Health Risks Imposed by the Beach

Written by: Alex Herndon, MD (NUEM ‘21) Edited by: Ashley Amick, MD, MS (NUEM ‘18) Expert Commentary by: Patrick Lank, MD

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With warm weather fast approaching, it’s time to break out the sunscreen and beach gear. Besides protecting oneself from UV rays and heat exhaustion, there are other dangerous pathogens lurking in the sandy shores that are worth being aware of as patients begin to flood the Emergency Department during summer vacation. Here are a few dangerous diseases to consider that masquerade as common chief complaints.  

1. More than just swimmer’s itch 

A 17 year old female presents to the Emergency Department complaining of a patchy skin rash that developed only a couple days after her first swim of the summer. Freshwater lakes house trematode parasites that upon contact leads to cercarial dermatitis, otherwise known as “swimmer’s itch”. Symptoms typically develop 2 days after exposure and last a week. Relief can be easily obtained with antihistamines and corticosteroid cream. [1]

Now consider that same patient is returning from a trip from Key West, Florida for a Bachelorette Party.  You notice that her legs are shaved and there are several small nicks around her ankles.  She is presenting with a worsening red rash on her lower leg that is red, warm, blistering, and in some locations has formed superficial ulcers. While it can be easy to chalk this us to severe sunburn and possible superimposed cellulitis, it is important not to miss this deadly necrotizing skin infection caused by Vibrio vulnificus, commonly known as one of many “flesh-eating bacteria.” Unlike the more benign trematode, V vulnificus can be found in brackish or saltwater, and in North America most commonly in the Gulf of Mexico. [2] V vulnificus infects wounds and leads to skin breakdown and ulceration and if not treated immediately infection has a mortality rate of anywhere from 25-50%. [3] Given the virulence of the disease, it is important to treat early and aggressively. The mainstay treatment for V vulnificus includes intravenous 3rd generation cephalosporins along with a tetracycline such as doxycycline. Source control becomes prudent and may require surgical debridement. [4]

2. “It’s just a cough”

With the warm weather finally here, a 60 year-old retiree began breaking in his paddle board along the shores of Lake Michigan. To cool off afterwards, he would hit the public beach showers. One week later he shows up at the Emergency Department complaining of body aches, low grade fevers, and a cough that won’t quit. While the bacteria Legionella pneumophila is typically associated with hot tubs, don’t forget other warm freshwater places this microbe loves to grow, including beach showers, air-conditioning units, and outdoor misters like those seen at amusement parks and sporting events. [4] People fall ill after inhaling aerosolized droplets from the contaminated sources.

Pontiac fever is a mild form of Legionella infection, presenting as vague flu-like symptoms that typically resolve in 2 to 4 days without treatment. However, the more severe form of infection, commonly known as Legionnaires disease, presents as pneumonia with cough, fever and myalgias. Unlike other bacterial pneumonias, Legionnaires is also more commonly associated with gastrointestinal symptoms like nausea, vomiting, and diarrhea, and can also cause hyponatremia. On average 15% of cases per year have been fatal, thus never forget to start atypical coverage for pneumonia, such as azithromycin, which provides adequate coverage for Legionella infection. [5]  And if Legionella is diagnosed or highly suspected, alerting local health authorities is important because early containment of possible sources, such as public showers, is imperative to preventing a deadly outbreak.

3. Beyond febrile seizures

A 10 year-old boy is sent to sailing camp in Wisconsin.  While he was well upon arrival, after only 3 days his parents get a call that their son has been hospitalized. His camp counselors brought him to the ED after he became febrile and had a seizure a day after capsizing in the lake. They reported throughout the day the boy had been complaining of a headache and was increasingly lethargic. Typically the constellation fever, headache, altered mental status, and seizure heralds bacterial meningitis. However given this child’s unique summer camp experience, one must consider other environmental exposures that pose a risk. 

