American Journal of Tropical Medicine and Hygiene最新文献

{"title":"Seroprevalence and Factors Associated with Infection with Toxoplasma gondii in Iquitos and Lima, Peru.","authors":"Carlos Alonso Flores B, Cusi Ferradas, Edith S Málaga-Machaca, Andrea Diestra, Hannah E Steinberg, Jaeson Calla, Guillermo Salvatierra, Catherine Apaza, Juan Jiménez, Natalie M Bowman, Robert H Gilman, Maritza Calderón","doi":"10.4269/ajtmh.25-0135","DOIUrl":"https://doi.org/10.4269/ajtmh.25-0135","url":null,"abstract":"<p><p>Toxoplasma gondii infection can pose a significant health risk, particularly among immunocompromised individuals, such as people living with HIV (PLHIV). This study aimed to evaluate the seroprevalence of T. gondii and associated factors among PLHIV and individuals who are HIV negative in two distinct regions of Peru: Iquitos and Lima. We conducted a cross-sectional study, enrolling 281 participants (100 PLHIV and 181 HIV-negative participants). An in-house ELISA was used to detect IgG antibodies against T. gondii after ensuring that its performance was comparable with the commercially available Vircell ELISA kit. Our in-house ELISA demonstrated high reliability, with a positive agreement of 98.3% and a negative agreement of 100% with the Vircell ELISA kit. The overall seroprevalence of T. gondii was 62.3%, with significantly higher rates observed in Iquitos (88.0%) than in Lima (29.3%). People living with HIV showed a notably higher prevalence ratio (PR) for T. gondii seropositivity in both cities, with PRs of 1.18 (95% CI, 1.07-1.29) in Iquitos and 2.29 (95% CI, 1.30-4.05) in Lima. This study highlights the significant regional disparities in T. gondii seroprevalence between Iquitos and Lima, which may be driven by environmental and socioeconomic factors. Our findings underscore the need for region-specific public health interventions to mitigate the impact of T. gondii infections in PLHIV in Peru. Enhanced public health strategies, including improved access to clean water and sanitation in high-risk areas like Iquitos, may be important to reduce the burden of T. gondii and prevent severe complications in vulnerable populations.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144590284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Unusually Mild Imported Case of Falciparum Malaria That Was Diagnosed and Successfully Treated during Concurrent Acute Leukemia Chemotherapy in Japan.","authors":"Fuyuki Mukaizawa, Hidetoshi Nomoto, Shigeyuki Kano, Takayuki Sato, Takeshi Maeda, Yasunori Ueda","doi":"10.4269/ajtmh.24-0866","DOIUrl":"https://doi.org/10.4269/ajtmh.24-0866","url":null,"abstract":"<p><p>A 30-year-old Japanese man who traveled to the Republic of Ghana was diagnosed with falciparum malaria while undergoing chemotherapy for acute leukemia in Japan. We considered him to be at high risk of severe disease; however, he showed no signs of severe malaria and was treated with 3 days of oral artemether/lumefantrine. The patient's medical history may have contributed to the suppression and successful treatment of falciparum malaria without severe complications.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clofazimine-Pigmented Intestine.","authors":"Hideharu Hagiya","doi":"10.4269/ajtmh.25-0182","DOIUrl":"https://doi.org/10.4269/ajtmh.25-0182","url":null,"abstract":"","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Return of Chikungunya in Bangladesh in 2024: Implications for Future Outbreaks.","authors":"Anamul Hasan, Md Fahad Zamil, Afrida Tabassum Trina, Mohammad Sharif Hossain, Sajia Afreen, Dilruba Ahmed, Mohammad Shafiul Alam","doi":"10.4269/ajtmh.25-0064","DOIUrl":"https://doi.org/10.4269/ajtmh.25-0064","url":null,"abstract":"<p><p>After a major outbreak in Bangladesh in 2017, chikungunya nearly vanished from its territory until its resurgence in late 2024. However, its symptomatic overlap with dengue virus (DENV), another major arbovirus, has hindered accurate diagnosis and reporting, resulting in limited molecular diagnostic efforts for chikungunya in this region. This diagnostic