Tropical Medicine and Infectious Disease最新文献

National Tuberculosis Reference Laboratories (NTRLs) are central to tuberculosis (TB) control programs. Between 2018 and 2024, the Republic of Congo, a country of 6 million inhabitants, achieved a transformative strengthening of its TB diagnostic system, coordinated by the NTRL. Strategic investments, supported mainly by international partners, enabled a substantial decentralization of services, expanding the diagnostic network from 38 to 113 diagnostic and testing centers and increasing GeneXpert sites from 3 to 31. The expansion of the diagnostic network and specimen referral system was associated with a reduced structural gap in diagnostic coverage by extending access to GeneXpert testing to a larger number of peripheral and previously underserved centers. Critically, the establishment of a BSL-3 laboratory and the deployment of advanced assays like Xpert MTB/XDR ended the reliance on overseas testing by introducing in-country capacity for multidrug-resistant and pre-extensively drug-resistant TB detection. These systemic improvements were associated with significant positive outcomes, including an annual molecular testing surging from 11,609 in 2022 to over 27,000 in 2024 and bacteriological confirmation rates rising from 34 to 73%. This comprehensive laboratory systems strengthening, which also facilitated cross-programmatic initiatives like HIV and Mpox testing integration, underscores how sustained investment in infrastructure, logistics, and quality management is fundamental to improving case detection, surveillance, and progress toward the WHO End TB Strategy milestones.

Lower respiratory infections (LRIs) are responsible for significant morbidity and mortality in Ecuador; however, evidence to support prevention strategies is limited. This study aimed to identify age-specific trends, spatial patterns, and sociodemographic risk factors of LRI mortality in Ecuador between 2012-2022, utilizing national mortality data sourced from the Ecuadorian National Institute for Statistics and Censuses (INEC). Age-sex-specific trend analysis was performed using Joinpoint regression. LRI age-standardized mortality rates (ASMRs) were mapped by province of death, and percentage change was calculated between 2012 and 2019. Multivariable logistic regression was performed to assess risk factors pre- and post-2020. A change in trend in LRI mortality rate, from a decreasing trend to a marginal increasing trend, was identified for both genders in children aged 0-4 and 5-15 years. There were significant increasing trends for males (2014-2019 APC: 2.21%, 95% CI: 0.57, 6.70) and females (2016-2019 APC: 4.62%, 95% CI: 0.84, 10.58) aged ≥ 70 years. From 2012 to 2019, the highest average LRI ASMR was in Guayas (30.90 deaths per 100,000 inhabitants), and the greatest percentage increase was observed in Orellana (419.54%). Before 2020, LRI mortality, compared to deaths of other causes, was significantly associated with sex, age, education, ethnicity, place of death and climate region, with major shifts post COVID-19 pandemic.

Background: Naegleria fowleri is a free-living amoeba that inhabits warm freshwater and causes primary amoebic meningoencephalitis (PAM), a rapidly fatal infection with >95% mortality. Due to the lack of early diagnosis and effective therapy, preventive vaccination represents a promising strategy.

Methods: This study evaluated short- and long-term immune protection in BALB/c mice (20 mice per group) immunized intranasally with total N. fowleri extract co-administered with cholera toxin (CT). Mice were challenged with a lethal dose of trophozoites either 24 h (short-term) or three months (long-term) after the fourth immunization; the latter group received a booster 24 h before challenge. Serum and nasal washes were analyzed for IgA and IgG antibodies by immunoblot, and lymphocyte subsets from nasal-associated lymphoid tissue (NALT) and nasal passages (NPs) were characterized by flow cytometry.

Results: Immunization conferred complete (100%) survival in the 24 h group and 60% protection in the 3-month group, whereas all control mice died. Immunoblotting showed that IgA and IgG antibodies recognized major N. fowleri antigens of 37, 45, 48 and 19, 37, and 100 kDa, respectively. Flow cytometry revealed increased activated and memory B lymphocytes, dendritic cells, and expression of CCR10, integrin α4β1, and FcγRIIB receptors, particularly in the 24 h group.

Conclusions: Intranasal immunization with N. fowleri extract plus CT elicited both systemic and mucosal immune responses capable of short- and long-term protection. These findings highlight the potential of this immunization strategy as a foundation for developing effective vaccines against PAM.

