HACEK Group Infections Follow-up

Updated: Jun 17, 2016
  • Author: Zartash Zafar Khan, MD, FACP; Chief Editor: Burke A Cunha, MD  more...
  • Print

Further Outpatient Care

Relapse may occur during the first 6 months following the end of treatment. Patients should be counseled and observed regarding relapse.


Further Inpatient Care

Careful clinical observation is the most important aspect of monitoring adequacy of therapy in HACEK group infections. Persistent or recurrent fever may be a sign of treatment failure, but it also may be due to hypersensitivity reactions, thrombophlebitis, or sterile embolization. Observe patients closely for signs of complications, such as embolic events or CHF.

Repeat blood cultures every 48 hours until they become negative.

Fever that lasts longer than 10 days after starting appropriate antibiotics should cause concern.

Causes of persistent fever include drug fever, antibiotic resistance, myocardial or septal abscesses, large vegetations that are difficult to sterilize, and metastatic infection (intracerebral mycotic aneurysms).


Inpatient & Outpatient Medications

In general, the entire course should be with intravenous antibiotics. Once the patient is stable and cultures are negative, completing intravenous therapy on an outpatient basis is reasonable. However, even in the outpatient setting, frequent evaluations are necessary to assess for response to therapy and for drug toxicity.

Although little evidence exists to support its use in this setting, ciprofloxacin could be used in oral form in certain circumstances. However, given the lack of evidence, this be reserved for special circumstances and in consultation with an infectious disease specialist. [11]



If HACEK infection is diagnosed early, managing the infection in a center that does not offer cardiovascular surgery services may be possible. However, consider transfer to a health center with complete cardiac and neurological care for any patient at high risk for complications.

If the patient is stable, has good social support, and is afebrile with negative blood cultures, outpatient therapy can then be offered for the remainder of the treatment course.



The risk of endocarditis due to HACEK organisms may be reduced by maintenance of good dental hygiene.

Guidelines for infective endocarditis (IE) prophylaxis prior to dental procedures were updated in 2007. Current recommendations support the use of prophylactic antibiotics for high-risk lesions only.

Antibiotic prophylaxis should be considered before oral/dental procedures in patients with high-risk cardiac conditions. [31]

High-risk conditions include the following:

  • Prosthetic valves
  • Previous bacterial endocarditis
  • Complex cyanotic congenital heart disease
  • Surgically constructed systemic pulmonary shunts or conduits
  • Valvulopathy in cardiac transplantation recipients


Many complications can result from IE, regardless of the causative organisms.

CHF is the complication of IE that has the greatest impact on prognosis. It may develop acutely from perforation of a valve leaflet, rupture of an infected chordae, valve obstruction, or because of sudden intracardiac shunts from fistulous tracts. When it appears more insidiously, CHF usually develops during the first month of therapy. Any deterioration in heart function should be taken very seriously because operative mortality increases dramatically after frank ventricular decompensation.

Neurologic complications, whether from emboli, abscess, hemorrhage, or arteritis, are the most frequent causes of death in patients with IE. Mycotic aneurysms are usually clinically silent until they rupture. Consider performing a magnetic resonance angiogram or cerebral CT scan to look for aneurysm in patients with subacute IE.

Splenic infarctions can occur in more than one third of patients but are often clinically silent.

Septic or bland emboli may reach the lung in right-sided endocarditis. These may cause pulmonary infarction, pneumonia, and empyema.



The prognosis is quite variable, depending on many factors, such as delay in diagnosis, age of the patient, and occurrence of complications. Patients with uncomplicated IE caused by HACEK organisms generally respond well to therapy and have an excellent prognosis. [8]