2025年 · 第14卷第03期

The continuous geographic expansion of ticks and the emergence of tick-borne diseases have raised tremendous global public health concerns, particularly in the East African Community (EAC). This study aimed to investigate the distribution of ticks and tick-associated microbes and to predict the potential extension of dominant tick species in the EAC.

Data were collected from literature reviews and related websites and analyzed using ArcGIS to generate maps showing the geographical distribution of ticks and associated microbes. Meta-analyses were conducted to estimate the positive rates of microbes. Ecological niche modelling was used to project the potential expansion of predominant tick species.

A total of 138 tick species were recorded in the seven EAC countries, including five genera of the Argasidae family, eight of the Ixodidae family, and monospecific Nuttalliellidae. Overall, 64 tick-associated microbes, including 22 viruses, 26 bacteria, and 16 protists, were identified, of which 43 (11 viruses, 21 bacteria, and 11 protists) were pathogenic to humans or animals. Among them, 5 (2 viruses and 3 bacteria) have been reported in humans, while 10 pathogens (1 virus, 4 bacteria, and 5 protists) have been reported in animals. The predictive model identified suitable habitats for four dominant tick species, with certain species flourishing under ideal conditions, such as elevation, temperature, and vegetation. Our study revealed that ticks might affect broader areas where they have never been previously reported.

Ticks are widely prevalent in the EAC, and some ticks harbor a variety of microbial agents that can have significant pathogenetic implications for human and animal health. Therefore, EAC authorities and medical personnel should acknowledge the potential threat posed by ticks and tick-associated pathogens to the well-being of people and animals. Surveillance and etiological diagnosis should be enhanced to control ticks and prevent tick-borne infections.

Malaria continues to pose a significant health challenge, particularly in low-resource settings (LRS), where access to reliable and timely diagnostics is often limited. In this context, point-of-care (POC) in vitro diagnostics (IVDs) play a key role in supporting early detection and treatment. The aim of this scoping review was to better understand the landscape of malaria IVD technologies, with the aim of identifying both their strengths and limitations to guide and accelerate the development of POC diagnostics suitable for endemic regions and LRS. To support this analysis, the ASSURED (Affordability, Sensitivity, Specificity, User-friendliness, Rapidity, Equipment-free, Deliverability) criteria were applied to rank each technology in terms of its potential for POC applications in LRS.

A literature search was conducted in PubMed and Web of Science for original research articles on malaria POC diagnostic devices published in English over the last 20 years (2003–2023). Records were screened based on eligibility criteria. For each paper, we identified biomarkers, biological specimens used, analytical methods, and readout technologies. Each record was ranked from low to high for its compatibility with the seven ASSURED criteria and for the Technology Readiness Level.

The final dataset included 118 records. Of the methods considered, immunoassays were the most frequently reported (41.5%), followed by loop-mediated isothermal amplification (LAMP, 22.8%), polymerase chain reaction (PCR, 6.7%) and optical microscopy (4.2%). The limit of detection was highest for LAMP and PCR. Biomarkers employed for diagnosis included the Plasmodium parasite, parasite protein antigens and hemozoin. Blood was the most commonly employed biological specimen (76.2%), followed by urine and saliva (5.1 %). Despite a focus on malaria IVDs for POC applications, only 8% of the records mentioned ASSURED criteria, with most studies manifesting low compatibility with the criteria.

Although meeting the ASSURED criteria remains challenging, microscopy is still the gold standard because of its diagnostic accuracy. Recent developments in low-cost, high-magnification lenses and innovative manufacturing techniques have enabled the production of microscopy devices in LRS. Combined with advancements in image processing and shape recognition through machine learning, there is strong potential for intellectual and economic investments to enhance microscopy for POC malaria diagnostics.

Tegumentary leishmaniasis (TL) caused by Leishmania infantum is an overlooked yet re-emerging disease endemic in Mediterranean Europe. Currently, no standardized molecular surveillance of circulating Leishmania strains is performed in European endemic areas, despite the potential public health implications of parasite biodiversity. This study aims to characterize parasite population haplogroups causing TL in two active endemic areas in southern Europe, i.e. Bologna (northern Italy) and Fuenlabrada (central Spain).

In this retrospective study, we typed 87 L. infantum samples from TL cases in the areas of Bologna and Fuenlabrada; these areas hosted the main European foci of human TL occurring in the last 15 years. Two Leishmania genomic typing targets were used: the heat shock protein 70 (Hsp70) and the cysteine peptidase b (Cpb). Simpson’s index was used to calculate the discriminatory power of the used typing methods.

