of our favorite tours offered on the island of Oahu is the Manoa Falls Hiking Tour. This is a stunning hike through Manoa Valley’s lush rain forest, ending at a magnificent 100+ foot waterfall. When we finally reach the pay off, and the refreshing water is just a few more steps, I stop. I remind everyone on the tour that they are taking a serious risk by stepping into the “freshwater” stream of the falls. We often witness locals and tourists alike taking photos and videos while in the Manoa valley water, and it sends shivers down my spine. After I explain why, most people agree. As refreshing as that freshwater might look, it may contain a microscopic bacteria called leptospira, which causes the disease- Leptospirosis (Lepto). The Hawaii Department of Health annually monitors reports of Lepto, and encourages people to take preventative measures against contraction. In Hawaii, most common cases of infection have been linked with recreational activities, such as swimming, hiking, camping and hunting. Historically, two-thirds of Hawaii’s leptospirosis cases occur during the warmer months, when there is increased outdoor activity in contaminated streams, ponds, and lakes. Within the past few years, there has been an increase in cases from the Big Island, and it is believed that there are even more cases which do not get reported.Everyone should be aware that wading in freshwater ponds, streams, waterfalls or muddy puddles – or even drinking untreated water– could lead to potential exposure to Lepto.Lepto is transmitted to humans by domestic and feral mammals. Exposure to water or mud contaminated with the urine of infected rodents, pigs, cows or dogs can lead to a person contracting Lepto. Direct contact with tissues or body fluids of infected animals can also be a culprit. The bacteria can potentially enter the human body through the eyes, nose, mouth, or a small cut.The bad news is that the onset of symptoms may range from two days to four weeks after exposure. Symptoms and the severity of the disease is variable. Most mild symptoms are similar manifestations to influenza. Fever, headache, chills, body aches, vomiting, diarrhea, rash, and/or red eyes are all common. However, if left untreated, those infected may develop kidney, liver, blood and nervous system damage. Some cases of Lepto have been fatal, although it is rare with the proper treatment. See a physician right away, if you start to develop any of these symptoms and be sure to include any additional information about your potential exposure to contaminated water, mud, plants or animals. The disease is easily treatable with antibiotics, if caught early on. Lepto symptoms may last from a few days to several weeks, but without treatment, recovery can take as long as several months.While there is currently no human vaccine available for Lepto, there are other ways to prevent infection:
Avoid swimming, wading, or submerging your head in freshwater streams, ponds and waterfalls.
Wear protective clothing, especially when you are gardening in mud or water, wading through standing water; or handling dead animals.
Do not drink stream water without boiling it for at least one minute or chemically treating it.
Be aware of the risk and the symptoms.
This is not to scare you out of the water (Lepto can only survive in freshwater, not saltwater)! We just want everyone to be informed. Again, cases of Lepto are rare, according to the CDC website, and there were only 27 cases in 2015. But, maybe next time you’ll take a second before diving into the tropical stream headfirst for an Instagram pic.