A Pandemic within Other Pandemics. When a Multiple Infection of a Host Occurs: SARS-CoV-2, HIV and Mycobacterium tuberculosis.

By the middle of 2021, we are still immersed in the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The concurrence of this new pandemic in regions where human immunodeficiency virus (HIV) and tuberculosis (TB) infections possess the same epidemiological consideration, has arisen concerns about the prognosis, clinical management, symptomatology, and treatment of patients with triple infection. At the same time, healthcare services previously devoted to diagnosis and treatment of TB and HIV are being jeopardized by the urgent need of resources and attention for COVID-19 patients. The aim of this review was to collect any article considering the three conditions (HIV, TB, and SARS-CoV-2), included in PubMed/Medline and published in the English language since the beginning of the COVID-19 pandemic. We focused on detailed descriptions of the unusual cases describing the three co-infections. Eighty-four out of 184 publications retrieved met our inclusion criteria, but only three of them reported cases (five in total) with the three concomitant infections. The clinical evolution, management, and therapy of all of them were not different from mild/severe cases with exclusive COVID-19; the outcome was not worse either, with recovery for the five patients. Cases of patients with COVID-19 besides HIV and TB infections are scarce in literature, but studies deliberately embracing the triple infection as a priori inclusion criterion should be carried out in order to provide a complete understanding of joint influence.

Cryptococcal infection in HIV-infected patients with CD4+ T-cell counts under 100/µL diagnosed in a high-income country: a multicentre cohort study.

OBJECTIVES: The World Health Organization recommends routinely screening HIV-infected patients with CD4+ T-cell counts <100/µL for cryptococcal infection to prevent cryptococcal meningitis (CM), based on studies in Sub-Saharan Africa where the prevalence of positive cryptococcal antigen (CrAg+) is ≥ 3% in this subgroup. Data about such prevalence in Spain are unavailable and rare in other European countries. Thus, the Spanish AIDS Study Group guidelines do not recommend routinely screening. We aim to determine the prevalence and outcomes of cryptococcal infection in this subgroup of patients in Spain. METHODS: We determined CrAg using a lateral flow assay in banked plasma from participants in the cohort of the Spanish AIDS Research Network. Eligible patients had CD4+ T-cell counts ≤100/µL at the time of plasma collection and a follow-up >4 weeks, unless they died. RESULTS: We included 576 patients from June 2004 to December 2017. Of these, 43 were CrAg+ for an overall prevalence of 7.5%. There were no differences depending on birthplace. The CrAg+ was independently associated with a higher mortality at eight weeks (hazard ratio (HR) 5.36, 95% confidence interval (CI) 1.46-19.56) and 6 months (HR 3.12, 95% CI 1.19-8.21). CM was reported in 10 of the 43 CrAg+ patients. There were no cases among negatives. Five patients had CM when the plasma was collected and five developed it during the follow-up. The number of subjects needed to screen to anticipate the diagnosis of one CM case was 114. CONCLUSIONS: The CrAg+ prevalence among HIV-infected patients with CD4+ T-cell counts ≤100/µL diagnosed in Spain, both immigrants and native-born Spanish, is >7%. Consequently, the Spanish AIDS Study Group guidelines have to be updated and recommend routine screening for cryptococcal infection in these patients. Future studies should explore whether this recommendation could be firmly applied to other European populations.

Incidence of lymphoma in HIV-HCV-infected patients. Modifications in function of the anti-hepatitis C virus therapy.

The change in the incidence of lymphomas in function of the presence or absence of sustained virological response after anti-hepatitis C therapy in a cohort of human immunodeficiency (HIV)-hepatitis C (HCV) viruses coinfected patients was analyzed. A prospective cohort of 755 HIV-HCV coinfected patients who received their first anti-HCV therapy, based on interferon + ribavirin schemas, was evaluated. Incidence and histologic types of lymphomas were analyzed in two periods: (1) before administration of anti-HCV therapy and (2) after anti-HCV therapy. The association between lymphoma incidence and demographic, HIV- (minimum CD4+ cell count and CD4+ cell count at diagnosis of lymphoma, antiretroviral therapy, maximal HIV load and HIV load at diagnosis of lymphoma) and HCV-related variables (HCV load, genotype, sustained viral response to anti-HCV therapy) were analyzed. A total of 13 lymphomas [incidence rate (95% confidence interval), 0.72 (0.33-1.11) × 1000 person-years, time from HIV diagnosis to lymphoma diagnosis (median, interquartile range), 15 (11-19) years] were diagnosed. Nine of them were non-Hodgkin and four Hodgkin lymphomas. The median CD4+ T cell count at diagnosis of lymphoma was 457/mm3, with only two cases with values lower than 200/mm3. The incidence rate of non-Hodgkin lymphomas was similar pre- and post-anti HCV therapy [0.33 (0.00-0.65) vs 0.68 (0.08-1.26) × 1000 person-years, respectively, p > 0.05]. Patients with sustained virologic HCV response showed similar incidence rate of lymphomas than that of those without anti-HCV response. In conclusion, anti-HCV therapy does not modify the incidence rate of lymphomas in HIV-HCV coinfected patients.

Metabolic stasis in an ancient symbiosis: genome-scale metabolic networks from two Blattabacterium cuenoti strains, primary endosymbionts of cockroaches.

BACKGROUND: Cockroaches are terrestrial insects that strikingly eliminate waste nitrogen as ammonia instead of uric acid. Blattabacterium cuenoti (Mercier 1906) strains Bge and Pam are the obligate primary endosymbionts of the cockroaches Blattella germanica and Periplaneta americana, respectively. The genomes of both bacterial endosymbionts have recently been sequenced, making possible a genome-scale constraint-based reconstruction of their metabolic networks. The mathematical expression of a metabolic network and the subsequent quantitative studies of phenotypic features by Flux Balance Analysis (FBA) represent an efficient functional approach to these uncultivable bacteria. RESULTS: We report the metabolic models of Blattabacterium strains Bge (iCG238) and Pam (iCG230), comprising 296 and 289 biochemical reactions, associated with 238 and 230 genes, and 364 and 358 metabolites, respectively. Both models reflect both the striking similarities and the singularities of these microorganisms. FBA was used to analyze the properties, potential and limits of the models, assuming some environmental constraints such as aerobic conditions and the net production of ammonia from these bacterial systems, as has been experimentally observed. In addition, in silico simulations with the iCG238 model have enabled a set of carbon and nitrogen sources to be defined, which would also support a viable phenotype in terms of biomass production in the strain Pam, which lacks the first three steps of the tricarboxylic acid cycle. FBA reveals a metabolic condition that renders these enzymatic steps dispensable, thus offering a possible evolutionary explanation for their elimination. We also confirm, by computational simulations, the fragility of the metabolic networks and their host dependence. CONCLUSIONS: The minimized Blattabacterium metabolic networks are surprisingly similar in strains Bge and Pam, after 140 million years of evolution of these endosymbionts in separate cockroach lineages. FBA performed on the reconstructed networks from the two bacteria helps to refine the functional analysis of the genomes enabling us to postulate how slightly different host metabolic contexts drove their parallel evolution.