Revista Do Instituto De Medicina Tropical De Sao Paulo最新文献

Antimicrobial resistance constitutes a significant global challenge to public health and development, in which non-typhoidal Salmonella emerges as a critical concern. This study investigates the prevalence and antimicrobial resistance profiles of Salmonella isolates from both human and nonhuman sources. A total of 2,511 Salmonella isolates that had been collected from 2016 to 2023 were analyzed, of which 1,724 underwent antimicrobial susceptibility testing. The main focus lied on the 10 most prevalent serotypes, totaling 957 isolates. Serotyping showed the diverse distribution of serotypes, with Heidelberg, Typhimurium, Enteritidis, and the monophasic Salmonella Typhimurium occurring most often. Antimicrobial resistance was common since 512 strains resisted at least one drug and 319 several drugs. Notably, the Heidelberg and Mbandaka serotypes, predominantly occurring in nonhuman samples, showed multidrug resistance. Salmonella Typhi remained susceptible to antimicrobials. Resistance to nalidixic acid, tetracycline, sulfonamides, and ampicillin was prevalent, whereas all isolates remained susceptible to imipenem. A reduction in susceptibility rates for aminoglycosides was observed over the study period. Extended-spectrum β-lactamase production occurred in 4.4% of the isolates, of which Heidelberg configured the most prevalent extended-spectrum β-lactamase-positive serotype. These findings underscore the importance of surveillance and effective monitoring to control this pathogen, highlighting the necessity of prioritizing public health efforts.

Currently, COVID-19 and tuberculosis (TB) are the deadliest infectious diseases worldwide. Their synergy, form of presentation, morbidity, and mortality are data that have been scarcely explored. Thus, this study aimed to characterize the clinical, epidemiological, and laboratory factors of this co-infection and to analyze the factors associated with the active TB among COVID-19 cases. A case-control study was conducted with a retrospective survey of 21 laboratory-confirmed COVID-19/TB co-infected patients (case group) and 21 COVID-19 patients (control group). The study included participants from eight hospitals in Campo Grande city, capital of Mato Grosso do Sul State, Brazil, from March 2020 to March 2022. Association analysis and binomial logistic regression were employed with statistical significance set at p≤0.05. From the 21 identified cases of COVID-19/TB co-infection, we found a more frequent association with HIV infection than the control-group, without worsening the outcome. COVID-19/TB patients had less dyspnea and less need for mechanical ventilation compared to the cases with COVID-19 only. On the other hand, COVID-19/TB patients had higher levels of C-reactive protein and lower hemoglobin levels, the latter variable was independently associated with COVID-19/TB. Among the clinical differences presented among COVID-19/TB co-infected patients, despite the association with HIV and lower clinical repercussions, only lower hemoglobin levels were associated with COVID-19/TB.

Aedes albopictus (Skuse) is a competent vector of dengue and Zika viruses in Mexico. Monitoring the level of resistance of local population is essential due to its epidemiological significance. This study aimed to identify mutations in the voltage-gated sodium channel (VGSC) as one of the mechanisms responsible for pyrethroid insecticide resistance in Ae. albopictus. Immature samples were collected in a rural town in Yucatan, Mexico, from May to October 2021. The pyrethroid insecticide lambda-cyhalothrin was impregnated in CDC bottles and bioassays were conducted on Ae. albopictus populations 3-5 days after emergence. The mosquitoes were susceptible to the insecticide. Females were taken for total DNA extraction. Fragments of domains II, III, and IV of the voltage-gated sodium channel (VGSC) were amplified and sequenced. The presence of synonymous and non-synonymous mutations was found in positions 1532 and 1534 of domain III of the sodium channel gene (VGSC). No mutant alleles in domain IV were detected. A homozygous mutant (ACG) coding for the amino acid threonine (1008Thr) was identified in domain II. Domain III included three heterozygous alleles (P1528S, L1530S, and Ile1410Thr). This last heterozygous allele is reported for the first time in Mexico. Homozygous mutants encoding the amino acids serine/serine and serine/proline in domain III were observed. These have been reported in Aedes aegypti from Mexico, but not yet in Ae. albopictus. This represents new findings for the region, as Ae. albopictus has only been introduced there for approximately five years. In conclusion, non-synonymous mutations were found in Ae. albopictus in a rural area of Yucatan, emphasizing the importance of integrated vector control to prevent Asian tiger mosquitoes from spreading these resistant alleles.

