Prevalence and risk factors for long COVID after mild disease: A cohort study with a symptomatic control group.

Background: There is limited data on the prevalence and risk factors for long COVID and few prospective studies with appropriate control groups and adequate sample sizes. We performed a prospective study to determine the prevalence and risk factors for long COVID. Methods: We recruited individuals aged ≥15 years who were clinically suspected of having an acute SARS-CoV-2 infection from September 2020 to April 2021. We collected nasopharyngeal swabs three to five days following symptom onset for analysing using reverse transcriptase polymerase chain reaction (RT-PCR). We also collected clinical and sociodemographic characteristics from both SARS-CoV-2 positive and negative participants using structured questionnaires. We followed-up the participants via telephone interview to assess early outcomes and persistent symptoms. For COVID-19 cases, 5D-3L EuroQol questionnaire was used to assess the impact of symptoms on quality of life. Results: We followed 814 participants (412 COVID-19 positive and 402 COVID-19 negative persons). Most (n = 741/814) had mild symptoms. Both groups had similar sociodemographic and clinical characteristics, except for the hospitalization rate (15.8% in the COVID-19 positive vs 1.5% in the COVID-19 negative group). One month after disease onset, 122/412 (29.6%) individuals in the COVID-19 positive (long COVID) and 24 (6%) in the COVID-19 negative group reported residual symptoms. In the long COVID group, fatigue, olfactory disorder, and myalgia were the most frequent symptoms in the acute phase. Compared to recovered individuals, older age and having more than five symptoms during the acute phase were risk factors for long COVID. Quality of life was evaluated in 102 out of 122 cases of long COVID, with 57 (55.9%) reporting an impact in at least one dimension of the European Quality of Life 5 Dimensions 3 Level (EQ-5D-3L) questionnaire. Conclusions: In this prospective study consisting predominantly of individuals with mild disease, the persistence of symptoms after an acute respiratory illness was associated with a diagnosis of COVID-19. Polysymptomatic acute disease and older age were risk factors for long COVID.

A Critical Analysis of the COVID-19 Hospitalization Network in Countries with Limited Resources.

To effectively combat the COVID-19 pandemic, countries with limited resources could only allocate intensive and non-intensive care units to a low number of regions. In this work, we evaluated the actual displacement of infected patients in search of care, aiming to understand how the networks of planned and actual hospitalizations take place. To assess the flow of hospitalizations outside the place of residence, we used the concepts of complex networks. Our findings indicate that the current distribution of health facilities in Bahia, Brazil, is not sufficient to effectively reduce the distances traveled by patients with COVID-19 who require hospitalization. We believe that unnecessary trips to distant hospitals can put both the sick and the healthy involved in the transport process at risk, further delaying the stabilization of the COVID-19 pandemic in each region of the state of Bahia. From the results found, we concluded that, to mitigate this situation, the implementation of health units in countries with limited resources should be based on scientific methods, and international collaborations should be established.

Clinical and laboratory evidence of Haff disease - case series from an outbreak in Salvador, Brazil, December 2016 to April 2017.

We describe a series of 15 Haff disease cases from an outbreak in Salvador, Brazil, starting early December 2016. Eleven cases were grouped in four family clusters of two to four individuals, four were isolated cases. All but one patient consumed cooked fish; 11 within 24h before symptoms onset. Cases consumed 'Olho de Boi' (Seriola spp.) and 'Badejo' (Mycteroperca spp.). A total of 67 cases were detected, the last case was reported on 5 April 2017.

Zika virus infection induces mitosis abnormalities and apoptotic cell death of human neural progenitor cells.

