Five Years’ Experience with Respiratory Syncytial Virus Among Hospitalized Patients: A Retrospective Study from Jazan, Saudi Arabia

Introduction

Respiratory Syncytial Virus (RSV) is a predominant cause of lower respiratory tract infections in children and less commonly adults, posing a significant public health burden and exerting a substantial impact both within Saudi Arabia and globally.^1–8 By the age of 2 years, a staggering 90% of respiratory infections can be attributed to RSV, with the peak incidence occurring between 6 weeks and 6 months of age.^9,10 The seasonality of RSV infections is reported and linked to regional weather patterns, actively spreading during cold months in areas characterized by a temperate climate while persisting throughout the year in regions with tropical climates.^2,8,9 In the United States, RSV infection rates were documented at 68.8 per 100 child years in infancy and 82.6 per 100 child years in the second year of life.¹⁰

The primary immune response against RSV involves the production of neutralizing antibodies and T-cell-specific immunity.¹ However, repeated infections are common across all age groups and do not provide lasting immunity against subsequent infections.² Globally, approximately 34 million cases of annual acute lower respiratory tract infections are linked to RSV, with 3.4 million cases severe enough to warrant hospitalization.⁹ Among hospitalized patients, 66,000 deaths have been associated with RSV, particularly affecting children at 2 years of age and those residing in developing countries.⁹

Various risk factors exacerbate RSV-associated complications and potentially intensive care admission, including congenital heart disease, congenital pulmonary malformations, prematurity, chronic lung disease, and neuromuscular disease.^1,5,6,11 Additional risk factors for hospitalization encompass infants below 6 months of age, male gender, children residing in shared households or attending daycare centers, and exposure to tobacco smoke.^1,5,6,11 Clinically, RSV presentations include rhinitis, cough, and fever.³ While croup may occur with RSV infection, bronchiolitis, and pneumonia emerge as the predominant manifestations in children.^3,5,6 Noteworthy predictors for admission of bronchiolitis cases include prematurity, a history of atopic conditions, chronic lung disease, passive smoking, age less than one year, and lack of exclusive breastfeeding.⁶

While numerous studies have been conducted in Saudi Arabia to explore the epidemiology of RSV,^2–8 none of these studies focused on the southwestern part of the country, where approximately 2 million people reside. This 5-year study aims to fill this gap by investigating RSV epidemiology among hospitalized patients in the southwestern region of Saudi Arabia. The study also aims to identify associated risk factors that could lead to intensive care admission. Providing insights that could inform targeted public health interventions, resource allocation, and clinical management strategies in the region.

Materials and Methods

Study Design and Population

We conducted a retrospective observational study to assess the epidemiology of RSV from January 2015 to December 2020. Our study included hospitalized cases with suspected respiratory infections from all ages, where laboratory results confirmed the presence of RSV using rapid tests. Cases involving other causative agents or repeated RSV-positive tests were excluded.

Data Collection

Data were sourced from the medical records and microbiology laboratory files of a 500-bed tertiary hospital and routinely collected by the infection control team. We extracted all positive RSV results for the BinaxNOW™ RSV Card (Abbott, ME, USA) rapid test, performed on nasopharyngeal swab specimens, a test with a specificity and sensitivity of 93% according to the manufacturer. Comprehensive biographical information, including age and sex, was gathered. Clinical data, such as the timing and month of clinical presentation, delivery details, term of birth (full-term or preterm), comorbidities, a requirement for oxygen support, admission to the intensive care unit (ICU), and outcomes (survival or mortality), were recorded.

Data Analysis

The data underwent cleaning and coding procedures. The study’s findings were summarized using frequencies and proportions. To compare variables associated with ICU admission, T-test and chi-square tests were employed in the data analysis process using SPSS version 23 (IBM Corp., Armonk, NY, USA).

Ethical Considerations

The study received ethical approval from the Health Ethics Committee in Jazan, Saudi Arabia. Confidentiality of collected data was rigorously maintained. This secondary analysis utilized routinely collected anonymized monitoring data in adherence to ethical principles outlined in the Helsinki Declaration and specific guidelines established by the National Committee of Bioethics in Saudi Arabia. Patient charts and laboratory databases provided data as part of routine clinical procedures, with personal and identifiable details systematically excluded. Informed consent was waived due to the retrospective nature of the study.

