swimmer's itch: what causes this neglected snail-borne disease?
Field study in the outbreak area. Credit: Professor Dr. Duangduen Krailas

Cercarial dermatitis, also known as swimmer’s itch or clam-digger’s itch, is caused by the larvae of blood flukes that are parasites of birds or mammals. When these larvae, called cercariae, penetrate human skin, they trigger an allergic reaction within 10-15 hours that takes about a week to heal. Unable to mature into adults, the larvae then die on the skin. The gravity of an outbreak depends on how humans and birds or mammals come in contract with the aquatic environment, but people engaged in water activities, such as farmers, fishermen, and agricultural workers, are most likely to be affected.

Between August and October 2020, a cercarial dermatitis outbreak with 359 confirmed cases occurred in Chana district, Songkhla Province, South Thailand. It mostly affected rice farmers from the area, who were busy with cultivation during the rainy season. Following a short investigation, three cases of patients were confirmed to be cercarial infections by skin biopsy (Bureau of Epidemiology, Department of Disease Control, Ministry of Public Health, Thailand).

“The study of intermediate host and definitive host in the outbreak area are important for the control program of snail-borne disease,” the researchers argue in their research paper, which was published in the open-access scientific journal Evolutionary Systematics.

Having studied six snail species from the area, they found out that two were infected, each with three different species of flatworms. The cercarial dermatitis outbreak was due to ruminant parasites, such as the blood fluke Schistosoma indicum, which often uses domestic animals as its host.

swimmer's itch: what causes this neglected snail-borne disease?
Collected snails from five locations of the cercarial dermatitis outbreak area. Credit: Professor Dr. Duangduen Krailas

“Ruminant-infecting trematodes, namely, S. indicum and S. spindale, cause a hepato-intestinal schistosomiasis resulting in reduced milk yield,” the authors explain. “This occurrence of S. indicum and S. spindale implies the spread of cattle blood fluke cercariae in aquatic environments.”

“Additionally, these species of the S. indicum group primarily cause cercarial dermatitis in humans, which has become an important public health issue for people living in endemic regions.”

swimmer's itch: what causes this neglected snail-borne disease?
Location of the outbreak area. Credit: Professor Dr. Duangduen Krailas

“In South India and Southeast Asia, where S. indicum and S. spindale have been reported to be widespread, they caused major pathology and mortality to livestock, leading to welfare and socio-economic issues, predominantly among poor subsistence farmers and their families.”

Some of the other worm species they found parasitized the intestines of fish, mammals, or birds, while others caused anemia and even death in ruminant animals.

swimmer's itch: what causes this neglected snail-borne disease?
Cercarial dermatitis cases from Chana district, October 2020. Credit: Professor Dr. Duangduen Krailas

“The results of this study will provide insights into the parasite species that cause cercarial dermatitis and may improve our understanding of public health problems in the outbreak and agricultural vicinity areas,” the authors of the study say. “In addition, the sequence data generated here are the first S. indicum DNA sequences from Thailand, which will be useful for further genetic study of the other blood flukes in this region.” More information: Duangduen Krailas et al, Cercarial dermatitis outbreak caused by ruminant parasite with intermediate snail host: schistosome in Chana, South Thailand, Evolutionary Systematics (2022). DOI: 10.3897/evolsyst.6.87670 Provided by Pensoft Publishers Citation: Swimmer’s Itch: What causes this neglected snail-borne disease? (2022, September 14) retrieved 14 September 2022 from https://phys.org/news/2022-09-swimmer-neglected-snail-borne-disease.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Keyword: Swimmer's Itch: What causes this neglected snail-borne disease?

TECH'S NEWS RELATED

Man City vs. Man United Livestream: How to Watch Premier League Soccer From Anywhere

Looking to catch the Manchester derby? Here's everything you need to watch Sunday's Premier League game.

