Determination of the degree of bacterial contamination of whole-blood collections using an automated microbe-detection system

BACKGROUND: The prevalence of bacterial contamination in whole-blood collections, either with immediate sampling or sampling after overnight storage as whole blood at 20 degrees C, is determined. STUDY DESIGN AND METHODS: Whole blood was collected under blood bank conditions in special five-bag systems, allowing sampling in a closed system for culture bottles. Samples were taken within 2 hours after collection (Group 1) or after overnight storage of the whole blood at 20 degrees C (Group 2). Culture bottles were incubated for 7 days, and positive samples were entered on agar plates for confirmation and determination. RESULTS: In Group 1, 9219 units were tested; 27 units were positive with positive subculture, that is, 0.29 percent with a 95% CI of 0.19 to 0.42 percent. In Group 2, 9038 units were tested; 36 units were positive with positive subculture, that is, 0.39 percent with a 95% CI of 0.28 to 0.55 percent. No significant difference could be found between the two test groups. The majority of bacteria were either Staphylococcus (all coagulase-negative) or Propionibacterium species. CONCLUSION: For a total of 18,257 units, 0.34 percent (CI, 0.25-0.44) of whole-blood collections appeared to have bacterial contamination (mainly skin-derived). Overnight storage of whole blood at 20 degrees C did not have a significant effect on the prevalence of bacterial contamination.     

献血员中TTV感染的检测及部分基因序列分析

目的　探讨湛江地区献血员中输血传播病毒 (TTV)的感染状况及部分TTV的基因序列。方法　采用SDS和蛋白酶K法提取 4 80份正常献血员、6 0份血清丙氨酸转氨酶 (ALT)异常献血员的血清标本DNA ,应用套式PCR方法检测TTV的感染状况 ,并对部分扩增出的阳性片段进行克隆测序 ,与国内外报道的序列进行同源性比较。结果　在 4 80份正常献血员血清标本中 ,5 2份 (10 83% )TTVDNA阳性 ;在ALT异常的 6 0份献血员血清标本中 ,15份TTVDNA阳性 ,阳性检出率为 2 5 % ,明显高于正常献血员人群 (χ2 =9 84 7,P <0 0 1)。序列分析结果显示 ,从献血员中随机选出的 5例TTVDNA阳性片段 ,其序列与日本株 (AB0 0 8394 )和中国株 (TTVCH1)相应位置核苷酸序列的同源性大于97% ,可能属同一基因型。结论　湛江地区献血员中存在TTV感染 ,输血可能成为TTV感染的传播途径之一。     

Blood donors’ positivity for transfusion-transmissible infections: the Serbian Military Medical Academy experience

Background

Members of armed forces worldwide are considered to be very susceptible to sexually transmitted infections, thus falling into a high-risk group of blood donors regarding transfusion-transmissible infections. In the Serbian Military Medical Academy a significant number (44% for the period 2005–2013) of blood donations were from members of the Serbian Army. The aim of this study was to determine the significance of military blood donors for the safety of blood transfusion.

Material and methods

Between January 2005 and December 2013, a total of 155,479 blood donations were tested for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) and syphilis using serological assays (enzyme immunoassays, chemiluminescent microparticle immunoassay and western blot) and molecular testing (polymerase chain reaction analysis).

Results

The percentage of blood donations positive for transfusion-transmissible infections in the estimated period was 0.38%, and the percentage of HBV, HCV, HIV and syphilis positive blood donations was 0.20%, 0.12%, 0.005% and 0.06%, respectively. During that period, the percentage of all transfusion-transmissible infections, and in particular of HBV and HCV, declined significantly. In contrast, the percentage of HIV and syphilis positive blood donations remained unchanged. Higher rates of positivity for transfusion-transmissible infections in blood donations from members of the Serbian Army were not found, especially after mandatory military service was abolished in 2009.

Discussion

The reported rate of positivity for transfusion-transmissible infections in blood donations from the Military Medical Academy was considered low. This information is of great significance for further implementation of public health measures.     

The status of blood safety in ECO member states

Background

Access to the information concerning blood safety is essential for managing problems and overcoming the challenges that are faced in any given region. Information on the availability and safety of blood in countries of the Economic Cooperation Organisation (ECO) is largely lacking. To address this problem, the Iranian Blood Transfusion Organisation, in collaboration with other ECO member states, initiated a research project in 2009 to collect, analyse and compare statistics on blood safety in the region.

Materials and methods

A modified and summarised version of the Global Database on Blood Safety (GDBS) questionnaire was used to collect data. The questionnaire was sent to all ten countries in the ECO region. The heads of the national transfusion services or focal points were requested to complete the form. Related literature and websites were also reviewed.

Results

Only three countries (Afghanistan, Iran and Turkey) completed the questionnaire, while other countries provided their available data on some parts of the questionnaire. The number of donations per year varied from 5 to 27/1,000 population. The rate of donors positive for human immunodeficiency virus ranged from 0.003% to 0.2%. The rate of donors positive for hepatitis C virus antibody varied from 0.05% to 3.9% while that of hepatitis B virus surface antigen ranged from 0.15% to 3.91% respectively.

Discussion

There is very clear diversity in blood transfusion services among ECO member states. Most countries in the region do not have a data-recording system. It is generally estimated that the need for blood is much higher than the supply in this region. Deficiencies in donor screening and a high prevalence of transfusion-transmitted infections are other important challenges.     

