American Journal of Tropical Medicine and Hygiene最新文献

Gram-negative bacteria pose a significant threat in hospitals and community settings across Thailand. Limited antimicrobial stewardship, access to and use of prevention measures, and gaps in national surveillance contribute to this ongoing global challenge. In the present review, the literature on Gram-negative hospital- and community-acquired infections in Thai adults published between 2010 and 2024 is summarized, focusing on data collection and reporting gaps. Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Burkholderia pseudomallei were the most frequently reported pathogens. Of these, A. baumannii, K. pneumoniae, and P. aeruginosa were the most common hospital-acquired infections, whereas E. coli and B. pseudomallei were the most common community-acquired infections. Although there is a critical need for studies on antibiotic resistance patterns, treatments, and specific Gram-negative pathogens, the authors of large-scale prevalence studies did not clearly outline the distribution of these types of infections. More inclusive nationwide studies in which both hospital- and community-acquired Gram-negative infections are examined would be beneficial.

Spinal cord (SC) narrowing has been documented in patients with human T cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM). However, it remains uncertain whether individuals who present with lower urinary tract symptoms (LUTSs) without motor disability (probable HAM) exhibit damage to the central nervous system. These patients typically experience nocturia, urgency, incontinence, and, less frequently, an arreflexic bladder, which requires intermittent catheterization for voiding. The aim for the present study was to investigate the effectiveness of magnetic resonance imaging with tractography in detecting abnormalities in HTLV-1-infected individuals with LUTS. The study participants included those with probable HAM (n = 39), HTLV-1 carriers (HCs; n = 41), and seronegative (SN) controls (n = 12). Magnetic resonance imaging with diffusion tensor imaging and tractography was performed, with two regions of interest positioned side-by-side at T5 and T12-L1. Measurements included the SC area, mean diffusivity, and fractional anisotropy (FA). No significant differences were found between groups regarding age or sex (P >0.05). The medians and interquartile ranges for the thoracic SC area were 0.41 (0.39-0.45), 0.36 (0.30-0.40), and 0.33 (0.27-0.36) in SN controls, HCs, and those with probable HAM, respectively (P <0.05). The lumbar SC area was smaller in patients with probable HAM compared with HCs and SN controls. Furthermore, the median FA in the lumbar region was significantly lower in patients with probable HAM (P <0.05). Urinary dysfunction is the most common manifestation in probable HAM, and the present study reveals SC narrowing in these patients, despite the absence of motor disability.

In the present article, two cases of envenomation by Rhabdophis subminiatus are reported, including a detailed analysis of the toxicological mechanisms, clinical manifestations, and therapeutic management, along with a systematic review of globally reported cases of Rhabdophis subminiatus envenomation. Both patients (both male, aged 58 years and 55 years, respectively) sought medical treatment several days after being bitten on the hand and developed life-threatening consumptive coagulopathy and hemorrhagic diathesis. The 58-year-old patient (Case 1) presented with local swelling, pain, abdominal hematoma, and shortness of breath. After treatment with antivenom, transfusion of packed red blood cells, fresh-frozen plasma, cryoprecipitate, and mechanical ventilation, his coagulation function returned to nearly normal levels. He was discharged 15 days after admission to the study hospital. The 55-year-old patient (Case 2) presented with oral bleeding and swelling distal to the bite site. After treatment with antivenom and transfusion of fibrinogen concentrate, packed red blood cells, and fresh-frozen plasma, his coagulation function returned to normal. He was discharged 11 days after admission to the study hospital. A literature review revealed more than 50 reported cases worldwide, all of which highlighted hemorrhagic syndrome and profound coagulopathy as hallmark features. Most cases were managed symptomatically, with only a minority receiving antivenom. Although the overall prognosis was generally favorable, the case fatality rate reached 12.7%. Envenomation by Rhabdophis subminiatus constitutes a significant medical emergency that requires early intervention with polyvalent antivenom (such as anti-Agkistrodon/Deinagkistrodon antivenom) combined with targeted supportive therapy to optimize clinical outcomes.

