Musculoskeletal Echinococcus infection as a rare first presentation of hydatid disease: case report

Musculoskeletal involvement in neglected tropical diseases: a comprehensive review

Neglected tropical diseases (NTDs) encompass a group of diseases predominantly found in tropical regions, with origins dating back to their inclusion in the United Nations Millennium Development Goals in 2000. This initiative aimed to raise awareness and global funding to combat these diseases, which thrive in areas with limited sanitation, healthcare, and education. NTDs are caused by various pathogens such as bacteria, fungi, parasites, and viruses and affect over two billion individuals in resource-poor communities, leading to preventable deaths and devastating consequences. While the musculoskeletal system is only occasionally affected, the resulting chronic disabilities prevent individuals from working, posing a significant socioeconomic burden in this region of the world. Some NTDs exhibit distinct imaging features, and radiologists need to be aware of these characteristics to facilitate early treatment. In this review, we delve into musculoskeletal NTDs, focusing on clinical features and imaging findings, differential diagnosis, and clinical management.

A case report of primary hydatidosis of ulna and adjacent soft tissue

Hydatidosis, is a zoonotic disease prevalent in sheep-raising regions globally. Musculoskeletal hydatidosis is uncommon and usually remains asymptomatic over a long period. The detection of musculoskeletal hydatidosis often signifies extensive cyst spread within the bone marrow cavity, making treatment difficult with a high recurrence rate. Unlike the conventional surgical approach for visceral hydatid cysts, treating osseous hydatidosis requires a strategy akin to oncologic therapy. We report a rare case of primary hydatidosis affecting the ulna and adjacent soft tissue in a 58-year-old woman. She presented with a painless forearm mass evolving over six years, accompanied by recent onset tenderness and restricted elbow joint mobility. Imaging revealed a cystic mass in the forearm, an intra-ulnar bone lesion, and an olecranon fracture. The primary diagnosis of musculoskeletal hydatidosis was made based on clinical findings and radiological imaging. Treatment involved resection of 2/3 of the proximal ulna and pericystectomy for the soft tissue hydatid cyst. Diagnosis of musculoskeletal hydatidosis is vital for effective preoperative planning, as internal fixation often fails without eradicating the infestation. Treatment typically involves radical operation with wide excision of the affected bone and adjacent joint structures, coupled with chemotherapy. Clinicians in endemic regions should consider musculoskeletal hydatidosis in the differential diagnosis of osteolytic lesions and slow-growing cystic masses. Diagnosis relies on clinical, serological, and radiological assessments.

Pharmacokinetics and tissue distribution study of liposomal albendazole in naturally Echinococcus granulosus infected sheep by a validated UPLC-Q-TOF-MS method

Albendazole (ABZ) is the first-line drug in treating echinococcosis, which is recommended by WHO. To address the poor bioavailability of albendazole, liposomal albendazole was formulated and is available in our hospital for many years. In this study, a sensitive, reliable and accurate UPLC-Q-TOF-MS method was developed and validated for the determination of albendazole and its metabolites, albendazole sulfoxide (ABZSO), albendazole sulfone (ABZSO₂) and albendazole-2-aminosulfone (ABZSO₂NH₂) in naturally echinococcus granulosus (E. granulosus) infected sheep plasma and tissues with mebendazole (MBZ) as the internal standard (IS). Plasma and tissues samples were prepared by protein precipitation method. The separation was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 μm) with a gradient mobile phase consisting of methanol and water containing 0.1% formic acid at 0.4 mL/min. The detection was performed on a quadrupole time-of-flight (Q-TOF) high-resolution mass spectrometer using positive electrospray ionization (ESI) source with a chromatographic run time of 6.0 min. The detection was operated using target ions of [M + H]⁺ at m/z 266.096 for ABZ, m/z 282.091 for ABZSO, m/z 298.086 for ABZSO₂, m/z 240.081 for ABZSO₂NH₂ and m/z 296.104 for IS in selective ion mode, respectively. This method was validated in terms of selectivity, linearity, precision, accuracy, recovery, matrix effect, dilution effect, carryover effects, stability, calibration curve and LLOQ. All validation parameter results were within the acceptable range described in guideline for bioanalytical method validation. This method has been successfully applied to the pharmacokinetic study following single and multiple oral dose of 10 mg/kg liposomal albendazole, and tissue distribution study following multiple oral dose of 10 mg/kg, with emulsion albendazole as the reference preparation. The results in the article will provide valuable information for use in clinical applications of liposomal albendazole and also be beneficial for further development of liposomal albendazole in future studies.

Designing a Recombinant Multi-Epitope Antigen of Echinococcus granulosus to Diagnose Human Cystic Echinococcosis

BACKGROUND

Cystic echinococcosis can cause severe disease and probable death in humans. Epitopes of its antigens play a key role in the sensitivity and specificity of immunodiagnostic tests.

METHODS

Epitope prediction software programs predict the most antigenic linear B-cell epitopes of AgB (8 kD), Ag5, and Ag95. Six such epitopes were predicted and connected by "Gly-Ser" linker and synthesized. The purity of the concentrated recombinant multi-epitope protein was assessed by 15% SDS-PAGE. Overall, 186 serum samples were collected from the Loghman Hakim Hospital and different laboratories, Tehran, Iran, from July 2016 to February 2017. Patients infected with hepatic hydatid cysts, patients infected by other parasites and viruses, and healthy individuals were used to detect the anti-CE IgG using recombinant multi-epitope protein.

RESULTS

Forty-one samples out of 43 cases of hydatidosis were diagnosed correctly as positive, and two were negative. In addition, six negative cases of healthy individual group were diagnosed as positive and negative with rMEP-ELISA and the commercial kit, respectively. Therefore, these six samples were considered as false positive using our method. In addition, a diagnostic sensitivity of 95.3% (95% CI, 84.19% to 99.43%) and a specificity of 95.0% (95% CI, 89.43% to 98.14%) were obtained using optimum cutoff value (0.20). The sensitivity and specificity of the commercial kit was 100%.

CONCLUSION

Our findings showed high diagnostic accuracy of the ELISA test using the developed recombinant protein, which encourages the use of this recombinant multi-epitope protein for rapid serological diagnosis of hydatidosis.

Cystic lesion of pectoralis minor muscle: learning from mistakes

Hydatidosis is a frequent infestation in large endemic areas, caused by helminths. Primary localization within the muscle or bone tissues is rare. We report the case of a 52-year-old woman with a cystic lesion located in the right pectoralis minor muscle, who was initially diagnosed with cystic lymphangioma by imaging examination. She was submitted for surgical treatment; in block resection of the tumor along with the involved muscle was performed. The histopathological diagnosis was of hydatid cyst. The contribution of the ancillary lab tests is analyzed for a precise preoperative diagnostic approach. This case well illustrates that the most likely is not always what it appears to be. Facing of a cystic lesion in the lungs, liver or muscle, clinicians should always think on hydatid disease, particularly in endemic areas.