Donor-derived infections-Insights from Singapore, Japan, and Thailand.

BACKGROUND: Solid organ transplantation (SOT) has expanded significantly in Asia over past few decades. Donor-derived infections (DDIs) remain a significant concern as they may adversely impact transplant outcomes. We aim to review the existing regulatory frameworks, screening protocols, and management practices for DDIs in Asia. METHODS: We reached out to transplant infectious diseases experts in Asia to provide standardized data on annual SOT numbers, incidence of DDIs, regulatory frameworks, donor and recipient screening protocols, and DDI surveillance measures. We present the data from Singapore, Japan, and Thailand. RESULTS: Donor screening for HIV, hepatitis B, hepatitis C, and syphilis is mandatory in all countries. Additionally, Japan screens for HTLV-1 antibody due to its endemicity. We also reviewed the protocols for screening and prevention of endemic infections in Asia. Singapore is the only country implementing universal screening for all donors for dengue, Zika, and chikungunya via blood and urine RT-PCR. Strongyloidiasis screening is not routinely done, although some transplant centers empirically give ivermectin prophylaxis to organ recipients. Tuberculosis screening with a donor questionnaire and chest radiograph is common for deceased donors, and some centers do Interferon Gamma Release Assay test for living donors. We also found a significant gap in the surveillance and reporting of potential DDIs in Asia and the overall incidence of DDIs in Asia is unknown and likely underreported. CONCLUSION: The experiences of Singapore, Japan, and Thailand offer valuable insights into current practices and the unmet needs regarding a DDI registry and call for coordinated efforts to address this critical issue in the region.

Donor-derived dengue infections - A review of screening protocol and outcomes in an endemic country.

BACKGROUND: Donor-derived dengue infections present significant challenges to organ transplantation, particularly in endemic regions like Singapore. Although primarily transmitted by Aedes mosquitoes, dengue can also be transmitted through organ transplantation, occasionally with fatal outcomes. This study aims to evaluate the outcomes and evolution of dengue screening protocols for potential deceased donors in Singapore from 2006 to 2022. METHODS: Initially, screening was done via dengue immunoglobulin M (IgM), targeting donors with specific clinical criteria (thrombocytopenia, drop in platelet count, prolonged prothrombin time/partial thromboplastin time, and discretion of the transplant team), later transitioning to blood dengue reverse transcription-polymerase chain reaction (RT-PCR) in 2007 with similar criteria, and subsequently universal screening in 2016. In 2021, urine dengue RT-PCR was added following a case of donor-derived dengue infection from an aviremic but viruric donor. RESULTS: Out of 431 potential deceased donors, 395 (91.6%) underwent dengue screening, with six (1.5%) testing positive for dengue. In 2006, three positive screens were identified: two through dengue IgM and one via blood dengue RT-PCR; subsequent years saw one positive screen each in 2007, 2008, and 2019 via blood dengue RT-PCR. Potential deceased donors with a positive blood dengue screen were rejected as solid organ and tissue donors. Those with negative blood dengue RT-PCR but positive urine dengue RT-PCR would be rejected as kidney donors, but the use of other organs and tissues was at the discretion of the transplantation team. CONCLUSION: The optimal screening protocol remains uncertain, but our findings suggest that a universal screening strategy utilizing both blood and urine dengue RT-PCR could be considered in dengue-endemic countries.

Dengue virus infection among renal transplant recipients in Singapore: a 15-year single-centre retrospective review.

