High sensitivity of ultrasound for the diagnosis of tuberculosis in adults in South Africa: A proof-of-concept study.

BACKGROUND: There are limited data on the performance characteristics of ultrasound for the diagnosis of pulmonary tuberculosis in both HIV-positive and HIV-negative persons. The objective of this proof-of-concept study was to determine the sensitivity and specificity of ultrasound for the diagnosis of tuberculosis in adults. METHODS: Comprehensive thoracic and focused abdominal ultrasound examinations were performed by trained radiologists and pulmonologists on adults recruited from a community multimorbidity survey and a primary healthcare clinic in KwaZulu-Natal Province, South Africa. Sputum samples were systematically collected from all participants. Sensitivity and specificity of ultrasound to detect tuberculosis were calculated compared to a reference standard of i) bacteriologically-confirmed tuberculosis, and ii) either bacteriologically-confirmed or radiologic tuberculosis. RESULTS: Among 92 patients (53 [58%] male, mean age 41.9 [standard deviation 13.7] years, 49 [53%] HIV positive), 34 (37%) had bacteriologically-confirmed tuberculosis, 8 (9%) had radiologic tuberculosis with negative bacteriologic studies, and 50 (54%) had no evidence of active tuberculosis. Ultrasound abnormalities on either thoracic or abdominal exams were detected in 31 (91%) participants with bacteriologic tuberculosis and 27 (54%) of those without tuberculosis. Sensitivity and specificity of any ultrasound abnormality for bacteriologically-confirmed tuberculosis were 91% (95% confidence interval [CI] 76%-98%) and 46% (95% CI 32%-61%). Sensitivity and specificity of any ultrasound abnormality for either bacteriologically-confirmed or radiologic tuberculosis were 86% (95% CI 71%-95%) and 46% (95% CI 32%-61%). Overall performance did not appear to differ markedly between participants with and without HIV. CONCLUSION: A comprehensive ultrasound scanning protocol in adults in a high TB burden setting had high sensitivity but low specificity to identify bacteriologically-confirmed tuberculosis

Comparative Genomics of the Apicomplexan Parasites Toxoplasma gondii and Neospora caninum: Coccidia Differing in Host Range and Transmission Strategy

Toxoplasma gondii is a zoonotic protozoan parasite which infects nearly one third of the human population and is found in an extraordinary range of vertebrate hosts. Its epidemiology depends heavily on horizontal transmission, especially between rodents and its definitive host, the cat. Neospora caninum is a recently discovered close relative of Toxoplasma, whose definitive host is the dog. Both species are tissue-dwelling Coccidia and members of the phylum Apicomplexa; they share many common features, but Neospora neither infects humans nor shares the same wide host range as Toxoplasma, rather it shows a striking preference for highly efficient vertical transmission in cattle. These species therefore provide a remarkable opportunity to investigate mechanisms of host restriction, transmission strategies, virulence and zoonotic potential. We sequenced the genome of N. caninum and transcriptomes of the invasive stage of both species, undertaking an extensive comparative genomics and transcriptomics analysis. We estimate that these organisms diverged from their common ancestor around 28 million years ago and find that both genomes and gene expression are remarkably conserved. However, in N. caninum we identified an unexpected expansion of surface antigen gene families and the divergence of secreted virulence factors, including rhoptry kinases. Specifically we show that the rhoptry kinase ROP18 is pseudogenised in N. caninum and that, as a possible consequence, Neospora is unable to phosphorylate host immunity-related GTPases, as Toxoplasma does. This defense strategy is thought to be key to virulence in Toxoplasma. We conclude that the ecological niches occupied by these species are influenced by a relatively small number of gene products which operate at the host-parasite interface and that the dominance of vertical transmission in N. caninum may be associated with the evolution of reduced virulence in this species

Evaluation of ultrasound for screening and diagnosis of pulmonary tuberculosis, KwaZulu Natal, South Africa, 2019-20

Evaluation of ultrasound for screening and diagnosis of pulmonary tuberculosis, KwaZulu Natal, South Africa, 2019-2

Sonographic findings in visceral leishmaniasis – A narrative review

Background: Visceral leishmaniasis (VL) is predominantly a neglected tropical parasitic disease but may also be acquired by travellers. We aimed at summarizing knowledge on sonographic presentation of VL to better understand sonographic features of VL. Methods: PubMed was searched for studies and case reports presenting original data on sonographic findings of VL, published before August 13th, 2019. Demographic, clinical, and sonographic data were extracted and summarized in a qualitative approach. Results: A total of 36 publications were included in this review; 27 of these were case reports and the remainder were prospective or retrospective studies. No study reported systematic cross-sectional comparative imaging. Overall, publications reported on 512 patients with VL of whom 12 were reported HIV-infected. Spleno- and hepatomegaly were the most frequently reported findings. Further relevant and repeatedly reported findings were splenic and hepatic lesions, abdominal lymphadenopathy, pleural and pericardial effusion and ascites. Reported focal splenic lesions were heterogeneous in size, shape, and echogenicity. Several publications reported gradual diminution and resolution of sonographic findings with VL treatment. Conclusion: Available literature on sonographic findings of VL is limited. Available reports indicate that spleno- and hepatomegaly, free fluid, abdominal lymphadenopathy, and focal splenic lesions may be common sonographic features in patients with VL. Because of the apparent overlap of sonographic features of VL, extrapulmonary tuberculosis and other conditions, interpretation of sonographic findings needs to be made with particular caution

Ultrasound findings in all participants stratified by TB status.

Ultrasound findings in all participants stratified by TB status.</p

Ultrasound findings in participants with bacteriologic TB compared to healthy participants.

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Classification of ultrasound findings.

Classification of ultrasound findings.</p

Typical thoracic ultrasound findings.

Panel A demonstrates the appearance of normal air-filled lung, characterized by a bright white horizontal pleural line interrupted by rib shadows, and repeating horizontal reverberation artifacts known as A-lines. Panel B shows lung consolidation, characterized by subpleural echo-poor region greater than 10 mm in depth or length. Panel C demonstrates a small subpleural consolidation (SPC), characterized by a hypoechoic subpleural region less than 10 mm in depth and length, with distinct borders and a trailing comet-tail artifact.</p