Latent tuberculosis infection (LTBI) and Schistosoma mansoni are common in Africa, and helminth-induced immunomodulation may affect LTBI detection. This study aimed to assess whether S. mansoni infection affects LTBI detection by the QuantiFERON-TB Gold Plus (QFT-Plus) assay and alters serum interferon-γ (IFN-γ) concentrations in response to Mycobacterium tuberculosis (Mtb) antigens at baseline and after 1 year, during which participants with S. mansoni infection received praziquantel treatment. At baseline, 65 individuals with schistosome infection had lower average IFN-γ concentrations in TB1-stimulated QFT-Plus supernatants compared with 83 uninfected individuals (10.4 versus 51.9 pg/mL, P = 0.038). Although not statistically significant, QFT-Plus test positivity rate was unexpectedly slightly higher among adults with schistosome infection at baseline (26.2% versus 18.1%, P = 0.24). The incidence over 12 months was higher posttreatment in participants initially infected with S. mansoni compared with those uninfected (13.9% [n = 5/36] versus 4.2% [n = 2/48], P = 0.13). By 12 months, IFN-γ concentrations were comparable between the two groups (53.8 versus 33.5 pg/mL, respectively, P = 0.56). Individuals who cleared S. mansoni infection experienced a nearly 12-fold increase in IFN-γ levels relative to those who remained uninfected, although this difference did not reach statistical significance (P = 0.17). In conclusion, baseline S. mansoni infection was associated with suppressed IFN-γ responses to Mtb antigens, suggesting helminth-induced immune dampening. Praziquantel treatment may partially restore TB-specific immune responses and facilitate LTBI detection. These findings highlight the potential role of S. mansoni as a critical cofactor affecting LTBI diagnosis in schistosomiasis-endemic regions.

Dengue remains a major public health challenge in Brazil, with recurrent outbreaks placing a strain on healthcare systems. The TAK-003 vaccine offers a promising control strategy, particularly for children. This cross-sectional study evaluated the seroprevalence of anti-dengue IgG in 643 children and adolescents aged 4-16 years in Dourados, Brazil, before being administered the TAK-003 vaccine. Capillary blood samples were collected on filter paper and analyzed using ELISA; sociodemographic data were obtained through questionnaires. Overall, 20.5% of participants were seropositive. Seropositivity increased with age, with 27.7% among those aged 13-16 years testing positive compared with 13.4% among children aged 4-8 years. Male sex was associated with lower IgG levels. The age-related increase in anti-dengue IgG seroprevalence reflects cumulative exposure to the virus during childhood and adolescence, highlighting the need for immunization strategies tailored to age. These findings emphasize the importance of baseline anti-dengue IgG seroprevalence data to guide vaccination, assess effectiveness, and monitor antibody-dependent enhancement risks.

Visceral leishmaniasis (VL) is a vector-borne disease caused by Leishmania infantum infections in Brazil, and Lutzomyia longipalpis is its main vector. It is not well understood how L. infantum circulates between three hosts of public health importance: dogs, humans, and sand flies. The focus of this study was to determine the detection rate of L. infantum DNA in sand flies and evaluate the relative contribution of the three hosts as sand fly blood sources. Insects were collected using light traps in households with recent history of human VL, close neighbors of VL cases, and households with no recent history of human VL. DNA was extracted from single sand fly guts and L. infantum DNA, and sources of blood were identified by quantitative polymerase chain reaction (qPCR) using specific cytochrome B. Among 248 female sand flies captured, qPCR detected L. infantum DNA in 56% of them. Sand flies captured in households with recent history of human VL or VL endemic neighbors were, respectively, 3.73 (95% CI: 1.64-8.48; P = 4.92e-04) or 6.38 (95% CI: 3.37-12.09; P = 4.62e-10) times more likely to carry L. infantum DNA compared with sand flies captured in houses with no history of VL. Dog blood was most common, but multiple blood sources were detected in individual flies. Our findings reaffirm the role of dogs as L. infantum reservoirs in northeast Brazil. These findings highlight the importance of topical insecticides as measures to prevent canine L. infantum infection and limit the risk of human infection.

