Journal of Tropical Medicine最新文献

Malaria disease is a major health issue in Ethiopia, affecting three-fourths of the country's land area and more than two-thirds of the population living below 2000 m altitude. Over 42 Anopheles species have been identified in the country, but Anopheles arabiensis was the only major malaria vector, accounting for the majority of illness and mortality. However, there is a new invasive malaria vector, Anopheles stephensi, which is strikingly similar to the primary vector. This species transmits both Plasmodium falciparum and Plasmodium vivax and has gained resistance to all four types of insecticides, such as A. arabiensis. Plasmodium falciparum and Plasmodium vivax accounted for the majority of malaria cases in the country. However, these species have evolved resistance to several antimalarial medications throughout the country, adding to the burden. Furthermore, the country has just had a long civil war, which has resulted in an alarming spike in malaria cases throughout the country. Even in a few regions, such as Amhara and Oromo, the disease is spreading rapidly and beyond the control of regional health bureaus. All of these issues constitute major impediments to the country's malaria elimination aim. This article provides a comprehensive summary of the status of new and invading species, the status of insecticide-resistant malaria vectors, the ranges of drug-resistant Plasmodium species, the impacts of neglected Plasmodium vivax, and the impacts of civil war on Ethiopia's malaria elimination aim.

Background: Understanding the immune pathogenesis mechanisms of leishmaniasis is crucial for developing effective therapeutic interventions. In this study, we investigated the effect of ivermectin (IVE) on the expression of transcription factors GATA-binding protein 3 (GATA-3), T-bet, and ROR-γt as well as wound healing Leishmania infection. Methods: Leishmania promastigotes were subcutaneously inoculated into the tail base of BALB/c mice (n = 10 per group) who later received phosphate-buffered saline (PBS), IVE, Glucantime, or a combination of IVE and Glucantime as soon as wounds developed, approximately three weeks' postinfection. The treatment continued daily for 2 weeks. The diameter of the wound was measured weekly over 6 weeks. In addition, in the sixth week, the mRNA expression of T-bet, GATA-3, and ROR-γt in splenic T cells was assessed through real-time PCR analysis. Results: The findings of this research indicated a significant reduction in the lesion size among the treated groups compared with the control group (p < 0.05). IVE had a similar effect to Glucantime in reducing wound diameter (p > 0.05). Furthermore, the combined use of Glucantime and IVE led to the most reduction in the lesion size among all groups. The treated groups exhibited higher expression levels of T-bet and ROR-γt and lower levels of GATA-3 compared with the control group (p < 0.05). Conclusion: IVE has shown significant efficacy in accelerating the healing process of wounds related to leishmaniasis. In addition, the administration of this medication has triggered a strong immune response, marked by activation of T helper 1 (Th1) and Th17 cells while also modulating Th2 responses.

Background: Q fever is a zoonotic bacterial infection with worldwide distribution. Based on seroepidemiology studies among the human population and also serological and molecular surveys of animals, Q fever is an endemic disease in Iran. However, the status of acute Q fever in many parts of Iran is still unknown. This study aimed to investigate acute Q fever among high-risk patients with fever and pneumonia symptoms in Western Iran. Methods: In this survey, 96 patients were included in the study in Kurdistan Province who had symptoms of suspected pneumonia or acute Q fever and epidemiological evidence for the risk of Q fever. From each individual, paired acute and convalescent serum samples were taken, and the elevation of the phase II IgG antibody titer against Coxiella burnetii was traced by ELISA. Also, molecular detection of C. burnetii was done in acute blood samples by real-time PCR. Results: Seven patients (7.3%) were diagnosed with acute Q fever who had seroconversion and a four-fold rise in the phase II IgG antibody titer against C. burnetii in their paired sera samples. Also, 22 of 89 (24.7%) individuals with a negative result for acute Q fever had a previous history of exposure to C. burnetii. There was a significant relationship between sheep husbandry and a previous history of exposure to C. burnetii (p=0.04). All molecular tests were negative. Conclusion: The results of this study showed that there are cases of acute Q fever in Western Iran, but it is not considered by the healthcare system or clinicians.

