Transmission of parasites by blood transfusion

Malignant human thyroid neoplasms associated with blood parasitic (haemosporidian) infection

Investigation of archival cytological material obtained by cytologists during fine-needle aspiration biopsy in follicular, papillary, and medullary human thyroid cancers revealed haemosporidian (blood parasitic) infection. Haemosporidian infection was detected as exo- and intraerythrocytic stages of development in thyrocytes schizogony. The exoerythrocytic stage of development is represented as microschizonts in a thyroid needle biopsy specimen. Probably, blood parasitic infection is the common etiology for these pathologies. All biopsy material in medical laboratories was stained with RomanowskyGiemsa stain. To clarify the localization of nuclei (DNA) of thyrocytes and nuclei (DNA) of haemosporidian infection in cytological material following investigation of the entire set of smears, a selective series of original archival smears was stained (restained) with a Feulgen/Schiff reagent. Staining of smears with RomanowskyGiemsa stain is an adsorption method that enables re-use of the same smears for staining with a Feulgen/Schiff reagent where the fuchsin dye, after DNA hydrolysis by hydrochloric acid, is incorporated into DNA and stains it in redviolet (crimsonlilac) color. An intentionally unstained protoplasm of blood parasitic infection was present as a light band around erythrocyte nuclei. In follicular thyroid cancer, Feulgen staining of thyrocytes revealed nuclear DNA and parasitic DNA (haemosporidium nuclei) as point inclusions and rings and diffusely distributed in the thyrocyte cytoplasm. The thyrocyte cytoplasm and nuclei were vacuolated, with thyrocyte nuclei being deformed, flattened, and displaced to the cell periphery. The erythrocytes, which were initially stained with eosin (orange color), contained haemosporidian nuclei (DNA). In some cases, endoglobular inclusions in thyrocytes and erythrocytes were of the same size. In papillary thyroid cancer, we were able to localize the nuclear DNA of thyrocytes and the parasitic DNA as point inclusions and diffusely distributed in the thyrocyte cytoplasm. Two or more polymorphic nuclei may eccentrically occur in the hyperplastic cytoplasm. Haemosporidian microschizonts occurred circumnuclearly in thyrocytes and as an exoerythrocytic stage in the blood. The erythrocyte cytoplasm contained redviolet polymorphic haemosporidian nuclei (DNA). In medullary thyroid cancer, the hyperplastic cytoplasm of thyrocytes contained eccentrically located nuclei (DNA) of thyrocytes and small haemosporidian nuclei (DNA), which may occupy the whole thyrocyte. There were thyrocytes with vacuolated cytoplasm and pronounced nuclear polymorphism. The size of hyperplastic nuclei was several times larger than that of normal thyrocyte nuclei. The color of stained cytoplasmic and nuclear vacuoles of thyrocytes was less redviolet compared with that of surrounding tissues, which probably indicates the presence of parasitic DNA in them. The haemosporidian nuclear material in erythrocytes is represented by polymorphic nuclei, which may indicate the simultaneous presence of different pathogen species and/or generations in the blood. Intracellular parasitism of haemosporidian infection in thyrocytes (schizogony) associated with three thyroid cancers leads to pronounced cytoplasmic hyperplasia, cytoplasmic vacuolization, and nuclear vacuolization of the thyrocyte, followed by impaired secretory function. Multinucleated thyrocytes with incomplete cytokinesis appear. The absence of lytic death of the affected thyrocytes indicates that the contagium is able to control apoptosis and influence physiological functions of the cell. There is deformation of the nuclei, which leads to a decrease in their size, their flattening and displacement to the cell periphery, with high risk of DNA mutations and deletions in affected cells, reaching a neoplastic level.

Prevention strategies of transfusion-transmitted parasitic infections (TTPIs): Strengths and challenges of current approaches, and evaluation of the strategies implemented in Iran

Background

Several strategies are being implemented in blood transfusion centers of the world to prevent the transfusion-transmitted parasitic infections (TTPIs). The objective of this study was to determine and describe the strategies to minimize the transmission risk of parasitic agents via blood transfusion in Iran.

Methods

This study was conducted in the Iranian blood transfusion organization (IBTO). The data were extracted from the latest version of the “medical interview” standard operating procedure (SOP).