While rare, warm freshwater lakes can house the deadly Naegleria fowleri, more commonly known as “the brain-eating amoeba.” [6] This amoeba enters via the swimmer’s olfactory nerve, reaching the brain where it causes primary amebic meningoencephalitis (PAM). Patients present within 1 day to 2 weeks after exposure, first with flu-like symptoms including fever, headache and vomiting, that eventually progress to involve hallucinations and seizures. Similar to any patient presenting with symptoms concerning for meningitis, performing a lumbar puncture is key in making the diagnosis. N fowleri can be identified within cerebral spinal fluid either via direct visualization, antigen detection or PCR. While the majority of cases have been fatal, with a fatality rate of nearly 98%, survival is possible if identified and treated early with miltefosine, an anti-leishmania drug. [7]

During these warm summer months it is vital to understand where your patients have been and what they have been doing because knowing those details can end up saving their lives.

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Expert Commentary

Thank you Drs. Herndon and Amick for these wonderful reminders that there are more things to be afraid of at the beach than sharks (and/or Sharknados). While this blog post contains great tidbits on three diagnoses, I think these cases also highlight times when a careful focused clinical history changes the emergent work-up and treatment. These patients could have easily been diagnosed with another condition and had their definitive care delayed, so thank you for these reminders. 

As a native Floridian who grew up within walking distance of the Atlantic Ocean, I think there are a few additional entities for the emergency physician to consider when treating beachgoers. My medical toxicology training is begging me to direct this commentary towards my wheelhouse, but I will resist and will be sure to mention some other diagnoses. 

But to start, I have to bring up intoxication. For those readers who do not live in the Midwest of the United States, I want to make you aware that Chicago has a wonderful series of beaches. Having been working in an emergency department in Chicago for 15 years now, I also have to point out that the number one reason patients are brought to the ED from a beach is for alcohol intoxication. Higher temperatures, increased thirst, increased physical activity, prolonged drinking, and possible co-ingestion of other mind-altering substances all increase the chances that a day at the beach will end in the ED. So be careful, warn your teenage/twenty-something family members, and consider checking an ethanol concentration in altered beachgoers.

The geographic proximity our ED has to the beach and Lake Michigan also means we see a lot of drownings. Some are intentional, others accidental; some are associated with traumatic injuries, others with intoxication; some patients are pediatric, some are geriatric. Despite their variations, all drowning should be taken seriously and involve aspects of resuscitation that are worth reviewing when you get a chance. Although it is now a few years old, I recommend reading the review article “Drowning” by D Szpilman, et al. from NEJM in 2012 (DOI: 10.1056/NEJMra1013317). It’s a great review with some helpful references for people interested in reading more. 

Finally I would recommend anyone working in a clinical environment where the weather is about to turn warmer should review the clinical features and resuscitation of patients with heat-related injuries and superficial burns. When I was a PGY-1 in Chicago and had my first patient check in with a sunburn, I was in complete shock. Why did this person not know homecare for a sunburn? Easy, I thought: lots of aloe, move like a mummy for a day, and bathe in self-loathing and regret. But years of experience in a northern clime have taught me that changes in seasons are particularly dangerous for these injuries – people are out of practice, they forget, or they simply don’t care. No matter the reason, these early parts of the season are when we see big upticks in significant presentations. 

In summary, thank you again for bringing up these infectious complications of having fun at the beach. But if you want to scare some sense into your 15-year-old nephew, don’t only tell him about Naegleria fowleri – please also terrify him with stories of overdoses, drowning, and severe hyperthermia.

Patrick Lank, MD, MS

Assistant Professor of Emergency Medicine

Medical Toxicologist

Department of Emergency Medicine

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How To Cite This Post:

[Peer-Reviewed, Web Publication] Herndon, A. Amick, A. (2021, Mar 15). Health Risks Imposed by the Beach. [NUEM Blog. Expert Commentary by Lank, P]. Retrieved from http://www.nuemblog.com/blog/health-risks-imposed-by-the-beach.

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References

1. Parasites: Cercarial Dermatitis. Centers for Disease Control and Prevention. 2012 January. <https://www.cdc.gov/parasites/swimmersitch/faqs.html>

2. Thompson, H. Eight diseases to watch out for at the beach: “Flesh-Eating” bacteria. The Smithsonian. 2014 August. <https://www.smithsonianmag.com/science-nature/diseases-watch-out-beach-18095234 6/>

3. Horseman, M. Surani, S. A comprehensive review of Vibrio vulnificus: an important cause of severe sepsis and skin and soft-tissue infection. Int J Infectious Diseases. 2011 March: 15(3): 157-166. 

