Positron emission tomography and magnetic resonance imaging in experimental human malaria to identify organ-specific changes in morphology and glucose metabolism: A prospective cohort study.

BACKGROUND: Plasmodium vivax has been proposed to infect and replicate in the human spleen and bone marrow. Compared to Plasmodium falciparum, which is known to undergo microvascular tissue sequestration, little is known about the behavior of P. vivax outside of the circulating compartment. This may be due in part to difficulties in studying parasite location and activity in life. METHODS AND FINDINGS: To identify organ-specific changes during the early stages of P. vivax infection, we performed 18-F fluorodeoxyglucose (FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) at baseline and just prior to onset of clinical illness in P. vivax experimentally induced blood-stage malaria (IBSM) and compared findings to P. falciparum IBSM. Seven healthy, malaria-naive participants were enrolled from 3 IBSM trials: NCT02867059, ACTRN12616000174482, and ACTRN12619001085167. Imaging took place between 2016 and 2019 at the Herston Imaging Research Facility, Australia. Postinoculation imaging was performed after a median of 9 days in both species (n = 3 P. vivax; n = 4 P. falciparum). All participants were aged between 19 and 23 years, and 6/7 were male. Splenic volume (P. vivax: +28.8% [confidence interval (CI) +10.3% to +57.3%], P. falciparum: +22.9 [CI -15.3% to +61.1%]) and radiotracer uptake (P. vivax: +15.5% [CI -0.7% to +31.7%], P. falciparum: +5.5% [CI +1.4% to +9.6%]) increased following infection with each species, but more so in P. vivax infection (volume: p = 0.72, radiotracer uptake: p = 0.036). There was no change in FDG uptake in the bone marrow (P. vivax: +4.6% [CI -15.9% to +25.0%], P. falciparum: +3.2% [CI -3.2% to +9.6%]) or liver (P. vivax: +6.2% [CI -8.7% to +21.1%], P. falciparum: -1.4% [CI -4.6% to +1.8%]) following infection with either species. In participants with P. vivax, hemoglobin, hematocrit, and platelet count decreased from baseline at the time of postinoculation imaging. Decrements in hemoglobin and hematocrit were significantly greater in participants with P. vivax infection compared to P. falciparum. The main limitations of this study are the small sample size and the inability of this tracer to differentiate between host and parasite metabolic activity. CONCLUSIONS: PET/MRI indicated greater splenic tropism and metabolic activity in early P. vivax infection compared to P. falciparum, supporting the hypothesis of splenic accumulation of P. vivax very early in infection. The absence of uptake in the bone marrow and liver suggests that, at least in early infection, these tissues do not harbor a large parasite biomass or do not provoke a prominent metabolic response. PET/MRI is a safe and noninvasive method to evaluate infection-associated organ changes in morphology and glucose metabolism.

Tissue (re)distribution of Trypanosoma equiperdum in venereal infected and blood transfused horses.

Dourine, caused by Trypanosoma equiperdum, is a life-threatening venereal disease in equidae. So far, there is no clear evidence on how and when stallions become infectious, nor which tissues are affected by the parasite in diseased animals. Post-infection, after a transient, temporary phase of parasitaemia, the parasite disperses to different tissues in an unknown distribution pattern. This study describes the distribution of the parasite after infection by artificial insemination (AI) or blood transfusion. Mares (N = 4) were artificially inseminated with T. equiperdum spiked semen whereas stallions (N = 4) were infected by blood transfusion. The course of the disease was monitored by parasitological (Woo) and molecular (PCR) tests and clinical signs and haematological parameters were recorded. At 120 days post infection, horses had a full necropsy, histopathology and PCR. A similar pattern of parasitaemia, disease progression and tissue distribution were seen in all horses. Ejaculated semen in the preclinical stage and epididymal semen in the chronic stage of the disease was positive on PCR and caused infection in mice. Cymelarsan® treatment in the chronic stage did not result in a clinico-haematological or histopathological improvement. At necropsy, lesions were observed in the nervous and reproductive system. Histopathological lesions were most severe in the peripheral nerves and associated ganglia, the testicles and genital mucosae with multifocal infiltration of lymphocytes, plasma cells and histocytes. The parasites disseminated to several tissues including the nervous system, testicles and semen. The results indicate that transmission of T. equiperdum is possible through semen even from symptomless stallions post-treatment.

