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

Evidence suggests a risk of maternal transmission of chikungunya virus (CHIKV) during the first and third trimesters, potentially leading to miscarriage or neurological consequences for the fetus. This study aimed to conduct a serological survey for CHIKV among women with high-risk pregnancies and analyze neonatal variables and placental tissue alterations. From March 2016 to April 2021, serological, histological, and molecular tests for CHIKV were performed. Blood samples were analyzed for anti-CHIKV IgG and IgM antibodies, and placental tissue was examined for CHIKV RNA and histological changes. Among pregnant patients, 1.33% (7/526) had reactive IgG, and 0.38% (2/526) had IgM/IgG-type antibodies during delivery. Although placental histology of CHIKV disease showed alterations, no viral genetic material was identified in the analyzed tissues. Therefore, further research is needed, including the use of complementary diagnostic techniques, to better understand the impact of this relatively new disease among high-risk pregnant women and newborns.

COVID-19, caused by SARS-CoV-2 virus infection, remains a public health concern in many countries. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a rapid and cost-effective alternative test for COVID-19 diagnosis. In this study, we developed and evaluated a real-time RT-LAMP (rRT-LAMP) assay coupled with a melting curve analysis to detect SARS-CoV-2. The reaction was carried out in a real-time thermal cycler at 63 °C for 45 min to amplify the region of SARS-CoV-2 orf8; real-time monitoring of amplification was performed by fluorescence detection. The performance was assessed by comparing it to a real-time reverse transcription-polymerase reaction (rRT-PCR) as a reference. The rRT-LAMP could detect as few as 15 copies of SARS-CoV-2 RNA per reaction. Positive results appeared within 30 min, while the melting-temperature analysis could verify the amplification specificity. No positive results from non-SARS-CoV-2 templates and no mis-amplification were observed. The comparative analysis using 262 RNA extracted from nasopharyngeal swab samples revealed the overall accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) of the rRT-LAMP at 88.55% (95% CI: 77.52-100%), 84.13% (95% CI: 71.56-98.27%), 100% (95% CI: 78.38-100%), 100% (95% CI: 85.06-100%), and 70.87% (95% CI: 55.55-89.11%), respectively. The greatest sensitivity was as high as 98-100% for specimens with threshold rRT-PCR cycle (Ct) values of less than 30 cycles. Overall, this rRT-LAMP showed good performance for the rapid detection of SARS-CoV-2. It is proposed as a potential method for real-time amplification detection, offering increased laboratory capacity for SARS-CoV-2 testing in a cost-effective and timely manner.

Rickettsia species are Gram-negative, pleomorphic coccobacilli that are obligate intracellular pathogens transmitted by arthropod vectors such as ticks. Among them, Rickettsia conorii, the causative agent of Mediterranean spotted fever (MSF), is endemic in many Mediterranean countries, including Turkey. This case series describes three patients from Balıkesir, Turkey, who developed high-grade fever, generalized maculopapular rash involving the palms and feet soles, arthralgia, and necrotic eschars (tache noire) at the tick bite sites. All cases occurred during summer and had documented exposure to Rhipicephalus sanguineus. Laboratory evaluations ruled out other tick-borne diseases, while real-time PCR performed on skin biopsy samples confirmed Rickettsia spp. Subsequent DNA sequencing of the gltA and ompA gene regions enabled species identification. Additionally, serological tests showed a significant rise in IgM and IgG antibody titers reacting with Rickettsia conorii antigen by indirect immunofluorescence assay. All patients were treated with doxycycline and recovered without complications. This case series highlights the importance of considering rickettsial infections in the differential diagnosis of febrile patients with rash and recent tick exposure, especially in endemic regions during warm seasons.

Mosquitoes (Diptera: Culicidae) are arthropods of medical importance because they can carry arboviruses. High-throughput sequencing (HTS) technology and metagenomic approaches conducted in mosquitoes have contributed to the discovery of many insect-specific viruses (ISVs), which have the potential to affect their vector competence. Mosquitoes were collected in urban parks in Sao Paulo city, Brazil and 20 pools with female mosquitoes were subjected to HTS by HiSeq 2500 sequencing system (Illumina). Long viral sequences (1,585-6,701 base pairs) were recovered from two pools of Aedes scapularis. BLASTx analyses revealed they had greater identity with segment L and S of Salarivirus and segment M of Furrundu phlebovirus, which encode, respectively, the RNA-dependent RNA polymerase (RdRd), the nucleocapsid protein, and a polyprotein. Phylogenetic tree of the segment L and S of the Phenuiviridae Family showed our sequences grouped with unverified sequences of Furrundu phlebovirus, an unclassified ISV that belongs to the Hareavirales Order and was first reported in mosquitoes in the Brazilian Pantanal, the largest natural tropical wetland worldwide. We report the second detection of Furrundu phlebovirus in mosquitoes collected in urban parks, showing it could be in mosquitoes from natural places and in green areas in urban cities. We conclude that Furrundu phlebovirus possibly occurs in Aedes scapularis in green areas, in Sao Paulo. Further studies should elucidate the role of this virus in the vector competence of Aedes scapularis and its interaction with different arboviruses.