4. Thompson, H. Eight diseases to watch out for at the beach: Pontiac Fever and Legionnaires Disease. 2014 August. <https://www.smithsonianmag.com/science-nature/diseases-watch-out-beach-180952346 /#mftUupdDj 5cwE00L.99>

5. Healthy Swimming: Respiratory Infections. Centers for Disease Control and Prevention. 2016 May. <https://www.cdc.gov/healthywater/swimming/swimmers/rwi/respiratory-infections.html>

6. Thompson, H. Eight diseases to watch out for at the beach: “Brain-Eating” Amoeba. The Smithsonian. 2014 August. <https://www.smithsonianmag.com/science-nature/diseases-watch-out-beach-180952346 /#mftUupdDj5cwE00L.99>

7. Parasites: Naegleria fowleri - Primary Amebic Meningoencephalitis - Amebic Encephalitis. Centers for Disease Control and Prevention. 2017 February. <https://www.cdc.gov/parasites/naegleria/pathogen.ht ml> 

Blood Cultures in Suspected Simple Cystitis vs Pyelonephritis

Written by: Em Wessling, MD (PGY-2) Edited by: Will Ford, MD (NUEM ‘19) Expert commentary by: Justin Morgenstern, MD

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While the Joint Commission historically focused their urinary interests on CAUTI protection, there is room for improvement in how we care for those with community acquired urinary tract infections. In many emergency departments, patients with suspected pyelonephritis are having blood cultures drawn to screen for bacteremia. However, these cultures may be unnecessary and costly for most patients.

The Choosing Wisely campaign from the ABIM Foundation started in 2012 with the goal to reduce “the overuse [of medical testing] that does not add value for patients” (1). In 2015, Choosing Wisely, in collaboration with the Society for Healthcare Epidemiology of America, recommended that blood cultures should not be performed unless there are appropriate symptoms due to false positives leading to over treatment (2).  When looking at emergency department data, the lack of utility of blood cultures in general holds true. A study from Glasgow found that only 1.4% of all blood cultures drawn in the emergency department were true positives. Of these, less than 15% (or less than 0.2% of all cultures drawn) were used to guide clinical treatment, regardless of the suspected source of infection (3). 

Similarly, Choosing Wisely Australia recommends avoiding blood cultures if patients are not systemically septic and have a “direct specimen for culture,” including urine (4). However, researchers in Australia continue to debate if this Choosing Wisely recommendation is based on enough evidence to apply broadly, or if blood cultures would still be useful for specific, more complicated populations. 

In patients with pyelonephritis, we can see that blood cultures rarely add clinical value. In 2017, it was shown that less than 10% of patients who were hospitalized for community acquired acute pyelonephritis had positive blood cultures (5). In the same study, only 2.3% of the cases had differing blood cultures when compared to urine cultures that resulted in a change of care (5).   This was also demonstrated in a review article from 2005 that looked at the utility of blood cultures in immunocompetent, non-pregnant, adult patients and concluded that there was no use for blood cultures in this population (6). Blood cultures also have limited utility in predicting prognosis in patients with pyelonephritis. A recent study from Spain looked at all-cause mortality in pyelonephritis and urinary sepsis patients with bacteremia vs those without and found that here was no change (7). The same prospective study found no significant difference in length of stay and ICU transfers (7). 

Blood cultures do occasionally have a role to play in the treatment of pyelonephritis. While the average person with an uncomplicated UTI or pyelonephritis may not have an indication for blood cultures, there are select populations for whom blood cultures show a distinct benefit. Initially, it was postulated that those groups would include those with instrumentation of the Genito-urinary tract and those who are immunocompromised (6).  Recent studies suggest that blood cultures may also be helpful in patients recently treated with antibiotics, as they are at a higher risk for sterile urine culture but may still have a positive blood culture. Additionally, chronically ill patients may have polymicrobial urine cultures, for whom a single clinically relevant organism may be able to be isolated from a blood culture (8). 

While there is a plethora of research to demonstrate that in pyelonephritis for which a urine cultures is available, blood cultures are often not clinically significant, researchers are still trying to parse out which select groups would benefit from them.

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Expert Commentary

This is an excellent post that clearly comes to the right conclusion: blood cultures are not necessary for most patients with pyelonephritis. (In fact, I think it’s likely that even urine cultures are overused.)

