Tick-borne diseases in transfusion medicine

Characteristics of Hard Tick Relapsing Fever Caused by Borrelia miyamotoi, United States, 2013-2019

Borrelia miyamotoi, transmitted by Ixodes spp. ticks, was recognized as an agent of hard tick relapsing fever in the United States in 2013. Nine state health departments in the Northeast and Midwest have conducted public health surveillance for this emerging condition by using a shared, working surveillance case definition. During 2013-2019, a total of 300 cases were identified through surveillance; 166 (55%) were classified as confirmed and 134 (45%) as possible. Median age of case-patients was 52 years (range 1-86 years); 52% were male. Most cases (70%) occurred during June-September, with a peak in August. Fever and headache were common symptoms; 28% of case-patients reported recurring fevers, 55% had arthralgia, and 16% had a rash. Thirteen percent of patients were hospitalized, and no deaths were reported. Ongoing surveillance will improve understanding of the incidence and clinical severity of this emerging disease.

Differential detection of tick-borne pathogens in human platelets and whole blood using microfluidic PCR

The tick-borne pathogens (TBPs) with adhesive phenotype can use platelets for dissemination and colonization of distant tissues and organs, and it has been shown that they can be found concentrated in the platelet fraction of blood. This study shows the differential presence of TBPs in samples of human platelet fraction (n = 68), whole blood samples (n = 68) and ticks collected (n = 76) from the same individuals, using an unbiased high-throughput pathogen detection microfluidic system. The clinical symptoms were characterized in enrolled patients. In patients with suspected TBP infection, serological assays were conducted to test for the presence of antibodies against specific TBPs. Tick species infesting humans were identified as Ixodes ricinus, Dermacentor reticulatus, and Haemaphysalis punctata. Eight patients developed local skin lesions at the site of the tick bite including non-specific lesions, itching sensation at the lesion site, and eschar. Most common TBPs detected in platelet fraction were Borrelia spielmanii and Rickettsia sp., followed by Borrelia afzelii and Anaplasma phagocytophilum. Multiple infections with three TBPs were detected in platelet fraction. In whole blood, most common TBPs detected were Anaplasma spp. and A. phagocytophilum, followed by Rickettsia spp. and B. afzelii. In ticks, the most common TBP detected was Rickettsia spp., followed by Borrelia spp. and Anaplasma spp. Overall, nine different pathogens with variable prevalence were identified using species-specific primers, and the most common was Rickettsia helvetica. In three patients, there were no coincidences between the TBPs detected in whole blood and tick samples. Only in one patient was detected A. phagocytophilum in both, whole blood and tick samples. These results suggest the unequal detection of TBPs in whole blood, platelet fraction and ticks collected, from the same individual. The results justify the use of both whole blood and platelet fraction for molecular diagnosis of TBPs in patients.

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.

Autoimmune hemolytic anemia associated with babesiosis

BACKGROUND

Babesiosis is endemic in selected areas in North America. Babesia infection is commonly associated with anemia, thrombocytopenia, hyponatremia and elevated liver enzymes. Autoimmune hemolytic anemia (AIHA) is known to be caused by parasitic and viral infections but has not been well characterized.

CASE PRESENTATION

We describe two cases diagnosed with babesiosis triggering severe AIHA. One case had history of splenectomy, and the other was an elderly patient. Older, immunocompromised and asplenic patients may be particularly at risk for post-babesiosis AIHA (PB-AIHA).

CONCLUSIONS

The pathogenesis for conventional AIHA and PB-AIHA appears to be different, since splenectomy is a treatment for conventional AIHA, whereas PB-AIHA is seen more often in asplenic patients. Further investigation into this intriguing mechanism of host immune response to babesiosis may help to elucidate the overall mechanism of infection- triggered AIHA.

Babesiosis-associated immune thrombocytopenia

Thrombocytopenia is a common feature of babesiosis. The mechanism for thrombocytopenia in babesiosis remains elusive. We report a case of babesiosis with severe new onset immune thrombocytopenia (ITP). In addition to antibiotics treatment for babesiosis, ITP therapy was administered. ITP in the present case was most likely triggered by the babesia infection. The severity of ITP in this case was not proportional to the severity of parasitemia. The neoantigen triggering the autoimmune response in babesiosis requires further characterization.

