American Journal of Tropical Medicine and Hygiene最新文献

The American Committee on Clinical Tropical Medicine and Travelers' Health's Students/Trainees Leadership Group launched their essay contest in 2025 to encourage the involvement of emerging voices in tropical medicine in key issues shaping the field's present and future. The following authors' won for their essay addressing the following prompt: "The Role of International Cooperation in Combating Tropical Diseases" These essays were reviewed by a panel of clinician judges with experience in tropical medicine and writing, and the winning entries reflect both academic excellence and practical insight. Together, the two winning essays show the wide scope of tropical medicine from policy and prevention to diagnosis and treatment and the shared responsibility to confront these challenges wherever they arise.

A previously healthy traveler of Togolese origin visiting friends and relatives presented with severe dengue complicated by acute liver failure. Despite intensive care management and listing for high-urgency liver transplantation, the patient succumbed to the disease. This case highlights the risk for life-threatening travel-related complications of dengue.

The Mandoto District in the central highlands of Madagascar experiences year-round transmission of Plasmodium vivax (P. vivax) and Plasmodium falciparum (P. falciparum). Monthly malaria case data from 27 health centers across Mandoto between 2019 and 2024 were analyzed alongside meteorological data to understand transmission dynamics and forecast potential influences of climate change using descriptive, cross-correlation, and seasonal autoregressive integrated moving average forecast models. Over a period of 6 years, 276,318 rapid diagnostic tests (RDTs) were performed, yielding a 39.6% positivity rate, totaling 109,428 malaria cases. After 2021, when multispecies RDTs became available, 71.5% of cases were attributed to P. falciparum, and 28.5% were attributed to P. vivax. Both species were co-endemic across all health centers, with the western region experiencing a higher transmission risk. Malaria cases peaked in January, with a second peak from April to June after the rainy season, and declined between July and September. Precipitation and temperature effectively revealed the seasonality of malaria dynamics, thereby improving model accuracy. Plasmodium falciparum exhibited stronger associations with precipitation and temperature variability. The present study highlights that combining time-series modeling with precipitation and temperature data can help predict malaria cases and support timely planning and resource allocation.

Human-induced climate change caused by fossil fuel-derived greenhouse gas emissions has disrupted global ecosystems, shifted disease-vector populations, and expanded vector-borne diseases into previously unaffected areas. As these changes occur, traditional epidemiological surveillance and control mechanisms face major challenges. Artificial intelligence (AI) is an emerging technology in epidemiology and public health that offers the promise of analyzing and interpreting vast datasets far more comprehensively than traditional methods. In this manuscript, we examine how artificial intelligence can enhance vector-borne disease prediction and surveillance, strengthen vector control and public health response, and support clinical and laboratory diagnostic capabilities in the context of a changing climate. Despite its environmental trade-offs, AI offers transformative potential to help humanity adapt to the coming climate impacts on infectious diseases.

Salmonella enterica (S. enterica) is an important pathogen responsible for bloodstream infections, particularly in developing nations. These infections often lead to bacteremia, with a few patients developing cardiac complications in high-risk populations. Myocarditis, a common manifestation, presents with fever, chest pain, and dyspnea and can lead to severe complications, such as cardiogenic shock. Salmonella endocarditis, although rare, predominantly affects the mitral valve and leads to critical complications, including valve perforation and dehiscence, with a high mortality rate. Patients with purulent pericarditis present more acutely with toxic features. Arrhythmias, notably third-degree atrioventricular block and ventricular fibrillation, are prevalent complications primarily due to myocarditis. Diagnostic methods range from isolating Salmonella from clinical samples to immunoblotting and polymerase chain reaction-based assays that target specific genes. Depending on severity, treatment includes supportive care or antibiotic therapy with fluoroquinolones in uncomplicated cases and cephalosporins in complicated cases. Timely diagnosis and appropriate management strategies are crucial for mitigating the morbidity and mortality associated with S. enterica infections.

School-aged children constitute an important asymptomatic reservoir for Plasmodium and may harbor the parasite through malaria transmission seasons in the absence of treatment. As WHO guidelines do not recommend chemoprevention for this group, there is a need to understand how such interventions could impact malaria transmission dynamics. This study investigated seasonal transmission patterns and the potential of mass drug administration (MDA) at the onset of the dry season to interrupt malaria transmission. Monthly parasitological surveys were conducted in Burkina Faso rural localities during the dry season targeting two cohorts of school-aged children: one of children uninfected at baseline who received no treatment and another of parasitemic asymptomatic children who received a full treatment dose of artemether-lumefantrine. Monthly blood samples were collected and analyzed using microscopy and polymerase chain reaction. Parasite diversity and drug resistance were assessed with msp1/msp2 typing and pfcrt/pfmdr1 genotyping, and entomological monitoring evaluated mosquito vector dynamics and infection status. Our results revealed that 93% of uninfected individuals remained Plasmodium infection free. Among treated individuals, 91% remained negative during follow-up. The prevalence of persistent infections among parasitemic individuals was stable over time at 5-9% in both cohorts. msp1/msp2 genotyping revealed the same haplotypes over time within participants, and analysis of drug-resistance markers showed low frequencies of mutations associated with antimalarial resistance. Our findings demonstrated that malaria transmission is interrupted during the dry season and that early MDA can effectively prevent infection, with over 90% of participants remaining parasite free, highlighting its potential to disrupt transmission dynamics.