Whenever we order a test, we should consider: how will the results change my management? 

Blood cultures are occasionally used diagnostically (for endocarditis), but pyelonephritis is a clinical diagnosis. The results of the blood culture is not going to change our final diagnosis. Therefore, the only management change we could possible make based on the blood cultures is a change in antibiotics. 

Our initial antibiotics cannot be guided by cultures, but luckily our empiric antibiotics are incredibly effective. There are only a handful of bacterial species that routinely cause urinary tract infections, and we have a handful of commonly used antibiotics, so we choose correctly most of the time. Even when the chosen antibiotic is reported as resistant on the culture, you will frequently find that the patient is better clinically. (In vitro antibiotic resistance is not the same as in vivo resistance.)

Only a small number of patients will have a positive blood cultures. Only a smaller number will have a positive culture demonstrating resistance to the original antibiotic. And an even smaller number will still be sick at the time that the culture is reported. For this small minority of patients, the culture will guide our new antibiotic choice, but considering the limited menu of antibiotics we use for UTIs, we probably could have made the same decision empirically, and we would be right most of the time. (Even in the era of multidrug resistance and ESBL, you should have a general sense of what antibiotics work in your community.)

However, that entire line of logic is unnecessary if you already took a urine culture. (The same line of reasoning can demonstrate why urine cultures are probably also overused, but I will admit that although I never send cultures in simple UTIs, I still send them in pyelonephritis.) Considering that it is the actual source of the infection, the urine culture is far more likely to grow the causative organism. So if you already have a test that will guide your antibiotic change in the case of resistance, the blood culture is completely redundant. It cannot help. So we should stop sending them. 

Justin Morgenstern, MD

Emergency Medicine

Toronto, Canada

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References

1. Levinson, Wendy, et al. "‘Choosing Wisely’: a growing international campaign." BMJ Qual Saf 24.2 (2015): 167-174.

2. Society for Healthcare Epidemiology of America. “Don’t Perform Urinalysis, Urine Culture, Blood Culture or C. Difficile Testing Unless Patients Have Signs or Symptoms of Infection. Tests Can Be Falsely Positive Leading to over Diagnosis and Overtreatment.” Choosing Wisely - An Initiative of the ABIM Foundation, ABIM Foundation, 1 Oct. 2015, www.choosingwisely.org/clinician-lists/shea-urinalysis-urine-culture-blood-culture-or-c-difficile-testing/.

3. Howie, Neil, Jan F. Gerstenmaier, and Philip T. Munro. "Do peripheral blood cultures taken in the emergency department influence clinical management?." Emergency Medicine Journal 24.3 (2007): 213-214.

4. Denny, Kerina J., and Gerben Keijzers. "Culturing conversation: How clinical audits can improve our ability to choose wisely." Emergency Medicine Australasia 30.4 (2018): 448-449.

5. Kim Y, Seo MR, Kim SJ, Kim J, Wie SH, Cho YK, Lim SK,
Lee JS, Kwon KT, Lee H, Cheong HJ, Park DW, Ryu SY,
Chung MH, Pai H. Usefulness of blood cultures and radiologic imaging studies in the management of patients with community-acquired acute pyelonephritis. Infect Chemother 2017;49:22-30.

6. Mills, Angela M., and Suzanna Barros. "Are blood cultures necessary in adults with pyelonephritis?." Annals of emergency medicine 46.3 (2005): 285-287.

7. Artero, Arturo, et al. "The clinical impact of bacteremia on outcomes in elderly patients with pyelonephritis or urinary sepsis: A prospective multicenter study." PloS one 13.1 (2018): e0191066.

8. Karakonstantis, Stamatis, and Dimitra Kalemaki. "Blood culture useful only in selected patients with urinary tract infections–a literature review." Infectious Diseases 50.8 (2018): 584-592.

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How to Cite This Post

[Peer-Reviewed, Web Publication] Wessling, E, Ford, W. (2020, Mar 26). Blood Cultures in Suspected Simple Cystitis vs Pyelonephritis. [NUEM Blog. Expert Commentary by Morgenstern, J]. Retrieved from https://www.nuemblog.com/blog/bcx-cystitis

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