At the Bern GP Day, Prof. Dr. med. Hansjakob Furrer from the University Clinic for Infectiology at Inselspital used three examples to show when empirical antibiotic therapy is indicated without pathogen detection, in which cases cultures should be taken, and when it is worth waiting until the pathogen is known.
(rs) In the first case, the topic was: wait or treat empirically? This question was answered by Prof. Dr. med. Hansjakob Furrer, interim chief physician at the University Clinic for Infectious Diseases at the Inselspital in Bern, using the case of a 23-year-old female patient who presented to her family doctor in the 22nd week of pregnancy with burning during urination. Urine status shows cloudy color and mild leukocytosis (250 leukocytes/μl), nitrite is positive. The diagnosis would be made quickly in a non-pregnant woman: The patient suffers from an uncomplicated urinary tract infection. “This would allow both: watchful waiting or empirical treatment ex juvantibus (without pathogen detection),” Prof. Furrer said at the Bern GP Day. Since it is a complicated urinary tract infection due to pregnancy, therapy is indicated. To do this, it is important to know the most common pathogens, their resistance levels, and the appropriate antibiotics. The general practitioner opts for empiric treatment with amoxicillin/clavulanic acid, which is correct with regard to pregnancy.
Case 2: Multi-resistant germs
Four days later, the woman is hospitalized with a reduced general condition, fever, and chills. The laboratory shows a left shift. The burning sensation during urination persists. “We are seeing more and more cases like this, where the usual antibiotic treatment is not working,” Prof. Furrer explained, referring to the local resistance overview published annually on the Inselspital website. This showed for 2013 that about 25% of infections caused by E. coli and about 15% by Klebsiella pneumoniae were not treatable with amoxicillin/clavulanic acid. “If there are symptoms of a severe infection or an increased risk for a severe course of infection, it is imperative that cultures be taken,” the infectiologist said. Once the antibiogram is available, antibiotic therapy must be targeted to the pathogen.
In the case of the young woman, it was urosepsis due to multidrug-resistant ESBL(“extended spectrum beta-lactamase”)-producing intestinal bacteria. In the most common cases, these are gram-negative bacteria such as E. coli and Klebsiella, which are resistant to β-lactam antibiotics such as penicillins and cephalosporins. In Switzerland, less than 5% of the population are currently carriers of multidrug-resistant ESBL intestinal bacteria. After a trip to South Asia, the proportion can rise to about 90%, unpublished data showed. “As long as those affected don’t need antibiotics, it’s not a problem,” the infectiologist said. It becomes dangerous when sufferers are given a first-line β-lactam antibiotic, because multidrug-resistant germs then take over in the gut. If these then lead to an invasive infection, there is a risk of sepsis with pathogens that are difficult to treat.
The case of the young woman ended smoothly. Targeted antibiotic therapy with a carbapenem successfully treated the urosepsis.
Case 3: Cerebral toxoplasmosis
Among the cases in which empiric antibiotic treatment should not be started was the subsequently presented 50-year-old man with an artificial mitral valve who had been suffering for days from an increase in word-finding and balance disorders and partial fascial paresis.
Based on a contrast MRI, a brain abscess is strongly suspected. Because the risk of acute exacerbation is low, infectious disease specialists recommend waiting to start antibiotic treatment until the causative agent is known or safe diagnostic material has been obtained. A subsequent biopsy of the abnormal foci leads to a surprising result: the affected person suffers from cerebral toxoplasmosis. Prof. Furrer used the case study to point out that more than 52% of HIV patients in Switzerland are so-called “late presenters”, i.e. already suffering from an AIDS-defining opportunistic infection at the time of diagnosis. This is despite the fact that, according to one study, about 75% of those affected had symptoms suggestive of the disease in the year prior to diagnosis and the same number visited a doctor at least once a year. “If diagnosed early enough, HIV-infected individuals today have a near-normal life expectancy,” Prof. Furrer said. In addition, many infections could be prevented, since HIV-infected people who have been successfully treated with antiretroviral drugs hardly ever transmit the HIV infection anymore.
Source: Bern GP Day, March 13, 2014, Bern
HAUSARZT PRAXIS 2014; 9(6): 44-45