Perioperative Occupational Exposure to Coxiella burnetii-Infected Thoracic Endovascular Aneurysm Stent Graft

We conducted this study to determine the risk of transmission of Q fever to health care workers (HCWs) during perioperative exposure to Coxiella burnetii-infected thoracic endovascular aneurysm stent graft. Pre-operative and 6-week post-operative phase I and II IgG Q fever antibody titers were determined in 14 staff members of an operation room. The room had a negative pressure and all the members of the surgical team wore either a fitted N-95 mask or a powered purified air respirator. Phase I and II IgG antibody titers were <1:16 for 11 of the 14 studied HCWs; 2 HCWs did not follow up at 6 weeks and 1 had a pre-exposure phase II IgG titer of 1:128 with no change 6 weeks later. We concluded that risk of transmission of C. burnetii in the operating room from infected patient to HCWs who wore appropriate personal protective equipment is low.

Risk assessment of transfusion-associated babesiosis in Tyrol: appraisal by seroepidemiology and polymerase chain reaction

BACKGROUND

After malaria, babesiosis is the second most common transfusion-transmitted parasitic disease in the United States. In Europe, one reported transfusion case, concerning Babesia microti, occurred in Germany.

STUDY DESIGN AND METHODS

Due to the fact that Babesia spp. are present in Tyrolean ticks, the aim of this study is to assess the occurrence of immunoglobulin (Ig)G antibodies against the Babesia divergens complex, including B. divergens and Babesia venatorum (EU1), as well as B. microti by screening a representative collective of 988 blood donors from North and East Tyrol (Austria) with indirect immunofluorescence antibody test. Additionally, we investigated 206 local ixodid ticks for the presence of babesial DNA by polymerase chain reaction.

RESULTS

Seroprevalence data resulted in rates of 2.1% for IgG antibodies against the B. divergens complex and 0.6% against B. microti in Tyrolean blood donors. All sera could be confirmed by independent retesting. Our data indicate that cross-reactivity is high between B. divergens and B. venatorum and lower than 19.8% between B. divergens and B. microti.

CONCLUSIONS

This study shows that Babesia spp. are present in the Tyrols, which blood donors come into serologic contact with, and that we have to consider how to sustain blood product safety concerning this new challenge. Additionally, it is the first description of B. venatorum in the Tyrols, found in one Ixodes ricinus at the Italian border.

Acute Q fever in Portugal. Epidemiological and clinical features of 32 hospitalized patients

INTRODUCTION

Q fever is a worldwide zoonosis caused by Coxiella burnetii. The main characteristic of acute Q fever is its clinical polymorphism, usually presenting as a febrile illness with varying degrees of hepatitis and/or pneumonia. Q fever is endemic in Portugal, and it is an obligatory notifiable disease since 1999. However, its epidemiological and clinical characteristics are still incompletely described.

METHODS

We performed a retrospective study of 32 cases admitted in the Infectious Diseases Department, Santa Maria's University Hospital, from January 2001 to December 2010, in whom acute Q fever was diagnosed by the presence of antibodies to phase II Coxiella burnetii antigens associated with a compatible clinical syndrome.

RESULTS

Out of the 32 cases recorded, 29 (91%) were male, with a male:female ratio of 9.7:1. Individuals at productive age were mainly affected (88%, n=28, with ages between 25 and 64 years). Clinically, the most common manifestation of acute Q fever was hepatic involvement (84%, n=27), which occurred isolated in 53% (n=17) of the cases. Hepatitis was more severe, presenting with higher values of liver function tests, in patients presenting both pulmonary and hepatic involvement. Additionally, we report one case of myocarditis and another one with neurological involvement. Empiric but appropriate antibiotic therapy was given in 66% (n=21) of the cases. There was a complete recovery in 94% (n=30) of the patients, and one death. We confirmed the sub-notification of this disease in Portugal, with only 47% (n=15) of the cases notified.

CONCLUSION

In Portugal further studies are needed to confirm our results. From the 32 cases studied, acute Q fever presented more frequently as a febrile disease with hepatic involvement affecting mainly young male individuals. Furthermore, acute Q fever is clearly underdiagnosed and underreported in Portugal, which suggests that an increased awareness of the disease is needed, together with a broader use of serological testing.

Transfusion-transmitted parasitic infections

The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas' disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply.

Q fever: clinical manifestations and treatment

Public awareness and advances in the diagnostic approach to Q fever have provided important information on epidemiological and clinical aspects of this zoonosis. Coxiella burnetii infection exhibits various acute or chronic clinical forms, and infection during pregnancy may jeopardize the integrity of the fetus. The presentation of infection is often nonspecific and this hinders prompt diagnosis. Therapeutic regimens vary, and treating Q fever during pregnancy and childhood is often challenging. Increasing clinical experience with C. burnetii infections has helped create treatment protocols and follow-up algorithms that have considerably improved management and prognosis. Vaccines are available, although their use is still limited.