The study of mosquito biology in a laboratory setting is an important first step in understanding the role of mosquitoes as vectors of pathogens and parasites. Although large-scale mosquito rearing technologies have progressed to support vector control initiatives, cheap and adaptable tools for small-scale laboratory experimentation remain relatively underdeveloped. In the present study, a modular emergence container was designed and fabricated using open-source computer-aided design software and a 3D printer. The emergence container enables precise monitoring of mosquito development from larval or pupal stages to adulthood. Two assays examining pupal-to-adult and larval-to-adult emergence were conducted using Aedes aegypti to validate container functionality. The emergence container effectively separated mosquitoes in immature stages from adults, with 78.2 ± 17.8% and 88 ± 5% (mean ± SD) emergence rates in the adult upper chamber when pupae and larvae were placed in the immature lower chamber, respectively. This 3D-printed emergence container serves as a low-cost, customizable, and reproducible tool for entomological research.

West Nile virus (WNV) is an endemic arboviral infection in the United States that has undergone phylogenetic evolution since its introduction 25 years ago. An integrated vector-human-pathogen study was conducted in the summer of 2023 to unearth contemporary Culex quinquefasciatus habitat patterns and human transmission spillover foci in South Carolina, a state with historically little WNV data. A serosurvey revealed WNV seroprevalence 10 times the national average (22% versus 2%, respectively), with unusual epidemiologic risk factors. Female Culex quinquefasciatus WNV positivity was low (2.7%), with viral phylogenetics 100% homologous to the WN02 clade. Mosquito vectors clustered in affluent urban neighborhoods with greater tree canopy cover and abundant waterbodies. Culex quinquefasciatus abundance was greatest when climate variance was nominal in the 72 hours preceding collection. An unusual bimodal mosquito temporal pattern was observed, reflecting changing climate patterns. The present comprehensive WNV study reveals emerging transmission factors as WNV continues to evolve and persist in the southeastern United States.

Trichinellosis, a zoonotic parasitic disease, is usually transmitted through raw or undercooked muscle tissue. We report a 25-year-old hunter from Hokkaido, Japan, who acquired trichinellosis by consuming a raw bear eyeball, a tissue previously presumed to be parasite-free. He developed fatigue and rash within 3 days, followed by fever and myalgia 9 days after consumption. Serology confirmed trichinellosis, and treatment with albendazole led to full recovery. Among five hunters who consumed meat from the same bear, only the two who ate raw eyeballs developed the disease, whereas those who ate only cooked meat remained asymptomatic. This appears to be the first report of trichinellosis linked to raw bear eyeballs. Clinicians and public health practitioners should be aware that any uncooked tissue may carry an infection risk. These findings underscore the need for vigilance against unconventional transmission routes and culturally sensitive education for accurate diagnosis and prevention.

Echinococcoses are neglected zoonotic diseases caused by larval cestodes of the genus Echinococcus. Regions of the United States rarely experience locally acquired infections, and most contemporary cases are presumed to be imported, predominantly from hyperendemic regions such as Central and East Asia, the Middle East, and North Africa. However, significant knowledge gaps remain regarding the current disease burden within the US healthcare system. The epidemiology, baseline clinical features, and outcomes are summarized for patients diagnosed with cystic echinococcosis (CE) or alveolar echinococcosis (AE) in the present study using retrospective, deidentified data from the TriNetX research network, a federated database that encompasses 89 healthcare organizations and more than 126 million patients (1997-2024). Individuals with Echinococcus infection were identified using International Classification of Diseases, 10th Revision, code B67, and demographic characteristics, geographic distribution, medical and surgical interventions, and mortality were assessed from 2003 to 2023. More than 36,000 patients with any B67 diagnosis were identified, of whom 728 had codes specific to CE, and 75 had codes specific to AE. There were more CE cases in the Southern United States, whereas most AE were reported in the Northeastern United States. Many patients were asymptomatic, with limited use of diagnostic imaging or serologic testing. Antiparasitic medication or surgical procedures were recorded most commonly in AE patients (18%), with mortality rates between 28% and 38% at 20 years post-index. Although locally acquired AE and CE appear to be emerging in the Northeastern United States, the overall prevalence remains low nationwide. The authors advocate for heightened awareness of echinococcoses among US-based clinicians and recommend prospective surveillance studies to improve clinical outcomes and understanding of local transmission risks.