Results

The donor selection is the first and only step to reduce the risk of TTPIs in endemic and non-endemic areas of Iran. In all blood transfusion centers of the IBTO, the blood donation volunteers with a previous history of malaria, Chagas disease, visceral leishmaniasis (VL), muco-cutaneous leishmaniasis and babesiosis, as well as those with clinical toxoplasmosis, cutaneous leishmaniasis (CL) and with a history of residence in, or travel to, malaria-endemic areas are permanently or temporarily deferred from the blood donation.

Conclusions

Since malaria, toxoplasmosis and VL are endemic in parts of Iran, as well as the increasing travels to endemic areas and immigrations from endemic to non-endemic areas of parasitic infections, the extensive use of blood and blood components and the asymptomatic occurrence of most parasitic infections in blood donors, the donor selection strategy is not sufficient to prevent the TTPIs. Therefore, the changing of donor selection process and the use of other common preventive strategies are recommended to reduce the risk of TTPIs, especially for high-risk groups of toxoplasmosis and VL.

Global status of visceral leishmanial infection among blood donors: A systematic review and meta-analysis

INTRODUCTION

Transmission of Leishmania through transfusion has been reported from various Visceral leishmaniasis (VL) endemic areas of the world. The true burden of Leishmania infection in blood donors remains generally unknown. Thus, the present systematic review attempted to determine the global prevalence of Leishmania infection among blood donors.

METHODS

Data were extracted through five English and five Persian databases during the period from 1997 to 2016. Overall, 16 articles fulfilled the inclusion criteria and were used for data extraction in this systematic review.

RESULTS

In total, 13,743 blood donors from different regions of world were examined. The prevalence rate of Leishmania infection according to seropositivity obtained 7% (95%CI: 5%, 8%). The lowest and the highest prevalence were related to Bangladesh 0.25% (95%CI: 0.0%, 1.0%) and Brazil, 16% (95%CI: 12%, 19%). Seroprevalence rate of leishmaniasis among females was more (4.60%) than males. Of 15 studies included in the meta-analysis, the pooled prevalence rate of molecular tests was obtained 2% (95%CI: 1%, 3%) in which Iran and Spain had the lowest and the highest prevalence, 0.05% and 7%, respectively. Our analysis showed that L. infantum was more common than L. donovani as etiological agent of VL among all donors.

CONCLUSION

Our data confirms the presence of asymptomatic carriers of VL in endemic areas and supplies as an attentive to the likelihood of these carriers acting as blood donors. Moreover, we conclude that molecular tests for screening in asymptomatic blood donor provide an accurate estimate of the rate of infection over serological tests.

Parasitic infections in solid organ transplant recipients

Parasitic diseases are rare infections after a solid organ transplant (SOT). Toxoplasmosis, Trypanosoma cruzi, and visceral leishmanias are the 3 main opportunistic protozoal infections that have the potential to be lethal if not diagnosed early and treated appropriately after SOT. Strongyloides stercoralis is the one helminthic disease that is life-threatening after transplant. This review addresses modes of transmission, methods of diagnosis, and treatment of the most serious parasitic infections in SOT. The role of targeted pretransplant screening of the donor and recipient for parasitic diseases is also discussed.

Transfusion-related Plasmodium ovale malaria complicated by acute respiratory distress syndrome (ARDS) in a non-endemic country

46year old female presented with a one week history of high grade fever, chills, cough, and severe nausea. The patient had been admitted a month earlier with severe lower gastrointestinal bleeding from hemorrhoids necessitating transfusion of 7 units of packed red blood cells. Initial work-up was unremarkable. Because of persistent symptoms, the patient was admitted 2 days later. Malaria smear was positive. Due to the severity of her symptoms, she was managed as falciparum malaria and was started on intravenous quinine and oral doxycycline. On the second day of treatment the patient developed respiratory failure, requiring intubation and ventilatory support with new bilateral pulmonary infiltrates. Antimalarial treatment was continued for a total of 7 days followed by primaquine for 14 days once the blood smear results revealed Plasmodium ovale infection. The patient remained intubated in the intensive care unit (ICU) for 16 days, and was later extubated successfully with a clear chest x-ray after a total of one month hospitalization. To our knowledge, this is the first case of acute respiratory distress syndrome (ARDS) secondary to blood transfusion related P. ovale malaria infection in a non-endemic country.