Transfusion-transmitted babesiosis in Rhode Island

BACKGROUND

Babesiosis is caused by an intraerythrocytic protozoan transmitted by ticks. Blood transfusion is another mode of transmission.

STUDY DESIGN AND METHODS

This was a retrospective study based on babesiosis cases reported to the Rhode Island Department of Health between 1999 and 2007. Additional cases were also identified.

RESULTS

Twenty-one cases of transfusion-transmitted babesiosis (TTB) were identified from 1999 through 2007. From 2005 through 2007, the incidence approached one case per 9000 units of blood transfused. One of 21 (5%) TTB cases was diagnosed in July, in sharp contrast to 65 of 152 (43%) of the total babesiosis cases diagnosed during July in Rhode Island. Many cases were identified when a complete blood count with a differential was routinely requested and parasites were noted by laboratory technologists. Most patients with TTB had underlying conditions known to predispose to symptomatic infection.

CONCLUSION

Blood transfusion is an important mode of Babesia transmission. The current screening method of omitting donors with a history of babesiosis may be effective in preventing some, but not all, cases of TTB and current processing of blood products does not eradicate this parasite. Thus, a better screening test is needed. Alternatively, pathogen reduction technology could be utilized to prevent this mode of transmission.

Unique macrophage and tick cell-specific protein expression from the p28/p30-outer membrane protein multigene locus in Ehrlichia chaffeensis and Ehrlichia canis

Ehrlichia chaffeensis and Ehrlichia canis are tick-transmitted rickettsial pathogens that cause human and canine monocytic ehrlichiosis respectively. We tested the hypothesis that these pathogens express unique proteins in response to their growth in vertebrate and tick host cells and that this differential expression is similar in closely related Ehrlichia species. Evaluation of nine E. chaffeensis isolates and one E. canis isolate demonstrated that protein expression was host cell-dependent. The differentially expressed proteins included those from the p28/30-Omp multigene locus. E. chaffeensis and E. canis proteins expressed in infected macrophages were primarily the products of the p28-Omp 19 and 20 genes or their orthologues. In cultured tick cells, E. canis expressed only the p30-10 protein, an orthologue of the E. chaffeensis p28-Omp 14 protein which is the only protein expressed by E. chaffeensis propagated in cultured tick cells. The expressed Omp proteins were post-translationally modified to generate multiple molecular forms. E. chaffeensis gene expression from the p28/30-Omp locus was similar in tick cell lines derived from both vector (Amblyomma americanum) and non-vector (Ixodes scapularis) ticks. Differential expression of proteins within the p28/p30-Omp locus may therefore be vital for adaptation of Ehrlichia species to their dual host life cycle.

Q fever

Q fever is a zoonosis with many manifestations. The most common clinical presentation is an influenza-like illness with varying degrees of pneumonia and hepatitis. Although acute disease is usually self-limiting, people do occasionally die from this condition. Endocarditis is the most frequent chronic presentation. Although Q fever is widespread, practitioner awareness and clinical manifestations vary from region to region. Geographically limited studies suggest that chronic fatigue syndrome and cardiovascular disease are long-term sequelae. An effective whole-cell vaccine is licensed in Australia. Live and acellular vaccines have also been studied, but are not currently licensed.

Neonatal babesiosis: case report and review of the literature

A case of transfusion-associated neonatal babesiosis is presented. Jaundice, hepatosplenomegaly, anemia and conjugated hyperbilirubinemia developed in this preterm infant. The diagnosis was eventually made by blood smear, serology and polymerase chain reaction. The patient was treated with clindamycin and quinine and made a favorable recovery. Of neonatal babesiosis reported in the literature, 9 other cases are reviewed, including 6 that were transfusion-associated, 2 congenital and 2 tick transmitted.

Ehrlichia chaffeensis expresses macrophage- and tick cell-specific 28-kilodalton outer membrane proteins

Ehrlichia chaffeensis, a tick-transmitted rickettsial agent, causes human monocyte/macrophage-tropic ehrlichiosis. In this study, proteomic approaches were used to demonstrate host cell-specific antigenic expression by E. chaffeensis. The differentially expressed antigens include those from the 28-kDa outer membrane protein (p28-Omp) multigene locus. The proteins expressed in infected macrophages are the products of p28-Omp19 and p28-Omp20 genes, whereas in tick cells, the protein expressed is the p28-Omp14 gene product. The differentially expressed proteins are posttranslationally modified by phosphorylation and glycosylation to generate multiple expressed forms. Host cell-specific protein expression is not influenced by growth temperatures and is reversible. Host cell-specific protein expression coupled with posttranslational modifications may be a hallmark for the pathogen's adaptation to a dual-host life cycle and its persistence.