Common Spinal Parasites.

AIM: To report the four most common spinal parasites for providing insight into definitive therapy. MATERIAL AND METHODS: Twelve patients with spinal parasites were diagnosed between 2009 and 2016. A definite diagnosis was established in the form of histopathology (n=9) and response to drug therapy (n=3). The minimum follow-up was 0.9 years and ranged to a maximum of 8 years, with a median of 3 years. RESULTS: Twelve patients aged between 8 and 69 years were reviewed, including nine hydatidosis and three non-hydatid cases. Occupational exposure to the endemic area and unclean food were the main routes of infestation. Spinal parasites can present symptoms that correlated with the level of the lesion. There was complete paraplegia in four patients and paraparesis in six patients before surgery. Seven hydatid patients underwent posterior decompression and pedicle screw fixation with posterolateral fusion. Two non-hydatid patients experienced laminoplasty after posterior decompression. Six hydatid patients had reoccurrences and two patients with intramedullary hydatidosis died of severe complications one year after surgery. CONCLUSION: Spinal hydatidosis significantly differs from the three other non-hydatid parasites in diagnosis and treatment. The final prognosis of spinal hydatidosis remains poor, especially for intramedullary hydatidosis.

Parasitic infections of the spine: case series and review of the literature.

OBJECTIVEAlthough parasitic infections are endemic to parts of the developing world and are more common in areas with developing economies and poor sanitary conditions, rare cases may occur in developed regions of the world.METHODSArticles eligible for the authors' literature review were initially searched using PubMed with the phrases "parasitic infections" and "spine." After the authors developed a list of parasites associated with spinal cord infections from the initial search, they expanded it to include individual diagnoses, using search terms including "neurocysticercosis," "schistosomiasis," "echinococcosis," and "toxoplasmosis."RESULTSTwo recent cases of parasitic spinal infections from the authors' institution are included.CONCLUSIONSKey findings on imaging modalities, laboratory studies suggestive of parasitic infection, and most importantly a thorough patient history are required to correctly diagnose parasitic spinal infections.

Vertebral alveolar echinococcosis-a case report, systematic analysis, and review of the literature.

Alveolar echinococcosis caused by Echinococcus multilocularis is an infrequent zoonosis with a high degree of disability, morbidity, and mortality, especially in disease clusters of the northern hemisphere. The diagnosis is complicated by extended incubation time, diverse clinical manifestations, and mimicking of differential diagnoses. The primary organ affected is the liver, but extrahepatic disease is possible, with vertebral involvement in only a few dozen cases described worldwide. Although vertebral alveolar echinococcosis seems to be rare, it might be under diagnosed, and it might be seen more often as the number of people with immunocompromised conditions increases. Recognition of this syndrome is crucial, because advances in medical and surgical management strategies since the introduction of benzimidazole in 1976 have controlled and relieved symptoms in most cases. In this Grand Round, we present the case of a 75-year-old woman who was referred for biopsy of a lumbar lesion 3 months after she was diagnosed with chronic myeloid leukaemia. The diagnosis of hepatic alveolar echinococcosis with metastasis to the lumbar spine and paravertebral region as well as the brain was confirmed by biopsy, PCR, and serology. The patient was given albendazole and referred for palliative surgery with the aim of pain control. Clinical features of the case are presented and discussed in the context of the literature. This case and review illustrate the complexity of extrahepatic alveolar echinococcosis manifestations and the necessity of an interdisciplinary approach.

Hydatid cyst in the spine. The alliance between surgeon and infectivologist is winning: a case report.