Typing results depicted the presence of a heterogeneous parasite population circulating in Bologna with two main haplogroups, i.e. Hsp70(A)_Cpb(F) (n = 7, 30.4%) and Hsp70(G)_Cpb(E/F) (n = 7, 30.4%), differing from the reference L. infantum strain JPCM5 haplogroup and partially overlapping with L. donovani lineages. Among the samples from Fuenlabrada, n = 19 samples were typed by both targets, revealing a homogeneous population expressing Hsp70(A) and Cpb(E), matching the JPCM5 reference strain haplogroup. Overall, the Cpb typing method exhibited higher discrimination power as compared to the Hsp70 method (Simpson’s index of diversity, P-value < 0.05).

Our findings show differences among L. infantum populations causing TL in two southern European epidemiological foci of human leishmaniasis and support the recent discovery of L. infantum/L.donovani hybrid strains circulating in northern Italy. These results underscore the critical need to identify the circulating Leishmania strains in endemic areas and assess their potential public health implications in active foci.

Schistosomiasis is a neglected tropical disease, primarily prevalent in tropical and subtropical regions. It imposes a significant health and economic burden in low- and middle-income countries, but a study of its comprehensive economic impact of the disease at the global level has not been carried out. As this is essential for evidence-based decision-making, this study aims to estimate the macroeconomic burden of schistosomiasis in 25 endemic countries.

We used a health-augmented macroeconomic (HAM) model, as well as observed data from 2010 to 2021 and projected data from 2022 to 2050, to model gross domestic product (GDP) under two scenarios: with and without schistosomiasis. The data were obtained from the Global Burden of Disease Study 2021 (GBD 2021), the World Bank database, the International Monetary Fund (IMF) database, the International Labour Organization (ILO) database, the United Nations Population Division’s World Population Prospects 2022 database, the Barro-Lee Educational Attainment dataset, the Penn World Table (PWT) database, and relevant literature. The economic burden was quantified as the difference in GDP between these two scenarios. The HAM model considered: (i) the impact of schistosomiasis mortality and morbidity on labor supply; (ii) age and gender differences in education and work experience among schistosomiasis patients; and (iii) the impact of schistosomiasis treatment costs on physical capital accumulation. To be able to compare the purchasing power of different countries, we used international dollars (INT$), a hypothetical currency unit based on purchasing power parity.

We estimated the macroeconomic burden of schistosomiasis in 25 schistosomiasis endemic countries was INT$ 49,504 million [uncertainty interval (UI): 48,668–50,339] for the study period, using a 3% discount rate in the main analysis. The result implies that the economic burden of schistosomiasis across these 25 countries during study period is equivalent to 0.0174% (UI: 0.0171–0.0177) of total GDP. Among all schistosomiasis-endemic countries included, Egypt had the largest absolute economic burden (INT$ 11,400 million, UI: 11,221–11,578), followed by Brazil (INT$ 9779 million, UI: 9717–9841) and South Africa (INT$ 6744 million, UI: 6676–6811).

The global economic burden of schistosomiasis remains substantial and is inequitably distributed among countries and regions. Our study highlights the need for increased investment and global collaborative efforts to control schistosomiasis and its associated health and economic burdens. By advancing the elimination of schistosomiasis, substantial economic returns can be achieved.

The seasonal cycle of the influenza virus causes substantial morbidity and mortality globally. The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the circulation of influenza viruses can influence influenza-associated excess mortality. Given the few studies that have explored this topic, the objective of this study was to evaluate influenza-associated excess mortality in the Chinese mainland from 2012 to 2021 and quantify the changes from 2020 to 2021 compared with 2012–2019.

Using data from national influenza surveillance report and disease surveillance points, we fitted a generalized additive model on all-cause (AC), pneumonia & influenza (P&I), and respiratory (R) mortality rates. In this model, we included data of influenza activity (A/H1N1, A/H3N2 and B), temperature, absolute humidity, the COVID-19 pandemic, and time trends. The excess mortality was estimated by subtracting the fitted baseline mortality from the predicted mortality, which set influenza activity to zero.

The respiratory mortality model explained more than 90% of the variance, indicating the good performance. We found that the influenza-associated mortality was generally decreasing from 2020 to 2021, for instance, influenza A/H1N1-associated excess respiratory mortality (ERM) decreased from 2.62 per 100,000 persons (95% confidence interval: 0.16–5.21) to 0.31 (0.02–0.60) in the northern region and from 3.79 (0.09–7.05) to 0.24 (0.02–0.46) in the southern region between 2012–2019 and 2020–2021. A similar pattern was observed for A/H3N2-associated ERM. While the influenza B remained similar scale, for instance, the ERM was 2.90 (0.72–4.3) and 2.26 (1.76–2.76) in the southern region between 2012–2019 and 2020–2021, respectively. Distinct pattern was observed for the AC and P&I outcomes.