Results

Among 1553 participants with RSV tests, the study included a total of 195 participants with RSV-positive cases, with a mean age of 21.28 months (SD = 33.25) (Table 1). Only three adult cases were found to be tested for RSV, and results were negative. Figure 1 represents the distribution of percentages of RSV across the studied years with the highest incidence observed in the year 2019, followed by years 2016 and 2018. In Figure 2, the monthly incidence is depicted in each given year or collectively with a higher incidence between December and January. Figure 3 describes the most common comorbidities associated with RSV infection. The distribution by sex revealed 85 males (43.59%) and 107 females (54.87%). Gestational age analysis indicated 159 participants were born full-term (81.54%), while 33 were preterm (16.92%). Monthly admissions varied, with January having the highest at 43 (22.05%) and September, August, and November having the lowest at 3 each (1.54%). The study lasted multiple years, with the highest representation in 2016 (43 participants, 22.05%) and the lowest in 2017 (18 participants, 9.23%). Ventilation was required for 78 cases (40.00%), and comorbidities were observed in 96 participants (49.23%) [Figure 3]. Outcomes included 175 discharges (89.74%) and 17 deaths (8.72%). Most deaths (14 cases) were among patients with a full-term birth history. Ten out of 17 cases had associated comorbidities, mainly congenital heart diseases (5 cases) followed by cerebral palsy (4 cases). Abnormal liver function tests (LFT) were reported in 30 cases (15.38%). The average length of stay (LOS) was 8.1 days (SD = 12.88), and 62 participants (31.79%) required ICU admission.

Table 1 Characteristics of the Included Population

Figure 1 Distribution of RSV cases during the studied years.

Figure 2 Number of RSV cases during the months of the studied period.

Figure 3 Description of the comorbidities associated with RSV cases.

Among patients categorized based on ICU admission, those admitted had a significantly lower mean age than those not admitted (34.03 vs 41.96, p-value = 0.0001) (Table 2). Gender distribution did not show a significant difference between the two groups (p-value = 0.121). Full-term births were more prevalent among patients not admitted to the ICU (89.31% vs 66.13%, p-value = 0.0001), while preterm births were more common among ICU-admitted patients (9.92% vs 32.26%, p-value = 0.0001). Monthly variations revealed significant differences in several months, such as January (p-value = 0.001), with higher admissions in December for the ICU group. The distribution across years also showed statistically significant differences (p-value = 0.0001), with higher ICU admissions in 2016 and 2018. Ventilation was required more frequently for ICU-admitted patients (90.32% vs 16.79%, p-value = 0.0001). The presence of comorbidities (64.52% vs 16.03%, p-value = 0.005), abnormal liver function tests (35.48% vs 29.77%, p-value = 0.0001), and longer mean length of stay (12.13 vs 11.31 days, p-value = 0.003) were significantly associated with ICU admission. However, sex distribution did not exhibit statistically significant differences between the two groups.

Table 2 Patients Categorized Based on ICU Admission

Discussion

This 5-year study elucidates the epidemiological patterns of RSV among hospitalized patients within the Jazan region of Saudi Arabia from 2015 to 2020. It provides significant insights into the prevalence and characteristics of RSV-positive cases, offering a comprehensive analysis of demographic distribution, comorbidities, outcomes, and seasonal variations in RSV infections.^2,8,9 Furthermore, this study will serve as a valuable database for future research, facilitating interventions, exploring alternative diagnostic modalities, and supporting national analyses of respiratory infections caused by RSV.

Among the 195 patients identified as RSV-positive during the study period, a notable overall prevalence of 12.5% was observed, with 54.87% being female and an average age of 21.28 months. Interestingly, 81.54% had no history of prematurity, while 16.92% did. The study delineated specific high-risk cohorts, including preterm infants born before 29 weeks, individuals with chronic lung diseases of prematurity, congenital heart diseases, and those with underlying immune deficiency.^1,5,6 The spectrum of comorbidities within the study population was diverse, with 13% exhibiting a suggestive history of bronchial asthma, 10.2% having underlying congenital heart diseases, and smaller proportions manifesting central nervous disorders, sickle cell anemia, and musculoskeletal disorders.