Hydatid Cyst is a protozoal disease, whose spinal localization may be cause of pain and severe inability due to neurological symptoms and instability. Treatment combines the difficulties to eradicate the cyst with the spine regional constraints. The case of a 45-year-old woman is reported, affected by hydatid cyst in the spine, submitted to combination of medical treatment and surgery (double approach gross total excision and reconstruction) and followed up for 6 years. The treatment strategy allowed an excellent quality of life without pain and neurological symptoms at the latest follow-up. This case supports the validity to combine anthelmintic medical treatment and excisional surgery in the treatment of hydatid cyst of the spine. The medical treatment makes surgery more effective maintaining the result over long term. Subtotal or total excision of the cysts can be performed, including decompression of neural structures and adequate spine reconstruction.

Parasitic and rare spinal infections.

The imaging features of spinal parasitic diseases and other rare infections are herein discussed. These diseases are distributed worldwide, with increased prevalence in areas with poor sanitary conditions and in developing countries. In nonendemic areas, sporadic cases may occur, consequent to increased international travel and immunocompromising conditions. Infectious diseases are usually treatable, and early detection is often crucial. A thorough comprehension of the imaging patterns associated with the clinical features, epidemiology, and laboratory results allows the radiologist to narrow down the options for differential diagnosis and facilitates the timely implementation of appropriate therapies.

Biomechanical Comparisons of Pull Out Strengths After Pedicle Screw Augmentation with Hydroxyapatite, Calcium Phosphate, or Polymethylmethacrylate in the Cadaveric Spine.

OBJECTIVE: In vertebrae with low bone mineral densities pull out strength is often poor, thus various substances have been used to fill screw holes before screw placement for corrective spine surgery. We performed biomechanical cadaveric studies to compare nonaugmented pedicle screws versus hydroxyapatite, calcium phosphate, or polymethylmethacrylate augmented pedicle screws for screw tightening torques and pull out strengths in spine procedures requiring bone screw insertion. METHODS: Seven human cadaveric T10-L1 spines with 28 vertebral bodies were examined by x-ray to exclude bony abnormalities. Dual-energy x-ray absorptiometry scans evaluated bone mineral densities. Twenty of 28 vertebrae underwent ipsilateral fluoroscopic placement of 6-mm holes augmented with hydroxyapatite, calcium phosphate, or polymethylmethacrylate, followed by transpedicular screw placements. Controls were pedicle screw placements in the contralateral hemivertebrae without augmentation. All groups were evaluated for axial pull out strength using a biomechanical loading frame. RESULTS: Mean pedicle screw axial pull out strength compared with controls increased by 12.5% in hydroxyapatite augmented hemivertebrae (P = 0.600) and by 14.9% in calcium phosphate augmented hemivertebrae (P = 0.234), but the increase was not significant for either method. Pull out strength of polymethylmethacrylate versus hydroxyapatite augmented pedicle screws was 60.8% higher (P = 0.028). CONCLUSIONS: Hydroxyapatite and calcium phosphate augmentation in osteoporotic vertebrae showed a trend toward increased pedicle screw pull out strength versus controls. Pedicle screw pull out force of polymethylmethacrylate in the insertion stage was higher than that of hydroxyapatite. However, hydroxyapatite is likely a better clinical alternative to polymethylmethacrylate, as hydroxyapatite augmentation, unlike polymethylmethacrylate augmentation, stimulates bone growth and can be revised.

Meningitis linfocitaria y neurocisticercosis espinal. A propósito de un caso y revisión de la literatura / Lymphocytic meningitis and spinal neurocysticercosis: A case report and literature review

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Spinal infection: state of the art and management algorithm.

INTRODUCTION: Spinal infection is a rare pathology although a concerning rising incidence has been observed in recent years. This increase might reflect a progressively more susceptible population but also the availability of increased diagnostic accuracy. Yet, even with improved diagnosis tools and procedures, the delay in diagnosis remains an important issue. This review aims to highlight the importance of a methodological attitude towards accurate and prompt diagnosis using an algorithm to aid on spinal infection management. METHODS: Appropriate literature on spinal infection was selected using databases from the US National Library of Medicine and the National Institutes of Health. RESULTS: Literature reveals that histopathological analysis of infected tissues is a paramount for diagnosis and must be performed routinely. Antibiotic therapy is transversal to both conservative and surgical approaches and must be initiated after etiological diagnosis. Indications for surgical treatment include neurological deficits or sepsis, spine instability and/or deformity, presence of epidural abscess and upon failure of conservative treatment. CONCLUSIONS: A methodological assessment could lead to diagnosis effectiveness of spinal infection. Towards this, we present a management algorithm based on literature findings.

