American Journal of Tropical Medicine and Hygiene最新文献

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.

Sepsis disproportionately impacts children in low-resource settings, where diagnostic tools like the Phoenix Sepsis Score (PSS) are constrained by reliance on laboratory testing. The objective of this research was to evaluate the use of continuous physiological data from low-cost wearable biosensors and machine learning models to predict pediatric sepsis, septic shock, and mortality in a low-resource, intensive care setting. This prospective observational single-site study analyzed 96 pediatric intensive care unit patients with suspected sepsis in Dhaka, Bangladesh. Physiological data were collected using a wearable biosensor patch, whereas clinical exams, laboratory tests, and PSS criteria identified sepsis, septic shock, and mortality. Least absolute shrinkage and selection operator (LASSO) regression models were developed and validated through leave-one-group-out cross-validation (LOGO-CV) using biosensor data. Our clinical diagnostic model for sepsis using biosensor-only features demonstrated an area under the receiver operating characteristic curve (AUROC) of 0.78 (null AUROC = 0.58). For septic shock, the model demonstrated an AUROC of 0.85 (null AUROC = 0.61). The mortality model demonstrated an AUROC of 0.87 (null AUROC = 0.64). Sensitivity analyses showed improvement of AUROC to 0.89 for prediction of sepsis with manual recorded oxygen saturation (SpO2) included. Although models were trained and tested retrospectively with internal validation, findings demonstrate the potential of wearable biosensors to support pediatric sepsis diagnosis without reliance on advanced diagnostics. These results encourage further external validation with larger, multisite cohorts and real-time mobile health (mHealth) integration to support clinical use in low-resource settings.

Oz virus (OZV) was first isolated from ticks in Japan in 2018, and human infections with OZV were reported in 2023. However, serosurveillance for OZV infections, compared with that for severe fever with thrombocytopenia syndrome (SFTS), is rarely performed among wild animals. We conducted a retrospective study on the epidemiology of SFTS virus and OZV infections in wild animals. Serum samples were collected from 289 deer, 158 raccoons, and 381 wild boars in this study. The positivity rates for the anti-OZV IgG antibody in deer (10.3%), raccoons (12%), and wild boars (12.1%) showed no difference. Both OZV and SFTS virus IgG antibodies were detected in wild animals. Wild animals in Oita Prefecture had anti-OZV antibodies, suggesting that human cases will occur in the future. We recommend educating the public about the tick-borne pathogen risks in this area and implementing tick bite prevention strategies.

Entebbe bat virus (ENTV) is a bat-associated flavivirus with no known arthropod vector. Research into the biology of this virus, including assessment of the possibility that it may be vector-transmitted, is hindered by a lack of molecular tools and robust genetic systems. Therefore, the complete 3' untranslated region, which was not previously available, was sequenced, and an infectious clone of ENTV was developed to facilitate further investigation of the virus. Virus derived from the clone replicated similarly to the parental virus isolate in various vertebrate cells. Surprisingly, ENTV replicated to high titers in the Aedes aegypti (Ae. aegypti) and Aedes albopictus (Ae. albopictus) mosquito cell lines, but there was no replication or infection in Culex tarsalis cells. In addition, phylogenetic and bioinformatics analyses strongly suggested that ENTV may be associated with a mosquito host. Given the bioinformatics support and efficient growth in Aedes cells, Ae. aegypti and Ae. albopictus were orally exposed to ENTV to evaluate infection. The ENTV blood-fed mosquitoes were all negative for infection; however, when ENTV was intrathoracically (IT) inoculated, bypassing the initial midgut infection and escape barriers, it replicated to high levels in the body without disseminating infectious virus into the saliva. These findings suggest that despite demonstrating high molecular compatibility at the cellular level in Aedes mosquitoes, Ae. aegypti and Ae. albopictus are unlikely to serve as competent vectors for ENTV transmission because of strong midgut infection barriers. The clone presented in this manuscript should help clarify the mechanisms for transmission and maintenance of ENTV, which remain poorly understood.

A 15-year-old adolescent with sickle cell disease (SCD) presented at a tertiary care children's hospital with severe hemolysis after returning from West Africa. Over a period of 5 weeks, the patient experienced recurrent hemolysis, fever, and neuropsychiatric symptoms, with worsening conditions despite immunosuppressive and broad-spectrum antibiotic treatment. Eventually, cerebral malaria (CM) was diagnosed and treated, leading to a prompt recovery; however, another episode of hemolysis occurred 12 days after artesunate treatment. The unusually prolonged course of CM in this case illustrates the complex interplay among malaria, SCD, autoimmune hemolytic anemia, and various treatments. Furthermore, the case highlights challenges related to managing severe malaria in non-endemic countries and underscores the importance of timely malaria testing, especially in vulnerable patients with a suitable travel history. A thorough travel history is essential for the early diagnosis and appropriate management of malaria. Heightened awareness is needed among both high-risk travelers and healthcare providers to reduce malaria-related morbidity and mortality.

