Sound Around the World: Ultrasound for Tropical Diseases

Concepts for point-of-care ultrasound training in low resource settings: a scoping review

BACKGROUND

Point-of-care ultrasound (POCUS) is a potent diagnostic tool especially in resource-limited settings. The implementation of POCUS diagnostics requires adequate training of POCUS operators. This scoping review aimed to identify and describe POCUS training concepts that have been applied in low-and middle-income countries (LMICs).

METHODS AND FINDINGS

All studies on diagnostic POCUS training in LMICs that could be found in the Cochrane, Embase, Google Scholar, and Medline databases up to July 6, 2023, were included and data was extracted for descriptive analysis. The review protocol was registered at OSF https://doi.org/10.17605/OSF.IO/8FQJW . A total of 53 publications were included with 59% of studies (n = 31) conducted in Africa and 23% (n = 12) in Asia. The majority of studies (n = 41, 81%) described short courses amongst which 40% were one-off sessions and 60% described longitudinal trainings. Curricula were mostly related to emergency medicine and obstetrics and organ-focused protocols (lung n = 29 (54%), cardiac n = 28 (53%), obstetric n = 23 (43%)). Trainees were largely medical doctors and clinical officers with minimal or absent ultrasound skills. Training challenges included resource constraints and lack of context adaptation. Best practice recommendations included focus on hands-on training, low trainer to trainee ratio, protected training time, online training options, use of local trainers, short and concise training manuals in print, continuous supervision and early and on-going evaluation, as well as tele-mentoring.

CONCLUSIONS

Context integration and focus on local needs, trainer availability and suitability, durable equipment and maintenance, as well as emphasis on hands on training including patients with relevant pathology, were key aspects for targeted and sustainable POCUS training in LMICs identified in this review.

Point-of-care ultrasound use in austere environments: A scoping review

BACKGROUND/OBJECTIVES

Technological developments in point-of-care ultrasound (POCUS), particularly with portable devices, are transforming POCUS use in austere, resource-limited environments (RLS) distinct from typical hospital or medical settings. POCUS has potential to improve diagnostic accuracy in military combat zones, low-resource environments such as the desert or tropics, microgravity, and high altitudes. Our updated narrative scoping review describes POCUS use in these global settings.

METHODS

Using the PRISMA-ScR guidelines, two ultrasound-trained emergency physicians searched PubMed, Embase, and Web of Science on August 6, 2024 for "point-of-care ultrasound in austere environments" and each individual category. Study titles and abstracts were independently screened, then full manuscripts, and data was abstracted with a data collection table. 324 articles met inclusion criteria: research studies describing POCUS in austere environments; involving healthcare professionals; and in English. We excluded abstracts, studies not involving POCUS in austere environments, and non-clinical studies. Reviewers critically appraised studies using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) Quality Assessment Tool.

RESULTS

There were 39 military or conflict zone studies, 101 prehospital, 148 in RLS including low- and middle-income countries, 12 outer space, 15 high altitude, and 32 involving POCUS use in multiple austere environments. There were 6 randomized-control trials, 11 systematic/scoping reviews, 13 narrative reviews, 112 prospective observational/cohort, 34 prospective cross-sectional studies, 23 retrospective, 6 feasibility, 45 case reports, 13 case series, and 5 educational curriculum studies. GRADE study quality was variable, with 74 high quality, 129 moderate, 82 low, and 56 very low.

CONCLUSION

The existing literature is mixed with variability in study settings, design, and POCUS examination types, providing an initial understanding of POCUS applications. Most studies are in RLS or prehospital settings. Additional high-quality studies are needed to guide POCUS training, disseminate use in non-hospital settings, and maximize impact for improved clinical outcomes in diverse austere environments.

Morbidity associated with schistosomiasis in adult population of Chókwè district, Mozambique

BACKGROUND

Mozambique is one of the countries with the highest prevalence of schistosomiasis, although there is little data on the prevalence of disease and associated morbidity in the adult population. This study aimed to describe and characterize the morbidity associated with schistosomiasis in the adult population of Chókwè district and to explore the use of anamnestic questionnaires and urine dipsticks, as well as point-of-care ultrasound for urinary related findings, to better characterize disease prevalence and morbidity.

METHODOLOGY

Between April and October 2018, we conducted a cross-sectional study embedded within the Chókwè Health Research and Training Centre. Data were collected on sociodemographic variables, signs and symptoms for schistosomiasis and water related activities. Infection status was determined by urine filtration, Kato-Katz thick smear and DNA detection. Point-of care urinary tract ultrasonography was performed to assess structural morbidity associated with Schistosoma haematobium infection. Multivariate logistic regression was used to search for associations between risk factors, signs and symptoms, infection status and ultrasound abnormalities.

PRINCIPAL FINDINGS

Our study included 1033 participants with a median age of 34 years old. The prevalence of Schistosoma haematobium, Schistosoma mansoni and ultrasound detected urinary tract abnormalities were 11.3% (95% CI 9.5%-13.4%), 5.7% (95% CI 4.3%-7.5%) and 37.9% (95% CI 34.8%-41.2%), respectively. Of the 37.9% with urinary tract abnormalities, 14.5% were positive for Schistosoma haematobium. Reported hematuria in the last month (p = 0.004, aOR 4.385) and blood in the urine dipstick (p = 0.004, aOR 3.958) were markers of Schistosoma haematobium infection. Reporting lower abdominal pain (p = 0.017, aOR 1.599) was associated with ultrasound abnormalities.

CONCLUSION

Using microscopy and DNA analysis for both Schistosoma haematobium and Schistosoma mansoni in conjunction with urinary ultrasound abnormalities gives us several insights into correlations between disease prevalence (microscopic and anatomical) and demographic details in a high-risk population.

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.