Intramedullary hydatid cyst of the cervical spine.

Hydatid disease (Echinococcosis) is a common parasitic infection caused by Echinococcus granulosus mainly in sheep-raising areas of the world. Liver, lungs and brain are the predominantly involved organs. However, 0.5-1% of the hydatid disease involves the spine and in 90% of the cases it is confined to the bone and the epidural space. Although intramedullary involvement is extremely rare, in this report, we present a 55-year-old female patient who was diagnosed with a cervical intramedullary hydatid cyst during magnetic resonance imaging of the cervical vertebrae. Accordingly, we imply that particularly in endemic areas, hydatid cyst disease should be kept in mind for the differential diagnosis of spinal mass lesions.

Philasterides dicentrarchi, a histophagous ciliate causing scuticociliatosis in olive flounder, Philasterides dicentrarchi--histopathology investigations.

Philasterides dicentrarchi is a histophagous scuticociliate infecting Korean olive flounder farms in Jeju Island, South Korea, where it causes significant economic losses. However, the route of entry of these parasites in olive flounder is currently unknown. In the present study, we attempted experimental infection with different doses (concentrations) of P. dicentrarchi by intraperitoneal (IP) injection; maximum cumulative mortality of 95% was recorded on the administration of 2.1×10(8) ciliates/ml. In small size group (3 cm length, 24±2 gwt) the ciliates were found in connective tissues of muscle, fins, and nervous tissue while in large size group (5 cm length, 47±3 gwt), the ciliates were predominantly occurred with associated symptoms of liquefaction in the central nervous system. The major clinico-pathological manifestations were loss of scales, appearance of bleached spots that coalesced to form brownish patches, hemorrhagic, and severe dermal necrotic lesion. In addition there was degeneration of muscle fibers, necrosis of the hepatic parenchyma, and severe edema of the intestinal walls, extensive fouling, necrotic degeneration and hyperplasia in the gill bronchial epithelium. In this study, many ciliates were found in the blood vessel, brain, dorsal fins, muscle, kidney, and vertebra of infected flounder. The histopathological investigations are of significant importance in view of possible routes of entry into the host and doses of ciliates that trigger fast infection for potential utility of drugs as a strategy for the control of P. dicentrarchi in farmed olive flounder.

Recurrent vertebral hydatid disease: spectrum of MR imaging features.

INTRODUCTION: This study aimed to describe a spectrum of magnetic resonance (MR) imaging findings in a case series of four patients with recurrent vertebral hydatid disease (HD). METHODS: Four patients with recurrent spinal HD, who were studied with MR imaging at 1.5T or 0.5T MR units, were encountered during a ten-year period. All patients had a history of repeated spinal surgery for hydatid resection. RESULTS: HD involving the lumbar spine was found in two patients, the thoracolumbar spine in one patient and the lumbosacral in one patient. Skip lesions were seen in one patient. All patients had extensive involvement of the extradural space, soft tissues of the back and posterior vertebral elements. HD involving the vertebral body, intervertebral disk and iliopsoas muscles were noted in three, two and three patients, respectively. Bone and extradural hydatids were typically small, and appeared hypointense on T1-weighted images, with a mildly enhancing rim on post-contrast T1-weighted images. Sacral hydatid was an expansile multicystic process. Muscle hydatids were large, surrounded by a gadolinium-enhancing rim and assumed a variety of patterns - either multilocular or a nonspecific inhomogenous cystic or dumbbell configuration. CONCLUSION: MR imaging is a valuable diagnostic tool for follow-up of patients with vertebral HD. Recurrent HD is characterised by extensive involvement of soft tissues of the back and extradural space. Extension into the intervertebral disk and iliopsoas muscles and skip lesions in the extradural space are not uncommon.

