Doctors Kimberly and Matthew Dickson, the married couple who own and run South Bay Urgent Care near Imperial Beach, have identified an unsettling pattern affecting the health of those living near South County beaches.
After rainstorms or malfunctions with wastewater treatment equipment, the amount of sewage-linked bacteria in the water increases. Days later, they observe that the number of people they treat for gastrointestinal symptoms also jumps.
“You can see, clearly, the correlation,” said Matthew Dickson. “The scary thing is these people hadn’t eaten something unusual, hadn’t traveled to other countries, or gone swimming in the ocean.”
The Dicksons suspect that these symptoms are caused by E. coli bacteria and other bacterial infections connected to wastewater spills, but they cannot say for sure because so few patients are getting tested.
Infections that are not confirmed with testing cannot be reported to the local public health department, potentially masking the true health impact of sewage pollution on tens of thousands of South Bay residents. The Dicksons hope that the information they are compiling will trigger a swift response from public health agencies to start testing and documenting cases.
“There has to be the will and the desire to get that done,” said Kimberly Dickson. “I almost feel like we’re sitting on something and nobody’s doing anything about it. It’s almost like Flint, Michigan. We know there’s a health problem, it’s related to an environmental issue and we need help.”
To detect bacteria in someone’s system, the Dicksons have taken the traditional route: ask patients to collect a stool sample at home and return it for a diagnosis. Many people have chosen to skip the process due to its overall ick factor, they said. So, the doctors changed their methods, instead asking those with symptoms such as diarrhea to use a swab to collect a targeted sample while they’re still in the doctor’s office.
Of three polymerase chain reaction tests performed in the last month, one came back positive for Shigella and one for E. coli, they said. PCR tests work by targeting and amplifying unique sections of a pathogen’s genetic code
“In the research world, one out of three (cases of E. coli) isn’t enough to make a study,” said Matthew Dickson. “But we just started. It’s going to be really interesting to see what happens when it starts raining.”
Though South Bay has seen an increase in the symptoms of bacterial illness that correlates with wastewater releases, local public health reports have not shown similar increases.
The region’s most recent monthly communicable disease report published by the county public health department lists 20 reported cases of Shiga toxin-producing E.coli in September, three more than were detected in August and 144 total from January through September. That’s slightly less than the number recorded during the same period in 2022.
The trend was similar for shigella, vibrio and salmonella.
Scripps Health provided positive results for its entire system, and year-over-year results for August and September this year, when Tropical Storm Hillary caused a large wastewater release, were roughly similar to the same period in 2022. But numbers increased by 50 percent in October when compared to 2022 totals with shiga toxin jumping from 1 in 2022 to 13 in 2023.
Sharp Health, which also operates a hospital in South Bay, said it has seen no spike in the numbers in its hospitals.
But only the most-severe cases end up in hospitals or emergency departments. And, in addition to a reluctance to participate in traditional stool sample-collection methods, which most find unpleasant, there is another fundamental reason why many with diarrhea never get tested.
As guidance from the U.S. Centers for Disease Control and Prevention attests, many such symptoms may be caused by viral infections. Testing is generally only indicated if there are additional symptoms that hint at the presence of a pathogenic bacteria. Those symptoms include blood in stool, fever, severe abdominal pain and prolonged diarrhea.
Generally, most patients who arrive in a doctor’s office with diarrhea alone, said clinical microbiologist Ian McHardy, never get tested because additional symptoms that may indicate a bacterial infection are not present.
McHardy, who directs microbiology and core laboratory services at Scripps Health, guessed that only about 10 percent of such cases are tested. Generally, if a virus is the cause, the test will not help treat the patient, so it is not ordered.
“The clinician is saying, ‘Am I going to do anything with that result?’” McHardy said. “If the answer is no, they’re probably not going to order that test because insurance companies don’t tend to pay for this type of testing, so it will ultimately come out of the patient’s pocket.”
But the Dicksons say that the fact that many living in South Bay are regularly exposed to polluted wastewater argues for a broader testing program aimed less at the treatment of individuals and more at understanding the true impact of such exposures.
Given that standard-of-care testing guidance often does not call for the identification of the specific cause of symptoms such as diarrhea, they argue that the local public health department should step in.
The South Bay Urgent Care in San Diego.
(Ana Ramirez / The San Diego Union-Tribune)
The Dicksons also note that nearly 12 percent of the estimated 500,000 South County residents do not have a place to go when feeling ill or needing medical advice, according to the county’s Health and Human Services Agency. South Bay Urgent Care, on Palm Avenue, is the primary care for many local residents. Its services are often the most accessible and affordable options for people.
“We’re gonna miss a lot of people if we don’t start changing how we’re looking at this,” Matthew Dickson said.
