American Journal of Tropical Medicine and Hygiene最新文献

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.

Yellow fever (YF) causes approximately 50,000 deaths annually worldwide and is transmitted by infection with the yellow fever virus (YFV), which is endemic in Sub-Saharan Africa and tropical South America. The live-attenuated YFV 17D vaccine, developed in 1937, is essential to control YFV transmission, but the finite shelf life and manufacturing constraints of egg-based vaccine production, the rare but severe adverse events, and the lack of effective therapeutic options for YF disease highlight the need for new YFV vaccines and therapies. Potent YFV antibodies that neutralize circulating strains could be promising passive immunizations or treatments and guide nonreplicating YF vaccine development. In this study, we captured and screened natively paired heavy and light chain antibody libraries from two donors immunized with the YFV 17D vaccine. Yeast surface display libraries were generated and stained using YF virus-like particles purified by chromatographic techniques. Three anti-YFV antibodies were identified with potent neutralizing activity against circulating strains from Western Africa and South America, including one potent antibody with a neutralizing half-maximal inhibitory concentration of <5 ng/mL against the 17D vaccine strain. These new YFV antibodies have the potential to serve as YFV outbreak countermeasures for treatment or prevention and guide future vaccine efforts.

The present report describes a case of tuberculous otitis media in a young Brazilian male recently diagnosed with pulmonary tuberculosis who presented with painless unilateral purulent otorrhea and hearing loss for several months. He had received several antibiotic regimens without a clinical response. An acid-fast bacilli test and polymerase chain reaction test from an ear secretion confirmed the diagnosis. Despite its rare occurrence, this case is very similar to others reported elsewhere and reinforces the relevance of investigating this infection in patients with chronic otitis media refractory to conventional therapy regardless of whether another anatomical site is involved or not.

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.

Mass azithromycin distribution has been shown to reduce all-cause child mortality in several settings in the Sahel by 14-18%. A trial in Niger found that mass azithromycin distribution to children ages 1-59 months old reduced cause-specific mortality because of malaria, dysentery, meningitis, and pneumonia. However, this study was done in the absence of seasonal malaria chemoprevention (SMC). Here, we assess the effect of mass azithromycin distribution on cause-specific child mortality in a setting receiving SMC. The Child Health with Azithromycin Treatment trial was a cluster-randomized, placebo-controlled trial of 341 communities in Nouna District, Burkina Faso. Eligible children (ages 1-59 months old) received a single oral 20-mg/kg dose of azithromycin or matching placebo. Six rounds of distribution occurred over a 36-month period. An enumerative census was conducted during each twice-yearly distribution, during which vital status for all children in the community was collected. Verbal autopsy was performed to assess cause of death. Of 1,086 deaths recorded in the trial, verbal autopsy results were available for 992 (91%). The most common causes of death were infectious, including malaria (34%), diarrhea (24%), and pneumonia (9%). Children living in communities receiving azithromycin had significant reduction in malaria mortality (incidence rate ratio, 0.67; 95% CI, 0.50-0.90; P = 0.008). Other infectious causes of mortality, including diarrhea and pneumonia, were lower in communities receiving azithromycin but were not statistically significantly different. Mass azithromycin distribution for child mortality has benefits in the context of SMC for reducing mortality, including for malaria mortality.

Malaria control in sub-Saharan Africa has stagnated despite widespread adoption of control measures such as long-lasting insecticidal nets (LLINs). Progress has stalled, in part, because of pyrethroid insecticide resistance, driving the need for retooling to increase the effectiveness of bed nets. Consequently, LLINs have been treated with the chemical synergist piperonyl butoxide (PBO). Piperonyl butoxide LLINs have been shown to be efficacious in controlled settings; however, their effectiveness in real-world settings warrants investigation. In Bungoma County, Western Kenya, a cohort of 768 participants was followed from June 2017 to December 2023 via active and passive surveillance. Household visits were conducted monthly, during which LLIN use for nets distributed in 2017 and 2021 was recorded, and symptomatic malaria cases were identified using rapid diagnostic tests (RDTs). The comparative effectiveness of PBO versus conventional LLINs was assessed in terms of malaria infections. A multilevel logistic regression model was fit with monthly RDT results as the dependent variable. The study results indicate that PBO LLINs provide greater protection against malaria at the individual level than conventional LLINs (odds ratio: 0.70; 95% CI: 0.47-1.03), although the findings were not statistically significant. The added protection against malaria infections provided by PBO LLINs compared with conventional LLINs observed in the current study aligns with findings from most previous studies, although this finding was not statistically significant. In areas with documented pyrethroid resistance, the use of LLINs with an added synergist, such as PBO, can provide additional protection against malaria infections (compared with pyrethroid-only LLINs) and should be considered for scaled-up scenarios despite the additional cost.