Primary extrahepatic alveolar echinococcosis of the lumbar spine and the psoas muscle.

Alveolar echinococcosis (AE) of human being caused by Echinococcus multilocularis is a rare but important zoonosis especially in tempered zones of middle Europe and Northern America with endemic character in many countries. Due to the long incubation period, various clinical manifestations, critical prognosis, and outcome AE presents a serious and severe disease. The primary focus of infection is usually the liver. Although secondary affection of visceral organs is possible extrahepatic AE is highly uncommon. Moreover, the involvement of bone and muscle presents with an even lower incidence. In the literature numerous cases on hepatic AE have been reported. However, extrahepatic AE involving bones and/or muscles was described very rarely. We report a case of an 80-year-old man with primary extrahepatic alveolar Echinococcosis of the lumbar spine and the psoas muscle. The etiology, diagnosis, differential diagnoses, treatment options and outcome of this rare disease are discussed in context with the current literature.

Intradural extramedullary spinal hydatidosis: case report.

The parasitic tapeworm Echinococcus granulosis causes hydatid disease, which is rarely encountered in nonendemic regions. It is a progressive disease with serious morbidity risks. Rarely, these cysts are found in the spine. They are mainly found epidurally, originating from direct extension from pulmonary, abdominal or pelvic infestation. Nevertheless, the main mechanism for intradural involvement is not yet clear. Antihelminthic treatment should be administered for a long period following early decompressive surgery. We report a case of recurrent hydatid disease that presented unusual intradural dissemination. Prognosis for spinal hydatid disease remains very poor and comparable to that of a malignant neoplasm.

Manejo anestésico de la hidatidosis sacroilíaca-vertebral / Anesthetic management of sacroiliac-vertebral echinococcosis

La hidatidosis afecta a la columna y a la pelvis en un60% de los casos, las lesiones en el hueso pueden estarsilentes de 10 a 20 años. Las vesículas progresan agresivamentepor el canal endomedular y sustituyen a las trabéculasóseas sin formar quistes como en las vísceras,por lo que la posibilidad de anafilaxia es rara. La combinaciónde quimioterapia y cirugía facilita el manejoanestésico, reduciendo la incidencia de reacciones anafilácticasy las recidivas de la enfermedad (AU)

Bone echinococcosis affects the spine and pelvis in60% of cases. Bone lesions may be silent for between 10and 20 years. The capsules progress aggressivelythrough the medullary canal and replace the trabecularbone without forming cysts, as occurs in the organs, thusmaking anaplylaxis rare. The combination ofchemotherapy and surgery facilitates anestheticmanagement and reduces the incidence of anaphylacticevents and disease recurrence (AU)

Unusual imaging characteristics of complicated hydatid disease.

Hydatid disease, a worldwide zoonosis, is caused by the larval stage of the Echinococcus tapeworm. Although the liver and the lungs are the most frequently involved organs in the body, hydatid cysts of other organs are unusual. Radiologically, they usually demonstrate typical imaging findings, but unusual imaging characteristics of complicated cyst of hydatid disease, associated with high morbidity and mortality, are rarely described in the literature. The purpose of this study is to review the general features of hydatidosis and to discuss atypical imaging characteristics of the complicated hydatid disease in the human, with an emphasis on structure and rupture of the cystic lesion as well as ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) features of the disease. In our study, the available literature and images of the cases with complicated hydatidosis involving liver, lung, brain, spine and orbit were reviewed retrospectively. In hydatid disease, there are many potential local and systemic complications due to secondary involvement in almost any anatomic location in humans. Radiologically, in addition to the presence of atypical findings such as perifocal edema, non-homogenous contrast enhancement, multiplicity or septations and calcification, various unusual manifestations due to rupture or infection of the cyst have been observed in our cases with complicated hydatid disease. To prevent subsequent acute catastrophic results and the development of recurrences in various organs, it should be kept in mind that complicated hydatid cysts can cause unusual USG, CT, and MRI findings, in addition to typical ones, in endemic areas. Therefore, familiarity with atypical radiological appearances of complicated hydatid disease may be valuable in making a correct diagnosis and treatment.