Yale Journal of Biology and Medicine最新文献

Lymphatic filariasis (LF) is a long-lasting, debilitating parasitic infection that has remained an immense burden to the endemic areas globally in the realms of physical, psychological, and socioeconomic suffering. LF presents itself in the form of lymphedema, hydrocele, and disfigurement, and limits motor activity, working capabilities, and interaction processes between people, significantly reducing self-esteem and life quality. LF brings significant socio-psychological distress besides the physical one. A decline in self-esteem often results in anxiety and depression; recognizable deformities are stigmatized and avoided. This social isolation and poverty become internalized, also with the misconceptions of contagion and impurity, and further bring about the perpetuation of vulnerability. Gender acts as a multifactor determinant force of the LF experience. It contains multiple layers of discrimination against women, concerning marriage refusal, and the workplace, where men are denied opportunities to earn their living and can become social outcasts. Such inequities, which are gender-based, are expected to be addressed when it comes to managing diseases. Constant obstacles put access to timely treatment and care in the spotlight, including the lack of awareness, financial constraints, and health facilities. The most effective interventions are the extension of the community participation levels and maximization of mass drug administration (MDA), which can considerably decrease the disease and burden of the disease and its burden. The world campaigns towards the abolition should not henceforth be geared towards pharmacological but rather take a rights-based approach. The psychological support, social rehabilitation, and gender-based interventions introduced into the social health systems can increase the inclusion and cost-efficiency of the individuals who have already experienced the widened perceived effects of LF and their dignity.

Scabies is a highly contagious skin infestation caused by the ectoparasitic mite Sarcoptes scabiei var. hominis, affecting over 200 million individuals worldwide at any given time. The World Health Organization (WHO) has recognized this infection as a neglected tropical disease (NTD) since 2017. Scabies mainly affects underdeveloped, overcrowded, and resource-limited communities, particularly in tropical and subtropical areas. Intense pruritus that gets worse at night and a distinctive rash with papules, burrows, and secondary bacterial infections from scratching are the clinical manifestations produced. Despite its pervasiveness, many national health agendas fail to adequately address it, misdiagnose it, and underreport it. Its persistence is further exacerbated by social stigma, a lack of awareness, and ineffective diagnosis and treatment. This review article highlights the disease's epidemiological significance, clinical manifestations, diagnostic capabilities, calls for enhanced surveillance, integrated control initiatives, and more funding for research.

Introduction: Dengue virus (DENV) is an arboviral infection transmitted by female mosquitoes of the Aedes genus.

Objective: To describe the epidemiological behavior of dengue cases in a population from the Andean region of Colombia.

Methods: This observational, descriptive, cross-sectional study analyzed 300 randomly selected patient records from a total of 1400 cases reported in 2024.

Results: No significant associations were found between disease severity and patient sex or geographical location. However, age range and platelet count were key factors, with younger patients more likely to have mild dengue and platelet abnormalities being the strongest predictor of severity.

Conclusions: This study identifies platelet count abnormalities as the strongest factor associated with dengue severity, reinforcing their role as a key predictor of disease progression.

Background: Cutaneous leishmaniasis (CL) is a neglected tropical disease endemic in the Peruvian Amazon. First-line treatment with pentavalent antimonials was unavailable in Madre de Dios, Peru in early 2024 due to a supply-chain crisis. Oral ketoconazole has shown in vitro activity and modest efficacy in small clinical series as a salvage therapy, though it is not established as standard treatment.

Case presentation: A 41-year-old woman (body mass index 48 kg/m²) from a rural community in Madre de Dios presented with two ulcerative lesions (0.8 cm and 1.2 cm) on the dorsal aspect of the left little finger, of 4 weeks' duration. CL was confirmed by Giemsa smear and PCR as Leishmania (Viannia) sp. (~98% homology with local reference strains). In the absence of antimonials, and after informed consent, she received oral ketoconazole 200 mg twice daily for 6 weeks. By week 4, total lesion area had contracted by ~65%, and follow-up polymerase chain reaction (PCR) turned negative. Near-complete re-epithelialization was achieved by week 6. No hepatotoxicity or serious adverse events occurred; only mild transient nausea was reported. At 12 months' follow-up, there was no relapse.