The COVID-19 pandemic has reduced influenza-associated excess mortality, which may be a result of the reduced activity of the influenza virus caused by nonpharmaceutical interventions. Different patterns of regional differences differed for influenza-associated AC, P&I and R mortality. It should be noticed that the contribution of influenza B was generally similar when comparing 2012–2019 and 2020–2021, which highlighted the attention on the influenza B activity. Additional studies are needed to explore the changes in influenza-associated excess mortality afterwards.

Despite being key components of global tuberculosis policy, poverty reduction and social protection interventions have been inconsistently implemented. We aimed to characterise how poverty and interrelated personal risk factors increase tuberculosis risk in Peru to inform the design of locally appropriate, person-centred, equity-oriented interventions.

We undertook a case-control study among people aged 15 years and over in 32 communities in Peru between 2016 and 2019. Cases (n = 2337) were people diagnosed with any form of tuberculosis. Controls (n = 981) were people living in randomly selected households in the same communities. We derived measures of household poverty from three dimensions (physical, human, and financial capital) and investigated the associations between these; personal risk factors more specifically linked to health (e.g. smoking); and tuberculosis. We used logistic regression to calculate adjusted odds ratios (aOR), 95% confidence intervals (95% CI), and population attributable fractions (PAF). A directed acyclic graph was used to inform the analytical approach.

Household poverty was strongly associated with tuberculosis (aOR = 3.1; 95% CI: 2.3–4.2 for people from the 'poorer’ versus 'less poor’ half of households). There was a non-linear social gradient across deciles of household poverty, with odds of tuberculosis increasing exponentially as poverty deepened (aOR = 12.6; 95% CI: 6.8–23.2 for the 'poorest’ decile versus the 'least poor’ decile). Overall, tuberculosis burden could be halved by reducing poverty in the 'poorer’ half of households to the level of the 'less poor’ half (PAF = 47%; 95% CI: 40–54). For key personal risk factors, we estimated PAF for alcohol excess (PAF = 12.3%, 95% CI: 7.2–17.2); underweight (PAF = 10.3%, 95% CI: 8.7–11.8); smoking (PAF = 8.8%, 95% CI: 3.8–13.5); HIV (PAF = 5.7%, 95% CI: 4.6–6.7); and diabetes (PAF = 4.6%, 95% CI: 3.3–6.0). We also identified other important risk factors including previous tuberculosis (PAF = 14.8%, 95% CI: 11.6–17.9); incarceration (PAF = 9.5%, 95% CI: 6.8–12.1); and lower social capital (PAF = 4.1%, 95% CI: 2.6–5.6). Most personal risk factors, particularly education and substance misuse, tuberculosis exposures (e.g. incarceration and homelessness), and undernutrition, exhibited a social gradient across quintiles of household poverty and were more prevalent in people living in poorer households (Cochran-Armitage test for linear trend P < 0.001 for variables showing these social gradients).

Interventions addressing multidimensional household poverty and interrelated personal risk factors could substantially reduce tuberculosis burden. Our results provide an evidence base for designing person-centred, equity-oriented interventions; and support more effective implementation of poverty reduction and social protection within the global tuberculosis response.

The rapid increase in the number of monkeypox cases poses a considerable threat to the international community, necessitating sensitive, fast, and available diagnostic methods. Therefore, the objective of this study was to develop a rapid, sensitive and simple method with high clinical applicability.

We developed a simple, rapid point-of-care assay to detect monkeypox virus (MPXV) using multienzyme isothermal rapid amplification (MIRA) coupled with the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas13a system. The detection system was optimized by synthesizing plasmids, and the detection sensitivity was explored by the continuous dilution of the plasmid. We validated the accuracy of this assay on 202 clinical MPXV samples and 104 interference samples through the kappa test. The visual interpretation of the results was realized by combining the assay with lateral flow strips. In addition, we developed a PCR-based method to identify MPXV Clades I and II, and the accuracy was tested through a kappa test on 202 clinical monkeypox samples and 104 interference samples.

