International review of blood donation nucleic acid amplification testing

BACKGROUND AND OBJECTIVES

Nucleic acid amplification testing (NAT), in blood services context, is used for the detection of viral and parasite nucleic acids to reduce transfusion-transmitted infections. This project reviewed NAT for screening blood donations globally.

MATERIALS AND METHODS

A survey on NAT usage, developed by the International Society of Blood Transfusion Working Party on Transfusion-transmitted Infectious Diseases (ISBT WP-TTID), was distributed through ISBT WP-TTID members. Data were analysed using descriptive statistics.

RESULTS

Forty-three responses were received from 32 countries. Increased adoption of blood donation viral screening by NAT was observed over the past decade. NAT-positive donations were detected for all viruses tested in 2019 (proportion of donations positive by NAT were 0.0099% for human immunodeficiency virus [HIV], 0.0063% for hepatitis C virus [HCV], 0.0247% for hepatitis B virus [HBV], 0.0323% for hepatitis E virus [HEV], 0.0014% for West Nile virus [WNV] and 0.00005% for Zika virus [ZIKV]). Globally, over 3100 NAT-positive donations were identified as NAT yield or solely by NAT in 2019 and over 22,000 since the introduction of NAT, with HBV accounting for over half. NAT-positivity rate was higher in first-time donors for all viruses tested except WNV. During 2019, a small number of participants performed NAT for parasites (Trypanosoma cruzi, Babesia spp., Plasmodium spp.).

CONCLUSION

This survey captures current use of blood donation NAT globally. There has been increased NAT usage over the last decade. It is clear that NAT contributes to improving blood transfusion safety globally; however, there is a need to overcome economic barriers for regions/countries not performing NAT.

An international review of the characteristics of viral nucleic acid-amplification testing (NAT) reveals a trend towards the use of smaller pool sizes and individual donation NAT

BACKGROUND AND OBJECTIVES

Nucleic acid-amplification testing (NAT) is used for screening blood donations/donors for blood-borne viruses. We reviewed global viral NAT characteristics and NAT-yield confirmatory testing used by blood operators.

MATERIALS AND METHODS

NAT characteristics and NAT-yield confirmatory testing used during 2019 was surveyed internationally by the International Society of Blood Transfusion Working Party Transfusion-Transmitted Infectious Diseases. Reported characteristics are presented herein.

RESULTS

NAT was mainly performed under government mandate. Human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) NAT was performed on all donors and donation types, while selective testing was reported for West Nile virus, hepatitis E virus (HEV), and Zika virus. Individual donation NAT was used for HIV, HCV and HBV by ~50% of responders, while HEV was screened in mini-pools by 83% of responders performing HEV NAT. Confirmatory testing for NAT-yield samples was generally performed by NAT on a sample from the same donation or by NAT and serology on samples from the same donation and a follow-up sample.

CONCLUSION

In the last decade, there has been a trend towards use of smaller pool sizes or individual donation NAT. We captured characteristics of NAT internationally in 2019 and provide insights into confirmatory testing approaches used for NAT-yields, potentially benefitting blood operators seeking to implement NAT.

A comparative study of SARS-CoV-2 and common human coronavirus infections among children presenting to tertiary care in Oman

OBJECTIVES

To compare clinical manifestations, laboratory characteristics, and outcomes of children presenting to tertiary care with SARS-CoV-2 or common human coronavirus (HCoV) infection.

METHODS

Children 13 years of age or younger presenting in 2020 with SARS-CoV-2 and those presenting with HCoV between 2017 and 2019 were included. Clinical and laboratory features were compared using appropriate statistical tests. The study was conducted at the two main tertiary hospitals in Muscat, Oman.

