A total of 557 confirmed COVID-19 cases admitted to Prince Hamzah Hospital (PHH) during the period from March 1, 2020 to August 1, 2020 were recruited prospectively to this study after giving formal voluntary consent, and they were followed daily for clinical, paraclinical, and outcome parameters. All COVID-19 cases were confirmed by at least one positive COVID-19 reverse transcription (RT)-PCR test performed by an accredited referral lab. All COVID-19 recovery cases were confirmed by complete clinical and laboratory resolution, including 2 negative COVID-19 RT-PCR tests within 2 days. The government of Jordan had a policy at the time of the study to admit all COVID-19–positive patients to the hospital for isolation regardless of symptom severity.

The study protocol was approved by the institutional review board (IRB) at the Hashemite University (No: 1∕5∕2019∕2020) and the Jordanian Ministry of Health/PHH IRB (No: 1/1631).

Confirmed COVID-19 patients’ demographics; clinical, social, and medical history; and laboratory and imaging data were obtained directly from patients, relatives, or medical records of patients admitted to PHH, Amman, Jordan (the main COVID-19 isolation and management center in Jordan). Data were recorded on the first day of admission and daily during follow-ups. Demographic data included age, gender, weight, height, BMI, and blood group. Clinical data included symptoms reported by patients, vital signs, medical and surgical history, and duration of hospitalization. Laboratory data included all laboratory tests performed for patients during their admission. Imaging data assessed by an accredited radiology specialist were extracted for the 135 patients who had imaging studies (questionnaire in Multimedia Appendix 1 and primary data file in Multimedia Appendix 2 are provided as supplementary material).

Descriptive statistical analysis was used for determination of demographic, clinical, laboratory, and imaging findings. Percentages and means (SD) were calculated to describe the distributions of categorical and continuous variables, respectively. Chi-square and Fisher exact tests were used to assess the association between the study participants’ age, gender, BMI, and duration of hospitalization with their clinical, laboratory, and imaging data. The level of statistical significance was set at P≤.05. Data were analyzed using Microsoft Excel 2010 and SPSS version 24.0.

Of the 557 COVID-19 cases who were admitted to PHH, the gender distribution was 86.0% (479/557) men and 14.0% (78/557) women. Among these patients, the mean age was 34.4 years (SD 18.95 years; range 5 weeks to 87 years), and the largest age group was 21-40 years old (190/557, 34.1%). BMI was documented in 163 patients: 8.0% (13/163) were underweight, 35.0% (57/163) were normal weight, 29.4% (48/163) were overweight, and 27.6% (45/163) were obese (Table 1). Blood groups were determined for 70 patients (70/557, 12.6%) with blood group A+ (29/70, 41%) and O+ (19/70, 27%) being the most common. Significant past medical history was documented in 25.9% (144/557) of patients, significant surgical history in 12.6% (70/557), current smoking in 14.9% (83/557), a history of allergies in 1.8% (10/557), and pregnancy in 0.5% (3/557). The mean duration of hospitalization was 16.4 (SD 9.3) days, ranging from 5 days to 70 days (Table 1).

The patients complained of a variety of symptoms; nevertheless, most of the patients (293/557, 52.6%) were asymptomatic, while 34.5% (192/557) had 1-5 symptoms, 9.0% (50/557) had 6-10 symptoms, and 3.9% (22/557) had more than 11 symptoms. Among the symptomatic patients, generalized malaise and dry cough were the most common symptoms, and they were documented in 21.5% (120/557) and 21.7% (121/557) of the patients, respectively. These were followed by fever (108/557, 19.4%), chills and rigors (77/557, 13.8%), headache (75/557, 13.5%), nasal congestion (72/557, 12.9%), loss of smell (70/557, 12.6%), myalgia (61/557, 11.0%), loss of taste (60/557, 10.8%), rhinorrhea (57/557, 10.2%), and shortness of breath (56/557, 10.1%). Gastrointestinal symptoms were less frequently documented with diarrhea (57/557, 10.2%) and abdominal pain (33/557, 5.9%) being most prevalent. The least reported symptoms were chest pain (29/557, 5.2%), palpitations (12/557, 2.2%), and hemoptysis (5/557, 0.9%; Table 1). Regarding the vital signs of admitted COVID-19 patients, about 50% (271/557, 48.7%) of patients had a heart rate >80 beats per minute and systolic blood pressure ≥120 mm Hg (265/557, 47.6%), while nearly 25% had a diastolic pressure ≥80 mm Hg (134/557, 24.1%). Only 2.5% (14/557) had a respiratory rate over 25 per minute, with about 2% having an oxygen saturation below 85% (10/557, 1.8%; Table 1).

