Diagnostic precision of local and World Health Organization definitions of symptomatic COVID-19 cases: an analysis of Mexico's capital.

OBJECTIVES: Case definitions are vital in a pandemic to effectively identify, isolate, and contact trace, particularly where testing is slow, scant, or not available. While case definitions have been developed in the COVID-19 pandemic, their diagnostic properties have not been adequately assessed. This study's objective is to determine the diagnostic properties of local and World Health Organization (WHO) COVID-19 case definitions in the large metropolitan area of Mexico City. METHODS: We calculated the diagnostic properties of five COVID-19 definitions (three of the Mexican government and two of the WHO) using open data of suspected COVID-19 cases in Mexico City from March 24th, 2020, until May 15th, 2021. RESULTS: All 2,564,782 people included in the analysis met the WHO suspected case definition (sensitivity: 100%, specificity: 0%). The WHO probable case definition was met by 1.2%, while the first and second Mexican suspected case had sensitivities of 61% and specificities of 61% and 67%, respectively. Confirmed case by epidemiological contact had a low sensitivity (32%) but slightly higher specificity (81%). CONCLUSIONS: Case definitions should maximize sensitivity, especially in a high-transmission area such as Mexico City. The WHO suspected case definition has the potential for detecting most symptomatic cases. We underline the need for routine evaluation of case definitions as new evidence arises to maximize their usefulness.

The effect of protease inhibitor-based dual antiretroviral regimens on CD4/CD8 ratio during the first year of therapy in ART-naïve patients with HIV-infection.

OBJECTIVES: To assess the effect of protease inhibitor (PI)-based dual therapy on CD4/CD8 ratio during the first year of therapy in antiretroviral therapy (ART)-naïve patients using data from randomized controlled clinical trials. METHODS: We pooled data from the GARDEL and ANDES studies, both randomized controlled clinical trials that recruited ART-naïve people living with HIV and randomly assigned them to receive PI-based dual therapy (DT) or triple therapy (TT) aiming to compare viral efficacy. We compared median CD4/CD8 ratios and the proportion of patients with CD4/CD8 ratio > 1 at 48 weeks after ART initiation in both treatment arms using the Mann-Whitney U-test and the χ2 test. We performed subgroup analysis for patients > 50 years old, with baseline CD4 counts ≤ 200 cells/µL, viral load > 100 000 HIV RNA copies/mL, and ritonavir-boosted lopinavir-based therapy. RESULTS: We analysed data from 571 patients: 292 on DT and 279 on TT. No differences were observed in CD4/CD8 ratio (0.632 vs. 0.617, P = 0.729) or in the proportion of patients with CD4/CD8 ratio > 1 (17.9% vs. 19.3%, P = 0.678) 48 weeks after ART initiation. Subgroup analysis showed no further differences. CONCLUSION: The impact of PI-based DT regimens on the CD4/CD8 ratio during the first year of treatment for ART-naïve patients is similar to that of TT.

Myocardial Inflammatory Changes Before and After Antiretroviral Therapy Initiation in People With Advanced Human Immunodeficiency Virus Disease.

Because of the high frequency of late presentation of human immunodeficiency virus (HIV) disease in our population, we decided to explore the presence of myocarditis among people with HIV infection and advanced immunosuppression (less than 200 CD4+ cells/µL) and to describe the inflammatory changes observed after combined antiretroviral therapy initiation in an observational, longitudinal, prospective cohort. We performed both cardiovascular magnetic resonance imaging and doppler transthoracic echocardiogram.

Immediate treatment of acute HIV in a tertiary healthcare center: bridging gaps in communication using smartphones.

OBJECTIVES: Early initiation of antiretroviral therapy (ART) during acute HIV infection is associated with favourable clinical and epidemiological outcomes. Barriers to prompt treatment initiation limit the benefits of universal access to ART in Mexico. We sought to create an algorithm for the immediate detection and treatment of patients with acute HIV infection. METHODS: A nationwide cohort of patients with acute HIV infection was created in 2015. In order to identify cases and treat them promptly at our centre, an interdisciplinary group coordinated through an instant-messaging tool using smart phones was established. When a probable case was detected, a discussion was initiated to confirm the diagnosis and facilitate the administrative processes to initiate ART as soon as possible. We compared time to ART initiation with that in a comparison group of patients with chronic HIV infection enrolled during the same period (May 2015 to February 2017) through routine care, using survival analysis estimators and log-rank tests. RESULTS: We recruited 29 patients with acute HIV infection. The median time to ART initiation was 2 days in these patients, in contrast to 21 days for patients with chronic infection. There were no significant differences in the percentages of patients engaged in care, on treatment or virologically suppressed at 1 year of follow-up. CONCLUSIONS: Implementing immediate ART initiation programmes is feasible in Mexico, in spite of the substantial administrative barriers that exist in the country. More extensive replication of this model in other centres and in patients with chronic infection is warranted to evaluate its effect on the continuum of care.

Trends in proportion of older HIV-infected people in care in Latin America and the Caribbean: a growing challenge.

We aimed to quantify the proportion of people receiving care for HIV-infection that are 50 years or older (older HIV patients) in Latin America and the Caribbean between 2000 and 2015 and to estimate the contribution to the growth of this population of people enrolled before (<50yo) and after 50 years old (yo) (⩾50yo). We used a series of repeated, cross-sectional measurements over time in the Caribbean, Central and South American network (CCASAnet) cohort. We estimated the percentage of patients retained in care each year that were older HIV patients. For every calendar year, we divided patients into two groups: those who enrolled before age 50 and after age 50. We used logistic regression models to estimate the change in the proportion of older HIV patients between 2000 and 2015. The percentage of CCASAnet HIV patients over 50 years had a threefold increase (8% to 24%) between 2000 and 2015. Most of the growth of this population can be explained by the increasing proportion of people that enrolled before 50 years and aged in care. These changes will impact needs of care for people living with HIV, due to multiple comorbidities and high risk of disability associated with aging.