American Journal of Tropical Medicine and Hygiene最新文献

{"title":"Association of Parasite Biomass with Disease Severity in Plasmodium vivax and Plasmodium falciparum Malaria Infections.","authors":"Prasad H Babar, Jacob A Tennessen, Rimi Chakrabarti, Jayashri T Walke, Usheer Kanjee, Anvily Almeida, Mezia Fernandes, Pooja Gawas, Laura Karschney, John White, Marina Vaz, Edwin Gomes, Pradipsinh K Rathod, Manoj T Duraisingh","doi":"10.4269/ajtmh.26-0106","DOIUrl":"10.4269/ajtmh.26-0106","url":null,"abstract":"<p><p>The clinical and parasitological factors underlying severe malaria pathogenesis remain incompletely understood, particularly in Plasmodium vivax (P. vivax). To address this issue, clinical and parasitological metrics, including circulating peripheral parasitemia and the parasite biomass (the total number of parasites in the body consisting of both circulating peripheral and noncirculating parasites), were measured in patients with severe and uncomplicated monoinfections of P. vivax and Plasmodium falciparum (P. falciparum) malaria who presented at a hospital in southwest India. Peripheral parasitemia was positively correlated with disease severity in P. falciparum but negatively correlated with disease severity in P. vivax. Contrarily, the parasite biomass, estimated by the levels of circulating antigens P. vivax lactate dehydrogenase and P. falciparum histidine-rich protein 2 for P. vivax and P. falciparum, respectively, was positively correlated with both the degree of severity and the length of hospital stay in both P. vivax and P. falciparum cases. Together, these observations indicate a significant hidden parasite biomass in P. vivax infections and suggest that parasite biomass is a more robust parasitological marker of severity than parasitemia. Notably, thrombocytopenia was also positively correlated with parasite biomass and longer hospital stay in both P. vivax and P. falciparum infections. These results highlight the importance of parasite biomass as a leading factor in the disease severity of malaria infections in India.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"795-806"},"PeriodicalIF":1.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527199/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determinants of Treatment Adherence in Hepatitis C Patients in a Public Sector Setting in India.","authors":"Sunvir Kaur Rai, Harpreet Singh, Simmi Oberoi, Amandev Singh, Rahul Bhargava","doi":"10.4269/ajtmh.26-0152","DOIUrl":"10.4269/ajtmh.26-0152","url":null,"abstract":"<p><p>The National Viral Hepatitis Control Program has rapidly scaled hepatitis C virus (HCV) treatment. However, poor adherence and loss to follow-up have led to drug resistance, treatment failure, and increased healthcare costs. Given this background, the present study was conducted to evaluate the rate of loss to follow-up, assess adherence patterns to treatment, and identify factors associated with both of these among HCV patients. A prospective cohort study was conducted among 385 adult HCV patients at Government Medical College, Patiala, Punjab, India. Patients were enrolled from April 2023 to December 2023 and followed from treatment initiation to sustained viral response assessment. Adherence was measured via monthly pill counts and self-reporting. Factors influencing loss to follow-up were analyzed using the χ2 and Fisher's exact tests for qualitative variables, as well as Student's t-test and the Mann-Whitney U test for quantitative variables. Adherence patterns between follow-up visits were assessed using the Wilcoxon signed-rank test. Multivariate logistic regression analysis was used to identify predictors of ≥90% pill adherence. Loss to follow-up was reported in 21.0% of patients and was significantly associated with intravenous drug use (P = 0.03; odds ratio [OR] 2.04 [95% CI: 1.17-3.55]), decompensated cirrhosis (P <0.001; OR: 4.95 [95% CI: 2.03-12.05]), taking sofosbuvir and velpatasvir (P = 0.012; OR: 1.99 [95% CI: 1.16-3.40]), and a treatment duration of 24 weeks (P = 0.001; OR: 3.90 [95% CI: 1.71-8.87]). Adherence improved notably between the first and second follow-ups (P <0.001), as well as between the third and fourth follow-ups (P = 0.003). Among the 304 patients who completed treatment, only 49% adhered to ≥90% of the pills. Younger age (adjusted OR [aOR]: 0.98 [CI: 0.96-0.99]), employment in the unorganized sector (aOR: 0.22 [CI: 0.07-0.63]), and cirrhosis (aOR: 1.98 [CI: 1.06-3.70]) emerged as significant predictors of greater adherence among patients who completed treatment. Patients with ≥90% adherence had higher treatment success rates (crude OR: 4.47 [CI: 1.77-11.28]). Attrition remained a major barrier to HCV care, and it was associated with intravenous drug use, decompensated cirrhosis, the sofosbuvir/velpatasvir regimen, and longer treatment duration. Adherence improved over time in follow-up, and good adherence was associated with good treatment outcomes.