Contrary to recent reports in various international studies, no positive RSV cases were recorded in hospitalized adult patients, despite the established prevalence of RSV infections in adults.^11,12 This observation raises speculation regarding potential factors inherent in the local setting, such as a shortage of tests to be conducted in the emergency rooms, which are mostly initiated based on test requests from treating physicians or non-admitted RSV-positive cases in adults. Thus, clinicians and treating physicians in our region are urged to consider RSV as a potential differential diagnosis in adults and older patients presenting with respiratory infection manifestations. It has been reported that among patients aged over 65 years, RSV positivity could be noted in about 20% of those hospitalized with other risk factors.^11,12

Among other factors associated with ICU admission, the U-shape of seasonal variations for RSV infections is well established and observed in the current study in Jazan. Furthermore, following a relatively calm RSV season in 2020 attributed to the SARS-CoV-2 pandemic, outbreaks were observed in subsequent seasons, notably in 2018–2019, as reported by others.^13–16 However, this study lacks further serotyping details that could explain this observation. The RSV cases in Jazan witnessed a significant decline after the enforcement of quarantine measures in March 2020. The region’s distinctive climate, characterized by a combination of tropical and temperate weather, likely accounts for the year-round persistence of infections, with peaks occurring during colder months.¹⁷ Additionally, the median duration of hospital stay for RSV cases in Jazan was 8 days in the general population and 12 days in patients admitted to the ICU, aligning with other national findings from Riyadh, Saudi Arabia, and several European countries.^7,8,18–22 Remarkably, RSV emerged as the most prevalent cause of hospitalization among children in their first year of life,^21–23 and among the admitted patients, 31.79% necessitated intensive care, 40% required oxygen support or ventilation, and unfortunately, 8.72% succumbed to death.^24,25

Given the retrospective nature of this study and its reliance on rapid RSV antigen tests, it is imperative to recognize the need for future investigations that encompass clinical signs, radiological findings, serotyping, and, most importantly, molecular methods to confirm the diagnosis. It is also essential to consider the impact of preventive measures or vaccination in the Jazan region during the COVID-19 pandemic.^26–28 Further, recent global research has shown that the epidemiology of RSV has undergone significant changes, particularly following the COVID-19 pandemic, with altered patterns of seasonality and transmission being reported.^29,30 In charting future directions, building upon the foundation laid by this 5-year study on RSV in the Jazan region is crucial. Subsequent investigations should seek the details of clinical signs and radiological findings, utilizing molecular methods and newly emerged syndromic tests to enhance diagnostic accuracy. The absence of positive RSV cases in adults, despite their documented prevalence, highlights the importance of focused research on this demographic, exploring potential factors influencing test requests and guidelines related to admission practices. Additionally, national efforts should be directed toward understanding the impact of preventive measures and vaccinations,¹⁸ which are crucial for mitigating the burden of RSV infections. By embracing a holistic approach encompassing both clinical and molecular dimensions, future studies can deepen our understanding of RSV dynamics in our region, offering invaluable insights to inform targeted interventions and contribute to the broader discourse on respiratory health in the region.

Conclusions

In conclusion, this five-year study on RSV among hospitalized individuals in Jazan, Saudi Arabia, from 2015 to 2020 provides valuable insights into demographics and outcomes of the infection. Identifying high-risk groups, with an overall prevalence of 12%, and noting with the absence of adult cases indicates critical considerations. The study serves as a foundational platform for future research, highlighting the importance of heightened clinical awareness, comprehensive diagnostics, and molecular investigations. The observed seasonal patterns and the impact of quarantine measures offer a contextual understanding of the variations in RSV throughout the studied years. Subsequent studies should cover molecular aspects, assess preventive measures, and focus on factors influencing adult cases to further enrich our understanding of RSV dynamics in the region.