Eosinophilia is a valuable biomarker for estimating the likelihood of parasitic infection in immigrants from tropical or subtropical regions. This study aimed to evaluate the frequency and etiology of imported eosinophilia in patients attending the Tropical Medicine Unit (TMU) of Salamanca, Spain, between 2008 and 2023. A total of 773 immigrant patients were assessed: 450 (58.2%) from Africa, 306 (39.6%) from Latin America, and 17 (2.2%) from Asia. Eosinophilia was observed in 338 patients (43.7%), of whom 15 (4.4%) had noninfectious causes. Among the remaining 323 evaluated for infections, 171 (52.9%) presented with relative eosinophilia and 152 (47.1%) presented with absolute eosinophilia. A specific diagnosis was reached in 49.2% of the cases, most commonly filariasis (12.1%), strongyloidiasis (9.9%), and schistosomiasis (4.6%): 58 patients had coinfections. In conclusion, eosinophilia is common among migrants and represents a valuable biomarker for helminthiasis. Despite protocolized evaluation, nearly half of the cases remain undiagnosed. The most frequent etiologies were filariasis, strongyloidiasis, and schistosomiasis, with African patients having the highest probability of diagnosis. Improved diagnostic approaches, including tests for less common parasites, may reduce uncertainty and enhance clinical management.

Background: Malaria remains a major public health concern in Africa, due to the persistence of Plasmodium falciparum gametocytes that sustain transmission post treatment. This study evaluated the effects of artemether-lumefantrine (AL) alone compared with AL combined with a single low-dose of primaquine (SLD-PQ) on gametocyte clearance and infectivity to Anopheles arabiensis post treatment.

Methods: A prospective cohort and entomological study were conducted from January to September 2025 in Northwest Ethiopia. Ninety-six microscopically confirmed cases of P. falciparum gametocytemia mono-infection were proportionally assigned to both treatment groups. Follow-up assessments were conducted on days 3, 7, 14, and 28, and mixed-species infections were assessed using molecular diagnostic assays. Additionally, membrane feeding assays (MFAs) were performed to evaluate mosquito infectivity post treatment.

Results: Gametocyte prevalence declined faster with AL + SLD-PQ (15.2% on day 3; 0% by day 7) compared to AL alone (28.9% on day 3: p = 0.001; 12.2% by day 7: p = 0.033). Higher baseline gametocyte density strongly predicted mosquito infection (95% in high vs. 59% moderate and 33% low). On day 3 post treatment, 28.6% of cases treated with AL only showed confirmed mosquito infection, compared to 6.8% in the AL + SLD-PQ group (p = 0.001). By day 7, 7.3% of cases remained infectious in the AL-only group, while none were detected in the AL+ SLD-PQ group (p = 0.01).

Conclusions: High baseline gametocyte density strongly correlated with increased infectivity. Adding SLD-PQ markedly accelerates gametocyte clearance and completely blocks post-treatment transmission. Submicroscopic gametocytemia contributed to residual transmission in the AL-only group. Incorporation of SLD-PQ alongside AL, in line with WHO recommendations, is advised to enhance post-treatment transmission blocking, with continued surveillance.

Leptospirosis remains a significant public health and economic burden in Southeast Asia, particularly in low- and middle-income countries where environmental, occupational, and socioeconomic factors contribute to its endemicity. Transmission is driven by close interactions between humans and infected animal reservoirs, alongside climatic conditions such as heavy rainfall and flooding. The region's high but variable seroprevalence reflects inconsistencies in diagnostic methodologies and surveillance systems, complicating disease burden estimation. Major gaps persist in diagnostic capabilities, with current tools often unsuitable for resource-limited settings, leading to underdiagnosis and delayed treatment. Environmental modeling and spatial epidemiology are underutilized due to limited interdisciplinary data integration and predictive capacity. Addressing these challenges requires a One Health approach that integrates human, animal, and environmental health sectors. Key policy recommendations include harmonized surveillance, standardized and validated diagnostics, expanded vaccination programs, improved animal husbandry, and targeted public education. Urban infrastructure improvements and early warning systems are also critical, particularly in disaster-prone areas. Strengthened governance, cross-sectoral collaboration, and investment in research and innovation are essential for sustainable leptospirosis control. Implementing these measures will enhance preparedness, reduce disease transmission, and contribute to improved public health outcomes in all sectors across the region.

Haemaphysalis qinghaiensis is an endemic tick species distributed in the western plateau areas of China. Although they are three-host ticks, infesting multiple animals (including humans), the occurrence of various tick-borne agents has barely been investigated. In this study, we collected 136 H. qinghaiensis specimens from sheep and goats in Menyuan County in Qinghai Province, northwest China. The Brucella, Coxiella, and Theileria/Babesia species' DNA were detected by nested or hemi-nested PCR and further identified by amplifying their key genes. Brucella abortus and B. melitensis DNA were detected, with positive rates of 3.68% and 4.41%, respectively. This may be the first report that suggests that H. qinghaiensis harbors Brucella spp., the agents of human brucellosis. The Coxiella endosymbiont of Haemaphysalis qinghaiensis, a non-pathogenic Coxiella, was identified with an extremely high positive rate of 97.06%. In addition, two Theileria species, Theileria luwenshuni (75.00%) and Theileria uilenbergi (16.18%), were detected. Our results suggest the circulation of Brucella spp. and Theileria spp. in goats and sheep in the study area. Whether H. qinghaiensis ticks play a role in the maintenance and transmission of these agents has yet to be determined. Due to their human pathogenicity and their high positive rates in ticks, surveillance in local populations with relative symptoms is necessary.

