Based on our national and also international guidelines, we would start treatment with hydroxychloroquine and azithromycin (https://eody.gov.gr/wp-content/uploads/2020/03/covid-19-algorithmos-therapeia.pdf; https://www.ema.europa.eu/en/news/update-treatments-vaccines-against-covid-19-under-development). We realised that quite a few women and younger men did not need more than that. Some of those patients could have probably required just azithromycin, a unique broad-spectrum antimicrobial with long intracellular half-life combined with anti-inflammatory properties, or maybe nothing at all. We avoided using hydroxychloroquine in patients with known G-6-PD deficiency, ischaemic heart disease with or without heart failure and macular degeneration (https://newsroom.heart.org/news/caution-recommended-on-covid-19-treatment-with-hydroxychloroquine-and-azithromycin-for-patients-with-cardiovascular-disease-6797342).
In case of intolerance or allergy to macrolides, we started using a similar unique class of antimicrobials, i.e. tetracyclines, most often doxycycline [2].
Overall, 46/49 patients received hydroxychloroquine (2 had known G-6PD deficiency and one with known macular degeneration) and 48/49 received azithromycin.
For more unwell patients on admission, especially with high fever, elevated C-reactive protein (CRP) and ferritin and lobar or multi-lobar infiltrates in addition to the ‘usual’ COVID-19-related interstitial pattern, we used on admission an additional antimicrobial agent approved for community-acquired pneumonia, for example amoxicillin with or without clavulanate or ceftriaxone.
For patients with significant penicillin allergies, we frequently elected to use teicoplanin due to in vitro data about possible direct antiviral activity, already published experience in patients with COVID-19 infection and low rate of adverse effects [3]. We noted that quite a few patients of various ages and both genders with diabetes mellitus seemed to be in need of such a regime and, thankfully, most of them responded well [4].
Overall, 33/49 patients received a 3rd agent for community acquired pneumonia.
We noticed that, despite the regimes used above, a few of our patients exhibited clinical, laboratory and radiological deterioration, most of them between days 7 and 12 from onset of symptoms. They exhibited worsening PaO2/FiO2 ratios, worsening interstitial infiltrates and/or superimposed lobar or multi-lobar infiltrates, indicating possibly a bacterial superinfection. Interestingly, we rarely noticed accompanying hypotension requiring fluid resuscitation or inotropic support, despite continuing most of the patients’ prior medications, especially angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB). Even though we did sent quite a few culture specimens (blood, and sputum) as well as urine pneumococcal and Legionella antigen in many patients, we essentially did not detect bacterial co-pathogens, except for a few instances of Candida in the sputum, which is frequently viewed as contaminant.
However, based on the veterinarian paradigm and lack of proven alternative therapeutic guidance or strategy for the deteriorating patient with COVID-19 infection, we started deploying a careful antimicrobial regime escalation strategy on those patients.
We used an ‘escalated’ regime that included broad spectrum agents for healthcare-associated pneumonia, tailored to our local susceptibility data. Examples were either piperacillin-tazobactam or a carbapenem, combined with teicoplanin or linezolid. We did use tigecycline in 1 patient, although one needs to monitor fibrinogen levels after a few days of treatment [5].
In a few patients, we ended up using the ‘escalated’ regime combined with corticosteroids, when the PaO2/FiO2 ratio dropped to 200 or lower but without ‘significant’ lymphopenia (see below).
Additionally, for people with ‘significant’ lymphopenia, which we defined as a total lymphocyte count of 850 per mm3 or lower (back in the AIDS era, this roughly corresponded to a CD4 count of 150 cells per mm3) and respiratory deterioration with a PaO2/FiO2 ratio of 200 or lower, we empirically used, for a few days, what used to be the treatment for Pneumocystis jiroveci pneumonia (PJP) in the AIDS era, i.e. high-dose trimethoprim-sulfamethoxazole and corticosteroids [6]. Trimethoprim-sulfamethoxazole is advantageous as a broad spectrum antibacterial and antifungal agent, while some believe it also possesses direct antiviral and anti-inflammatory properties [7].
Two of our patients presented on days 7–10 of symptoms with ‘unexpected’ oral candidiasis (no risk factors like known immunosuppression or recent antimicrobial use). Interestingly, one of them had symptoms compatible with oesophageal candidiasis, which in our view was indicative of a more profound and acute T cell immunologic deficit, already described in the literature [8]. We have not come across yet of other similar reports in the literature.
We used corticosteroids at a dose of 4 mg of dexamethasone every 6 h for non-diabetics and 8 mg every 6 h for people with diabetes mellitus for 48–72 h and then started rapid tapering.
Overall, 22/49 patients received the ‘escalated’ regime, 8 patients received trimethoprim-sulfamethoxazole and 11 patients received corticosteroids.
Out of the 49 patients we treated, we had 6 deaths. Three patients, ages 90, 92 and 95, died from healthcare-associated pneumonia rather than pneumonia due to COVID-19 infection and they were not intubated. Two patients died from likely cytokine release syndrome, which we attempted to treat with corticosteroids only, as immunomodulatory therapies were not available at that time. A total of 8 patients had to be intubated, 7 of them were transferred to another hospital (Table 1).