Paracoccidioidomycosis, the most important systemic mycosis in Latin America, is closely linked to rural activities. In Brazil, it is an endemic disease, with an estimated 4,000 to 6,000 annual cases, accounting for over 80% of the global diagnoses. We present an intriguing case of this disease with an intestinal manifestation in a 71-year-old woman. The involvement of the cecal appendix led to a complication of cholangitis that mimicked cholangiocarcinoma.

Tuberculosis (TB) is a global public health concern and a leading cause of death. Its persistence occurs mainly because barriers in the care cascade are not being fully addressed. Healthcare professionals and scientists have been addressing treatment challenges such as abandonment and irregular drug intake via strategies such as directly observing treatment and singular therapeutic projects to improve adherence. However, while protocols and guidelines advocate these strategies, their implementation requires a broader approach from healthcare teams. This article examines the importance of such strategies in clinical TB management and analyzes an unfavorable outcome in an immunocompetent patient treated for pulmonary tuberculosis (PTB) from 2017 to 2022. After recurrence and treatment, the patient continued to have persistent acid-fast bacilli in the sputum, positive cultures for Mycobacterium tuberculosis, and progressive lung lesions, despite receiving the recommended treatment. Although categorized as having an intermediate risk of treatment abandonment, the patient faced challenges, such as the COVID-19 pandemic, pregnancy, and being diagnosed with COVID-19. After therapeutic failure and the loss of beneficial prospects, palliative care was initiated. This case illustrates the complexities of managing TB in patients with recurrent disease despite apparent adherence to treatment. After reassessing the risk of abandonment score, the patient was categorized as high-risk. This underscores the importance of singular therapeutic projects, such as psychological support for high-risk or intermediate patients, to prevent negative outcomes. This case reinforces the critical need for comprehensive patient-centered approaches to successfully treat and manage TB.

Toxoplasmosis is a widespread zoonotic disease that poses significant public health concern globally, with neurotoxoplasmosis being a severe complication associated with high mortality rates. The standard therapy for neurotoxoplasmosis involves a combination of sulfadiazine and pyrimethamine, which, despite its efficacy, is often limited by adverse effects leading to treatment discontinuation. This study aimed to evaluate the in vivo efficacy of nitazoxanide in treating neurotoxoplasmosis in mice infected with the Me49 strain. The study comprised two groups: Group I, including subgroups of uninfected, infected and treated with saline, and infected and untreated mice; and Group II, comprising infected mice treated with nitazoxanide at 100 mg/kg/day, nitazoxanide at 150 mg/kg/day, and pyrimethamine combined with sulfadiazine. After 14 days of treatment, the mice were euthanized for organ collection. Histopathological examination of the brains revealed that the highest dose of nitazoxanide reduced parasitic load and cerebral hemorrhages. Biochemical and histopathological analyses of liver and kidney tissues demonstrated toxicological profiles comparable to pyrimethamine and sulfadiazine. However, despite showing efficacy and similar toxicity levels, nitazoxanide treatment was less effective regimen in controlling neurotoxoplasmosis in this experimental model compared to the pyrimethamine and sulfadiazine. Thus, while nitazoxanide presents potential in neurotoxoplasmosis treatment, pyrimethamine combined with sulfadiazine remains the preferred therapeutic choice based on better efficacy observed in this study.

