The patient was started on treatment to cover both the normal causes of community acquired pneumonia and other travel related microorganisms. Samples were taken to try and discover the cause of the infection. Benzylpenicillin PLUS Levofloxacin was chosen as this provides the best cover for both Streptococcus pneumoniae (common cause of community acquired pneumonia) as well as Legionnaire’s Disease (uncommon and often related to travel). Later that day the diagnosis was confirmed, the patient did have Legionnaire’s Disease, the Benzylpenicillin was stopped and the patient continued on the Levofloxacin.
The patient, in his late forties, had a history of chronic Hepatitis C infection resulting in severe liver cirrhosis. He presented with a fever and was very short of breath with a dry cough, which had got progressively worse over 2 weeks. A chest x-ray showed patchy bilateral consolidation more marked in the hilar regions. A diagnosis of severe community acquired pneumonia was made and he was started on IV Co-amoxiclav PLUS IV Clarithromycin. Blood cultures, sputum, HIV test and urine for Legionella and Pneumococcal antigens were sent to the microbiology laboratory but these all failed to identify a cause.
I have been asked a question via the Facebook page which I will answer in this week’s blog. Thank you Suraiya for your excellent question which I have repeated below; I hope the discussion gives you the answers you need.
“My understanding has always been that Gentamicin provides mainly Gram-negative cover with some Gram-positive cover (Staphylococcus spp., Streptococcus spp. and maybe Enterococcus spp.) and better Gram-positive cover is provided when combined with a beta-lactam or glycopeptide. I've recently been told that the combination of Aztreonam, Gentamicin and Metronidazole provides a similar cover to Amoxicillin, Gentamicin and Metronidazole which is what we recommend for intra-abdominal infections. What are suitable penicillin alternatives for intra-abdominal infections?”
The patient is a man in his 60s who has chronic obstructive pulmonary disease (COPD), and presented to his Respiratory Physician with a worsening of his respiratory function. The patient has a severe beta-lactam allergy so the Physician started PO Clarithromycin as per guidelines but a week later the patient was no better. At this stage a sputum sample was sent to the microbiology laboratory and the prescription was changed to PO Doxycycline. After a further week the patient was actually a bit worse. The sputum sample showed a heavy growth of Haemophilus influenzae sensitive to Amoxicillin, Doxycycline and Levofloxacin but resistant to Clarithromycin. The Physician decided to admit the patient and give IV Levofloxacin. Two days later the patient was improving and so he was changed to PO Levofloxacin and discharged from hospital to be seen in clinic a week later.
At the clinic visit the patient’s respiratory function had once again deteriorated, and both he and his physician were understandably frustrated by this turn of events. The Physician called the Microbiologist for advice about what to do next.