The identification of Leishmania species is crucial for eco-epidemiological purposes and may be useful for clinical management. Notably, archived smear slides can be valuable in this scenario. ITS-1 PCR followed by sequencing was used to identify Leishmania species from archived lesion smears of patients with suspected cutaneous leishmaniasis in Santarem city, Para State, Brazil. A total of 44 microscopically positive lesion smears were analyzed, of which 34 yielded positive PCR results. Of these, 22 were subjected to Sanger sequencing and 15 were successfully sequenced, revealing five Leishmania species. This study demonstrates the applicability of molecular testing on archived samples. ITS-1 sequencing effectively differentiated between species, revealing significant diversity of Leishmania in the Brazilian Amazon.

Gastrointestinal mucormycosis (GIM) and leptospirosis are two severe diseases associated with high morbidity and mortality rates. The coexistence of these two conditions has not yet been reported in the literature. This study presents a case involving this rare association. A 49-year-old man from Sao Paulo, Brazil, was hospitalized with acute abdominal pain, low blood pressure, and jaundice. He had a history of contact with floodwater and ingestion of contaminated water, was hospitalized with acute abdominal pain, low blood pressure, and jaundice. Upon ICU admission, he developed jaundice, acute renal failure requiring hemodialysis, and alveolar hemorrhage necessitating intubation. Leptospirosis was confirmed by serological tests and treated with ceftriaxone for 14 days. Two weeks later, he developed severe enterorrhagia, requiring a massive transfusion and a total colectomy with terminal ileostomy. Histopathology revealed necrotizing granulomatous inflammation with hyphae indicative of mucormycosis. He was treated with amphotericin B for 7 weeks, followed by posaconazole. Abdominal CT scans over the next five months showed complete clinical and radiological improvement. The association between mucormycosis and leptospirosis has not been previously documented, highlighting the diagnostic challenges and the critical importance of early detection. Successful management in this case required timely surgical intervention combined with prolonged antifungal therapy.

Chlamydia trachomatis infection has been implicated as a potential risk factor for ovarian cancer (OC), but evidence remains inconclusive. This study aims to assess the association between C. trachomatis infection and OC risk using a systematic review and meta-analysis. A comprehensive literature search was conducted in PubMed, Embase, Scopus, Web of Science, and SciELO from their inception to October 2024. Observational studies examining the association between C. trachomatis infection and OC risk were included. Pooled odds ratios (ORs) were calculated using random-effects models. Subgroup and sensitivity analyses were performed based on diagnostic methods and control group types, and publication bias was assessed using Egger's test. Out of 3,288 records, 11 studies involving 4,518 participants were included. The overall meta-analysis revealed a non-significant association between C. trachomatis infection and OC risk (OR = 1.30, 95% CI = 0.99-1.70). However, sensitivity analysis excluding two studies demonstrated a significant association (OR = 1.37, 95% CI = 1.16-1.61). Subgroup analysis showed that PCR-diagnosed C. trachomatis infection was significantly associated with an increased risk (OR = 6.64, 95% CI = 1.62-25.71), while serology-based studies yielded non-significant results. Heterogeneity was high (I² = 70.83%), and publication bias was detected (Egger's test p = 0.015). These findings highlight the role of infection chronicity in OC pathogenesis and suggest that diagnostic methodology significantly impacts observed associations. Future research should employ longitudinal designs with serial molecular testing to establish temporality and evaluate whether targeted Chlamydia screening or treatment interventions could mitigate OC risk in high-prevalence populations.

To assess SARS-CoV-2 reinfection incidence in the post-vaccination period, we carried out a prospective cohort study of blood donors from Amazonas and Sao Paulo States, Brazil. Anti-nucleocapsid immunoglobulin (IgG anti-N) tests carried out by blood centers in 2020 were used to identify previous SARS-CoV-2 infections in blood donors and divide them into two groups: prior infection (n=386) and no prior infection (n=111). From March 2021 to January 2022, donors were followed up for six months, during which IgG anti-N and real-time reverse transcription polymerase chain reaction tests were performed every two months to detect SARS-CoV-2 infections. Symptoms and vaccination status were also recorded. Most participants (93.6%) received at least one COVID-19 vaccine dose. Reinfection incidence in the prior infection group equaled 1.39 per 100 person-months (95% CI: 0.90-2.06), in comparison to 2.68 per 100 person-months (95% CI: 1.28-4.93) for new infections in those without prior infection. The incidence risk ratio showed no significant association (0.52, 95% CI: 0.25-1.13). However, prior infection significantly increased the probability of remaining uninfected (Log-rank: p=0.009). Most reinfections (84%) showed no symptoms and occurred post-vaccination during the Delta and Omicron waves. IgG anti-N seroprevalence decreased in the prior infection group (from 35.5% at baseline to 22.5% after six months, p=0.003). Despite no significant incidence risk ratio differences, donors with prior infection had lower infection rates and a higher likelihood of remaining uninfected. Persistent post-vaccination asymptomatic infections emphasize the need for ongoing prevention, genomic surveillance, and booster programs to address emerging variants and protect vulnerable populations.