RESULTS

The study included 255 cases (131 SARS-CoV-2 and 124 HCoV). Median age was 1.7 years (interquartile range 0.5-5.6), and 140 patients (55%) were males. Among children with HCoV infection, diarrhea was less common compared to children with SARS-CoV-2 (4% vs 23%, P <0.001), while respiratory symptoms such as cough were more common (74% vs 31%, P <0.001). Intensive care admission was more frequent with SARS-CoV-2 infection compared to HCoV (22% vs 11%, P = 0.039). Three virus-related deaths were recorded, all of which occurred among patients with SARS-CoV-2 and multisystem inflammatory syndrome in children.

CONCLUSION

Lower respiratory tract disease is more frequent among children with HCoV infection compared to SARS-CoV-2, while gastrointestinal symptoms are more frequent with SARS-CoV-2. Critical illness is more likely with SARS-CoV-2 infection, driven mostly by multisystem inflammatory syndrome in children.

Seroprevalence of Human T-cell Lymphotropic Virus Types I/II Among Blood Donors in a Tertiary Hospital in Oman

Objectives

Routine blood donor screening of human T-cell lymphotropic virus (HTLV) has been practiced in Oman since 2017. Limited data exists on HTLV seroprevalence among Omanis. This study aims to determine the seroprevalence of HTLV-I/II among blood donors attending a hospital-based blood bank to assess the need for a universal versus targeted screening.

Methods

We conducted a retrospective review of blood donors' results attending a hospital blood bank between January 2017 and February 2020. Blood samples were screened for HTLV-I/II antibodies using ARCHITECT i2000SR. Reactive samples underwent further testing by immunoblot assay (MP Diagnostics HTLV Blot 2.4). Age, gender, and nationality were assessed. All components manufactured at the blood bank undergo leukoreduction before storage.

Results

A total of 24 469 first-time blood donors were screened for HTLV antibodies. Most participants were male (n = 22 186, 90.7%), and the majority were Omani (n = 22 711, 92.8%). The age range was 18 to 64 years, with a median of 32 years. The seroreactivity rate was 0.2% (43; 95% CI: 0.12-0.23). Confirmatory testing by immunoblot revealed three indeterminate results (7.9%), of which two were Omani and one non-Omani donor, and the remaining 40 seroreactive donors tested negative.

Conclusions

Our study revealed zero seroprevalence of confirmed HTLV among blood donors. The continuation of universal screening for first-time donors is a standard of care. With universal leukoreduction at Sultan Qaboos University Hospital and a very low risk of HTLV in Oman's population, the need for screening regular donors can be reconsidered if these findings are confirmed on a larger scale involving other blood banks in Oman.

The Burden of Human Parechoviruses Among Children in Oman: A retrospective study

Objectives

This study aimed to evaluate the burden, clinical and laboratory features and outcomes of human parechoviruses (HPeVs) infection among children in Oman.

Methods

This retrospective study included children (aged <18 years) with molecularly proven HPeV infection who were managed at Sultan Qaboos University Hospital, Muscat, Oman, between January 2017 and December 2019. Data were obtained from the patients' medical records and analysed to describe their demographics, clinical and laboratory features, management and outcomes.

Results

HPeV was detected in 61 patients, 44 (72%) of whom were males. The median age of these patients was nine months (interquartile range [IQR]: 6-15 months). HPeV was detected throughout the year without any significant peaks. Majority of the patients (n = 51, 84%) had co-infection with other viruses. Forty-eight (79%) children with HPeV infection required hospitalisation, and their median length of hospital stay was five days (IQR: 3-8 days). Ex-prematurity (n = 10, 16%) was the commonest comorbidity among this group. Fever (n = 41, 67%) and cough (n = 41, 67%) were the commonest presenting symptoms among the children. Two-thirds of the HPeV-infected children in this cohort were managed for lower respiratory tract infection; none was managed for meningitis. Gastroenteritis was not common in this cohort; only eight children had diarrhoea. All children made a full recovery.

Conclusion

HPeVs infection does not show a clear seasonality in Oman. Most of the children were aged <2 years and had a viral co-infection. The outcomes of HPeV infection were favourable, with no mortalities, but a thorough follow-up for neurological outcomes was lacking.