A 55-year-old male from El Salvador presented to an emergency department in the northeastern United States with diarrhea, vomiting, dizziness, and melena. Shortly after arrival, the patient's heart rate increased to 235 beats/min with a narrow QRS complex, which subsequently degenerated into a wide complex ventricular tachycardia (VT). Initial workup revealed severe transaminitis, reduced systolic function, and an anomalous right coronary artery. After extensive diagnostic workup, including cardiac magnetic resonance imaging and serologies, a diagnosis of Chagas cardiomyopathy was made. Given the presence of arrhythmogenic substrate and a high Rassi score for sudden cardiac death, the patient underwent placement of an implantable cardioverter-defibrillator (ICD) for secondary prevention of VT. This case underscores the increasing importance of considering Chagas disease in patients in the United States coming from endemic countries and the decision-making process regarding ICD placement in a patient with underlying Chagas-related cardiomyopathy.

Mass drug administration (MDA) of ivermectin is currently being evaluated for malaria control. Uptake and adherence to MDA are shaped by various individual, social, and operational factors; however, the authors of most studies have focused on individual drivers of uptake. In the present paper, a longitudinal qualitative study undertaken alongside the Broad One Health Endectocide-Based Malaria Intervention in Africa (BOHEMIA) ivermectin MDA clinical trial is reported to examine community experiences and perceptions of the trial and the ivermectin MDA. Using purposive maximum variation sampling, researchers selected five villages involved in the BOHEMIA trial (two in the intervention arm and three in the control arm). Before the trial, researchers lived in each village for 1 month, making observations and conducting in-depth interviews (IDIs) and focus group discussions (FGDs). They returned before the first MDA round and remained throughout all three rounds, gathering insights on trial implementation, community perceptions, and perceived effects of the MDA. During this period, a total of 22 IDIs were conducted, along with structured observation reports. Two months after the MDA, 15 FGDs were held in eight additional villages. The findings indicate that during the trial, addressing needs and confidence in the implementing institution fostered participation, whereas previous negative experiences with MDA interventions and perceived exclusion from community engagement activities reduced involvement. The MDA was widely perceived as effective in reducing mosquitoes and malaria in both arms of the trial. It was also seen as highly effective against bedbugs in the intervention arm. These insights highlight the importance of trust, engagement, and previous experiences in shaping community participation in MDA programs.

Tuberculosis (TB) in pregnancies conceived via in vitro fertilization (IVF) presents unique diagnostic and management challenges, especially in TB-endemic regions. This systematic review synthesizes evidence on maternal and neonatal TB outcomes after IVF. We conducted a systematic review of case reports, case series, and cohort studies, following PRISMA 2020 guidelines. Databases searched included PubMed, Scopus, Embase, and Google Scholar. Quality assessment was performed using Murad's framework and the Newcastle-Ottawa Scale. Seventy-three IVF pregnancies complicated by maternal TB were analyzed. Median maternal age was 32 years; 63.0% had no prior TB history. TB was diagnosed during pregnancy (56.2%) or postpartum (38.4%). Miliary TB (38.4%) and genital TB (27.4%) were most common; central nervous system (CNS) TB occurred in 13.7%. Microbiological confirmation was achieved in 38.4%. Anti-TB therapy was administered to 79.5%; 8.2% had drug-resistant TB. Neonatal TB manifestations included congenital TB (39.7%), miliary TB (34.2%), and CNS TB (15.1%). Of 55 live births, 28 infants survived, 12 died neonatally, and outcomes were missing for 15; there were 18 pregnancy losses. Most mothers recovered, some had residual deficits, and three deaths occurred. Seven cohort studies from China reported earlier TB onset in IVF pregnancies (11-19 weeks' gestation), higher incidence of miliary and CNS TB, and poor fetal outcomes, including >80% pregnancy terminations or losses, in comparison with natural conceptions. TB after IVF is often undiagnosed before conception and carries high fetal risks. Routine TB screening before IVF is essential in endemic areas. Early diagnosis and maternal-neonatal management can improve outcomes.

This study investigated the epidemiologic and clinical characteristics of patients with dengue fever complicated by alopecia. Of the 1,302 patients diagnosed with dengue fever at a tertiary hospital in Guangdong Province between September 2024 and December 2024, 15 were identified with concurrent alopecia. Clinical data from these patients were systematically analyzed along with relevant literature. The incidence of dengue fever with alopecia was approximately 1.15% and occurred predominantly in females (93.33%). Hair loss most frequently developed during the convalescent phase of dengue fever, with telogen effluvium identified as the most common type. Platelet count and hematocrit values were significantly lower in patients with dengue fever and alopecia than those without alopecia. These findings suggest that dengue fever-associated alopecia primarily presents as telogen effluvium, predominantly affects females, and may be associated with reduced platelet count and hematocrit as potential risk factors.