Re-examine the transfusion transmitted risk of SARS-CoV-2 virus during a major COVID-19 outbreak in 2022

INTRODUCTION

Although no case of COVID-19 transmission through transfusion has been reported, blood transfusion service (BTS) continues to implement pre-donation and post-donation measures to minimise the risk. In year 2022, when local healthcare system was badly impacted by a major outbreak, it opened an opportunity to re-examine the viraemia risk in these asymptomatic donors.

MATERIALS AND METHODS

Records were retrieved from blood donors who reported COVID-19 after donation and follow-up was also made for recipients who received their blood. Blood samples at donation were tested for SARS-CoV-2 viraemia by single-tube nested real-time RT-PCR assay designed to detect most SARS-CoV-2 variants including the prevailing delta and omicron variants.

RESULTS

From 1 January to 15 August 2022, the city with 7.4 M inhabitants recorded 1 187 844 COVID-19 positive cases and 125 936 successful blood donations were received. 781 donors reported to the BTS after donation with 701 being COVID-19 related (including close contact and symptoms respiratory tract infection). 525 COVID-19 were positive at the time of call back or follow-up. Of the 701 donations, they were processed into 1480 components with 1073 discarded upon donors' call back. For remaining 407 components, no recipient was found to have adverse event or COVID-19 positive. 510 samples from the above 525 COVID-19 positive donors were available and all tested negative for SARS-CoV-2 RNA.

DISCUSSION

With the negative SARS-CoV-2 RNA in blood donation samples and follow up data in transfusion recipients, the risk of transfusion transmitted COVID-19 appears negligible. However, current measures remains important in securing blood safety with ongoing surveillance of their effectiveness.

Non-compliance to infectious disease deferral criteria among Hong Kong's blood donors

BACKGROUND AND OBJECTIVES

Donor screening alone cannot eliminate the risk of transfusion-transmitted HIV infection. Donor deferral according to established criteria is a supplemental strategy, which has focused largely on men who have sex with men (MSM). A study was conducted to determine the compliance of non-MSM donors with such criteria and examine its implications on blood safety.

MATERIALS AND METHODS

Chinese donors who have just donated blood at blood donor centres in Hong Kong were recruited. Based on the contents of the routinely administered predonation Health Screening Questionnaires, participants were requested to complete a survey to assess their practice of deferrable risk behaviours and lifestyle encounters, using tablet computers.

RESULTS

Over an 8-week period in mid-2016, 1614 donors (male-to-female ratio 1·23) had enrolled in the survey, accounting for 40% of donors giving blood on the survey days. The proportion of respondents who gave blood despite having deferrable HIV risk was 5%: MSM 1·2% (of the male donors); non-MSM risk behaviours 2·6%; risky lifestyle encounters 2·1%. If inconsistent declaration and suspected risk behaviours were included, the total non-compliance rate became 10·8%. Male donors had a higher prevalence of deferrable behavioural risk, even after excluding MSM. Unawareness and non-acceptability were main reasons for non-compliance.

CONCLUSION

The non-compliance rate of donors to deferral was high, although the ultimate infection risk might be small in the presence of universal screening. Simplification of questionnaires, focus on time-limited deferral and a reduction of deferral items may improve the deferral mechanism without compromising blood safety.

A study of the predonation hemoglobin and iron status among Hong Kong Chinese blood donors

BACKGROUND

Predonation hemoglobin (PDH) is used to safeguard donors' welfare, and low hemoglobin (Hb) is known to be the most frequent reason for donor deferral. A study was initiated to assess the PDH and iron status of blood donors in Hong Kong.

STUDY DESIGN AND METHODS

This observational study was designed with four groups of whole blood donors invited (group 1-eligible first time donors, group 2-eligible repeat donors with zero or one donation in preceding 12 months, group 3-eligible repeat donors with at least two donations in preceding 12 months, group 4-repeat donors being deferred for low PDH). Predonation blood samples were obtained for blood counts and iron status. Mann-Whitney test, Kruskal-Wallis test, and chi-square test for trend were applied for statistical analysis.

RESULTS

A total of 836 donors were recruited, of which 35 were excluded because of hemoglobinopathy. An inverse relationship between serum ferritin level and number of donations in the preceding 12 months was observed in both sexes. Iron deficiency was significantly seen in 35.1% of male and 65.3% of female deferred donors. More importantly, up to 7.2, 5.8, and 29.5% of the female donors in groups 1, 2, and 3 were found to be iron deficient despite having a high enough PDH.

CONCLUSION

This is the first study to assess PDH and iron status in Chinese blood donors. Iron depletion is noted with increasing number of blood donations in the preceding 12 months. Advice on iron repletion is a necessary step for donor welfare and strategies should be developed to ensure that donors have adequate PDH.

Risk factor analysis of hepatitis C virus infection among Chinese blood donors in Hong Kong

BACKGROUND

Hepatitis C virus (HCV) infection can result in serious hepatic complications and hence potentially significant burden to the society. Despite advances in technology, transfusion-transmitted HCV infection still exists. To further minimise the risk, a review on the epidemiology of HCV infection among Chinese blood donors in Hong Kong was conducted.

METHODS

All donations associated with HCV infection confirmed by positive serologic diagnosis with or without molecular confirmation during the period from 2003 to 2010 were studied. Demographic data were retrieved and risk factors were identified.

RESULTS

HCV infection was more commonly seen in first time donors and donors with blood transfusion history before the availability of HCV testing, whereas its association with intravenous drug use was noted to be decreasing. Interestingly, half of the HCV positive donors in 2008-2010 were young donors aged below 21, which was also the group with the highest rate of no known source of infection.

CONCLUSION

A subgroup of younger age donors was found to have no known risk factor. To develop better screening strategy, it is recommended that a more detailed analysis of this group of donors is required.

Multicentric osteosarcoma presenting as retrobulbar mass: a diagnostic enigma

Osteosarcoma is the most common primary malignant bone tumor of children and adolescents. It often presents as a solitary lesion; multicentric osteosarcoma with synchronous lesions occurring at multiple skeletal sites is very rare. We report a 9-year-old boy with multicentric osteosarcoma who presented with a left retrobulbar non-sclerotic mass. The multiple lesions in bone were mostly non-sclerotic on radiological examination except for a single lesion in the left tibia. Biopsy of the retrobulbar mass showed an unclassifiable poorly differentiated malignant tumor. Marrow aspiration smears showed many large, often segregated, round cells that expressed NB84a. However, trephine biopsy showed the formation of tumoral osteoid by the malignant cells, finally permitting the definitive diagnosis of osteosarcoma to be made. A hypertetraploid clone with complex structural abnormalities was demonstrated by cytogenetic study.