{"id":33154,"date":"2026-03-27T10:16:55","date_gmt":"2026-03-27T14:16:55","guid":{"rendered":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/?p=33154"},"modified":"2026-04-15T14:44:18","modified_gmt":"2026-04-15T18:44:18","slug":"spring-2026-disease-detective","status":"publish","type":"post","link":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/spring-2026-disease-detective\/","title":{"rendered":"The Disease Detective"},"content":{"rendered":"\n\n\n\n\n
.<\/p>\n\n\n\n Glory Kidimbu investigates the transmission of<\/em> parasitic pathogens to waterways.\u00a0<\/em><\/p>\n <\/div>\n<\/blockquote>\n\n\n\n For centuries, people have brought plants and animals to new places, intentionally or unintentionally. Sometimes these new species harm the surrounding environment, jeopardizing the health of other plants and animals, or even creating human health risks.<\/p>\n\n\n\n Freshwater golden clams (Corbicula fluminea<\/em>) came to North Carolina in the early 1970s, likely from the West Coast, where fishers have cultivated them for bait since the late 1930s. Today golden clams inhabit streams and lakes across our state. Although it isn\u2019t entirely clear how the clams came to the United States, according to the U.S. Fish and Wildlife Service, their presence is the result of human action.<\/p>\n\n\n\n Golden clams are an eco-harmful species because they outcompete other clams for food and space. However, \u201cthey also have a history of being bioindicators <\/em>for human pathogens,\u201d says East Carolina University’s Glory Kidimbu, a Mountains to Sea Fellow with North Carolina Sea Grant and the NC Water Resources Research Institute. Bioindicators are living plants, animals, and microorganisms that can be used to screen and monitor the health of an ecosystem.<\/p>\n\n\n\n Clams and other bivalves \u2014 such as oysters, mussels, and scallops \u2014 eat by drawing water into their gills, trapping plankton and algae. Because they are constantly and nondiscriminately taking in water, the health of clams is an indicator of the health of the surrounding ecosystem.<\/p>\n\n\n\n In the past, scientists have used golden clams to indicate if viral pathogens are present in the water, such as Avian Influenza. Kidimbu is currently investigating their potential for tracking parasitic pathogens as well.<\/p>\n\n\n\n Specifically, Kidimbu is investigating the parasites Cryptosportum parvum<\/em> and Toxoplasma gondii<\/em> in the water and soil that golden clams inhabit, as well as in the clams themselves. Both parasites are protozoa \u2014 animal-like, single-celled organisms that live in and survive off a host organism. Although C. parvum<\/em> and T. gondii<\/em> are relatively common on land, storms and floods sometimes carry these parasites into waterways.<\/p>\n\n\n\n Both parasites can bring human health risks.<\/p>\n\n\n\n C. parvum<\/em> causes the infection Cryptosporidiosis (\u201ccrypto\u201d). According to the Cleveland Clinic, there are an estimated 700,000 Crypto cases annually in the United States. Symptoms include low fever, nausea, diarrhea, stomach pain, and other gastrointestinal symptoms that often resolve on their own in healthy adults. Children and immunocompromised adults are at greater risk for severe and prolonged symptoms.<\/p>\n\n\n\n T. gondii<\/em> causes toxoplasmosis (\u201ctoxo\u201d), which often has no symptoms, although healthy adults may experience mild flu-like symptoms, such as fever, swollen lymph nodes, and muscle aches. Even if the symptoms go away within a few weeks, T. gondii<\/em> stays in the body in an inactive state, and the infection can reactivate in a weakened immune system. According to the Centers for Disease Control and Prevention (CDC), over 40 million people are infected with toxo in the United States.<\/p>\n\n\n\n One of the greater dangers of toxo is for a mother during or just before becoming pregnant, in which cases the parasite then can transfer to the fetus and cause infection. According to the CDC, this raises the risk of miscarriages, still-born children, and physical complications for newborns, as well as vision loss, seizures, and mental disabilities later in life.