Conclusions: In this single-patient experience, oral ketoconazole (200 mg every 12 hours for 6 weeks) appeared to be an effective and well-tolerated alternative for CL during an antimonial shortage. Given the possibility of spontaneous healing in CL and the lack of a control group, controlled clinical trials are warranted before broader adoption.

Occupational exposure remains a major driver of parasitic infections in India, largely due to caste-based discrimination that severely limits job opportunities for certain communities. Historically marginalized groups, particularly Scheduled Castes (SC) and Scheduled Tribes (ST), often have little choice but to engage in high-risk occupations such as manual scavenging, landless farming, inland and coastal fishing, tea-estate labor, informal mining, and backyard pig-rearing. Passed down through generations of exploitation, these occupations typically involve minimal or no personal protective equipment and significantly raise the risk of infections like hookworm, strongyloidiasis, visceral leishmaniasis, lymphatic filariasis, Taenia solium cysticercosis, and schistosomiasis. Because social discrimination, even in 2025, restricts these groups from accessing safer employment options, they remain trapped in a cycle of poverty and disease. Add to this their living conditions like mud houses, open defecation practices, segregation, non-secure informal jobs without proper healthcare access, and low literacy, and it is clear why these curable infections persist despite national efforts like mass drug administration and vector control. Addressing this issue effectively means directly tackling caste-driven occupational segregation. Workplace-based preventive treatment, targeted surveillance, and equity-focused policies are essential to sustainably eliminate these parasitic infections and finally close these deep-rooted health disparities that are not commonly addressed in both policy-making and literature.

Rationale: Trachoma remains a leading cause of preventable blindness that has long persisted in Egypt. Global estimates tend to undervalue the actual national prevalence, and no previous analysis has comprehensively mapped the temporal and regional trends within the country. The present study addresses these gaps to guide elimination efforts and policy planning.

Objective: To estimate the prevalence of active and chronic trachoma and associated visual impairment and blindness in Egypt through a comprehensive systematic review and meta analysis.

Methods: We prospectively registered with PROSPERO (CRD420251070078) and adhered to PRISMA 2020 and Cochrane standards. Three independent reviewers searched 10 databases without language restrictions for population-based, cross-sectional surveys that reported WHO-graded trachoma outcomes. Two reviewers independently screened records, extracted data, and assessed bias using the Joanna Briggs Institute (JBI) checklist; Grading of Recommendations, Assessment, Development and Evaluations (GRADE) appraised evidence certainty. We transformed proportions using the Freeman-Tukey double arcsine transformation, pooled estimates using random-effects meta-analysis and directly age-standardized them to Egypt's 2000-2020 population structure. We performed sensitivity, subgroup, and meta-regression analyses to explore heterogeneity.

Results: From 16 cross sectional surveys (n = 45 934), the pooled age standardized prevalence estimates were as follows: active trachoma in children (1-9 years) 10.8% (95% CI; 7.0-14.6), visual impairment in those cases 5.3% (95% CI; 3.2-7.5), chronic trachoma in adults (≥ 15 years) 7.2% (95% CI; 4.0-10.4), associated visual impairment 1.6% (95% CI; 1.0-2.2), and blindness 0.7% (95% CI; 0.1-1.9). Sensitivity, subgroup, and meta regression analyses demonstrated consistent estimates and no evidence of small study effects.

Conclusion: Despite substantial declines, active and chronic trachoma remain well above elimination thresholds in Egypt. These findings underscore the need for sustained implementation of the SAFE strategy-particularly enhanced water, sanitation, and hygiene (WASH) infrastructure, ongoing surveillance, and targeted surgical outreach-and call for harmonized survey methods to guide and evaluate future control efforts.

This article hypothesizes the possible involvement of Lutzomyia lenti in the transmission cycle of leishmaniases. Although its vector competence has not been confirmed, this study emphasizes the need for further research on the ecology of this species, its interactions with hosts, and the environmental factors influencing its distribution and population density to assess its potential role as a Leishmania vector.