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527195/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Approach to the Landscape of Bacterial Diseases in Wayuu Communities, Colombia: Acute Diarrheal Disease and Febrile Bacterial Syndromes.","authors":"Paula Lucía Díaz-Guevara, Zonia Alarcón, Nancy Yaneth Flórez-Delgado, Lucy Angeline Montaño, Laura Gómez, Vanessa Melo, Diego Prada, Daniel Velandia-Rodriguez, Gloria Mercedes Puerto-Castro, Patricia Escandón, Jaime Moreno","doi":"10.4269/ajtmh.26-0272","DOIUrl":"10.4269/ajtmh.26-0272","url":null,"abstract":"<p><p>Indigenous communities face a disproportionate burden of neglected communicable diseases, particularly acute diarrheal disease (ADD) and bacterial febrile illness (BFI), in contexts with limited access to diagnosis and medical care. The circulation of bacteria associated with ADD and BFI was evaluated in Wayuu indigenous communities of northern Colombia. Four health brigades were conducted in 14 Wayuu communities, with 86 ADD samples, 210 BFI blood samples, and 237 BFI serum samples for BFI collected according to clinical symptoms. The samples were analyzed using conventional bacteriology, real-time polymerase chain reaction tests, serological tests, and whole-genome sequencing for the recovered isolates. In ADD, a bacterial agent was isolated in 17.4% of the fecal samples. Salmonella enterica was the predominant enteropathogen (12.8%), with four identified serovars. The serovars Salmonella Poona (0 single-nucleotide polymorphisms [SNPs]) and Salmonella Uganda (0-2 SNPs) were closely related, suggesting clonal patterns compatible with independent outbreak events within the community. Escherichia coli O157:H7-, Vibrio cholerae non-O1/non-O139, and Listeria kieliensis were also detected. Genomic analyses did not reveal determinants of highly invasive or multidrug-resistant strains, although plasmids with horizontal transfer potential were detected. In BFI, the seroprevalence was 3.4% for Brucella spp., 6.8% for Leptospira spp., and 14.2% for Rickettsia rickettsii, revealing exposure to bacterial zoonoses. The Wayuu community exhibits circulation of bacteria associated with both ADD and BFI, including underdiagnosed zoonotic pathogens. These findings highlight the need to strengthen integrated surveillance and One Health approach strategies, involving the active participation of vulnerable indigenous populations.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527192/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Group C Orthobunyavirus Infection in a Patient from the Amazon Putumayo Region of Colombia During an Oropouche Fever Epidemic.","authors":"Sully Márquez, Lizeth Salazar, John Collins, Victoria Nipaz, Vanessa Dávila Campos, Jacob Van der Ende, J Kenneth Wickiser, Thomas Briese, Josefina Coloma","doi":"10.4269/ajtmh.25-0652","DOIUrl":"10.4269/ajtmh.25-0652","url":null,"abstract":"<p><p>Orthobunyaviruses, one of the largest and most diverse genera of viruses, include numerous reassortant viruses and present diagnostic challenges due to similar clinical presentations with other arboviral infections. The detection and isolation of a group C orthobunyavirus from a patient with acute febrile illness from Puerto Ospina, Putumayo Department, Colombia during the 2023-2024 Latin American Oropouche fever regional outbreaks are reported in the present study. Using a vertebrate virus-focused metagenomics sequencing approach with VirCapSeq-VERT, a virus related to the Caraparu complex was identified, and a virus isolate was obtained. Although limited to a single case and without serological or longitudinal clinical confirmation, these findings underscore the value of unbiased molecular approaches for unresolved febrile illness diagnosis in endemic settings such as the Amazon basin.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"851-855"},"PeriodicalIF":1.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13550754/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148839009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lessons Learned from Bidirectional Fetal Anomaly Ultrasound Training between Ghanaian and American Maternal-Fetal Medicine Programs.","authors":"Sarah Boudova, Alim Swarray-Deen, Catalin Buhimschi, Samuel Oppong","doi":"10.4269/ajtmh.26-0467","DOIUrl":"10.4269/ajtmh.26-0467","url":null,"abstract":"<p><p>Congenital anomalies cause significant morbidity and mortality globally. Diagnosis and exchange of information about management of fetal anomalies is an essential component of Maternal-Fetal Medicine (MFM) training. Bidirectional partnerships can enhance MFM education and improve patient care. We have modeled a bidirectional fetal anomaly training program between the University of Ghana and the University of Illinois Chicago in which a multidisciplinary team meets virtually once a month and trainees from both universities can present cases for discussion. This approach has been well-received and has expanded the education of fellows at both sites regarding the breadth of pathology and management strategies. Key lessons learned from this collaboration include the importance of mutual and reciprocal learning, long-term partnership, a structured program, multidisciplinary perspectives, and interlacing research with education.