The selection of authors for editorials reflects perceptions of expertise and influence. Our objectives were to determine author geographic and gender distribution, determine temporal trends in editorial authorship, and identify factors associated with the inclusion of authors affiliated with low- and middle-income countries (LMICs) in editorials on research conducted in LMICs. We conducted a cross-sectional study of editorials on research in LMICs published in 15 global health, pediatrics, and general medicine journals from 2014 to 2024. To assess temporal changes in authorship, we plotted the proportion of editorial authors affiliated with LMICs and those with female names by year. We used multivariable logistic regression to identify factors associated with the inclusion of one or more LMIC-affiliated authors. There were 107,629 publications and 1,350 editorials on research in LMICs with 2,401 authors. Authors of editorials were most often affiliated with institutions in North America (38.1%) and high-income countries (71.6%). The proportion of authors of editorials affiliated with institutions in high-income countries decreased from 84.9% in 2014 to 65.3% in 2024. Authors of editorials more commonly had male names than female (60.1% versus 38.7%, P <0.001). The proportion of editorial authors with female names increased from 32.1% in 2014 to 48.2% in 2024. Editorials accompanying publications reporting studies with larger sample sizes (aOR = 1.52, 95% CI: 1.03-2.26) and research conducted in sub-Saharan Africa (aOR = 2.84, 95% CI: 1.74-4.68) were more likely to include LMIC-affiliated authors. Additional efforts are needed to include authors affiliated with LMICs in editorials on research conducted in LMICs.

Sepsis is a leading cause of neonatal mortality. Current knowledge of etiology, antimicrobial susceptibility, and outcomes provides evidence for judicious antimicrobial use. The aim for the present study was to identify etiologic organisms, antimicrobial susceptibility, and treatment outcomes at a tertiary hospital in Jos, Nigeria. A retrospective case review of neonates hospitalized for sepsis was conducted between August 25, 2017 and December 31, 2020. Clinical and laboratory data were collected from 1,984 neonates admitted, of whom 516 (26%) were diagnosed with neonatal sepsis (NNS). The clinical and blood culture data were available for 380 (74%) neonates, of whom 226 (60%) were male. The majority (63%) were diagnosed with early-onset sepsis, of whom 146 (38%) had severe sepsis. The mean age of the mothers was 29.5 ± 5.5 years. Of the 207 cultures obtained, 87 (43%) yielded pure isolates, with 50 (58%) of these being Gram-positive. For neonates born outside the study hospital, 6/36 (17%) were methicillin-sensitive, compared with 6/44 (14%) neonates born at the study hospital. Gram-negative isolates, predominantly Klebsiella pneumoniae, grew in 36 (41%) of all positive cultures (27/87; 31%). More organisms were sensitive to piperacillin-tazobactam (19/19; 100%), gentamicin (21/27; 78%), imipenem (4/8; 50%), and ceftazidime (17/28; 61%) than to the other antibiotics tested. Mortality in all patients with proven or presumed NNS was 31/380 (8%), with increased mortality in those without cultures (8/71; 11% versus 39/71; 55%). Neonatal sepsis-related mortality is high in the study center in Jos, Nigeria. Additional work is needed to mitigate NNS mortality and the rising problem of antimicrobial resistance.

Despite the implementation of effective vaccines to reduce measles- and mumps-related morbidity and mortality, occasional outbreaks can occur. Monitoring the transmission of these infections in the community is important and could provide useful information for policymakers to develop effective disease control plans. Therefore, this study aimed to describe the epidemiology and age-specific trend of measles and mumps in eastern Libya. We estimated the burden of measles and mumps in a vaccinated population using data from the main medical center in the Tobruk region in eastern Libya from January 2003 to December 2020. In total, 208 cases of measles and 111 cases of mumps in those younger than 1 year old and older than 1 year old were registered over the study period. The occurrence of these infections varied, and some notable outbreaks of measles and mumps occurred during the study period. There was a minor seasonal variation in the disease occurrence over the study period. In conclusion, this study quantified the burden and age-specific occurrence of measles and mumps in the region. It also highlights the importance of maintaining high immunization rates through routine and supplemental campaigns to achieve coverage levels sufficient for preventing future outbreaks.