Revista da Sociedade Brasileira de Medicina Tropical最新文献

Background: Few studies in routine settings have confirmed the high accuracy of the Xpert MTB/RIF assay for detecting rifampicin resistance (RR) and the first-line probe assay (FL-LPA) for detecting both RR and isoniazid resistance (INHR).

Methods: The performance of Xpert MTB/RIF and MTBDRplus VER 2.0 LPA was evaluated in 180 Mycobacterium tuberculosis samples collected from January 2018 to December 2019 in Rio de Janeiro, Brazil. The results were compared with those from BACTEC MGIT 960 culture and drug susceptibility testing (DST). Whole-genome sequencing was performed on the samples with discordant results.

Results: The Xpert MTB/RIF assay showed a sensitivity (Se) of 93.3% and a specificity (Sp) of 97.6%, detecting RR. The performance of FL-LPA to identify RIF and INH resistance was, respectively, (Se) 100% and 83.3% and (Sp) 98.8% and 100%. Among 18 clinical isolates with INHR detected by FL-LPA, mutations in the katG gene were observed in 100% of samples, of which only two (11.1%) had mutations in both katG and inhA genes. Overall, the discordant results were identified in 9 (5%) samples. Among the four Xpert RIF-resistant and DST-sensitive, two harbored mutations in rpoB Leu430Pro. Among the four FL-LPA-sensitive and DST-resistant, one had a mutation in inhA 17G>T. FL-LPA showed high accuracy in detecting RR and INHR.

Conclusions: The MTBDRplus test demonstrated excellent performance in detecting RR, and INHR in clinical isolates under routine conditions at a reference laboratory in Rio de Janeiro, Brazil. Incorporating both tests can improve drug-resistant tuberculosis treatment outcomes and monitor the INHR incidence.

Background: Healthcare systems are currently ill-equipped to diagnose arboviruses rapidly and efficiently or to differentiate between various viruses.

Methods: Utilizing molecular techniques, this study examined arbovirus infections in 459 patients from a public health unit in Goiânia-Goiás, Brazil, a region where arbovirus infection poses a significant public health challenge.

Results: Nearly 60% of the analyzed samples tested positive for at least one arbovirus, and over 10% of the patients were co-infected with more than one virus.

Conclusions: Fast and accurate diagnostic tools are essential for informing public health policy and enhancing epidemiological surveillance.

Background: Trachoma is the leading infectious cause of blindness worldwide. It is a neglected tropical disease caused by Chlamydia trachomatis. The objective of this study was to analyze the trachoma-associated morbidity and mortality in Brazil from 2000 to 2022. This ecological time-series study was based on secondary data on trachoma obtained from hospital admissions (trachoma as the primary or secondary cause) and death certificates (trachoma as the underlying or associated cause).

Methods: We calculated the sex- and age-standardized rates of hospital admissions and trachoma-specific mortality according to sociodemographic variables and analyzed the spatial distribution.

Results: We identified 141/263,292,807 hospital admissions (primary cause: 83.0%) and 126/27,596,830 death certificates (associated cause: 91.3%) related to trachoma. Trachoma-related sequelae were reported in 8.5% of hospital admissions and 6.3% of death certificates. Trachoma was more common in males (hospital admissions and death certificates), people aged ≥70 years (hospital admissions and death certificates), those with brown skin (hospital admissions and death certificates), and those living in the North (hospital admissions) and Northeast (death certificates) regions of Brazil.

Conclusions: Despite the relatively low rates of trachoma morbidity in Brazil, the associated mortality rates are of concern. The heterogeneous patterns of occurrence in the country in terms of population and territory reinforce the need to evaluate and monitor the available data, despite the low prevalence, in order to achieve and maintain the elimination targets in Brazil in the future.

Acquired thrombotic thrombocytopenic purpura (TTP) is a rare life-threatening disorder characterized by microangiopathic hemolytic anemia, severe thrombocytopenia, and organ damage. We present the case of a 71-year-old man initially diagnosed with malaria-like symptoms and displaying markers of microangiopathic hemolytic anemia, severe thrombocytopenia, renal injury, and neurological impairment. Despite antimalarial treatment, acquired TTP was suspected. Plasma exchange and immunosuppressive therapy led to clinical improvement, normalizing the platelet count and hemolytic profile. Diagnostic confirmation revealed significantly reduced ADAMTS13 levels. Following the proposed treatment, the patient's ADAMTS13 levels normalized. This case illustrates acquired TTP linked to uncomplicated Plasmodium vivax malaria.