Cytomegalovirus Infection Post-hematopoietic Stem Cell Transplant: Incidence, Risk Factors, and Outcome in an Omani Cohort

Objectives

To estimate the incidence, risk factors, and outcome of cytomegalovirus (CMV) infection during the first year following hematopoietic stem cell transplant (HSCT) among Omani patients.

Methods

This retrospective study included allogenic HSCT recipients between January 2006 and December 2018. We investigated the possible factors associated with CMV infection and CMV impact on one-year mortality.

Results

Among 556 recipients of allogenic HSCT, 308 (55.4%) were male, the median age was 12 years, and 366 (65.8%) had benign conditions. One-year after transplants, the prevalence of CMV infection was 59.4%, and that of CMV disease was 1.8%. Multivariate analyses revealed significant relationships between CMV infection and haploidentical transplant (p = 0.006), graft versus host disease (p = 0.013), myeloablative conditioning (p = 0.001), and patient age ≥ 12 years (p < 0.001). CMV infection was associated with an increased risk of one-year mortality (p = 0.001). One-year overall mortality was 8.3%.

Conclusions

The incidence of CMV infection in this Omani cohort was comparable with earlier findings, but the disease incidence and overall mortality were lower. Older age, haploidentical transplant, myeloablative conditioning, and graft versus host disease were significantly associated with a higher risk of CMV infection. In addition, CMV infection was associated with an increased risk of overall mortality in the first year post-transplant. Our findings support early initiation of preemptive therapy at low-level CMV viremia.

Identification of Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections Among Healthcare Workers at Sultan Qaboos University Hospital, Oman

Objectives

This study aimed to describe the incidence and features of asymptomatic COVID-19 infections among healthcare workers (HCWs) at a tertiary hospital in Oman.

Methods

This cross-sectional study was conducted between August 2020 and February 2021 among HCWs with no history of COVID-19 infection. An online questionnaire collected sociodemographic and clinical data. COVID-19 infection was diagnosed using nasopharyngeal/throat swabs, which were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Analyses were performed using the Chi-squared test, Fisher's exact test or univariate ordinary least squares regression, as appropriate.

Results

A total of 583 HCWs participated in the study, most of whom were female (56.6%), and the mean age was 35 ± 8 years. Only 9.6% (95% confidence interval [CI]: 7.3-12.3%) of the HCWs were at high exposure risk as they were directly involved in the care of COVID-19-infected patients. Overall, 4.1% (95% CI: 2.7-6.1%) of the HCWs screened positive for SARS-CoV-2, of which 20.8% developed symptoms within two weeks. The frequency of SARS-CoV-2 positivity among HCWs working in high-, intermediate-, low- and miscellaneous-risk areas was 1.8% (95% CI: <0.1-9.6%), 2.6% (95% CI: <0.1-6.5%), 5.3% (95% CI: 0.3-9.3%) and 4.8% (95% CI: <0.1-69.3%), respectively. Working in high-risk areas was associated with increased compliance with various infection control strategies (P <0.001).

Conclusion

There was a greater frequency of SARS-CoV-2 positivity among HCWs working in low-risk areas, whereas HCWs who worked in high-risk areas were significantly more likely to report increased compliance with infection control strategies.

Short and long-term immune changes in different severity groups of COVID-19 disease

BACKGROUND

There are limited data on short- versus long-term changes in adaptive immune response across different COVID-19 disease severity groups.

METHODS

A multicenter prospective study of 140 adult patients with COVID-19 (a total of 325 samples) were analyzed for inflammatory markers and lymphocyte subsets at presentation, week 2, and week 24.

RESULTS

Inflammatory markers at presentation were higher in the critical/severe than in moderate and mild groups. A predominance of memory B cell response in the mild and moderate group was noted by week 2. In contrast, the immune system in the severe/critical group was dysfunctional, with expansion of exhausted CD8+ T cells and atypical memory B cells. By 24 weeks, there was a possible trend of normalization.