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"865-868"},"PeriodicalIF":1.9,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527191/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148817211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the Dimensions of Caregiver-Perceived Seasonal Malaria Chemoprevention Delivery Quality in Nigeria: A Structural Equation Modeling Analysis of Door-to-Door Seasonal Malaria Chemoprevention.","authors":"Tingkai Zhang, Sikai Huang, Taiwo Ibinaiye, Olusola Oresanya, Kevin Baker, Sol Richardson","doi":"10.4269/ajtmh.25-0661","DOIUrl":"10.4269/ajtmh.25-0661","url":null,"abstract":"<p><p>Seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine (AQ) has been implemented in Africa since 2012 to prevent malaria among children ages 3 to 59 months old. As SMC expands to new regions, concerns are emerging about sustainability and quality of implementation. Successful SMC delivery depends on not only effective drug administration but also caregiver engagement, adherence to at-home AQ administration, retention of Child Record Cards, and overall malaria prevention practices. Although caregivers' perceptions of delivery quality as well as knowledge and trust of SMC may play critical roles in shaping these behaviors, these associations remain underexplored. We conducted secondary analyses of SMC delivery quality and its associations with key SMC outcomes using two cross-sectional end-of-round SMC coverage surveys in 11 Nigerian states in 2021 and 2022 (N = 22,122). Exploratory factor analysis identified a single latent factor representing perceived SMC delivery quality based on six items reflecting distributor behavior and quality of communication. Logistic regression models revealed significant positive associations between higher index scores and days 2 and 3 AQ adherence as well as Child Record Card retention. Higher delivery quality was associated with reduced caregiver refusal of SMC. Structural equation modeling showed that perceived SMC delivery quality had significant direct effects on all three outcomes, with indirect effects significant only for days 2 and 3 AQ adherence. Findings highlight that improving and monitoring caregiver-perceived SMC delivery quality is essential to sustaining SMC effectiveness and suggest the need for strengthened distributor training and community engagement.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"778-784"},"PeriodicalIF":1.9,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527193/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148817251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From Suppurative Inflammation to Fibrotic Remodeling in Cutaneous Nocardiopsis Infection.","authors":"Naixuan Lin, Keke Huang, Degang Yang","doi":"10.4269/ajtmh.26-0141","DOIUrl":"10.4269/ajtmh.26-0141","url":null,"abstract":"<p><p>In the present case report, a cutaneous infection caused by the rare actinomycete Nocardiopsis sp. TSRI0078 is described. A 77-year-old woman with a medical history of hypertension and diabetes presented with ulcerated purplish-red nodules on the lower extremities that had persisted for 3 months. A histopathological examination revealed infectious granulomas predominantly composed of neutrophils. After empirical antibiotic therapy proved ineffective, the pathogen was confirmed to be Nocardiopsis sp. TSRI0078 via polymerase chain reaction testing, gene sequencing, and microbial culture. Subsequent treatment with oral trimethoprim-sulfamethoxazole led to gradual regression of the lesions and scar formation. With only 11 human infection cases reported globally, a clear understanding of the clinical manifestations of Nocardiopsis infections is lacking. This pathogen should be considered in the differential diagnosis of chronic, unexplained cutaneous lesions, particularly in patients with underlying diseases. A combination of molecular and conventional microbiological examinations facilitates early diagnosis, and trimethoprim-sulfamethoxazole may represent an effective therapeutic option.