<\/p>\n\n\n\n Previous researchers have found DNA of both C. parvum<\/em> and T. gondii<\/em> in various aquatic animals, but how these animals become infected is still unclear. Kidimbu is investigating whether golden clams can provide the much-needed answers about the origins of these pathogens and their transmission in aquatic environments.<\/p>\n\n\n\n \u201cThere are definite hosts, such as cats for toxo,\u201d she says. \u201cBut these hosts are not living in the water or interacting with aquatic wildlife. So, what we are trying to figure out is what is causing this. What is the connection between terrestrial and aquatic transmission of pathogens?\u201d<\/p>\n\n\n\n On land, these parasites spread through the consumption of improperly prepared, contaminated meat, or by coming in contact with feces from an infected animal. Kidimbu\u2019s hypothesis is that precipitation, which is becoming more intense and more frequent in North Carolina, is washing higher concentrations of contaminants into the lakes and rivers, causing an accumulation of these parasites. Because \u201cgolden clams are able to reproduce really fast, and filter water really fast,\u201d she adds, the clams could show if pathogens are present and also explain the spread of the parasites.<\/p>\n\n\n\n Currently she is sampling across the Tar-Pamlico watershed. The results are still preliminary, but she has seen positive results for C. parvum<\/em> in soil, water, and clams. However, her results for T. gondii <\/em>have been a bit more perplexing.<\/p>\n\n\n\n \u201cWe\u2019ve only seen it in a soil sample,\u201d says\u00a0Kidimbu. She calls it a \u201cpicky pathogen,\u201d because it tends to accumulate in low concentrations and in localized areas. \u201cThis doesn\u2019t mean that T. gondii<\/em> isn\u2019t present, but rather that we simply need to take a lot of samples to know anything for sure.\u201d However, even in low concentrations, exposure to T. gondii<\/em> can result in symptoms of an infection.<\/p>\n\n\n\n \u201cObviously, we can\u2019t collect the entire Tar-Pamlico watershed,\u201d joked Kidimbu. \u201cSo, we are looking to do some in-lab experiments for T. gondii<\/em>.\u201d She says she plans to \u201cspike\u201d water with T. gondii<\/em> in the lab and test if the clams host this parasite, like they are able to host C. parvum<\/em>.<\/p>\n\n\n\n \u201cWe are testing whether the clams can filter the parasite and if the clams are able to retain that parasite,\u201d she explains. \u201cOnce we have confirmed answers to those questions, we can better gauge what could be the reason for these low positive environmental samples, especially since there are<\/em> cases of other species of aquatic wildlife being infected with toxo.\u201d<\/p>\n\n\n\n If golden clams prove to be a reliable source of information on new patterns of transmission for the parasites, the clams could be useful in creating new surveillance efforts to protect the health of humans, wildlife, and the environment.<\/p>\n\n\n\n \u201cAs we are seeing more emerging pathogens, it raises the question of how we can better protect ourselves,\u201d says Kidimbu.<\/p>\n\n\n\n Water quality experts often test for a single pathogen or, as she says, \u201ca certain amount of concerns. But a lot of emerging pathogens are not tested for because they are emerging and often understudied.\u201d<\/p>\n\n\n\n Kidimbu emphasizes that this study is more than an investigation of emerging pathogens but is also a look at how human activity \u2014 such as introducing new species like golden clams \u2014 and shifts in the environment can have a direct impact on changing how pathogens spread through our communities.<\/p>\n\n\n\n \u201cEnvironmental health is connected to both animal health and human health,\u201d says Kidimbu. \u201cWhen one part of this triad is being negatively impacted, it impacts the others. What you do isn\u2019t isolated. So, it is important to be intentional.\u201d <\/p>\n\n\n\n More<\/strong> on cryptosporidiosis<\/strong><\/a><\/p>\n\n\n\n
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<\/a>Parasitic Pathogens<\/h4>\n\n\n\n
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<\/a>From the Land to the Water<\/h4>\n\n\n\n
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<\/a>Human Origins<\/h4>\n\n\n\n