evaluation study aimed to detect and characterize arboviral infections at the molecular level, focusing on the re-emergence of chikungunya and implications for future outbreaks. Febrile individuals aged 5-65 years old presenting with fever onset within 2-5 days along with other corresponding febrile symptoms were prospectively recruited from the International Centre for Diarrhoeal Disease Research, Bangladesh diagnostic facilities in Dhaka, Bangladesh. After meeting inclusion and exclusion criteria, 569 of 1,280 screened individuals were enrolled, providing informed written consent/assent. Serum samples from 474 participants underwent real-time reverse transcription-polymerase chain reaction testing, revealing 213 positive cases for at least one arbovirus. Chikungunya cases totaled 55, including seven coinfections (six with DENV and the first documented chikungunya virus-Zika virus coinfection in Bangladesh). No infections were reported from January to August, with a peak in October and November. Most chikungunya virus infections (72.7%) had moderate to high viral loads, with symptoms of joint pain, myalgia, and headaches. This resurgence of chikungunya in late 2024 highlights the potential for a major outbreak in 2025, necessitating proactive measures to mitigate public health impact and ensure a robust response to this re-emerging threat.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Case of Infection with Leptospires from Three Different Serovars During a Flood in the Philippines.","authors":"Yasutake Yanagihara, Toshiyuki Masuzawa, Masashi Shingai, Marumi Ohno, Toshiki Sekiya, Naoki Nomura, Tomomi Kawakita, Chimuka Handabile, Yuichi Koshiishi, Richard Obeng-Kyeremeh, Toshihiro Ito, Mitsumasa Saito, Sharon Y A M Villanueva, Nina G Gloriani, Hiroshi Kida","doi":"10.4269/ajtmh.24-0403","DOIUrl":"https://doi.org/10.4269/ajtmh.24-0403","url":null,"abstract":"<p><p>Leptospirosis a significant and life-threatening zoonosis with global reach. If diagnosis and treatment are delayed, the infection may lead to fatal Weil's disease. In the Philippines, a 21-year-old man was admitted to the hospital with leptospirosis-like symptoms, including fever, myalgia, headache, anuria, jaundice, hemorrhage, skin rash, and diarrhea. Although he was immediately treated with penicillin G, the patient died shortly after admission. The serological test result was negative for Leptospira; however, three leptospires were isolated from the patient through selective cultivation under varying conditions. Microscopic agglutination tests and a phylogenetic analysis of the flaB gene encoding the flagellin subunit protein revealed that the isolates belonged to three different serovars, suggesting that the patient was simultaneously infected with at least three distinct Leptospira serovars. In this case report, we highlight the potential risk of multiple infections with leptospires in humans, a critical consideration for diagnosis and treatment strategies.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activity Patterns of St. Louis Encephalitis Virus (Flaviviridae) in Mosquito Communities in a Subtropical Region of Argentina.","authors":"Griselda I Oria, Ornela S Stechina, Adrián Diaz, Eduardo Etchepare, Carlos M Hisgen, Marina Stein","doi":"10.4269/ajtmh.23-0737","DOIUrl":"https://doi.org/10.4269/ajtmh.23-0737","url":null,"abstract":"<p><p>Our aim with this study is to analyze the temporal and spatial dynamics of St. Louis encephalitis (SLEV) in mosquitoes collected from urban and rural environments in the central region of Chaco Province in the subtropical region of Argentina. Mosquitoes were captured between 2012 and 2015. A total of 81 mosquito pools were analyzed (2,105 mosquitoes) for SLEV detection, and 41 of these pools tested positive for SLEV (n = 1,675 individuals; 50%). Thirteen mosquito species were found to be infected with SLEV during this study, nine of which were reported infected for the first time in Argentina. The virus activity was recorded throughout the study period, both in urban and rural environments. The