Tropical Medicine and Infectious Disease最新文献

Scrub typhus has emerged as a life-threatening and increasingly prevalent vector-borne disease. While the spatial and temporal distributions of scrub typhus have been studied by the research community, the main driving factors that influence the spatiotemporal patterns of the disease remain under investigation. Using Guangdong Province as a case study, we combined monthly scrub typhus case data from 2010 to 2019 and environmental and vector-related datasets with a Bayesian hierarchical mixed model to elucidate the spatiotemporal characteristics of the disease. This study revealed that the most highly endemic areas of scrub typhus are concentrated in the western and southern parts of Guangdong Province. A distinct bimodal pattern of scrub typhus was observed, with peaks typically occurring from May to July and October to November. The fitted model indicated that forest, cropland, and chigger mites were positively associated with scrub typhus transmission. Furthermore, climate and vectors were identified as key factors shaping the bimodal seasonal patterns of scrub typhus. Despite data-related limitations, including the treatment of population as a time-invariant variable and the binary simplification of vector suitability, sensitivity analyses confirmed the robustness of the model, offering valuable insights for scrub typhus prevention in Guangdong.

Leishmaniasis remains a global health challenge, and the search for effective and selective therapeutic agents is crucial. This study evaluated the in vitro antileishmanial and cytotoxic activities of thiosemicarbazone compounds (LT-70, LT-73, LT-75, and LT-89) against Leishmania infantum promastigote and axenic amastigote forms. The compounds demonstrated strong leishmanicidal activity, with IC₅₀ values ranging from 10.5 to 14 µM. At the lowest tested concentration (20 µM) the compounds produced percent inhibitions of 100% (LT-70), 100% (LT-73), 100% (LT-75) and 100% (LT-89). Cytotoxicity assays on J774.A1 macrophages revealed CC₅₀ values from 60 µM to >75 µM, with LT-73 and LT-75 showing low toxicity (CC₅₀ > 75µM). Selectivity index (SI) ranged from 7.1 for LT-75 and 5.8 for LT-73, indicating potential for further development. Ultrastructural analysis by SEM and TEM revealed cellular and organelle damage, including membrane rupture and mitochondrial swelling, especially after LT-73 and LT-75 treatment. Immunomodulatory assays indicated induction of TNF-α and IFN-γ production, with significant IL-6 reduction. Flow cytometry data suggest mitochondrial dysfunction and apoptosis-like features, particularly for LT-73. Membrane potential assays suggested mitochondrial depolarization by LT-73. LT thiosemicarbazone derivatives present specific structural modifications that enhance antileishmanial selectivity and reveal a dual mechanism of action combining mitochondrial dysfunction and immunomodulatory effects. These findings support the potential of thiosemicarbazone derivatives as promising antileishmanial agents with selective cytotoxicity and immunomodulatory effects.

Intestinal protozoa are a common cause of morbidity in people living with HIV (PWH), particularly in tropical regions with poor sanitation. We conducted a cross-sectional study in 315 PWH from Iquitos, Peru, between October 2023 and May 2024, to assess their prevalence and risk factors. Stool samples were examined using Lugol's iodine, modified Ziehl-Neelsen (MZN) staining, and immunochromatography (ICT). The mean age was 41 years, with a median CD4+ count of 431 cells/µL; 12.4% were in the AIDS stage, and 21.5% had a detectable viral load. 51.4% of the participants tested positive for any intestinal protozoa. The overall Cryptosporidium spp. prevalence (by combining MZN and ICT results) was 25.7%. The overall Giardia spp. and Entamoeba spp. prevalences (by combining Lugol's iodine and ICT results) were 2.9% and 1.9%, respectively. Blastocystis spp. was frequently isolated, though its pathogenicity remains uncertain. Diagnostic agreement was almost perfect between Lugol and ICT for Giardia and Entamoeba (κ = 0.87; p < 0.001 and κ = 0.91; p < 0.001, respectively), but only slight between MZN and ICT. Homosexual practices were identified as a significant risk factor for pathogenic protozoa infection (AOR 2.52; 95% CI: 1.04-6.12). In conclusion, the high prevalence of protozoa infection reflects ongoing fecal-oral exposure, underscoring the need for public health education, routine diagnosis, and treatment in similar settings.

Background: Toxoplasmosis, caused by the parasite Toxoplasma gondii, is a zoonotic disease that poses significant health risks to immunocompromised individuals, pregnant women, and infants. Transmission occurs primarily through infected cat feces or contaminated food. Awareness of transmission routes, prevention strategies, and health consequences remains limited in high-prevalence humid regions such as Jazan, Saudi Arabia.

Methods: This cross-sectional study was conducted in Jazan, Saudi Arabia, between April and May 2025, surveying 485 adults using a five-section questionnaire covering demographics, knowledge, practices, medical history, and recommendations. The survey was distributed in both English and Arabic. Self-reported previous diagnoses were used to estimate prevalence, with risk factors presented as frequencies and percentages. Binary logistic regression analyzed categorical variables, and independent t-tests assessed continuous variables to identify predictors of awareness and knowledge regarding toxoplasmosis.

