Sound Around the World: Ultrasound for Tropical Diseases

Implementation of point-of-care ultrasonography in an infectious disease ward

INTRODUCTION

Point-of-care ultrasonography (POCUS) has emerged as an essential supplement to physical examination in many specialties. In contrast, its use by infectious diseases (ID) specialists remains anecdotal. Here, we report on the acquisition of an ultrasonography device in a French ID ward, and we describe its everyday use.

METHODS

A preliminary audit was conducted to evaluate the potential impact of the acquisition of an ultrasonography device. A second audit was performed during the first year following the acquisition of the device to quantify its everyday use. We also evaluated the impact of POCUS implementation on medical imaging requests by comparing the number of intra-hospital transports before and after the acquisition.

RESULTS

According to the first audit, 81 of the 199 (41%) imaging examinations that were prescribed during a two-month period could have been replaced by POCUS. During the first year following the acquisition of the ultrasonography device, POCUS was performed 240 times by 31 different operators. The operators were a senior physician, an intern, and a medical student in 94 (39%), 135 (57%), and 11 (5%) cases, respectively. The organs most frequently explored were the genito-urinary tract (n=74), the joints (n=35), and the lungs/pleura (n=35). Acquisition of the device was followed by a significant decrease in the number of transports to the ultrasonography room, whereas the total number of transports to the medical imaging ward did not change.

CONCLUSION

Opportunities to use POCUS in the ID ward are numerous. POCUS training should be part of the ID specialist's curriculum.

Context-Specific Procedures for the Diagnosis of Human Schistosomiasis – A Mini Review

Schistosomiasis is a parasitic disease caused by trematode blood flukes of the genus Schistosoma, affecting over 250 million people mainly in the tropics. Clinically, the disease can present itself with acute symptoms, a stage which is relatively more common in naive travellers originating from non-endemic regions. It can also develop into chronic disease, with the outcome depending on the Schistosoma species involved, the duration and intensity of infection and several host-related factors. A range of diagnostic tests is available to determine Schistosoma infection, including microscopy, antibody detection, antigen detection using the Point-Of-Care Circulating Cathodic Antigen (POC-CCA) test and the Up-Converting Particle Lateral Flow Circulating Anodic Antigen (UCP-LF CAA) test, as well as Nucleic Acid Amplification Tests (NAATs) such as real-time PCR. In this mini review, we discuss these different diagnostic procedures and explore their most appropriate use in context-specific settings. With regard to endemic settings, diagnostic approaches are described based on their suitability for individual diagnosis, monitoring control programs, determining elimination as a public health problem and eventual interruption of transmission. For non-endemic settings, we summarize the most suitable diagnostic approaches for imported cases, either acute or chronic. Additionally, diagnostic options for disease-specific clinical presentations such as genital schistosomiasis and neuro-schistosomiasis are included. Finally, the specific role of diagnostic tests within research settings is described, including a controlled human schistosomiasis infection model and several clinical studies. In conclusion, context-specific settings have different requirements for a diagnostic test, stressing the importance of a well-considered decision of the most suitable diagnostic procedure.

Emerging applications of clinical ultrasonography

In this work, we introduce the numerous emerging areas and frontiers in the use of point-of-care ultrasonography. Of these, we review the following three: 1) the use of clinical ultrasonography in infectious and tropical diseases (we address its usefulness in the diagnosis and follow-up of the main syndromes, in tropical diseases, and in areas with scarce resources); 2) the usefulness of clinical ultrasonography in the assessment of response to volume infusion in severely ill patients (we review basic concepts and the main static and dynamic variables used for this evaluation); and 3) the use of clinical ultrasonography in the assessment of muscle mass in elderly patients with primary sarcopenia (we review the main muscles and measurements used for it).

Emerging applications of clinical ultrasonography

In this work, we introduce the numerous emerging areas and frontiers in the use of point-of-care ultrasonography. Of these, we review the following three: 1) the use of clinical ultrasonography in infectious and tropical diseases (we address its usefulness in the diagnosis and follow-up of the main syndromes, in tropical diseases, and in areas with scarce resources); 2) the usefulness of clinical ultrasonography in the assessment of response to volume infusion in severely ill patients (we review basic concepts and the main static and dynamic variables used for this evaluation); and 3) the use of clinical ultrasonography in the assessment of muscle mass in elderly patients with primary sarcopenia (we review the main muscles and measurements used for it).

Ventricular Tachycardia and the Cystic Heart: A Case Report

BACKGROUND

Hydatid cysts are caused by Echinococcus granulosus infection, and hydatidosis is recognized as a re-emerging zoonotic disease globally. While the liver is the most commonly affected organ, other organs can also be affected, including the heart. Because of the low sensitivity and specificity of serologic diagnostic tests, ultrasound and echocardiography are increasingly used to make the diagnosis of cardiac hydatid cyst.

CASE REPORT

We report the case of a cardiac hydatid cyst, detected by point-of-care ultrasound (POCUS), in a 79-year-old woman who presented with shortness of breath and was in ventricular tachycardia. The diagnosis was further confirmed with a computed tomography scan. Although cases of alveolar and liver hydatid cysts are seen, this is the first case of a cardiac hydatid cyst in Bhutan. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case illustrates the importance of POCUS in reaching a diagnosis, particularly in resource-poor areas where other sophisticated diagnostic tools are not easily available. A cardiac hydatid cyst must be in the differential for structural causes of dysrhythmias. This is especially so because treatment of unstable dysrhythmias in the acute setting of an emergency department has to be modified from the usual algorithm in the presence of a cardiac hydatid cyst, due to the potentially fatal risk of cyst rupture and anaphylaxis.