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Background In 2021, Mozambique initiated community-based oral HIV self-testing (HIVST) to increase testing access and uptake among priority groups, including adult males, adolescents, and young adults. Within an HIVST pilot project, we conducted a performance evaluation assessing participants' ability to successfully conduct HIVST procedures and interpret results. Methods A cross-sectional study was performed between February-March 2021 among employees, students (18­24 years of age), and community members, using convenience sampling, in two rural districts of Zambézia Province, Mozambique. We quantified how well untrained users performed procedures for the oral HIVST (Oraquick®) through direct observation using a structured checklist, from which we calculated an HIVST usability index (scores ranging 0­100%). Additionally, participants interpreted three previously processed anonymous HIVST results. False reactive and false non-reactive interpretation results were presented as proportions. Bivariate analysis was conducted using Chi-square and Fisher exact tests. Results A total of 312 persons participated (131[42%] community members, 71[23%] students, 110[35%] employees); 239 (77%) were male; the mean age was 28 years (standard deviation 10). Average usability index scores were 80% among employees, 86% among students, and 77% among community members. Main procedural errors observed included "incorrect tube positioning" (49%), "incorrect specimen collection" (43%), and "improper waiting time for result interpretation" (42%). From the presented anonymous HIVST results, 75% (n = 234) correctly interpreted all three results, while 9 (3%) of study participants failed to correctly interpret any results. Overall, 36 (12%) gave a false non-reactive result interpretation, 21 (7%) a false reactive result interpretation, and 14 (4%) gave both false non-reactive and false reactive result interpretations. Community members generally had lower performance. Conclusions Despite some observed testing procedural errors, most users could successfully perform an HIVST. Educational sessions at strategic places (e.g., schools, workplaces), and support via social media and hotlines, may improve HIVST performance quality, reducing the risk of incorrect interpretation.

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siendo el test de aliento con urea carbono-14 (C-14) uno de los métodos de diagnóstico no invasivos; sin embar-go, no ha sido comprobada su utilidad en la población ecuatoriana.Objetivo: Evaluar la sensibilidad y especificidad del test de aliento con urea C-14 para predecir la infección por HP en la población ecuatoriana.Métodos: Estudio de Pruebas Diagnósticas realizado en pacientes que acudieron a la consulta externa del servicio de gastroenterología del Hospital Teófilo Dávila de la ciudad de Machala, en el periodo abril 2018 a marzo 2019. Los pacientes se sometieron a una endoscopia superior de luz blanca (ES) con toma de biopsias para investigar la infec-ción por HP; además, se realizó un test de aliento con urea C-14, para compararla con los resultados de las biopsias.Resultados: Se estudiaron 78 pacientes con una edad media de 33.76±11.2 años. El diagnóstico de gastritis se confirmó a través de la ES e histopatología en el 100% de los pacientes. El test de aliento con urea C-14 fue positi-va en 47/78 (60.3%) pacientes. Se demostró evidencia de infección por HP en biopsias gástricas de 50/78 (64.1%) pacientes. La sensibilidad, especificidad, VPP, VPN, observada y la concordancia entre evaluadores fue de 94%, 100%, 100%, 90%, 96% y 92% (P <0.001), respectivamente.Conclusiones: El test de aliento con urea C-14, es una herramienta útil para predecir infección por HP en la población ecuatoriana

Background: Early detection of Helicobacter pylori infection has become more relevant, with urea carbon-14 (C-14) breath test as one of the non-invasive diagnostic methods; however, it has not been proven in Ecuadorian population.Objective: To evaluate the sensitivity and specificity of the C-14 urea breath test to predict HP infection in the Ecuadorian population.Methods: : Study of diagnostic tests performed on patients who attended the outpatient gastroenterology service of the Hospital Teófilo Dávila in the city of Machala, in the period April 2018 to March 2019. The patients underwent an upper endoscopy of white light (WLE) with biopsies taken to investigate HP infection. In addition, a breath test with C-14 urea was performed to compare it with the biopsies results.Results: 78 patients with a mean age of 33.76±11.2 years were studied. The diagnosis of gastritis was confirmed through endoscopy and histopathology in 100% of the patients. The breath test with urea C-14 was positive in 47/78 (60.3%) patients. Evidence of HP infection was demonstrated in gastric biopsies from 50/78 (64.1%) pa-tients. Sensitivity, specificity, PPV, NPV, and inter-rater reliability were 94%, 100%, 100%, 90%, 96%, and 92% (P <0.001), respectively.Conclusions: The C-14 urea breath test is a useful tool for predicting HP infection in the Ecuadorian population

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One of most intriguing features of the HIV-1 subtype B epidemic in Brazil is the high frequency of isolates exhibiting tryptophan (W) in the tetramer (GWGR) at the tip of the V3 loop. We observed that the frequencies of glutamic and aspartic acids at site 25 of the V3 loop are quite distinct in GWGR isolates compared with viruses with other tetramers. The basic amino acids at sites 11 and 25 of V3 are strongly linked with CCR5-to-CXCR4 coreceptor shift. We therefore predicted phenotype usage and found that GWGR isolates are exclusively CCR5-using. Further evidence of this came from intrahost sequences, where basic amino acid substitutions at sites 11 and 25 emerged only in isolates presenting a tryptophan-to-glycine replacement at the tetramer of the V3. In addition, modeled 3D-structures of the V3 loop of GWGR and GGGR in intrahost viruses differ essentially in the binding region of the coreceptor.

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