Background: Although China has eliminated indigenous malaria, imported cases, particularly among young and middle-aged workers returning from Africa, constitute a major challenge for current epidemic prevention and control. In contrast, imported malaria in children is extremely rare and often subject to diagnostic delays in non-endemic areas due to atypical clinical presentations.

Case presentation: We report a case of a 2-year-11-month-old boy who returned from Sudan, a malaria-endemic region, presenting with fever and diarrhea as the initial symptoms. The case was identified by the laboratory through the blood routine re-examination rules, crucially informed by the patient's epidemiological history. The diagnosis was ultimately confirmed as Plasmodium falciparum malaria by rapid diagnostic testing and microscopic examination.

Conclusion: This diagnostic pathway exemplifies a closed-loop model of "clinical suspicion → targeted laboratory testing → definitive pathogen identification." It provides a practical framework for the early detection and diagnosis of pediatric imported malaria with atypical presentations in non-endemic areas.

Dermatomycoses pose significant zoonotic and public health challenges, involving interactions among fungal agents, host immunity, and environmental reservoirs. Eight cases of dermatophyte infection involving five humans, two cats and one dog were investigated in the Umbria region applying a One-Health approach, as recommended by the CDC. Fungal isolates were identified by mycological and molecular methods as Microsporum canis (n = 4), Nannizzia gypsea (n = 3), and Trichophyton mentagrophytes var. mentagrophytes genotype III* (n = 1). The source of infection was identified in four cases enabling the implementation of appropriate treatment, removal of fomites, and environmental sanitization; as a result, no recurrences were observed. In the remaining cases, environmental assessments showed no fungal burden, indicating likely incidental transmission. Close cohabitation or contact with cats emerged as a risk factor. The patient's medical history should always include exposure to animals in order to facilitate early recognition, correct management, and prevention. Interdisciplinary collaboration among dermatologists, veterinarians, and laboratory technicians is essential to optimize therapeutic outcomes and to prevent potential antifungal resistance phenomena. Moreover, continuous surveillance under a One-Health framework will enable better epidemiological understanding of dermatophyte species dynamics, particularly zoonotic agents.

Millions of healthcare workers experience percutaneous exposure to bloodborne communicable infectious disease pathogens annually, with the risk of contracting occupationally acquired infections. In this study, we aimed to assess the status of occupational safety and outbreak preparedness in Congolese nurses and laboratory technicians in Kongo central and the Katanga area, amidst multiple ongoing public health emergencies in the Democratic Republic of the Congo (DRC). This was a multicenter analytical cross-sectional study conducted in five referral hospitals located in Kongo central province and the Katanga area between 2019 and 2020 amidst Ebola, Yellow fever, Cholera and Chikungunya outbreaks. Participants were adult A0 grade nurses, A1 nurses, A2 nurses and medical laboratory technicians (N = 493). They answered a structured, self-administered questionnaire related to hospital hygiene and standard precautions for occupational infection prevention. The majority of the respondents were females (53.6%), and 30.1% of them have never participated in a training session on hospital infection prevention during their career. The proportions of those who have been immunized against hepatitis B virus (HBV) was markedly low, at 16.5%. Of the respondents, 75.3% have been using safety-engineered medical devices (SEDs), whereas 93.5% consistently disinfected medical devices after use. Moreover, 78% of the respondents used gloves during medical procedures and 92.2% wore masks consistently. A large majority of the respondents, 82.9%, have been recapping the needles after use. Regarding participation in outbreak response, 24.5% and 12.2% of the respondents were Chikungunya and Cholera epidemic responders, respectively; 1.8% have served in Ebola outbreak sites. The proportion of the respondents who sustained at least one percutaneous injury by needlestick or sharp device, blood/body fluid splash or both in the previous 12-month period was high, 89.3% (41.8% for injury, 59.2% for BBF event), and most of them (73%) reported over 11 events. Compared to laboratory technicians, nurses had higher odds for sustaining percutaneous injury and BBF events [OR = 1.38 (0.16); p < 0.01], whereas respondents with longer working experience were less likely to sustain those events [OR = 0.47 (0.11); p < 0.001]. Findings from this study suggest that Congolese nurses and laboratory technicians experience a high frequency of injury and BBF events at work, and remain at high risk for occupationally acquired infection. There is a need for periodic capacity-building training for the healthcare workforce to improve infection prevention in health settings, the provision of sufficient and appropriate PPE and SEDs, post-exposure follow-up and keeping records of occupational injuries in hospitals in Congolese healthcare settings.