Despite technological advancements in the field of medicine, humans remain vulnerable to emerging infectious threats. A viral pneumonia of unknown etiology that first surfaced in Wuhan, China has since spread rapidly across the globe. Various mitigation and suppression strategies for disease control have yielded mixed results. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has established itself as a highly adaptable pathogen that is easily transmissible, causing asymptomatic infections in a large majority of people and inflicting great damage when it encounters a vulnerable host [1,2].

As of November 12, 2020, it had killed more than 1.3 million people and led to nearly 52 million confirmed cases around the world [3]. Early studies revealed that the most frequent presenting symptoms of this disease to be fever, cough, fatigue, sore throat and dyspnea [4]. Elderly patients and those with a higher comorbidity burden have a worse prognosis when compared to their younger and healthier counterparts. The former are also at a higher risk of developing acute respiratory distress syndrome (ARDS) and cytokine storm, to devastating effect [5]. To validate these findings, we investigated the clinical features and outcomes of hospitalized coronavirus disease 2019 (COVID-19) patients admitted to our quaternary care center.

Sixty-six laboratory-confirmed cases of COVID-19 were admitted to Aga Khan University Hospital during the study period. There were more males (61%) in our cohort; the mean age was 50.6 ± 19.1 years. Nine patients (14%) presented asymptomatically, while fever (60%) was the most common presenting symptom. Mean time from symptom onset to presentation at the hospital and subsequent hospitalization was 3.8 ± 2.3 days. Twelve patients (18%) had a recent travel history with the United Arab Emirates being the most frequent country of stay. Tables 1 and 2 detail the baseline characteristics and hospitalization factors of patients who died compared with those who survived.

Serial chest radiography (CXR) was obtained in all patients and 33 (50%) showed bilateral pulmonary opacities at some point during their stay. The mean length of hospital stay was 8.4 ± 8.9 days. Twelve (18%) received a hydroxychloroquineazithromycin combination, 23 patients (35%) received hydroxychloroquine alone and 16 (24%) received azithromycin alone. Hydroxychloroquine was discontinued in one patient due to QT prolongation. Furthermore, five patients (8%) received tocilizumab. Eighteen patients (27%) were started on broad spectrum antibiotics on suspicion of a secondary bacterial infection. Only three of the subsequent blood cultures were positive, showing Pseudomonas aeruginosa, Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus, respectively.

Non-ST elevation myocardial infarction during the hospital stay was observed in 5% of cases. Ten patients (15%) developed moderate-to-severe ARDS and were managed in the ICU with prone positioning and noninvasive ventilation. Six of these patients (9%) required mechanical ventilation due to respiratory failure. There were three (50%) and one (25%) deaths in the mechanical ventilation and noninvasive ventilation groups, respectively (Figure 1). The overall mortality rate was 14%. Mortality in the ICU was 40% compared to 9% in the general ward. The five ward patients that expired had issued do-not-resuscitate orders.

Factors associated with ICU admission included diabetes, hypertension, ischemic heart disease, neutrophil to lymphocyte ratio ≥ 3.3 and international normalized ratio (INR) ≥ 1.2. The odds of ICU admission are presented in Table 3. Factors associated with mortality included age ≥ 60 years, diabetes, hypertension, ischemic heart disease, ICU admission, neutrophil to lymphocyte ratio ≥ 3.3 and INR ≥ 1.2. The odds of mortality are presented in Table 4.

In this study, we present clinical characteristics and outcomes of 66 COVID-19 patients admitted to a quaternary care center in Karachi, Pakistan. Younger patients and females of all age groups were less likely to be hospitalized compared to males of older age. This is consistent with results from recent studies conducted in China, Italy and the United States [6-8]. However, whether these differences are due to less exposure to the virus or an innate biological resistance to it remains unclear.

A history of recent travel from the Middle East and the United Kingdom was observed in 19% of our cases. Fever and cough were the most common initial symptoms on admission while 11% of patients presented asymptomatically within another medical or surgical condition and were diagnosed on screening. Only 60% of patients with COVID-19 presented with fever, which is much lower than that in Wuhan (98%) and Shanghai (84%) [9,10]. While body temperature remains the main monitoring tool for surveillance of cases, many afebrile patients in our population would have been missed. Our results corroborate findings from a study conducted by Mao et al. [11], which assessed 50,000 patients presenting to 25 fever clinics in China, and concluded that fever was not a reliable indicator for COVID-19 screening.

Chest computed tomography (CT) reveals typical radiographic features, namely ground-glass opacities and multifocal patchy consolidations, in almost all COVID-19 patients, even when COVID-19 PCR is negative [12-14]. Unfortunately, due to limited resources and financial constraints, chest CT was not performed in any of our patients during the initial weeks of the pandemic; CXR was used as a cheaper and more readily available alternative. Bilateral infiltrates were seen in exactly half of the patients and these findings were also significantly associated with a poor prognosis when compared with those who had normal CXR findings. The utilization of CXR instead of CT in COVID-19 patients’ needs to be studied further, especially in resource-restricted settings. Similarly, lung ultrasound is another cost-effective radiological modality that has proven to be extremely useful in triaging patients with suspected COVID-19. It can rapidly detect extensive pulmonary involvement in COVID-19 patients, allowing for timely referral to the ICU if needed [15].

Several therapeutic agents have been evaluated for the treatment of COVID-19, but none have been established to be efficacious. The usefulness of hydroxychloroquine in COVID-19 remains inconclusive. Tang et al. [16] performed a randomized control trial assessing 150 patients admitted at 16 hospitals in China and reported no significant improvement in clinical outcomes. Adverse events were more common in hydroxychloroquine recipients than in non-recipients. Our study showed similar results. The use of hydroxychloroquine appeared to be associated with poor outcomes. Remdesivir, an inhibitor of the viral RNA-dependent-RNA polymerase has been identified as a promising therapeutic candidate for COVID-19 because of its ability to inhibit SARS-CoV-2 in vitro. Beigel et al. [17] performed a randomized controlled trial that enrolled 1,063 patients and concluded that Remdesivir was superior to placebo in shortening the time to recovery in hospitalized COVID-19 patients with evidence of respiratory tract infection.

We found a higher mortality rate (14%) in our patients compared to the rates that have been reported in other countries [8,10,18,19]. Many patients who were asymptomatic or had mild symptoms did not present to COVID-19 screening clinics, and hence were not tested. Therefore, realistically, the mortality rate can be presumed to be significantly lower. ICU admission and the need for mechanical ventilation in our cohort were reflective of disease severity; mortality was higher among patients who required invasive ventilation. The mortality rate of 40% in ICU patients is slightly lower than the rate reported among critically ill patients in the United States and China [6,20,21]. As confirmed by recent studies worldwide, male sex, older age and comorbid conditions were significant also risk factors for ICU admission and mortality in our study [22,23].

Our study has potential limitations. Since this is a singlecenter study conducted over a limited time period, the sample size was relatively small. Furthermore, the confidence interval for many factors was wide, likely due to the small number of patients in the study. Our results revealed an extremely high mortality rate in COVID-19 patients with moderate-to-severe disease who required hospitalization. COVID-19 cases are still increasing exponentially around the globe and may overwhelm healthcare systems in many countries. Our findings can be used for early identification of patients who may require intensive care and aggressive management in order to improve outcomes.