mosquito species in both environments that were infected with SLEV included Culex maxi, Culex brethesi/eduardoi, Culex bidens, and Aedes scapularis. Similar species composition and marked fluctuation in monthly activity were observed for species of the genus Culex between environments. Likewise, a similar seasonal pattern of infected species with a higher frequency of positive SLEV results was recorded during Autumn (19/41) in both environments. Our study confirms the active circulation of SLEV throughout the analyzed period in several mosquito species and its generalist nature in terms of the vectors it can infect in a subtropical region.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water Insecurity, Sociopolitical Instability, and Resurgence of Cholera in Haiti, 2022: An Outbreak Investigation.","authors":"Stanley Juin, Edwige Michel, Wilfredo R Matias, Evenel Thermidor, Molly F Franke, Michelle V Evans, Hetsner Denis, Yodeline Guillaume, Roberta Bouilly, Wisnel Mathurin, Katilla Pierre, Valusnor Compere, Kenold Rendel, Hebrelienne Amelus, Lesly Andrecy, Gerard A Joseph, Jacques Boncy, Donald Lafontant, Louise C Ivers","doi":"10.4269/ajtmh.24-0755","DOIUrl":"https://doi.org/10.4269/ajtmh.24-0755","url":null,"abstract":"<p><p>We investigated a resurgence of cholera in Haiti in 2022, occurring after 3 years without cases. We analyzed data from the National Cholera Surveillance System for the first reported cases in 2022 and interviewed field epidemiology teams. We used logistic regression to identify risk factors associated with confirmed cholera. Few suspected cases reported ever receiving oral cholera vaccine (14%) or previous hospitalization for cholera (7%). Recently changing water sources were associated with culture-confirmed cholera (odds ratio 5.55, 95% CI 2.13-15.12). Spatial analysis of cholera cases revealed significant clustering (P = 0.001) and low prevalence (11%, 15 of 136) of residual chlorine in private water points in the affected area. Qualitative analysis suggested a link between cholera resurgence and an acute lack of access to safe water because of gang violence. Ongoing response to cholera in Haiti is crucial, alongside sustained investment in long-term solutions like improved water and sanitation infrastructure and addressing socioeconomic issues.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence and Coronavirus Disease 2019 Vaccination Trends: Findings from Surveillance Conducted at First Antenatal Care Visits in Kenya, Nigeria, Malawi, Mozambique, Uganda, and Zambia, 2021-2022.","authors":"Victoria Seffren, Ruchi Yadav, Nnaemeka C Iriemenam, Oluseye Ajayi, Olabanjo Ogunsola, Conceptor Mulube, Felix Bwalya Chilambe, Monica Soko, Francis Ogollah, Miriam Chomba, Brian Seda, Idalécia Cossa-Moiane, Zainabo Langa, Paul Oboth, Richard Kwizera, Eric Rogier, Julie R Gutman","doi":"10.4269/ajtmh.24-0826","DOIUrl":"https://doi.org/10.4269/ajtmh.24-0826","url":null,"abstract":"<p><p>Estimates of exposure to coronavirus disease 2019 (COVID-19) on the African continent are limited, constrained by availability of testing and case report data. To improve understanding of COVID-19 burden, monthly severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurveillance was implemented at first antenatal care visits (ANC1) across six sub-Saharan African countries (Kenya, Malawi, Mozambique, Nigeria, Uganda, and Zambia). A standardized questionnaire, including COVID-19 vaccination history, was administered, and a blood sample was collected. Serology was conducted with two assays: in Nigeria, a multiplex bead-based assay targetting spike protein, receptor binding domain (RBD) 591, and nucleocapsid (N) protein and in all other countries, a SARS-CoV-2 human IgG antibody test including RBD, N protein, and hybrid RBD-N. The largest monthly change in seropositivity was between December 2021 and January 2022 for five countries (Kenya: 33.2-70.3%, Malawi: 28.3-59.6%, Mozambique: 29.3-72.8%, Nigeria: 52.4-77.4%, Uganda: 55.7-80.6%), coinciding with the Omicron wave. Aside from Mozambique, there