Our assay achieved an analytical sensitivity of 14.4 copies/ml and high selectivity, as it differentiated MPXV from three other Orthopoxvirus species. The clinical testing results for 202 monkeypox samples and 104 interference samples demonstrated 100% sensitivity and specificity. Compared with quantitative PCR (qPCR), three samples tested as positive using our assay, which showed that the performance of this assay was superior to that of the qPCR assay. Combined with lateral flow strips, its availability and simplicity provide an alternative point-of-care diagnostic method for MPXV testing in remote settings and resource-poor areas. The results of 32 clinical samples showed that lateral flow strips had a high detection sensitivity and could identify samples with Ct value of 39 as positive. The clade identification assay detected as few as 200 copies/ml within 40 min and no cross-reaction was observed between Clades I and II. The clinical samples tested were all Clade II, which was consistent with the circulating clade in the Chinese mainland.

The MIRA-CRISPR-Cas13a-MPXV system offers a rapid, sensitive and specific approach for monkeypox diagnosis, with significance for monitoring monkeypox epidemics. The clade identification assay based on PCR could accurately distinguish Clade I from Clade II within 40 min and can be implemented for high-throughput operation.

Echinococcosis remains highly endemic in some nomadic communities on the Qinghai-Tibet Plateau, China, where alveolar echinococcosis (AE) and cystic echinococcosis (CE) exhibit notably high prevalence rates of 3.64% and 2.37%, respectively. Recent settlement expansion in the region has raised concerns, as smaller, remote settlements often lacked waste disposal and sewage systems, potentially facilitating echinococcosis transmission. The aim of this study is to investigate how settlement characteristics influence echinococcosis transmission.

The study was conducted from 2022–2024 in nomadic communities of Shiqu County in China. The overall prevalence rate of echinococcosis in 51 settlements was found to be 2.34% (321/13,701; 95% CI: 2.10–2.61), which included a prevalence rate of 1.62% (222/13,701; 95% CI: 1.42–1.85) for AE and a prevalence rate of 0.72% (99/13,701; 95% CI: 0.59–0.88) for CE. The prevalence rate of AE was significantly (χ² = 49.57, P < 0.01) higher than that of CE. Settlements with a smaller population size (Z = -4.27, P < 0.01), a greater distance to the township center (Z = 2.66, P < 0.01) and a higher density of owned dogs (Z = 5.90, P < 0.01) were associated with higher prevalence rates of CE. These associations were also observed for AE prevalence, except for the density of owned dogs.

This study indicates that the transmission of AE was more active than that of CE in the nomadic communities. Smaller, remote settlements had higher prevalence rates for both CE and AE. The density of owned dogs was a significant risk factor for CE prevalence but not for AE prevalence. Targeted interventions are needed in these high-risk settlements. Future research should investigate how settlement characteristics interact with hygiene practices, the infection status of intermediate and definitive hosts, and their population dynamics to better understand combined effects on echinococcosis prevalence.

Human babesiosis, caused by intraerythrocytic protozoa of the genus Babesia (Piroplasmida, Babesiidae), is a globally emerging zoonosis transmitted primarily through Ixodes spp. ticks. Babesia microti, which is endemic particularly in the northeastern and midwestern United States, accounts for the majority of globally reported human cases. Recent studies highlight its spread to non-traditional regions and cross-border transmission, driven by climate change, blood transfusions and increased human mobility. Despite increasing reports of autochthonous B. microti infections in certain areas of China, imported cases remain critically underrecognized due to overlapping clinical manifestations with malaria and limited diagnostic awareness.

We report a diagnostically challenging case of acute B. microti infection in a 52-year-old Chinese woman, presenting with a sudden recurrent fever (39.0–41.0 °C), hemolytic anemia (hemoglobin 104 g/L), thrombocytopenia (platelet 78×10⁹/L) and splenic hypodense lesions on July 11, 2023, seven days after returning from a 14-day visit to rural Wisconsin, United States. Peripheral blood smears demonstrated characteristic intraerythrocytic ring forms (parasitemia: 7800 organisms/μl) and pathognomonic "Maltese cross" tetrads. Polymerase chain reaction (PCR) targeting the 18S rRNA gene confirmed B. microti infection (GenBank No. PP087232), showing 99.8% identity with the US-type strain Gray (AY693840) and the sequence obtained from a US travel-acquired case in Singapore (MK609547). The patient received intravenous clindamycin (600 mg twice daily), oral dihydroartemisinin (80 mg twice daily), packed red blood cell transfusions, and supportive care, ultimately achieving full recovery after 17 days.

This study documented the first imported cases of human babesiosis in China, emphasizing the need for heightened clinical and public health vigilance. Screening travelers from endemic areas presenting with fever or hemolytic anemia for Babesia, bolstering molecular diagnosis, improving transfusion safety, and intensifying regional surveillance are crucial in reducing underdiagnosis and preventing transmission. These measures are essential for controlling babesiosis in China.