Helicobacter pylori is a spiral bacillus that can also adopt a coccoid form, a morphology associated with antibiotic resistance and the ability to withstand unfavorable environmental conditions. The relationship between coccoid forms, virulence, and the development of gastroduodenal diseases remains unclear. Therefore, this study aimed to determine the association between virulence and the induction of coccoid forms in H. pylori isolates from patients in Antioquia, Colombia. DNA from 30 clinical isolates was extracted, and the vacA and cagA genes were amplified to classify strains into high, intermediate, or low virulence groups. Four methodologies-each with specific modifications-were evaluated to induce coccoid forms. Bacterial morphology was assessed by optical microscopy, and coccoid cells were quantified using ImageJ. The association between virulence level and coccoid induction was analyzed using the Mann-Whitney U test. Before induction, cultures contained more than 90% spiral forms. The solid medium protocol under aerobic conditions was identified as the fastest in promoting coccoid conversion. After induction, high-virulence isolates showed a higher proportion of coccoid forms (72.6%) compared with low-virulence isolates (49.6%). A significant association was observed between virulence level and the induction of coccoid forms (p = 0.014). The findings suggest a relationship between the presence of vacA and cagA genes and the ability of H. pylori to adopt coccoid morphologies as an adaptive response. However, variability among induction protocols may introduce methodological biases and contribute to divergent interpretations of the biological role of coccoid forms. Further studies are needed to determine whether recurrences represent recrudescence or reinfection and to clarify the role of coccoid forms.

Background: Sexually transmitted diseases (STDs) remain a major global public health challenge because their health consequences lead to severe complications, especially among sexually active populations. Trichomonas vaginalis (TV), Chlamydia trachomatis (CT), and Neisseria gonorrhoeae (NG) are three common non-viral STDs which are increasing worldwide, and co-infections are common.

Methods: Designed and evaluated the performance of a multiplex polymerase chain reaction (PCR) in both dry and wet samples to detect three non-viral STDs, which were diagnosed based on syndromic case management (SCM) and uniplex PCR tests. We collected samples in duplicate (n=133), one as dry swab and the other swab was immediately put in transport medium and brought to the laboratory at ambient temperature within 4-5 hours. The total DNA was isolated from dry and wet swabs.

Results: Out of 133 samples, six were positive for all three infections in both dry and wet swabs, while 127 were negative for all three. All clinical samples were then tested using uniplex PCR for each pathogen and also using triplex PCR for clinical evaluations.

Conclusions: Multiplex PCR developed in-house is an effective test for simultaneous diagnosis of CT, NG, and TV and may be used for accurate and confirmed diagnosis especially in asymptomatic and suspected co-infection in low-income countries. Further evaluations of the clinical performance and the cost-effectiveness of this rapid diagnostic test on the management of multiple STI are underway.

Neglected tropical diseases (NTDs) primarily affect populations in economically disadvantaged regions globally, yet they remain underfunded and understudied. Leishmaniasis, an infection caused by parasites and transmitted by vectors, originates from protozoa in the Leishmania family, and affects 700 000 to a million new cases yearly. Despite its significant health burden and potentially fatal consequences, research into new treatments remains minimal. Current treatments like pentavalent antimonials, amphotericin B, and miltefosine have considerable side effects, high costs, lengthy treatment periods, and face drug resistance. These limited therapeutic options emphasize the need for safer, more effective treatments accessible in resource-constrained settings. Epigallocatechin gallate (EGCG), a polyphenolic compound from green tea (Camellia sinensis), shows promise as an antileishmanial agent. It disrupts the parasite's redox balance through the production of reactive oxygen species (ROS), inhibits growth, and enhances immune responses. However, poor bioavailability and rapid metabolism limit its clinical use; nanoformulations may improve its effectiveness. This review highlights the mechanism of action of EGCG against Leishmania parasites, examining its impact on parasite metabolism and cellular processes. It also explores various preclinical studies, therapeutic limitations and challenges, as well as advancements in drug delivery of EGCG for treating leishmaniasis.