For infectious disease doctors, it’s part of the job description.
In addition to treating acute and chronic infections caused by bacteria, parasites, fungi and viruses, these specialists treat acute infections of unknown etiologies. Which means they often work as detectives, tracking the clues, doing the research, in order to find the source of the problem. As the long-time director of the Division of Infectious Diseases, Dr. Judy Berger is SBH Health System’s chief sleuth.
“One of the things that I stress to the residents is that when someone has an infection, particularly a bacteria in the blood, we need to find the underlying cause so we treat the obvious problem but also uncover the underlying disease and prevent future issues,” she says. “So the questions are: Why does the person have it? And where is it coming from? Figuring that out is where it all begins.”
In what Dr. Berger calls “a fascinating case because it has so many layers,” she and her infectious disease colleague, Dr. Carol Epstein, saw a 58-year-old man originally from Honduras. He pre-sented in the hospital’s emergency room with an acute infection that featured headaches, fever, chills, neck rigidity, photophobia, and tachycardia, with chronic left ear pain and a recent UTI.
“He comes in pretty sick and he definitely has symptoms of what looks like meningitis although he’s alert and oriented,” says Dr. Berger. “So they treat him in the E.R. with vancomycin, ceftriax-one and steroids. If you think it’s going to be pneumococcus, you’re treating to decrease inflamma-tion and hearing loss.”
Various lab tests are performed. The cbc shows a wbc count of 8600. Blood cultures were ob-tained and a spinal tap done. The tap reveals a white blood cell count of 407 when normal is about 5. The differential shows 99% neutrophils – acute inflammatory cells – which are indicative of possible bacterial meningitis. The protein is high at 308 mg/dL. The most significant finding, however, is a glucose level of 1 mg/dL, when normal is above 40. “The very low glucose is alarming and a dangerous thing to see,” she says. “Although, this could be indicative of other pathogens like TB or fungal infections, everything at this time points to bacte-rial meningitis until proven otherwise.” No organisms grow on the CSF cultures, although the bacteria could be inhibited from growing due to the antibiotic treatment. However, blood cultures are positive for Streptococcus bovis. “So we could stop there with the diagnosis of Strep bovis bacteremia, but Strep bovis is known to cause endocarditis and is associated with colon cancer,” says Dr. Berger. “The next step was to plan the work-up for endocarditis with an echocardiogram, both transthoracic and transesophageal.”
There was another layer though.
“What was unusual was that he had meningitis as well, and I have never seen Strep bovis meningi-tis,” says Dr. Berger. “There was something concerning here. I was curious. So I started to re-search this and found a case series, a group of patients with Strep bovis meningitis. They didn’t have colon cancer, but they did have Strongyloides.”
Dr Epstein quickly ordered the stool exam and Strongyloides antibody. The stool exam is found to be positive for Strongyloides larvae.
Strongyloides is caused by the rhabditid nematode, a roundworm, commonly found in Honduras and other countries in South and Central America, as well as in Africa and Asia. The parasite lar-vae penetrate the intact skin of its human host and migrate to the small intestine where it develops into a female adult worm that lays eggs. The eggs are deposited in the intestinal mucosa. Resulting larvae may invade the GI tract or perianal skin and migrate via the blood to other organs. Bacteria piggyback on the larvae to these other organs including the brain meninges. Untreated infections can result in persistent infection, even after many decades and, in some cases, death, especially in an immunosuppressed individual.
“Not only did he have Strep bovis, but the source from the GI tract was Strongyloides, whose dis-semination caused the meningitis,” she says. Dr. Epstein treated the Strongyloides with Ivermectin for several days, which prevents recurrent infections from the roundworm. This is in addition to treating the Strep bovis.
“Strongyloidis can cause an autoinfection that goes around and around,” says Dr. Berger. “Without treatment the patient can remain infected for a lifetime. He could have come back with something else years from now and somebody might never have found it.
“He was fortunate that he presented in the E.R. within 48 hours and the antibiotics were started immediately. The sooner you start, even within the hour, these antibiotics make a difference in mortality.
“A diagnosis of meningitis was made and treated. The E.R. physician’s job is to make a quick diagnosis and treat it. In ID, our job is to treat the infection but also to be detailed oriented, be curious, be a good detective and look for answers to the underlying problem.”