Evaluation of Plasmodium vivax ELISA for the blood screen

Plasmodium vivax malaria is the indigenous strain in the Republic of Korea (ROK). Plasmodium vivax can be transmitted through the transfusions of various blood components, which became a severe problem with the safety of blood transfusions and blood-related products in ROK. We evaluated a P. vivax-specific enzyme-linked immunosorbent assay (Genedia Malaria Ab ELISA 2.0, Green Cross, ROK) with blood samples from four groups: 251 samples from P. vivax-infected patients, 39 samples from post-treatment patients upon follow-up, 200 samples from healthy volunteers and 421 samples from domestic travellers to and from high endemic areas of ROK. The positive cases from the ELISA test were confirmed by both Giemsa microscopic and polymerase chain reaction methods. The clinical sensitivity and specificity of detecting P. vivax with ELISA test were 94.4% and 99.0%, respectively. Thirteen of 421 domestic travellers (3.0%) to endemic areas tested positive. The results indicate the effectiveness of detecting antibodies against P. vivax in blood with Genedia Malaria Ab ELISA 2.0 test in a large blood screen setting.

Parasitic infections in solid organ transplant recipients

Parasitic infections are an uncommon but potentially severe complication in solid organ transplant (SOT) recipients. An increase in donors who have emigrated from tropical areas and more transplant recipients traveling to endemic areas have led to a rise in parasitic infections reported among SOT recipients. Clinicians should include these infections in their differential diagnosis and promote adherence to preventive measures in SOT recipients.

Morphological diagnosis by bone marrow aspirate of toxoplasmosis infection in an HIV-positive patient

An HIV-positive woman receiving antiretroviral therapy developed an opportunistic toxoplasma infection, detected by morphological examination of bone marrow aspirate in the absence of serological positivity. The intracellular presence of Toxoplasma gondii was confirmed by indirect immunofluorescence microscopy, using a polyclonal antitoxoplasma antiserum on marrow smears. This case report confirms the utility of morphological bone marrow examination for the diagnosis of parasitic infections in patients with impaired host defenses.

FML vaccine against canine visceral leishmaniasis: from second-generation to synthetic vaccine

The Leishmania donovani glycoprotein fraction, known as FML, successfully underwent preclinical and clinical (Phase I-III) vaccine trials against canine visceral leishmaniasis (92-95% of protection and 76-80% of vaccine efficacy) when formulated with a QS21 saponin-containing adjuvant. It became the licensed Leishmune vaccine for canine prophylaxis in Brazil. The immune response raised by the vaccine is long lasting, immunotherapeutic and reduces dog infectivity blocking the transmission of the disease, as revealed by an in vivo assay. The preliminary epidemiological control data of vaccinated areas in Brazil indicate that, in spite of the still low vaccine coverage, there was a significant decrease in the incidence of the human and canine disease. A 36-kDa glycoprotein, in the FML complex, is the human marker of the disease, which was protective in mice as native recombinant protein or DNA vaccine. The DNA vaccine is now being tested against the canine disease. This review resumes the development of the second-generation FML-saponin-Leishmune vaccine, its adjuvant and of the NH36 DNA vaccine, toward the identification of its major epitopes that might be included in a possible future synthetic vaccine.

Evaluation of a malaria antibody enzyme immunoassay for use in blood screening

Transfusion-transmitted malaria is rare, but it may produce severe problem in the safety of blood transfusion due to the lack of reliable procedure to evaluate donors potentially exposed to malaria. Here, we evaluated a new enzyme-linked immunosorbent assay malaria antibody test (ELISA malaria antibody test, DiaMed, Switzerland) to detect antibodies to Plasmodium vivax (the indigenous malaria) in the blood samples in the Republic of Korea (ROK). Blood samples of four groups were obtained and analyzed; 100 samples from P.vivax infected patients, 35 from recovery patients, 366 from normal healthy individuals, and 325 from domestic travelers of non-endemic areas residents to risky areas of ROK. P.vivax antibody levels by ELISA were then compared to the results from microscopic examination and polymerase chain reaction (PCR) test. As a result, the ELISA malaria antibody test had a clinical sensitivity of 53.0% and a clinical specificity of 94.0% for P.vivax. Twenty out of 325 domestic travelers (6.2%) were reactive and 28 cases (8.6%) were doubtful. Of the reactive and doubtful cases, only two were confirmed as acute malaria by both microscopy and PCR test. Thus we found that the ELISA malaria antibody test was insufficiently sensitive for blood screening of P.vivax in ROK.