Laboratory investigations for COVID-19 patients admitted to PHH (Table 2 and Table 3) showed low hemoglobin and hematocrit in 9.9% (55/557) and 7.7% (43/557) of patients, respectively. Total white blood cell count was low in 7.2% (40/557) and high in 4.8% (27/557) of patients. Differential count showed that the neutrophil percentage was low in 14.2% (79/557), the lymphocyte percentage was low in 12.6% (70/557) and high in 28.7% (160/557), the basophil percentage was low in 44.9% (250/557), the eosinophil percentage was low in 43.4% (242/557), and the monocyte percentage was high in 26.2% (146/557). Platelet count was low in 6.6% (37/557), with high prothrombin time, international normalized ratio, and D-dimer found in 2.3% (13/557), 3.6% (20/557), and 13.1% (73/557), respectively. Inflammatory markers including CRP and ESR were elevated in 28.7% (160/557) and 26.4% (147/557) of patients, respectively. Urea and creatinine were elevated in 3.4% (19/557) and 4.8% (27/557) respectively. Aspartate transaminase (AST), alanine transaminase (ALT), and lactate dehydrogenase (LDH) were elevated in 10.2% (57/557), 8.8% (49/557), and 5.0% (28/557), respectively. Bilirubin total and direct were elevated in 9.2% (51/557) and 4.1% (23/557), respectively. Hyponatremia and hypokalemia were found in 5.0% (28/557) and 4.1% (23/557), respectively (Table 3).

The following radiological data were obtained for 135 COVID-19 patients. CT scan studies of the chest showed that the most common appearance of infiltrates was ground glass opacity (44/135, 32.6%), followed by broncho-alveolar consolidation (14/135, 10.4%). Central involvement was noticed in 7.4% (10/135) of the patients, while peripheral involvement was observed in 26.0% (35/135) of the patients. Also, 25.2% (34/135) of the patients had lesions that were located posteriorly, in comparison to 8.1% (11/135) who had anterior lesions and 25.2% (34/135) who had mediastinal lymphadenopathy. The most affected lobe was the right lower lobe (38/135, 28.1%), followed by the left lower lobe (33/135, 24.4%), left upper lobe (23/135, 17.0%), right upper lobe (22/135, 16.3%), and right middle lobe (20/135, 14.8%; Table 4).

X-ray scans showed that 3 patients (3/135, 2.2%) had solitary infiltrates, while 20 patients (20/135, 14.8%) had multiple infiltrates. Also, it showed that 4 patients (4/135, 3.0%) had peripheral lesions, 3 patients (3/135, 2.2%) had central lesions, and 1 patient (1/135, 0.7%) had both peripheral and central lesions. Regarding the most affected lung lobes, the data showed the following: left lower lobe (17/135, 12.6%), right lower lobe (21/135, 15.6%), right middle lobe (17/135, 12.6%), right upper lobe (12/135, 8.9%), and left upper lobe (12/135, 8.9%). Only 1 patient (1/135, 0.7%) had affected lung apices, and only 2 patients (2/135, 1.5%) had a pleural effusion. No patient had hilar involvement or a widened mediastinum (Table 5).

Men had a significantly higher frequency of having symptoms (symptom score) than women (244/479, 51.0% vs 19/78, 24.4%, P=.004). Furthermore, generalized malaise, diarrhea, chills/rigors, dry cough, rhinorrhea, and fever were significantly more frequent in men than in women (P≤.05). Mean heart rate and frequency of elevated heart rate were significantly higher in men than in women (P=.02). Past medical, past surgical, allergy, and smoking history were significantly higher in men than in women (P≤.001). Hemoglobin, hematocrit, monocyte %, basophile %, and creatinine levels were significantly higher in men than in women (P<.05), while ESR, alkaline phosphatase (ALP), and D-dimer levels were significantly higher in women than in men (P≤.05). Hospitalization duration and intensive care unit (ICU) admissions were significantly higher in men than in women (P=.000); 7 men and 1 woman were admitted to the ICU, and 2 men died. Table 6 shows the associations between age, gender, BMI, and hospitalization duration in relation to symptoms and signs, laboratory data, and imaging findings.