CONCLUSION

There was substantial difference in the degree of inflammation and distribution of different B and T cell subsets in the different disease severity groups. Despite the initial dysfunctional immune response in the severe/critical group, a comparable memory B and CD8+ T cell responses to the mild group was achieved at 24 weeks.

Circulating activated neutrophils in COVID-19: An independent predictor for mechanical ventilation and death

OBJECTIVES

Critical illness in COVID-19 is attributed to an exaggerated host immune response. Since neutrophils are the major component of innate immunity, we hypothesize that the quantum of activated neutrophils in the blood may predict an adverse outcome.

DESIGN

In a retrospective study of 300 adult patients with confirmed COVID-19, we analyzed the impact of neutrophil activation (NEUT-RI), interleukin-6 (IL-6) and the established clinical risk factors of age, diabetes, obesity and hypertension on the clinical outcome.

RESULTS

Significant predictors of the need for mechanical ventilation were NEUT-RI (Odds Ratio (OR) = 1.22, P < 0.001), diabetes (OR = 2.56, P = 0.00846) and obesity (OR = 6.55, P < 0.001). For death, the significant predictors were NEUT-RI (OR = 1.14, P = 0.00432), diabetes (OR = 4.11, P = 0.00185) and age (OR = 1.04, P = 0.00896). The optimal cut-off value for NEUT-RI to predict mechanical ventilation and death was 52 fluorescence intensity units (sensitivity 44%, specificity 88%, area under the curve 0.67 and 44%, 86%, 0.64, respectively).

CONCLUSION

This finding supports an aberrant neutrophil response in COVID-19, likely due to uncontained viral replication, tissue hypoxia and exacerbated inflammation, introduces a novel biomarker for rapid monitoring and opens new avenues for therapeutic strategies.

"Virtual Interdisciplinary COVID-19 Team": A Hospital Pandemic Preparedness Approach

The COVID-19 pandemic continues to move at record speed. Health systems and hospitals worldwide face unprecedented challenges to effectively prepare and respond to this extraordinary health crisis and anticipated surge. Hospitals should confront these unparalleled challenges with a comprehensive, multidisciplinary, coordinated, and organized strategy. We report our experience with the systematic application of the "4S" principle to guide our institutional preparedness plan for COVID-19. We used an innovative "virtual interdisciplinary COVID-19 team" approach to consolidate our hospital readiness.

Fatal hepatitis A virus infection in an adolescent

Acute hepatitis A infection is largely self-limiting illness, rarely resulting in fulminant course with consequent hepatic failure and death. We present a 13-year old previously healthy Omani with fatal hepatitis A virus infection. This case highlights the critical role of hepatitis A vaccination and argues for consideration of its inclusion in national vaccination programs in order to avert similar devastating consequences of yet another vaccine preventable disease.

Pandemic Influenza A H1N1 in Oman: Epidemiology, Clinical Features, and Outcome of Patients Admitted to Sultan Qaboos University Hospital in 2009

OBJECTIVES

Oman experienced the H1N1 pandemic in 2009 that initially started in Mexico and the United States. We present the epidemiology, clinical features, and outcome of cases admitted to Sultan Qaboos University Hospital.

METHODS

We retrospectively reviewed all patients admitted with confirmed influenza A H1N1 infection from August to December 2009. The study included adults and pediatric patients. We looked at the clinical and laboratory factors associated with increased length of hospital stay.

RESULTS

There were 68 patients admitted with influenza A H1N1 infection, and their median age was 23 years. The most common symptoms were fever (100%) and cough (79.4%). The most common reason for admission was the severity of illness (69.1%). Lymphopenia was the most common hematological abnormality (41.8%). All patients received treatment with oseltamivir. One patient died secondary to multi-organ failure. On multivariate analysis, severity of illness, use of steroids, anemia, lymphopenia, and abnormal alanine amino transferase levels were associated with increased length of stay.

CONCLUSIONS

The H1N1 pandemic in Oman followed the international trends in terms of clinical presentation and laboratory values for patients admitted to the hospital.