was an increase in the proportion of women reporting COVID-19 vaccination beginning in January 2022, with highest vaccination rates between April and August 2022. Relatedly, there was an increase in the proportion vaccinated among those with detectable SARS-CoV-2 antibodies. Adenoviral vector accounted for at least half of the vaccines reported in all countries. If pregnant women are not differentially infected, ANC1 can be leveraged for serosurveillance during a pandemic. Monthly seroprevalence estimates alongside vaccination rates can provide evidence for changes in protective immunity in response to case waves and the introduction of protective measures.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mpox, HIV, and a Compounding Sepsis Crisis in Africa.","authors":"Barnabas Bakamutumaho, Matthew J Cummings, Shevin T Jacob, Joseph F Wamala, Christopher Nsereko, Andrew Obuku, Hakim Sendagire, Wilber Sabiiti, John Bosco Nsubuga, Bruce J Kirenga, Henry Kyobe Bosa, Misaki Wayengera","doi":"10.4269/ajtmh.25-0125","DOIUrl":"10.4269/ajtmh.25-0125","url":null,"abstract":"<p><p>Mpox, a zoonotic disease caused by the monkeypox virus (MPXV), has reemerged as a significant global public health threat, particularly in sub-Saharan Africa, where more than 50,000 cases have been reported since 2022. Although HIV-related immunosuppression is a known risk factor for severe MPXV infection, the intersection of mpox, HIV, and critical illness has been largely overlooked in ongoing outbreaks in East and Central Africa. We describe a case of a 45-year-old woman in Uganda, living with WHO stage 3 HIV and active pulmonary tuberculosis (TB), who developed mpox-associated sepsis and acute hypoxemic respiratory failure. One month after initial mpox diagnosis and receipt of supportive care, she developed high fever, hypotension, and hypoxemia and was hospitalized. Painful oropharyngeal and mucocutaneous lesions limited her adherence to oral antiretroviral and anti-TB therapy. Despite oxygen therapy, judicious fluid resuscitation, and empiric antibiotics, the patient deteriorated rapidly and died on hospital day two. This case illustrates the emerging burden of mpox-related critical illness in persons living with HIV in sub-Saharan Africa. In this context, we propose key actions to improve the international mpox response, focusing on the clinical management of mpox-associated sepsis and critical illness.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144551746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Threat of Avian Influenza in the Eastern Mediterranean Region: A One Health Perspective.","authors":"Mira Samer Alamer, Muna Horabi, Furat K Al-Nawaiseh, Ammar Abu Ghalyoun, Ala'a B Al-Tammemi","doi":"10.4269/ajtmh.24-0683","DOIUrl":"https://doi.org/10.4269/ajtmh.24-0683","url":null,"abstract":"<p><p>Avian influenza viruses (AIVs) pose a significant threat to global public health because of their widespread global circulation. The Eastern Mediterranean Region (EMR) is located along the major flyways of migratory birds; thus, this geographic location raises the risks of AIV circulation in the region. In the context of Avian influenza, which is primarily a zoonotic disease, the One Health approach is essential for an effective preparedness and response strategy. Risk factors such as dense poultry populations, migratory bird flyways, and close human-animal interactions contribute to the vulnerability of many countries in the EMR to AIV outbreaks. For instance, the overlap of migratory bird routes with human settlements poses a significant risk in countries like Egypt, Iran, and Jordan. Although the One Health approach provides a robust framework for addressing Avian influenza, several challenges remain in the EMR because of political instability, armed conflicts, and constraints in the resources, all of which hinder effective surveillance and outbreak management.</p>","PeriodicalId":7752,"journal":{"name":"American Journal of Tropical Medicine and Hygiene","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}