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"721-723"},"PeriodicalIF":1.9,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527196/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148817225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Brief Case: Acute Gangrenous Appendicitis with Incidental Schistosoma Eggs in a Malian Migrant.","authors":"Harold Bermúdez-Marval, José Sanz-Moreno, Elena Aguirregoicoa Garcia, Ramón Pérez-Tanoira","doi":"10.4269/ajtmh.26-0067","DOIUrl":"10.4269/ajtmh.26-0067","url":null,"abstract":"<p><p>Acute appendicitis is a common surgical emergency worldwide, but appendiceal involvement by Schistosoma species is rare, particularly in nonendemic settings.1 We report a 28-year-old male migrant from Mali presenting to the emergency department with 24 hours of right lower abdominal pain, anorexia, and low-grade fever. Physical examination and elevated inflammatory markers suggested acute appendicitis. Abdominal ultrasound demonstrated a thickened, noncompressible appendix with surrounding fat stranding. The patient underwent urgent laparoscopic appendectomy, which revealed a gangrenous, perforated appendix with localized inflammatory exudate. Histopathological evaluation unexpectedly identified numerous Schistosoma ova embedded throughout the appendiceal wall, surrounded by eosinophilic granulomatous inflammation, compatible with chronic schistosomal infection complicated by acute bacterial appendicitis. Postoperative recovery was uneventful; because of transfer of care, definitive antiparasitic therapy could not be administered locally. This case underscores the need to consider imported parasitic infections in the differential diagnosis of acute abdomen among migrants from endemic regions in nonendemic countries.1 It also highlights the crucial role of multidisciplinary collaboration among clinicians, surgeons, pathologists, and microbiologists for accurate diagnosis and appropriate management.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"816-818"},"PeriodicalIF":1.9,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527197/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148817227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex-Based Differences in Imported Schistosomiasis among Sub-Saharan African Migrants in Spain.","authors":"Mercedes Rodríguez-Pérez, Belén Rivaya, José Antonio Boga, Rita García Jimenez, Lorena Fernández, Edurne Rodrigo Arrazola, Azucena Rodríguez-Guardado","doi":"10.4269/ajtmh.26-0163","DOIUrl":"10.4269/ajtmh.26-0163","url":null,"abstract":"<p><p>Schistosomiasis remains a significant but frequently underrecognized parasitic infection among migrants from endemic regions living in Europe. A retrospective cross-sectional study of sub-Saharan African migrants diagnosed with schistosomiasis was conducted at a referral center in northern Spain between 2012 and 2023. Cases were primarily defined by positive serological results, with parasitological confirmation available only in a minority of patients. The aim was to describe demographic, clinical, and diagnostic characteristics, with particular attention to sex-based differences. Among 538 screened individuals (52.8% men), 121 (22.5%) were diagnosed with schistosomiasis, including 59 women (48.7%). The mean age was 33 ± 14 years. Women had a longer duration of residence in Spain before diagnosis compared with men (39 ± 59 versus 30 ± 37 months; P = 0.037). Most patients were asymptomatic (62.7% of women and 58% of men). Hematuria was observed exclusively in men (P = 0.001), with bladder abnormalities confirmed in two cases. Among 33 women with available gynecological history, 60.6% reported reproductive tract morbidity, including recurrent miscarriage and infertility. These findings highlight the substantial burden of imported schistosomiasis among migrants from sub-Saharan Africa and reveal clinically relevant sex-related differences in presentation and associated conditions. The study results support the need for targeted screening strategies in nonendemic settings and emphasize the importance of incorporating reproductive health assessment into the evaluation of women with suspected schistosomiasis.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"819-823"},"PeriodicalIF":1.9,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527194/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148787060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response to \"Diagnostic Caveats and Clinical Pitfalls in the Overlap of Leprosy and Para-Kala-Azar Dermal Leishmaniasis\".","authors":"Rowena Lee Ying Kwan, Hui Yi Chia, Shawn Vasoo, Jiun Yit Pan","doi":"10.4269/ajtmh.26-0451a","DOIUrl":"10.4269/ajtmh.26-0451a","url":null,"abstract":"","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":"880"},"PeriodicalIF":1.9,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13531664/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148787052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}