Increased age was significantly associated with a higher frequency of symptoms (symptom score; P=.03); increased frequency of generalized malaise, headache, loss of smell, diarrhea, loss of taste, rhinorrhea, wet and dry cough, shortness of breath, chest pain, and palpitations; higher frequency of significant past medical, past surgical, and smoking history; and increased blood pressure, lower oxygen saturation, and higher BMI (P≤.05). Furthermore, increased age was significantly associated with elevated CRP, ESR, urea, creatinine, ALT, and ALP levels and positive imaging findings (P≤.05; Table 6). Higher BMI was associated with increased age; higher symptom score; elevated blood pressure, CRP, ESR, creatinine, ALT, and ALP levels; and positive imaging findings (P≤.05; Table 6). Hospitalization duration was positively associated with increased age, male gender, higher symptom score, history of smoking, significant past medical and surgical histories, elevated systolic blood pressure, elevated respiratory rate, lower oxygen saturation, elevated monocyte %, elevated CRP and ESR, increased creatinine, and elevated D-dimer (P<0.05; Table 6).

Jordan has successfully managed to contain the first wave of the SARS-CoV2 virus by implementing early lockdowns. The lockdown began on March 18, 2020, when the number of known cases of the virus was less than 20. Jordan closed its borders on March 16, 2020 and kept arriving passengers in quarantine. Extensive contact tracing was carried out, and every person who tested positive for the virus was admitted to the hospital to control the spread of the virus [17]. These measures resulted in Jordan having fewer COVID-19 cases per capita compared with other countries in the region and around the world. By May 15, 2020, Jordan had 58 cases per 1 million population (1 M pop) and 0.9 deaths/1 M pop, compared with Portugal, which has about the same population and had 2776 cases/1 M pop and 116/1 M pop death, and with Greece, with 266 cases/1 M pop and 15 deaths/1 M pop. Neighboring Saudi Arabia had 1349 cases/1 M pop and 8 deaths/1 M pop [3,16-18].

Having all COVID-19–positive patients admitted to the hospital for isolation provided an opportunity to study the clinical and laboratory characteristics in patients with SARS-CoV2 viral infection in Jordan. PHH in Jordan was the main hospital designated to admit patients positive for the SARS-CoV2 virus. The patients were admitted regardless of their symptoms. In Jordan, most cases were in the age range of 21-40 years (34.1%), which is comparable to other studies [2,19]. Furthermore, a meta-analysis later in the pandemic by Pormohammad et al [4] had a mean age of 48 years for patients from studies around the world.

In this study, the younger age group (0-20 years old) represented about 29% of the cases, which was higher than the percentiles of young people infected in Saudi Arabia and China, where the percentages were about 15% [2,19]. More recently, in the United States, children under 18 years old represented 12% of all COVID-19 cases [20]. In South Korea, where all patients with positive tests were also admitted, only 9% of the patients were under 20 years of age, with the population under 24 years old representing about 24% of the nation’s population [21]. The age group under 20 years old represents about 44% of the Jordanian population [18], and this is the most likely reason for this higher percentage of COVID-19 cases among the young. Also likely contributing to this is the fact that all patients with positive tests were admitted, and extensive contact tracing was carried out.

There were more men than women in this study (86% men), which is different from other studies that either showed a slightly increased percentage of male patients [4,19] or, in a more recent meta-analysis of 3 million patients, showed equal infection rates between the 2 sexes [22]. This difference is difficult to explain but could be caused by the fact that SARS-CoV2 infection was mainly contracted by travelers and men working in the trucking business who then spread the disease to their family members [16]. Regarding the symptoms of COVID-19 in this study, most patients were asymptomatic (52.6%), and among symptomatic patients, dry cough (21.7%) and generalized malaise (21.5%), followed by fever (19.4%), were the most prevalent symptoms. This is quite similar to other studies, including 2 meta-analyses that showed that fever and cough were the most common symptoms [10,23]. Less common symptoms such as headache (13.5%), rhinorrhea (10.2%), and diarrhea (10.2%) were reported at much higher percentages in this study [24]. This is most likely explained by the fact that all patients with SARS-CoV2 viral infection were admitted regardless of symptoms, whereas other studies mainly included patients hospitalized due to their symptoms.