Results: Participants comprised 58.6% females, 97.3% Saudis, and 69.1% individuals aged ≤30 years; 49.7% had heard of toxoplasmosis. Females (adjusted odds ratio [AOR]: 1.67, 95% CI: 1.13-2.5, p < 0.01) and those >30 years old (AOR: 1.8, 95% CI: 0.80-4.29, p > 0.05) demonstrated greater awareness and knowledge, though this was not statistically significant. No significant differences were observed based on marital status (p > 0.05). Risk behaviors included consuming unwashed fruits and vegetables (27.6%) and unpasteurized dairy products (28.2%), with 62.7% always washing hands after handling raw meat or soil. Cat ownership (20.6%) was not associated with knowledge (p = 0.97). Self-reported diagnosis prevalence was 1.9%.

Conclusions: Low awareness and prevalent risky behaviors underscore the urgent need for targeted public health education interventions focusing on hygiene practices and zoonotic disease prevention in Jazan. Serological studies are recommended to obtain more accurate prevalence estimates and guide evidence-based interventions.

This study represents the first investigation into the prevalence of pathogenic bacteria in isolated, free-ranging Eastern Grey Kangaroos (Macropus giganteus) inhabiting a human-shared environment. Samples were collected from the nasal and rectal passages of state-authorised culls of M. giganteus within a military training area, where recruits had reported recurrent cases of skin and soft tissue infections. The objective was to identify clinically relevant pathogenic microorganisms present in the nasal and rectal flora of these kangaroos. Analysis revealed carriage rates of 11% for methicillin-sensitive Staphylococcus aureus (MSSA) and 2% for methicillin-resistant S. aureus (MRSA). Other potentially pathogenic bacteria isolated included Pseudomonas spp., Streptococcus (Groups B and D), Acinetobacter spp., and multiple coagulase-negative Staphylococcus (CoNS) species. Notably, CoNS species were present in 17% of nasal isolates, with Mammaliicoccus sciuri (formerly Staphylococcus sciuri) detected in 41% of these isolates, suggesting a potential reservoir for antibiotic resistance genes and virulence factors. These findings support a One Health perspective, highlighting the interconnectedness of pathogenic bacteria, M. giganteus, humans, and their shared environment.

Strongyloidiasis is an underappreciated helminth infection that belongs to a group of neglected tropical diseases. The aim of this systematic review and meta-analysis was to determine the pooled prevalence of Strongyloides stercoralis infection in humans in 16 West African countries. We searched African Journals Online, Embase, Horizon, Google Scholar, ProQuest, PubMed, Scopus, and Web of Science to identify articles assessing S. stercoralis prevalence data. The search was restricted to articles published between 1 January 1975 and 31 December 2024 without language restriction. We followed the PRISMA guidelines. A total of 21,250 articles were identified, 336 of which met the inclusion criteria. The most frequently used diagnostic tools were Kato-Katz (35.1%) and formol-ether coprological methods (23.4%). Strongyloidiasis was reported in 15 of the 16 West African countries; Mali was the only country where it was absent. The S. stercoralis regional prevalence was 4.4%, ranging from 0.2% in Burkina Faso to 18.9% in The Gambia. S. stercoralis infection prevalence decreased from 14.0% (1975-1984) to 4.1% (2015-2024). S. stercoralis prevalence showed strong heterogeneity with the highest prevalence mainly observed in countries in the Gulf of Guinea. Most of the employed diagnostic techniques were inappropriate; the reported S. stercoralis prevalence is, thus, likely an underestimation of the true situation. Our observations call for more sensitive S. stercoralis diagnostic tools and strategies for strongyloidiasis control that are tailored to the different social-ecological settings of West Africa.

Leishmaniasis and Chagas disease, caused by Leishmania spp. and Trypanosoma cruzi, are neglected tropical diseases with significant global health burden, particularly in resource-limited regions. Despite their impact, diagnosis and treatment remain challenging due to limited diagnostic tools and the toxicity of available therapies. Our objective is to propose the incorporation of markers for the diagnosis of leishmaniasis and Chagas disease using ncRNA. This narrative review evaluates studies published between 2010 and 2024 (PubMed, Scopus, Google Scholar) using the SANRA scale to assess the potential of non-coding RNAs (ncRNAs) as biomarkers for these infections. Both parasites release small RNAs via extracellular vesicles that modulate host-pathogen interactions and gene expression. Although RNA interference machinery is absent in T. cruzi and most Leishmania species, it persists in early-diverging lineages. In leishmaniasis, distinct miRNA expression profiles-including miR-155-5p, miR-5011-5p, miR-6785-5p, and miR-361-3p-demonstrate high diagnostic accuracy for detecting infection (AUC up to 1.0). Serum long ncRNAs such as MALAT1 and NUTM2A-AS1 show potential diagnostic value, though clinical validation remains pending. For Chagas disease, the available evidence on ncRNAs primarily addresses the diagnosis of clinical manifestations rather than initial infection. Host miRNAs, including miR-21, miR-145, miR-146a/b, and miR-19a-3p, correlate with cardiac involvement, immune dysregulation, and inflammation during chronic T. cruzi infection. Circulating miRNAs exhibit modest sensitivity (57-67%) and specificity (57-80%) for diagnosing chronic Chagas cardiomyopathy, indicating their utility in assessing disease progression and organ damage rather than detecting early infection. This review distinguishes between ncRNAs that diagnose infection and those that evaluate disease severity or organ involvement. Altered ncRNA expression profiles represent promising biomarkers for species differentiation, treatment monitoring, and assessing cardiac complications in Chagas disease, with broader diagnostic applications emerging for leishmaniasis.