INTRODUCTION: Dengue is a mosquito-borne viral infection endemic in Singapore. Its impact in renal transplantation is limited to small case series. We aimed to characterise the clinical presentation and outcomes of dengue infection among renal transplant recipients in Singapore. METHODS: We conducted a 15-year retrospective review of dengue in renal transplant patients treated at Singapore General Hospital between January 2005 and October 2019. The diagnosis of dengue was made if there were a compatible clinical syndrome and a positive dengue diagnostic assay (Dengue NS1 antigen, IgM or RT-PCR). RESULTS: 31 patients were diagnosed with dengue, 18 (58.1%) were deceased donor recipients. The median age was 52 (IQR 40-61) years; 16 (51.6%) were females. The median time to diagnosis was 99 (IQR 18-169) months from transplant. The most common clinical symptoms were fever (87.1%), myalgia (41.9%), gastrointestinal symptoms (38.7%) and headache (25.8%). 19 (61.3%) patients had dengue without warning signs, 9 (29.0%) had dengue with warning signs, 3 (9.7%) had severe dengue and 30 (96.8%) were hospitalized. 17 (54.8%) patients had graft dysfunction, 16 (94.1%) of whom had recovery of graft function. 1 (3.2%) patient required dialysis and subsequently died. There were two cases of donor-derived infections (DDIs) with favourable outcomes. CONCLUSION: Our experience with dengue in renal transplant recipients is concordant with published data. Although graft dysfunction is common, it is often transient with favourable outcomes. Outpatient management may be considered for mild infections. Although dengue DDIs are uncommon, more stringent donor screening may be considered in endemic regions.

Risk factors for pregnancy-associated venous thromboembolism in Singapore.

OBJECTIVES: Pregnancy-associated venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), is associated with increased risk of maternal mortality and morbidity. This study aimed to assess potential risk factors for pregnancy-associated VTE. METHODS: In this case-control study, women with pregnancy-associated VTE were identified via International Classification of Diseases codes and included if they had been objectively diagnosed with VTE during pregnancy or within six weeks postpartum, from 2004 to 2016, at KK Women's and Children's Hospital or Singapore General Hospital in Singapore. Controls, i.e. pregnant women without VTE, were selected from a prospective longitudinal study. The odds ratio (OR) for VTE was computed for a range of maternal and obstetric factors. RESULTS AND CONCLUSIONS: From 2004 to 2016, 89 cases of pregnancy-associated VTE and 926 controls were identifed and analysed using logistic regression. The most significant risk factors for pregnancy-associated VTE were smoking (OR 5.44, p=0.0002) and preterm delivery (OR 5.06, p=0.023). Malay race, multiparity, non-O blood group and caesarean section, were also identified to be of higher risk. These risk factors should be useful in the development of thromboprophylaxis strategies for pregnancy and the postpartum period, especially in Singapore.

Epidemiology of pregnancy-associated pulmonary embolism in South Asian multi-ethnic country: Mortality trends over the last four decades.

OBJECTIVE: To determine the cumulative incidence, time of occurrence and risk factors of pregnancy-associated pulmonary embolism (PE) in Singapore, and to review the maternal mortality ratio of PE over the last four decades. STUDY DESIGN AND SETTING: In this retrospective epidemiology review, women with pregnancy-associated PE were identified via International Classification of Diseases codes and included if they had been objectively diagnosed on imaging with PE during pregnancy or within 6 weeks postpartum from 2004 to 2016 at KK Women's and Children's Hospital (KKH) and Singapore General Hospital (SGH) in Singapore. The medical records were reviewed and the time of occurrence of confirmed PE cases and risk factors for PE were noted. RESULTS: There were 18 PE cases out of 174 708 deliveries, of which two were fatal, giving a cumulative incidence of PE at 1.03 per 10 000 deliveries and a mortality rate of 11.1%. The maternal mortality ratio is 1.14 per 100 000 deliveries, the lowest compared to that of the previous three decades (2.5-4.9 per 100 000 deliveries). Majority of PE (66.7%) occurred during the first 2 weeks postpartum. Cumulative incidence of postpartum PE was four times more in caesarean section compared to vaginal delivery at 1.58 per 10 000 deliveries and 0.40 per 10 000 deliveries, respectively. CONCLUSION: Although the cumulative incidence of pregnancy-associated PE in Singapore is low, it is comparable to the United Kingdom (UK) and United States (US). Risk assessment and thromboprophylaxis have decreased PE mortality significantly during this period.