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Introduction: Dengue is a vector-borne disease, especially important in tropical and subtropical areas. The first presentation of many arboviral diseases occurred mainly in animals, including multiple Alphaviruses and Flaviviruses, such as dengue. Objective: To determine the serological and molecular frequency of the dengue virus in animals. Methods: A systematic literature review was carried out in five databases for the proportion of animals infected with dengue, defined by molecular and serological tests. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence and 95% confidence intervals (CI). Cochran?s Q test and the I2 statistic were used to assess the heterogeneity between the two studies. Results: The presence of dengue in bats, primates, birds, sheep, horses, cattle, pigs, rodents and buffaloes, according to serological methods, had a prevalence of 10%, 29%, 8%, 1%, 11%, 0%, 49%, 2%, 7%, respectively. According to molecular methods, the presence of dengue in bats had a seroprevalence of 6.0%. Conclusion: The present study confirms the presence of the Dengue virus in a large group of animal species, with potential implications as possible reservoirs of this virus, raising the possibility of zoonotic transmission.
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Introduction: Avian influenza A H5N1 is a significant global public health threat. Although relevant, systematic reviews about its prevalence in animals are lacking. Methods: We performed a systematic literature review in bibliographic databases to assess the prevalence of H5N1 in animals. A meta-analysis with a random-effects model was performed to calculate the pooled prevalence and 95 % confidence intervals (95%CI). In addition, measures of heterogeneity (Cochran's Q statistic and I2 test) were reported. Results: The literature search yielded 1359 articles, of which 33 studies were fully valid for analysis, including 96,909 animals. The pooled prevalence for H5N1 in birds (n = 90,045, 24 studies) was 5.0 % (95%CI: 4.0-6.0 %; I2 = 99.21); in pigs (n = 3,178, 4 studies) was 1.0 % (95%CI: 0.0-1.0 %); in cats (n = 2,911, 4 studies) was 0.0 % (95%CI: 0.0-1.0 %); and in dogs (n = 479, 3 studies) was 0.0 % (95%CI: 0.0-2.0 %). Conclusions: While the occurrence of H5N1 in animals might be comparatively limited compared to other influenza viruses, its impact on public health can be substantial when it transmits to humans. This virus can potentially induce severe illness and has been linked to previous outbreaks. Therefore, it is essential to closely monitor and comprehend the factors influencing the prevalence of H5N1 in both avian and human populations to develop effective disease control and prevention strategies.
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Objective: We aimed to review the available evidence on the association between vitamin B12, folate, and homocysteine levels with worse outcomes among COVID-19 patients. Methods: The search was carried out in ten databases simultaneously run on 10 May 2023, without language restrictions. We included cross-sectional, case-control, and cohort studies. The random-effects meta-analysis was performed using the Sidik-Jonkman method and corrected 95% confidence intervals using the truncated Knapp-Hartung standard errors. Standardized mean difference and 95% CI was used as the measure effect size. Results: Thirteen articles were included in this review (n = 2134). Patients with COVID-19 who did not survive had the highest serum vitamin B12 values (SMD: 1.05; 95% CI: 0.31-1.78; p = 0.01, I2 = 91.22%). In contrast, low serum folate values were associated with patients with severe COVID-19 (SMD: -0.77; 95% CI: -1.35 to -0.19; p = 0.02, I2 = 59.09%). The remaining tested differences did not yield significant results. Conclusion: Elevated serum levels of vitamin B12 were associated with higher mortality in patients with COVID-19. Severe cases of COVID-19 were associated with low serum folate levels. Future studies should incorporate a larger sample size.
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Background and aims: The presence of fungal infections has been described in patients after recovering from COVID-19. This study aims to conduct a systematic review of studies that reported fungal infections (Mucor spp., Pneumocystis jirovecii, or Aspergillus spp.) in adults after recovering from COVID-19. Methods: We performed a systematic review through PubMed, Web of Science, OVID-Medline, Embase, and Scopus. The study selection process was performed independently and by at least two authors. We performed a risk of bias assessment using the Newcastle-Ottawa Scale for cohort and case-control studies, and the Joanna Briggs Institute's Checklists for Case Series and Case Reports. Results: The systematic search found 33 studies meeting all inclusion criteria. There was a total population of 774 participants, ranging from 21 to 87 years. From them, 746 developed a fungal infection. In 19 studies, Mucor spp. was reported as the main mycosis. In 10 studies, P. jirovecii was reported as the main mycosis. In seven studies, Aspergillus spp. was reported as the main mycosis. Regarding the quality assessment, 12 studies were classified as low risk of bias and the remaining studies as high risk of bias. Conclusion: Patients' clinical presentation and prognosis after recovering from COVID-19 with fungal infection differ from those reported patients with acute COVID-19 infection and those without COVID-19 infection.
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Background & aims: Metabolic syndrome (MetS) is associated with life-threatening conditions. Several studies have reported an association of vitamin B12, folic acid, or homocysteine (Hcy) levels with MetS. This systematic review and meta-analysis assessed the association of vitamin B12, folic acid, and Hcy levels with MetS. Methods: PubMed, Scopus, Embase, Ovid/Medline, and Web of Science were searched up to February 13, 2023. Cross-sectional, case-control, or cohort studies were included. A random-effects model was performed using the DerSimonian and Laird method to estimate the between-study variance. Effect measures were expressed as odds ratios (OR) with their corresponding 95% confidence intervals (95% CI). Between-study heterogeneity was evaluated using Cochran's Q test and the I2 statistic. Results: Sixty-six articles (n = 87,988 patients) were included. Higher vitamin B12 levels were inversely associated with MetS (OR = 0.87; 95% CI: 0.81-0.93; p < 0.01; I2 = 90%). Higher Hcy levels were associated with MetS (OR = 1.19; 95% CI: 1.14-1.24; p < 0.01; I2 = 90%). Folate levels were not associated with MetS (OR = 0.83; 95% CI: 0.66-1.03; p = 0.09; I2 = 90%). Conclusion: Higher vitamin B12 levels were inversely associated with MetS, whereas higher Hcy levels were associated with MetS. Studies assessing the pathways underlying this association are required.