Background: Vectorial transmission through hematophagous triatomine insects remains the primary mode of Chagas Disease contagion. These insects have become increasingly common in urban environments. Therefore, this study aimed to report an encounter of triatomines with trypanosomatid infection in a vertical residential condominium in Rio Branco, the capital of the state of Acre, in the western Brazilian Amazon.

Methods: Triatomines were collected from residents and sent to the municipality's Entomological Surveillance sector. Trypanosomatid positivity was evaluated using optical microscopy, followed by species and genotype identification using molecular biology techniques.

Results: Twenty-five adult triatomine specimens were collected from two of three condominium buildings invading apartments from the 2nd to 13th floors. Six specimens were identified as Rhodnius sp. and 19 as R. montenegrensis. Among these, molecular tests were conducted on seven specimens, with five testing positive for Trypanosoma cruzi, all belonging to genotype TcI.

Conclusions: These findings underscore the need for further studies to better understand the invasive capacity of these insects in these environments and the mechanisms involved in this process.

Background: Global dengue cases are rising, notably in Brazil.

Methods: By using monthly data, we estimated linear regressions with ARIMA errors to measure the influence of temperature and precipitation on dengue incidence in the city of Campinas, São Paulo State, Brazil.

Results: Findings suggest that a 1°C increase in mean temperature can lead to a cumulative increase of up to 40% in dengue incidence within 2 months. Precipitation shows no significant impact.

Conclusions: Results highlight the importance of temperature on the spread of dengue and potentially other mosquito-borne diseases.

Background: Triatomines are biological vectors of Trypanosoma cruzi, the etiological agent of Chagas Disease (CD) and have various mammalian hosts. This study evaluated the entomological indicators and food sources of triatomines in Petrolina in the semi-arid region of Brazil, where CD is endemic.

Methods: Triatomines were captured indoors and outdoors through an active search and entomological indices (household and natural infections) were calculated. Parasitological analyses were performed through microscopic visualization using Giemsa-stained insect feces, and DNA sequencing was employed to identify food sources from the gut contents of 82 insects (9.05%) that were better preserved.

Results: We captured triatomines (906) in peridomicile (807) and intradomicile (99): Triatoma brasiliensis (84.7%, 767 specimens), Triatoma spp. (8.2%, 74 specimens), T. pseudomaculata (6.5%, 59 specimens), Rhodnius spp. (0.4%, four specimens), R. nasutus (0.1%, one specimen), and T. sordida (0.1%, one specimen). The household infestation index is 11.8%. Thirty-five triatomines were infected (33 T. brasiliensis and two T. pseudomaculata), corresponding to a natural infection index of 3.8%. The identified food sources were human T. pseudomaculata and T. brasiliensis, dogs for T. brasiliensis and rodents (Mus musculus) for T. brasiliensis.

Conclusions: The results reinforce the need to intensify CD diagnosis, surveillance, and control actions, as an increase in entomological indices was recorded. Blood from humans and domestic and synanthropic animals was detected in the infected triatomines, suggesting a risk of CD vector transmission in Petrolina. As CD is a zoonosis, multidisciplinary and intersectoral CD surveillance must be conducted in the context of the One Health.

Background: The current treatments for Chagas disease (CD) include benznidazole and nifurtimox, which have limited efficacy and cause numerous side effects. Triazoles are candidates for new CD treatments due to their ability to eliminate T. cruzi parasites by inhibiting ergosterol synthesis, thereby damaging the cell membranes of the parasite.

Methods: Eleven synthetic analogs of the kinase inhibitor SRPIN340 containing a triazole core (compounds 6A-6K) were screened in vitro against the Tulahuen strain transfected with β-galactosidase, and their IC50, CC50, and selectivity indexes (SI) were calculated. Compounds with an SI > 50 were further evaluated in mice infected with the T. cruzi Y strain by rapid testing.

Results: Eight compounds were active in vitro with IC50 values ranging from 0.5-10.5 µg/mL. The most active compounds, 6E and 6H, had SI values of 125.2 and 69.6, respectively. These compounds also showed in vivo activity, leading to a reduction in parasitemia at doses of 10, 50, and 250 mg/kg/day. At doses of 50 and 250 mg/kg/day, parasitemia was significantly reduced compared to infected untreated animals, with no significant differences between the effects of 6E and 6H.

Conclusions: This study identified two new promising compounds for CD chemotherapy and confirmed their activity against T. cruzi.