In this study, only 13.1% of COVID-19 patients had lymphopenia, while 30% had lymphocytosis and 56.9% of patients had a normal lymphocyte count. This contrasts with most other studies that tended to show an association between lymphopenia and COVID-19 [4,10]. Some studies hypothesized that lymphopenia may correlate with disease severity, such that lymphocyte count could possibly be used as a prognostic factor for COVID-19 patients [25,26]. Since more than half of the patients in our study were asymptomatic, this may explain the low percentage of COVID-19 patients found to have lymphopenia.

Inflammatory markers in COVID-19 patients in our study, including CRP, ESR, and LDH, were inconsistent with the findings of 2 meta-analyses [4,10]. This is most likely due to the high percentage of asymptomatic (52.6%) patients in this study. This finding increases the possibility of a positive association between high inflammatory markers and the severity of COVID-19, as proposed by yet another meta-analysis [27]. Abnormal liver enzymes, including AST and ALT, were present at lower rates compared with the results found elsewhere [28].

The radiological data from CT and x-ray scans of 135 patients were collected and analyzed. The most common lesion detected by CT scan was ground glass appearance, and this is consistent with what was found in the meta-analysis done by Bao et al [9], but at a much lower rate than those authors found (32.6% vs 90.35%, respectively). Peripheral involvement was more common than central involvement, and posterior involvement was more common than anterior involvement. These findings are similar to what was found by another study [29]. Multilobar distribution was more common than unilobar distribution, and the lower lobes were more affected than the upper lobes. Other studies found similar results [30,31]. The majority of patients who underwent chest x-ray had normal results, while Wong et al [31] found that 69% of the patients had abnormal findings on their chest radiography. This may be related to the fact that the majority of the patients in our study were asymptomatic.

When comparing male patients to female patients admitted with SARS-CoV2 infection, it was noted that male patients were more symptomatic than female patients (51.0% vs 24.4%, P<.05). Men were also more likely to be admitted to ICUs. In a meta-analysis that compared around 3 million patients from around the world [22], men had higher rates of ICU admission and mortality as well. The reason for this difference in morbidity and mortality between the sexes may be due to differences in the adaptive and innate immune systems, as the adaptive immune system in women has a higher number of CD 4 T cells [32,33] and stronger CD 8 cytotoxic activity [34]. Women also have more B cells and antibody production [32,35]. The reason for these differences is due to X-linked genes that affect the immune response to viruses [15,35].

Age was associated with increased symptoms (P<.05) and abnormal lab results. This has been documented in many other studies [36,37]. Age is also related to increased comorbidities, and in 1 meta-analysis in which there was an attempt to control for comorbidities, age itself remained a weak risk factor [38]. In our study, having an increased BMI was associated with having more symptoms, and this finding is similar to other studies and meta-analyses [39,40].

This study is the first to address the clinical, laboratory, and radiological features of COVID-19 patients in Jordan, and it was conducted with 557 patients, a considerable number of participants. A downside of this study is that all of the participants were from 1 center (PHH). Also, the data regarding laboratory testing and imaging were incompletely collected.

This is the first study to describe in detail all the clinical, laboratory, and imaging findings of the first 557 confirmed COVID-19 patients admitted to PHH in Jordan. Most cases were asymptomatic, male, and overweight or obese. Generalized malaise and dry cough were the most common symptoms. Only 2.5% had a respiratory rate over 25 breaths/minute, and 2% had an oxygen saturation below 85%. Lymphocytosis and elevated CRP, ESR, and D-dimer were the most common laboratory abnormalities, while ground glass opacity was the most common imaging finding. Men had a significantly higher frequency of symptoms, smoking, abnormal laboratory findings, and ICU admissions compared to women. Hospitalization duration was positively correlated with increased age, male gender, symptom score, history of smoking, elevated systolic blood pressure, elevated respiratory rate, elevated monocyte %, and elevated CRP, ESR, creatinine, and D-dimer.