This study aimed to assess the prevalence and reporting rate of adverse events following immunization (AEFIs) among healthcare professionals (HCPs) and students of health-related disciplines after COVID-19 vaccination. It was conducted at the beginning of the vaccination campaign in Poland (February 2021), when vaccines were only available to limited groups of recipients, mainly those related to healthcare. Questionnaires were distributed among HCPs in the Pomeranian voivodeship (N = 1063) and students at the Medical University of Gdańsk (N = 1506). The primary objective was to compare respondents' self-reported AEFI notifications with official reports published by the National Sanitary Inspectorate. A total of 240 participants declared having reported at least one AEFI, whereas official reports from the same period indicated that only 194 individuals had reported AEFIs in the entire voivodeship. This translates into significant differences in notification rates (14.9% and 0.09%, respectively). A detailed breakdown into local and systemic AEFIs also revealed significant discrepancies with official reports (850 vs. 329 and 1137 vs. 46, respectively). The most common reasons for not reporting were managing the symptoms on one's own and perceiving the symptoms as not severe enough to report. Underreporting of AEFIs is an issue that requires attention from both the scientific community and public health authorities, as it may hinder reliable vaccine safety assessment and contribute to increased vaccine hesitancy.

Human Immunodeficiency Virus (HIV) infection is associated with a wide spectrum of urological manifestations, reflecting both the direct effects of viral infection and the indirect consequences of immunosuppression, opportunistic infections, malignancies and long-term combined antiretroviral therapy (cART). This narrative review provides a contemporary, multifaceted overview of the clinical and pathological presentations of urological conditions in people living with HIV (PLWHIV), based on articles published between 1989 and 2025. Conditions discussed include HIV-associated nephropathy (HIVAN), opportunistic genitourinary infections, malignancies such as Kaposi sarcoma and lymphoma, as well as non-infectious complications such as HIV-associated nephropathy and erectile dysfunction (ED). The review highlights the evolving epidemiology of these conditions in the cART era, with a noted decline in opportunistic infections but a rising burden of chronic kidney disease and malignancies, largely due to improved survival and ageing of the HIV-positive population. Pathological insights are explored and discussed, including mechanisms of HIV-associated renal injury, such as direct viral infection of renal epithelial cells and genetic predispositions linked to Apolipoprotein L1 (APOL1) variants. In addition, psychosocial factors, including anxiety, stress, stigma, and alcohol use, are discussed, as they may contribute to late presentation to clinical urology services. The review also considers the challenges faced in low and middle-income countries, the impact of HIV on urological services, and the important role of palliative care in advanced disease. Ultimately, this review underscores the need for early recognition, comprehensive diagnostic and surgical evaluation, and integrated social, psychological, and palliative management strategies tailored to the unique needs of PLWHIV. A deeper understanding of the interplay between HIV, cART, psychosocial determinants, and urological health is essential for improving patient outcomes and guiding future research in this evolving field.

We previously described an increased incidence of HIV among individuals infected with Wuchereria bancrofti (WB). However, no host, parasite, or viral factors were reported as directly associated with the increase in HIV incidence in this group. To investigate this, we compared T cell phenotypes between WB+ and WB- women. Flow cytometry analysis of activation and differentiation markers on CD4 T cells, as well as HIV entry receptor CCR5 was performed on cervical and peripheral blood samples from 54 women living without HIV (WLWoH). Additionally, HPV testing was performed on their specimens and for 13 WLWH. WB infection was associated with a significantly increased frequency of CD3⁺γδ2⁺ T cells in the cervical mucosa (median 4.0% vs. 1.4%, p = 0.012). Contrary to our expectations, we found lower frequencies of CCR5 on total, memory and activated memory CD4 T cells in the WB+ group. However, differences diminished after accounting for age and site of recruitment. WB and HIV infections were associated with an increased likelihood of high-risk human papillomavirus (HR HPV) positivity. (WB status: odds ratio (OR) 4.1, p = 0.066; HIV status: OR 5.5, p = 0.068). Our findings suggest immunological mechanisms by which WB increases the risk for other infections, e.g., HIV and HR HPV, albeit independent of the CCR5 receptor.