Cutaneous leishmaniasis represents 99% of all reported leishmaniasis cases in Mexico and typically occurs in agricultural or sylvatic areas. Campeche State is endemic for leishmaniasis; however, there are no previous records of urban Leishmania transmission. This report presents a case of cutaneous leishmaniasis in a 75-year-old man residing in an urban area. The patient presented with a three-month-old lesion on the right ear following an initial misdiagnosis of a bacterial infection. Given the suspicion of leishmaniasis, a tissue imprint was collected, revealing the presence of Leishmania amastigotes. Subsequently, amplification and sequencing of the Alanine aminotransferase and Internal transcribed spacer subunit 1 genes confirmed the presence of Leishmania mexicana. The patient was then treated with intralesional meglumine antimoniate. This case is significant as it marks the first confirmed human transmission of L. mexicana in an urban environment in Campeche State, demonstrating the importance of considering this pathology in patients with skin lesions originating from non-endemic areas in Mexico.

Piedras are small nodules found on the hair shafts. White piedra was initially described as caused by Trichosporon beigelii, which was later reclassified in several species. We describe the first case of white piedra caused by Cutaneotrichosporon debeurmannianum. Affected hairs were examined in natura with scanning electron microscopy, after gold metallization. The typical whitish cerebriform creamy colony was obtained in Sabouraud medium. Fungal genomic DNA extracted from cultures and locus was amplified with the NL1/NL4 primer pair from the D1/D2 region of the large ribosomal subunit (LSU) of 28S rRNA. With scanning electron microscopy, nodules are easily identified surrounding the hair shaft; with high magnifications, rounded structures adhered to each other were identified. Comparison of the nucleotide sequences of IMT-1703 Cutaneotrichosporon debeurmannianum revealed 99.6% similarity with the 28S large ribosomal unit rDNA sequence. This case of white piedra was caused by Cutaneotrichosporon debeurmannianum.

Acute respiratory distress syndrome is a significant complication in critical care patients. COVID-19 (C19)-associated severe respiratory failure is related to it, and d-dimer rise predicts a worse outcome. To investigate the association between d-dimer and the severity of this respiratory syndrome, we conducted a study in C19 intubated patients. A retrospective, single-center observational study was conducted with 64 C19 adult intubated patients. Strata of d-dimer results between patients was evaluated using survival analysis. Survival was higher in mild respiratory distress patients. D-dimer showed poor sensitivity and specificity in predicting respiratory failure severity. Risk assessment for death showed a higher prevalence of admission d-dimer results (HR 1.335; 95% CI 0.695-2.564). Our sample confidently represented the medical profile of C19 severe patients. Sepsis development in C19 is associated with the inflammatory storm in respiratory distress syndrome. As the receiver operating curves show, the increase in d-dimer results is consistent with inflammation rather than a prognostic biomarker. As expected, severe respiratory distress patients presented higher mortality. In summary, d-dimer results are not associated with the prognosis of C19 respiratory distress syndrome patients.

The genus Flavivirus (Family: Flaviviridae) comprises arboviruses with the capacity to infect humans and animals. It also integrates insect-specific viruses. This study aimed to identify Flavivirus in mosquitoes captured in 17 municipalities in Yucatan State, Mexico. The mosquitoes were caught in households from November 2021 to May 2022. A total of 4,321 adult mosquitoes from five species were caught. The most abundant were Culex quinquefasciatus (n = 3,563) and Aedes aegypti (n = 734). For molecular investigations, 600 female mosquitoes were split into groups of 10, mostly for species and site location. Reverse transcriptase polymerase chain reaction (RT-PCR) amplified a region of the NS5 gene to find the Flavivirus ribonucleic acids (RNA). A total of 24 pools that were positive for Flavivirus were detected in Ae. aegypti specimens and subsequently subjected to sequencing using the Sanger method. A total of 12 sequences matched the established quality criteria and were subsequently employed for sequence homology analysis. We found that one sequence corresponded to the Zika virus (ZIKV), and 11 sequences had sequence similarity with Phlebotomus-associated flavivirus (PAFV), an insect-specific virus (ISF). In conclusion, we found ZIKV in the Merida municipality, Yucatan State, which suggests that the virus is silently circulating. Phlebotomus-associated flavivirus is distributed in five municipalities in Yucatan State, Mexico. Future studies could focus on isolating this virus and studying its biological role within Ae. aegypti.