Point-of-care ultrasound for tuberculosis and HIV-revisiting the focused assessment with sonography for HIV-associated tuberculosis (FASH) protocol and its differential diagnoses

BACKGROUND

The 'Focused assessment with sonography for HIV-associated tuberculosis' (FASH) protocol has been applied and researched for over a decade in HIV-infected patients with suspected extra-pulmonary tuberculosis. Interpretation of target FASH features may be challenging as they can also indicate alternative opportunistic diseases.

OBJECTIVES

The primary aim of the review was summarizing the accumulated evidence on the diagnostic accuracy of the FASH protocol including description of diagnoses of target FASH features.

SOURCES

Literature was searched using PubMed, Google Scholar, and publications referencing the original FASH publications; data from identified studies were compiled with data from studies identified by a preceding Cochrane review. A meta-analysis was performed based on a generalized linearized mixed model. Data on differential diagnoses were compiled by literature review and retrospective evaluation of clinical data.

CONTENT

We identified ten studies; abdominal target FASH features were most studied. Sensitivity and specificity estimates were 39% (95% CI 25-54) and 89% (95% CI 83-96) for enlarged lymph nodes (ten studies), and 30% (95% CI 16-45%) and 93% (95% CI 89-98%) for hypoechoic spleen lesions (eight studies). In people living with HIV differential diagnoses of target FASH features are multiple and primarily include other opportunistic infections and malignancies such as non-tuberculous mycobacterial infection, bacillary angiomatosis, hepato-splenic brucellosis, meliodiosis, visceral leishmaniasis, invasive fungal infections, and lymphoma as well as Kaposi sarcoma. Ultrasound-guided diagnostic sampling may assist obtention of a definitive diagnosis.

IMPLICATIONS

On the basis of current evidence, although limited by methodology, and personal experience, we recommend basic ultrasound training, including the FASH protocol and ultrasound-guided diagnostic interventions, for all healthcare providers working with people living with HIV in resource-limited settings.

Tuberculosis infection and disease in South African adolescents with perinatally acquired HIV on antiretroviral therapy: a cohort study

INTRODUCTION

There are limited data on Tuberculosis (TB) in adolescents with perinatally acquired HIV (APHIV). We examined the incidence and determinants of TB infection and disease in the Cape Town Adolescent Antiretroviral Cohort (CTAAC).

METHODS

Youth between nine and fourteen years on antiretroviral therapy (ART) for more than six months in public sector care, and age-matched HIV-negative adolescents, were enrolled between July 2013 through March 2015 and followed six-monthly. Data were censored on 31 October 2018. Symptom screening, chest radiograph, viral load, CD4 count, QuantiFERON (QFT) and sputum for Xpert MTB/RIF, microscopy, culture and sensitivity were performed annually. TB infection was defined by a QFT of >0.35 IU/mL. TB diagnosis was defined as confirmed (culture or Xpert MTB/RIF positive) or unconfirmed (clinical diagnosis and started on TB treatment). Analyses examined the incidence and determinants of TB infection and disease.

RESULTS

Overall 496 HIV+ and 103 HIV-negative participants (median age at enrolment 12 years (interquartile range, IQR 10.6 to 13.3) were followed for a median of 3.1 years (IQR 3.0 to 3.4); 50% (298/599) were male. APHIV initiated ART at median age 4.4 years (IQR 2.1 to 7.6). At enrolment, 376/496 (76%) had HIV viral load <40 copies/mL, median CD4 count was 713 cells/mm3 and 179/559 (32%) were QFT+, with no difference by HIV status (APHIV 154/468, 33%; HIV negative 25/91, 27%; p = 0.31). The cumulative QFT+ prevalence was similar (APHIV 225/492, 46%; 95%CI 41% to 50%; HIV negative 44/98, 45%; 95% CI 35% to 55%; p = 0.88). APHIV had a higher incidence of all TB disease than HIV-negative adolescents (2.2/100PY, 95% CI 1.6 to 3.1 vs. 0.3/100PY, 95% CI 0.04 to 2.2; IRR 7.36, 95% CI 1.01 to 53.55). The rate of bacteriologically confirmed TB in APHIV was 1.3/100 PY compared to 0.3/100PY for HIV-negative adolescents, suggesting a fourfold increased risk of developing TB disease in APHIV despite access to ART. In addition, a positive QFT at enrolment was not predictive of TB in this population.

CONCLUSIONS

High incidence rates of TB disease occur in APHIV despite similar QFT conversion rates to HIV-negative adolescents. Strategies to prevent TB in this vulnerable group must be strengthened.

Cardiac ultrasound in resource-limited settings (CURLS): towards a wider use of basic echo applications in Africa

Background

Point-of-care ultrasound is increasingly being used as a diagnostic tool in resource-limited settings. The majority of existing ultrasound protocols have been developed and implemented in high-resource settings. In sub-Saharan Africa (SSA), patients with heart failure of various etiologies commonly present late in the disease process, with a similar syndrome of dyspnea, edema and cardiomegaly on chest X-ray. The causes of heart failure in SSA differ from those in high-resource settings. Point-of-care ultrasound has the potential to identify the underlying etiology of heart failure, and lead to targeted therapy. Based on a literature review and weighted score of disease prevalence, diagnostic impact and difficulty in performing the ultrasound, we propose a context-specific cardiac ultrasound protocol to help differentiate patients presenting with heart failure in SSA.

Results

Pericardial effusion, dilated cardiomyopathy, cor pulmonale, mitral valve disease, and left ventricular hypertrophy were identified as target conditions for a focused ultrasound protocol in patients with cardiac failure and cardiomegaly in SSA. By utilizing a simplified 5-question approach with all images obtained from the subxiphoid view, the protocol is suitable for use by health care professionals with limited ultrasound experience.

Conclusions

The “Cardiac ultrasound for resource-limited settings (CURLS)” protocol is a context-specific algorithm designed to aid the clinician in diagnosing the five most clinically relevant etiologies of heart failure and cardiomegaly in SSA. The protocol has the potential to influence treatment decisions in patients who present with clinical signs of heart failure in resource-limited settings outside of the traditional referral institutions.

Streptococcus agalactiae Serotype Distribution and Antimicrobial Susceptibility in Pregnant Women in Gabon, Central Africa

Neonatal invasive disease due to Streptococcus agalactiae is life threatening and preventive strategies suitable for resource limited settings are urgently needed. Protective coverage of vaccine candidates based on capsular epitopes will relate to local epidemiology of S. agalactiae serotypes and successful management of critical infections depends on timely therapy with effective antibiotics. This is the first report on serotype distribution and antimicrobial susceptibility of S. agalactiae in pregnant women from a Central African region. Serotypes V, III, and Ib accounted for 88/109 (81%) serotypes and all isolates were susceptible to penicillin and clindamycin while 13% showed intermediate susceptibility to erythromycin.