[Transfusion-transmitted malaria, preventive measures]

Malaria is a blood parasitic disease in the first place among the most prevalent communicable infectious diseases over the world, which leads to an increased risk of transfusion transmitted malaria. Preventive measures have been undertaken to screen blood donors such as discarding red cell donations according to the medical history, travel history and detection of malarial antibodies. However, these measures may be not sufficient and reliable to avoid the risk of transmission. Preliminary data indicates that combination of travel history, detection of malarial antibodies and antigens by commercialized kits adapted to blood transfusion centres either in endemic or non endemic areas may improve malaria transfusion risk management.

Protecting the blood supply from emerging pathogens: the role of pathogen inactivation

Although the risk of infection by blood transfusion is relatively low, breakthrough infections still occur, Transfusion-related fatalities caused by infections continue to be reported, and blood is not tested for many potentially dangerous pathogens. The current paradigm for increasing the safety of the blood supply is the development and implementation of laboratory screening methods and restrictive donor criteria. When considering the large number of known pathogens and the fact that pathogens continue to emerge, it is clear that the utility of new tests and donor restrictions will continue to be a challenge when considering the cost of developing and implementing new screening assays, the loss of potential donors, and the risk of testing errors. Despite improving the safety of blood components, testing remains a reactive approach to blood safety. The contaminating organisms must be identified before sensitive tests can be developed. In contrast, pathogen inactivation is a proactive strategy designed to inactivate a pathogen before it enters the blood supply. Almost all pathogen inactivation technologies target nucleic acids, allowing for the inactivation of a variety of nucleic acid-containing pathogens within plasma, platelets, or red blood cells thus providing the potential to reduce transfusion-transmitted diseases. However, widespread use of a pathogen inactivation technology can only be realized when proven safe and efficacious and not cost-prohibitive.

The risks associated with blood and blood product transfusion

Although transfusion of blood and blood products is often of life-saving benefit for the many patients who receive transfusions every year, it is not without considerable risk. Nurses need to be aware of these risks so that they can respond to patient anxiety about transfusion. This article outlines risks associated with transfusion and the measures taken to minimize them. Attention will be focused principally on the two most significant risks: transmission of serious blood-borne infection and the potentially fatal acute immune haemolytic reaction that can occur if patients receive incompatible red cells. Other significant adverse effects will be discussed briefly. Recent initiative aimed at monitoring the incidence of these adverse effects and increasing the safety of blood transfusion will be discussed, with special emphasis on the nurse's role in the transfusion process.

Identification of Babesia microti-specific immunodominant epitopes and development of a peptide EIA for detection of antibodies in serum

BACKGROUND

Babesia microti is a tick-borne agent that is increasingly implicated in transfusion-acquired infection, especially in immunocompromised and elderly recipients. To develop a test that can detect antibody responses to B. microti, peptide epitopes identified in two serocomplementary B. microti-specific antigens were used in a prototype EIA.

STUDY DESIGN AND METHODS

A prototype peptide EIA was used to detect B. microti-specific antibodies in 15 sera taken before infection and 107 taken after infection from 59 individuals with known tick-borne infections previously confirmed by other methods. Three additional groups of samples were also tested: a proficiency panel of 18 sera positive for B. microti by IFA, 38 sera from blood donors confirmed positive by IFA, and 30 sera from random blood donors.

RESULTS

The combination peptide detected 98 out of 107 sera taken after infection that were IgG blot positive (4 equivocal). This included all 12 samples that were PCR positive and six sera from smear-negative patients that were confirmed positive by PCR, immunoblot, or IFA. Of the IgG blot-positive specimens that were equivocal (four specimens) or did not react (nine specimens) by EIA, most had low IFA titers consistent with previous exposure. In a second evaluation, 15 out of 15 Babesia IFA-positive sera and 3 out of 3 Babesia-Ehrlichia IFA-positive sera were positive, whereas sera from 30 random donors were negative. Finally, of 38 IFA-positive blood-donor samples, 35 were positive by peptide EIA. The three EIA-negative sera were Western blot negative.

