As scientists gain better understanding of the disease, cures evolve too.
Cholera is incredibly rare in the United States, but the disease remains a public health risk around the world. This summer, there have been cholera outbreaks in the Democratic Republic of Congo and Yemen. According to the World Health Organization, there are between 1.3- and 4-million cholera cases worldwide annually, with 21 thousand to 143 thousand people dying from the disease.
Cholera is caused by waterborne bacteria Vibrio cholerae and is spread through unsafe food and water contaminated by human feces carrying the bacteria. Only humans are affected by the disease. Spread for centuries, cholera and its causes weren’t identified until the 19th century. As scientists gain a better understanding of the disease, technology helps curb its spread.
Here are seven inventions helping stop the spread of cholera.
Sari: The traditional Indian draped garment goes back to at least 1800 BCE, but in modern times the sari can be used to prevent cholera. In Bangladesh, women filter surface water through sari cloth to keep bugs and leaves out. However, research shows a four-layer sari filter holds back over 99% of cholera bacteria.
Microscope: In order to fight cholera, scientists first had to understand what caused cholera. While the microscope was invented in 1660, it wasn’t until the mid-1800s that scientists used it to understand the disease. During the Asiatic Cholera Pandemic, Italian anatomist Filippo Pacini used his microscope to first isolate and identify the bacterium Vibrio cholerae. Unfortunately, Pacini’s discovery wasn’t well known; but in 1883, German physician Robert Koch used his microscope to identify V. cholerae as the cause of the disease.
Dry Toilet: In areas where the water supply is limited, dry toilets are very helpful in the fight against diseases like cholera. As the name implies, dry toilets are not connected to a water source, which helps to keep fecal material from tainting the water supply. Dry toilets can be as simple as outhouse latrines far from water sources or more complex designs like composting toilets, which turn human waste into fertilizer. Following the English cholera epidemics of 1849 and 1854, English priest Henry Moule was inspired to invent a dry toilet, while in the 21st century, the United Nations have used urine-diverting dry toilets following a cholera outbreak in Haiti.
Ringer’s lactate solution: In the 1880s, British physician Sydney Ringer created a saline solution used to help people with dehydration. In the 1930s, American pediatrician Alexis Hartmann added sodium lactate to Ringer’s solution to create what has since been called Ringer’s lactate solution. Ringer’s lactate solution is now a commonly used intravenous fluid and is often used to help people who are suffering from cholera related dehydration.
Cholera vaccine: In 1885, Spanish physician Jaime Ferrán developed the first vaccine for cholera and used the vaccine to immunize more than 30 thousand people during an outbreak in Valencia, Spain. The vaccine has evolved over the years, and in the 1990s oral cholera vaccines first made their debut. In 2016, the Food and Drug Administration approved a single-dose oral vaccine called Vaxchora for people who are traveling to areas where cholera is common.
Toilet Tracker database: Collecting and plotting data has been a part of the fight against cholera since John Snow identified the source of an outbreak in London in 1854. Snow used a dot map of cholera cases to discover all the deaths came from near the same well. In 2017, Water & Sanitation for the Urban Poor developed a database to track the fullness of pit latrines in the Kanyama district of Lusaka, Zambia. By using this database, government sanitation organizations can track which latrines need the most attention and can clean them out. Cleaning these latrines out before the rainy season hits prevents waste from flooding into the water supply. WSUP has also worked on a mobile app that will help officials and Lusaka residents keep track of pit emptying progress.
“Cholera detection lab” smartphone-enabled platform: Admittedly, this is still in the beta phase and hasn’t stopped any cholera outbreaks yet, but it does show what the future can bring. In July 2019, Purdue University announced an affiliated startup, OmniVis, had teamed up with the International Centre for Diarrhoeal Disease Research, Bangladesh to create a “cholera detection lab” smartphone-enabled platform. The still unnamed technology uses disposable test kits and modern technology to test water samples for cholera. The startup claims the technology can detect cholera in 30 minutes, rather than the typical three to five days.
Michael Darling is a journalist in Los Angeles.