View more: Man City vs. Man United Livestream: How to Watch Premier League Soccer From Anywhere

Bad Dental Health Linked to a Greater Risk of Dementia

Tooth loss alone was linked to a 13% higher risk of dementia. New research indicates tooth loss and poor periodontal health could raise the risk of both cognitive decline and dementia. According to a review of all relevant studies in the medical literature, having poor periodontal health and losing ...

View more: Bad Dental Health Linked to a Greater Risk of Dementia

Dimensity 9000+ beats all Snapdragon processors on AnTuTu

AnTuTu most powerful smartphones: Dimensity 9000+ beats all Snapdragon 8+ Gen 1 smartphones Gizchina News of the week AnTuTu has today published the list of the most powerful Android smartphones for September in China. The Dimensity 9000+ SoC outperformed all Snapdragon processors and topped the ranking. So, according to ...

View more: Dimensity 9000+ beats all Snapdragon processors on AnTuTu

50 Years of Searching – Promising Treatment for Chagas Disease Discovered

Chagas disease is a potentially fatal illness caused by the protozoan parasite Trypanosoma cruzi. Tens of millions of people in the Americas are affected by the condition, yet there are no effective treatments. Researchers at the University of Georgia have identified a potential treatment for Chagas disease, marking the first ...

View more: 50 Years of Searching – Promising Treatment for Chagas Disease Discovered

Chinese billionaire Richard Liu settles civil suit over alleged rape in US a day before the JD.com founder was to face trial

Chinese tech billionaire Richard Liu Qiangdong has reached a settlement with former University of Minnesota student Liu Jingyao, who accused the JD.com founder of rape in 2018, a day before a jury trial was to start in Hennepin County District Court in the state of Minnesota. “The incident between ...

View more: Chinese billionaire Richard Liu settles civil suit over alleged rape in US a day before the JD.com founder was to face trial

JD.com Founder Richard Liu Settles Rape Allegation Ahead of Trial

The 2018 Rape Case Allegation JD.com After the Incident Richard Liu, the founder of the JD.com e-commerce company, arranged a settlement with Liu Jingyao, the Minnesota college student who accused the Chinese billionaire of rape back in 2018. The settlement happened less than 48 hours before the scheduled US ...

View more: JD.com Founder Richard Liu Settles Rape Allegation Ahead of Trial

Nobel season is here: 5 things to know about the prizes

A national library employee shows the gold Nobel Prize medal awarded to the late novelist Gabriel Garcia Marquez, in Bogota, Colombia. The beginning of October means Nobel Prize season. That is when committees in Stockholm and Oslo announce the winners of what many consider the most prestigious awards in ...

View more: Nobel season is here: 5 things to know about the prizes

Tesla robot walks, waves, but doesn't show off complex tasks

Tesla Motors, Inc. CEO Elon Musk speaks at the Paris Pantheon Sorbonne University as part of the COP21, United Nations Climate Change Conference in Paris on Dec. 2, 2015. An early prototype of Tesla Inc.’s proposed Optimus humanoid robot slowly and awkwardly walked onto a stage, turned, and waved ...

View more: Tesla robot walks, waves, but doesn't show off complex tasks

Firefly Aerospace reaches orbit with new Alpha rocket

Powerful earthquake shakes Indonesia's Sumatra, kills 1

Behind C919: China's path to first self-developed large passenger aircraft

iPhone 14 Pro has the best selfie camera on a smartphone, according to DxOMark

NASA’s Ingenuity Helicopter Spots Foreign Object Debris on Mars

MediaTek, Invendis join hands for 5G, Wi-Fi router solutions

NASA Updates Crew Assignments for First Boeing Starliner Mission to Space Station

Google Pixel 7, Pixel 7 Pro pre-orders in India kicks off on October 6

China's Shenzhou-13 taikonauts to conduct second spacewalk on Sunday

Exclusive interview: China's C919 features safety, comfort, efficiency

Samsung launches Galaxy Z Flip 4 in blue in India

Hong Kong start-up archiREEF wants to commercialise 3D-printed tiles, restore corals around the world

OTHER TECH NEWS

;