Zika virus (ZIKV) infection has been associated with severe complications both in the developing and adult nervous system. To investigate the deleterious effects of ZIKV infection, we used human neural progenitor cells (NPC), derived from induced pluripotent stem cells (iPSC). We found that NPC are highly susceptible to ZIKV and the infection results in cell death. ZIKV infection led to a marked reduction in cell proliferation, ultrastructural alterations and induction of autophagy. Induction of apoptosis of Sox2+ cells was demonstrated by activation of caspases 3/7, 8 and 9, and by ultrastructural and flow cytometry analyses. ZIKV-induced death of Sox2+ cells was prevented by incubation with the pan-caspase inhibitor, Z-VAD-FMK. By confocal microscopy analysis we found an increased number of cells with supernumerary centrosomes. Live imaging showed a significant increase in mitosis abnormalities, including multipolar spindle, chromosome laggards, micronuclei and death of progeny after cell division. FISH analysis for chromosomes 12 and 17 showed increased frequency of aneuploidy, such as monosomy, trisomy and polyploidy. Our study reinforces the link between ZIKV and abnormalities in the developing human brain, including microcephaly.

Coinfections of Zika and Chikungunya Viruses in Bahia, Brazil, Identified by Metagenomic Next-Generation Sequencing.

Metagenomic next-generation sequencing (mNGS) of samples from 15 patients with documented Zika virus (ZIKV) infection in Bahia, Brazil, from April 2015 to January 2016 identified coinfections with chikungunya virus (CHIKV) in 2 of 15 ZIKV-positive cases by PCR (13.3%). While generally nonspecific, the clinical presentation corresponding to these two CHIKV/ZIKV coinfections reflected infection by the virus present at a higher titer. Aside from CHIKV and ZIKV, coinfections of other viral pathogens were not detected. The mNGS approach is promising for differential diagnosis of acute febrile illness and identification of coinfections, although targeted arbovirus screening may be sufficient in the current ZIKV outbreak setting.

Distinct Zika Virus Lineage in Salvador, Bahia, Brazil.

Sequencing of isolates from patients in Bahia, Brazil, where most Zika virus cases in Brazil have been reported, resulted in 11 whole and partial Zika virus genomes. Phylogenetic analyses revealed a well-supported Bahia-specific Zika virus lineage, which indicates sustained Zika virus circulation in Salvador, Bahia's capital city, since mid-2014.

High prevalence of giardiasis and stronglyloidiasis among HIV-infected patients in Bahia, Brazil

Diarrhea due to intestinal microbial infections is a frequent manifestation among HIV-infected patients. It has been postulated that HIV-infected patients may have special types of intestinal infections, and that immune activation from such parasites may affect the progression of HIV disease. To evaluate these associations, the frequency of infections was examined in HIV-infected patients in Bahia, Brazil. To determine the potential impact of the presence of intestinal parasitic infections on HIV disease progression, a retrospective study approach was used. The medical charts of 365 HIV-infected patients who had been treated at the AIDS Clinic of the Federal University of Bahia Hospital were reviewed, and the prevalence of parasites was compared with 5,243 HIV-negative patients who had attended the hospital during the same period of time. Among HIV-infected subjects, CD(4) count, RNA plasma viral load (VL), and number of eosinophils were compared according to their stool examination results. The overall prevalence of each parasite was similar for HIV-positive and HIV-negative patients. However, the prevalence of S. stercoralis (p<10(-7)) and G. lamblia (p=0.005) was greater for HIV-infected subjects. The mean CD(4) count and viral load of HIV patients in our clinic who had stool examinations was 350 cells +/- 340 and 4.4 +/- 1.4 log RNA viral load, respectively. In this patient group there was no clear association between the level of the absolute CD(4) count or the viral load and a specific parasitic infection. The presence of an intestinal parasitic infection was not associated with faster progression of the HIV disease among HIV-infected patients. We conclude that strongyloidiasis and giardiasis are more frequent in HIV-infected patients in Bahia, Brazil. If this association is due to immune dysregulation, as has been proposed elsewhere, it must occur in patients after only minor shifts in CD(4) count from normal levels, or as a result of immune dysfunction not represented by CD(4) count. These infections do not appear to alter the progression of HIV disease.