Transfusion transmitted leishmaniasis: a case report and review of literature

Leishmaniasis is caused by the infection of haemoparasite Leishmania . The disease is a major public health problem in at least 88 countries, including India. Various species of Leishmania are involved in causing this disease. In India, Leishmania donovani species causes visceral leishmaniasis or kala-azar. The parasite is mainly transmitted from infected to uninfected person through the bites of female sandfly. Rarely the parasite can transmit through placenta from mother to child, through sexual intercourse, as laboratory acquired and through blood transfusion. This paper reports a unique case of transfusion-transmitted fatal kala-azar in an Indian infant who acquired this infection within few days of his birth after receiving blood from his maternal uncle, who was asymptomatic at the time of blood donation but died due to severe kala-azar within three months. The baby started having fever and developed hepatosplenomegaly within one month of blood transfusion and in spite of repeated anti-leishmanial treatment with sodium antimony gluconate the child died at the age of 7 months. This paper details the clinico-pathological findings of this child and also reviews the literature on this aspect and its impact on transfusion medicine.     

某市在校学生无偿献血者传染病筛查结果分析

目的 调查某市参加无偿献血的在校学生输血传染病指标的筛查结果,为完善招募策略、确保安全供血提供依据.方法 检测无偿献血学生和普通献血人群HBsAg、抗-HCV、抗-HIV、抗-TP,对4项感染指标的检出结果进行分析比较.结果 在校学生输血传染病指标检测总阳性率低于普通献血人群.学生无偿献血者中出现了HIV感染个例.结论 在校学生是无偿献血的主要群体、低危群体,向学生积极宣传无偿献血知识的同时,加强艾滋病防治教育势在必行.     

Transfusion-transmitted virus infection in China: Prevalence in blood donors and in patients with liver diseases

BACKGROUND: Prevalence of transfusion-transmitted virus (TTV) infection among blood donors and in patients with liver diseases in China was studied. METHODS: DNA was extracted from serum and amplified by seminested polymerase chain reaction with reported primer sets from a conserved region of the TTV genome. RESULTS: TT Virus DNA was detected in 55 of 196 blood donors (28%); 31% (40 of 127) in the north and 22% (15 of 69) in the south. TT Virus DNA was also detected in 14 of 31 patients (45%) with non-A-non-G fulminant hepatitis and in eight of 25 patients (32%) with non-A-non-G chronic hepatitis. The rate of TTV viraemia in these patients with liver disease was comparable to that in blood donors. TT Virus DNA sequencing of 12 isolates showed that the prevalence of genotype 2 was significantly higher than that reported in Japan (66.7 vs 2.6%, P < 0.001). Furthermore, genotyping assays based on restriction fragment length polymorphism were carried out on all 88 TTV DNA-positive samples. It was found that 42 isolates (47.7%) belonged to genotype 1 and 40 (45.5%) to genotype 2. It was of particular interest that the prevalence of genotype 1 in patients with non-A-non-G fulminant hepatitis was significantly higher than that in blood donors (10/14 vs 22/55, P < 0.05). CONCLUSIONS: The data indicate that TTV infection is common in China and that the pathogenic potential of TTV toward the liver (if any) may differ between genotypes.     

Sensitivity of individual donor nucleic acid testing (NAT) for the detection of hepatitis B infection by studying diluted NAT yield samples

BackgroundScreening blood donors for the presence of hepatitis B virus surface antigen (HBsAg) has been the backbone of blood safety. However, occult hepatitis B infection (OBI) in donors can be missed when only HBsAg screening is used. Nucleic acid testing (NAT) is capable of detecting OBI among donors. The aim of our study was to analyse the sensitivity of NAT for detecting OBI.ResultsOf the 18 samples studied, nine were NAT-reactive at a dilution of <1:4 and five out of these showed presence of antibody to core antigen (IgG+IgM). Antibody to surface antigen was present in only two of the nine NAT-reactive samples, one with antibody to core antigen and the other without. Six had a viral load in the range from <10 to 38 IU/mL whereas the viral load in the remaining three samples was not determined. Among the other nine samples which were NAT-reactive at dilutions ≥1:4, antibody to core antigen (IgG+IgM) was present in seven.DiscussionOur study showed that ID-NAT testing along with HBsAg screening could detect most potentially HBV infectious donors (including those with OBI). NAT screening for HBV on diluted samples could compromise blood safety because samples with a low viral load will escape detection.     

Viral Infections and Systemic Lupus Erythematosus: New Players in an Old Story

A causal link between viral infections and autoimmunity has been studied for a long time and the role of some viruses in the induction or exacerbation of systemic lupus erythematosus (SLE) in genetically predisposed patients has been proved. The strength of the association between different viral agents and SLE is variable. Epstein–Barr virus (EBV), parvovirus B19 (B19V), and human endogenous retroviruses (HERVs) are involved in SLE pathogenesis, whereas other viruses such as Cytomegalovirus (CMV) probably play a less prominent role. However, the mechanisms of viral–host interactions and the impact of viruses on disease course have yet to be elucidated. In addition to classical mechanisms of viral-triggered autoimmunity, such as molecular mimicry and epitope spreading, there has been a growing appreciation of the role of direct activation of innate response by viral nucleic acids and epigenetic modulation of interferon-related immune response. The latter is especially important for HERVs, which may represent the molecular link between environmental triggers and critical immune genes. Virus-specific proteins modulating interaction with the host immune system have been characterized especially for Epstein–Barr virus and explain immune evasion, persistent infection and self-reactive B-cell “immortalization”. Knowledge has also been expanding on key viral proteins of B19-V and CMV and their possible association with specific phenotypes such as antiphospholipid syndrome. This progress may pave the way to new therapeutic perspectives, including the use of known or new antiviral drugs, postviral immune response modulation and innate immunity inhibition. We herein describe the state-of-the-art knowledge on the role of viral infections in SLE, with a focus on their mechanisms of action and potential therapeutic targets.