CONCLUSION

Reactivity of the B. microti-specific peptide EIA shows a high correlation with IFA, PCR, and B. microti immunoblot in confirmed B. microti cases. The peptide EIA may be the most suitable B. microti infection test for adaptation to the blood bank environment if testing for B. microti is required in the future.

High prevalence anti-Trypanosoma cruzi antibodies, among blood donors in the State of Puebla, a non-endemic area of Mexico

Blood transfusion is the second most common transmission route of Chagas disease in many Latin American countries. In Mexico, the prevalence of Chagas disease and impact of transfusion of Trypanosoma cruzi-contaminated blood is not clear. We determined the seropositivity to T. cruzi in a representative random sample, of 2,140 blood donors (1,423 men and 647 women, aged 19-65 years), from a non-endemic state of almost 5 millions of inhabitants by the indirect hemagglutination (IHA) and enzyme linked immunosorbent assay (ELISA) tests using one autochthonous antigen from T. cruzi parasites, which were genetically characterized like TBAR/ME/1997/RyC-V1 (T. cruzi I) isolated from a Triatoma barberi specimen collected in the same locality. The seropositivity was up to 8.5% and 9% with IHA and ELISA tests, respectively, and up to 7.7% using both tests in common. We found high seroprevalence in a non-endemic area of Mexico, comparable to endemic countries where the disease occurs, e.g. Brazil (0.7%), Bolivia (13.7%) and Argentina (3.5%). The highest values observed in samples from urban areas, associated to continuous rural emigration and the absence of control in blood donors, suggest unsuspected high risk of transmission of T. cruzi, higher than those reported for infections by blood e.g. hepatitis (0.1%) and AIDS (0.1%) in the same region.

Update on Transfusion Therapy

The science and technology of transfusion have improved dramatically over the past decade. Improvements in screen ing for viral pathogens have reduced the risk of transfusion transmitted viral infections to historic lows. Newly recog nized entities, including the transfusion transmitted virus and Parvo viruses are being investigated as pathogens. There is increasing appreciation that bacterial infection and parasites may be transmitted via transfusion, and a variety of approaches are being developed to deal with them. Clin ical studies continue to conflict about what the ideal hemo globin for patients with cardiovascular disease should be, but several studies suggest that higher hematocrits may be beneficial. Factor deficiency may play a more important role in massive transfusion than previously believed. The impor tance of autologous predeposit of red cells and hemodilu tion may diminish as the blood supply becomes ever safer, but intraoperative salvage is likely to remain an important technique. Finally, although blood substitutes have been under development for more than 10 years, they have not yet become widely used in medicine. The few remaining products under development are presently in advanced clin ical trials but face a variety of clinical and economic obsta cles before they can rise to their potential.

Serological expression cloning of novel immunoreactive antigens of Babesia microti

Increased recognition of the prevalence of human babesiosis in the United States, together with rising concern about the potential for transmission of this infection by blood transfusion, has provided motivation to develop definitive serologic and molecular tests for the causative agent, Babesia microti. To develop more sensitive and specific assays for B. microti, we screened a genomic expression library with patient serum pools. This screening resulted in the identification of three classes of novel genes and an additional two novel, unrelated genes, which together encode a total of 17 unique B. microti antigens. The first class (BMN1-2 family) of genes encodes seven closely related antigens with a degenerate six-amino-acid repeat that shows limited homology to Plasmodium sp. merozoite and sporozoite surface antigens. A second class (BMN1-8 family) of genes encodes six related antigens, and the third class (BMN1-17 family) of genes encodes two related antigens. The two remaining genes code for novel and unrelated sequences. Among the three classes of antigens and remaining novel sequences, five were chosen to code for the most immunodominant antigens (BMN1-2, -9, -15, and -17 and MN-10). Western blot analysis with the resulting recombinant proteins indicated that these antigens were targets of humoral immune responses during B. microti infection in humans.