“Let’s start doing some more testing,” he added. “Are you having asthma problems? Are you having gastrointestinal problems? Are you having skin and soft tissue issues? And do you feel it’s either associated with the air or exposure to the water?”
The county public health department said in a brief statement that it has been in contact with South Bay Urgent Care but reiterated previous statements that it has not observed a significant enough increase in activity to warrant increased action.
“The county has not seen a rise in gastrointestinal illness in emergency departments, but does continue to monitor and take all concerns seriously that are brought to us, such as was the case in early October with this South Bay Urgent Care Clinic,” a county spokesman said in a written response.
Imperial Beach Mayor Paloma Aguirre said that even just a few documented cases of bacterial illnesses in a community where its beach waters are contaminated and the air sometimes wreaks of sewer gas, is more than enough cause for concern and prompt action.
“It’s alarming,” she said. “We need more help. We need more funding. We need more focus, both at the regional level from our county health department, but also the California Department of Public Health and maybe even the Centers for Disease Control and Prevention.”
Data matters, the Dicksons said, who are working with UC San Diego researchers to better understand the public health ramifications of cross-border pollution. Here’s part of what they have found so far.
More poop, more illnesses
Three events this summer prompted the South Bay doctors to get a side-by-side view of the county’s water testing data and the cases of patients stopping by their urgent care center feeling ill.
The first was Tropical Storm Hilary, which made landfall in San Diego in August. Then the boil water advisory that was issued Aug. 24-26 after a sampling location in Imperial Beach tested positive for E. coli. Thirdly, a sediment buildup at the Hollister Street pump station in the Tijuana River Valley resulted in more than 20,000 gallons of sewage spilling onto the road on Aug. 28.
The county warns of potential sewage contamination in the water when tests show levels of Enterococcus above 1,413. Enterococci are bacteria found in the gut of warm-blooded animals, including humans, and can indicate that fecal matter is present in water. Sources of this bacteria include wastewater treatment plant effluent, stormwater runoff and sewage discharge, according to the U.S. Environmental Protection Agency.
A month before the storm, levels of Enterococcus near the Imperial Beach shoreline managed to stay well below 500. But four days after Hilary and through mid-September, levels gradually increased, reaching as high as 2,000 on Sept. 5.
Simultaneously, cases of diarrhea and gastrointestinal illnesses jumped.
South Bay Urgent Care has typically seen an average of 5 people per week suffering from diarrhea. But four days after the storm and through September, the average was 35. Gastrointestinal illnesses peaked at 105 on Aug. 28, compared to less than 50 in early July.
A similar scenario played out earlier this year. A major pipeline south of Tijuana ruptured and caused millions of gallons of raw sewage to spill into San Diego for several days starting Feb. 10. Shorelines as far north as Coronado shut down thereafter.
By Feb. 19 and through the first week of March, South Bay Urgent Care was seeing anywhere between 26 to 37 people with diarrhea per week.
“We get more poop in the water, more people are getting sick,” said Matthew Dickson.
“These are people that aren’t necessarily out swimming in the ocean,” Kimberly Dickson added. “These are people out in the community. So, that was the concerning part.”
Renee Archuletta, who lives about one mile from the ocean in Imperial Beach, is among many who reportedly got ill days after Tropical Storm Hilary struck the area with 2 billion gallons of rainwater laced with sewage. She decided to ride out her “painful and disgusting” symptoms at home but suspected she had an E. coli infection.
The Dicksons are calling on the county to help them test more people the way it did during the COVID-19 pandemic with pop-up test sites.
“When COVID testing started, guess what? We found a lot of COVID,” said Matthew Dickson. “So, same concept.”
They hope that more data will reveal the true short- and long-term health effects the sewage crisis has had on people.
“When people are getting sick, I don’t have anything to tell them,” said Matthew Dickson. “I can tell them to stay out of the ocean when the bacteria counts are high but … people are getting sick despite that.”
One state agency has joined the call for more to be done after officials visited South County last month to see and hear directly from those affected by cross-border pollution. Alarmed with what they had heard, including from the Dicksons, the California Coastal Commission agreed last week to request that the county start conducting epidemiological tests.
“I went up to my (hotel) room and I opened the door because I figured, I’m just gonna stand out here and just breathe the ocean air,” said Chair Donne Brownsey about the Commission’s visit to Imperial Beach. “And all I could smell was poop. … This is what (residents) talked to us about all day long. … I’ve never been to a coastal community where if there’s a beautiful beach, that I haven’t walked on it. And I didn’t walk on this beach.”
The Dicksons said they will soon start tracking cases of asthma and overlaying them with data UCSD atmospheric chemist Kim Prather is collecting. She recently published a study that found sewage-linked bacteria in waters off Imperial Beach are becoming airborne. The doctors plan to do the same with data collected by newly installed air monitors, which already have detected levels of wastewater gases above state thresholds.
