Individuals with immune-suppression, advanced liver cirrhosis or renal insufficiency should receive a dual pneumococcal vaccination.
Patients with immune-suppression are exposed to a significantly higher risk of severe pneumococcal infections, depending on the kind of immune suppression, with the highest risk after splenectomy. Additional conditions which are associated with immune-suppression such as chronic liver cirrhosis and renal insufficiency or certain anatomical risks (e.g. cerebrospinal fluid leaks or cochlea implants) are predisposing factors for pneumococcal infections. Since 2016, the “STIKO” (the German Commission on Vaccination) recommends a dual vaccination with the 13-valent conjugate vaccine (PCV13) followed by the 23-valent polysaccharide vaccine (PPSV23) 6–12 months later in these patient groups. If the polysaccharide vaccine has been given previously, the conjugate vaccine should not be used before the course of 1 year, to achieve a better immune response. There are specific vaccination schedules for patients after stem cell transplantation. Compared to the polysaccharide inoculum, the conjugate vaccine induces memory cells. Especially for HIV infected individuals, a protective effect of the conjugate inoculum was shown whereas this could not be demonstrated for the polysaccharide vaccine. The 13-valent conjugate vaccine, however, comprises only about 30% of pneumococcal infections in adults, in contrast the 23-valent polysaccharide inoculum about 60–70%. Therefore, the sequential vaccination with both inocula conveys the best protection against pneumococcal infections at the moment [3,4,5,6,7,8].
In case of positive blood cultures with
spp. thorough diagnostics and treatment should be initiated.
Candida spp. are a frequent cause of bloodstream infections und are associated with a mortality of 30–40%. Even a single positive blood culture with Candida spp. is relevant. For the medical treatment, echinocandins are primarily used due to their superior efficacy and their favourable profile regarding adverse events. Fluconazole is not a safe first-line regimen. Treatment duration is at least 14 days starting with the first negative blood culture which should be performed on close follow-up after the first positive culture. After documented clearance of Candida spp. from the blood stream, the therapy can be switched to fluconazole or voriconazole if the causative organism was tested susceptible and the clinical status is stable. In certain cases, oral administration of antifungals is also possible. One of the key factors in the management of Candida spp. bloodstream infections is the identification of the correct focus. Intravascular catheters should be removed immediately. If the Candida spp. bloodstream infection persists for more than 4 days echocardiography should be performed to rule out Candida endocarditis [9,10,11].
Recommendations for the emergency department
In case of suspected meningitis, adult patients should receive dexamethasone and antibiotics immediately after venipuncture for blood cultures and before potential imaging.
Bacterial meningitis is a severe infection with high morbidity and mortality. Every delay in treatment is associated with a worse prognosis. Antibiotics—directly after dexamethasone—should be given as soon as possible after presentation to the emergency department.
Typical symptoms are fever, headache, nuchal rigidity, altered mental status and massive reduction of well-being; the absence of single symptoms including nuchal rigidity, however, does not exclude bacterial meningitis. In suspected meningitis, blood draw and lumbar puncture should be performed immediately. In case of a delay of lumbar puncture (e.g. indication for cranial CT before the procedure), antibiotics should be given before lumbar puncture is performed [12,13,14,15,16].
In case of suspected meningitis a CT scan before lumbar puncture should not be ordered—except for symptoms indicating high cerebrospinal fluid (CSF) pressure or focal brain pathology or in cases of severe immuno-suppression.
Within the diagnostics for bacterial meningitis, a lumbar puncture is of paramount importance in order to confirm the diagnosis, to identify the causative agent and its resistance profile. It is mandatory for an optimal antibiotic therapy. A cranial CT scan before lumbar puncture can delay the application of antibiotics and dexamethasone and is performed too often in daily clinical practice which is not according to current guidelines. Indications for a cranial CT scan preceding lumbar puncture are: (1) focal neurological symptoms, (2) first-time epileptic seizures, (3) massive altered mental status (GCS < 10) or (4) severe immunosuppression.
Patients without one of the aforementioned criteria do not need a cranial CT scan because the detection of abnormalities leading to contraindication against lumbar puncture is highly unlikely.
Severe immunosuppression is defined—among others—as: severe innate immunodeficiency, CD4 cell count < 200/µl, status post allogeneic stem cell or organ transplantation, intensive immunosuppression with two or more drugs, corticosteroid intake of > 0.5 mg/kg/day (prednisolone equivalent) within the last 4 weeks or longer [16,17,18,19,20,21,22,23,24].
In patients with suspected severe infections, a minimum of two pairs of blood cultures should be drawn using separate venipunctures prior to antibiotic therapy—regardless of body temperature. There is no necessity of a minimum time interval in between these blood draws.
Severe infections (e.g. sepsis, septic shock, meningitis, pneumonia, endocarditis) requiring hospital admission are common diseases in emergency departments. For optimal treatment of these severe diseases, knowledge of the causative agent is essential. Bacteremia is frequently associated with a severe course of infection, e.g. concomitant bacteremia is found in about 40% of the cases in pneumococcal pneumonia. Therefore, blood cultures are an important diagnostic tool. Contrary to earlier assumptions, there is no correlation between rising fever and a high bacterial load in the blood. The sensitivity of blood culture diagnostics increases from 73 (one pair of blood cultures) to 90% in case that two pairs of blood cultures are drawn. In suspected endocarditis, three pairs of blood cultures should always be drawn. The time interval between the blood culture venipunctures is not important. However, blood cultures should be drawn at different venipuncture sites in order to be able to recognize contamination easily. The time point of venipuncture is rather secondary and it should not delay the urgent start of antimicrobial therapy [25,26,27,28,29].