Background: Intestinal parasitic infections (IPIs) are a persistent public health challenge in low- and middle-income countries, particularly among school-aged children. Objective: This study aimed to compare IPI prevalence and risk factors before and after the COVID-19 pandemic in Eswatini, based on the hypothesis that pandemic-related disruptions may have influenced infection dynamics, despite no formal interventions being introduced. Methods: A prospective cohort of 128 schoolchildren from Manzini and Lubombo Provinces was followed from 2019 to 2022. Stool samples were analyzed using the merthiolate-iodine-formaldehyde (MIF) method. Structured interviews assessed hygiene behaviors and household factors. Logistic regression was used to identify associations with infection risk, reported as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results: Overall, IPI prevalence remained consistent (43.0% in 2019 vs. 42.2% in 2022), with protozoan infections predominating and helminth infections remaining low (1.6% in 2019 and 2.4% in 2022, respectively). In 2022, children with only one employed parent had significantly higher odds of IPIs (aOR = 3.97; 95% CI: 1.48-10.64; p=0.006) and pathogenic protozoan infections (aOR = 4.33; 95% CI: 1.41-13.27; p=0.01). Handwashing before meals was protective in 2019 (aOR = 0.10; 95% CI: 0.02-0.58; p=0.01) but not significant in 2022. Notably, Giardia intestinalis infections declined, while Blastocystis hominis increased. Conclusion: The stable infection rates and changing species composition suggest that pandemic-associated shifts in behavior and public health disruptions may have influenced IPIs' epidemiology. Continued surveillance and targeted hygiene interventions are needed to mitigate the burden of IPIs in schoolchildren.

Current French guidelines on the diagnosis of dengue infection recommend both nucleic acid testing and serology as tools for laboratory confirmation. This study aimed to evaluate the performance of the fully automated Virclia IgM assay for the diagnosis of dengue infection. Samples from patients with a suspicion of dengue were prospectively tested using the Virclia Dengue IgM assay (Vircell) and subsequently underwent additional investigations (dengue RT-PCR and conventional dengue IgM EIA) at the French Reference Center for Arboviruses. A total of 104 patients were included with a median age of 34.3 years old and a median time since symptom (TSS) of 6 days. Dengue RT-PCR was positive in 57 patients (54.8%). The agreement was excellent (90.5%; κ = 0.81) between RT-PCR and Virclia Dengue IgM assay on samples collected from Day 5 postsymptom onset. On these samples, the sensitivity and specificity of the Virclia IgM assay were 95.7% (95% CI: 84.7%-96.9%) and 96.4% (95% CI: 80.8%-100%), respectively. In addition, the agreement was also excellent between the Virclia Dengue IgM assay and the Euroimmun plate-based Dengue IgM ELISA (92.7%; κ = 0.85). In conclusion, the Virclia Dengue IgM assay showed a good performance in the diagnosis of dengue infection and can be recommended in addition to nucleic acid testing to broaden the diagnostic window. The automation coupled with the monotest format is well-adapted for nonendemic areas.

Background: Although MMR vaccination can induce mumps infections, clustered cases right after the vaccination are rarely reported. On September 10, 2024, the Department of Disease Control, Thailand, received a report of a cluster of practical nursing students (PNSs) with jaw and ear swelling following an MMR (L-Zagreb strain) vaccination. An investigation was conducted to confirm the outbreak, identify sources and risk factors, and recommend preventive measures. Methods: Active case findings were conducted among PNS and hospital service recipients who received the suspected vaccine batches. Suspected cases of MMR-related mumps infection were defined as individuals experiencing either jaw swelling/pain, testicular swelling/pain, or groin pain 12-25 days postvaccination. Confirmed cases had positive RT-PCR for mumps. SH gene sequencing determined mumps phylogenetics, while nanopore sequencing of the NP gene assessed polymorphisms. Group and in-depth interviews with vaccine suppliers, pharmacists, nurses, and PNS evaluated the vaccine cold chain and setting. A retrospective cohort study among PNS used questionnaires on demographics and vaccination history to identify risk factors, analyzed via multivariable logistic regression. Qualitative data underwent content analysis. Results: Two batches of MMR vaccine were suspected and immediately suspended. Of the 108 vaccinated PNS, 12 met the case definition (eight suspected and four confirmed), yielding an attack rate of 11.1% (12.5% in males and 10.9% in females). Among 61 hospital vaccine recipients who received the same vaccine batches, 30 were contactable, and none met the case definition. All cases had ear/jaw pain, with 41.7% experiencing sore throats and 33.3% myalgia, though none were severe. Three confirmed cases had genetic material aligning with the L-Zagreb strain (Accession AY685920). No NP gene polymorphisms were detected in vaccines, though specimen buccal swabs had insufficient genetic material. Two factors may link to the adverse event: prior MMR vaccination (aOR = 12.90, 95% CI: 1.39, 172.00) and a delay of over 15 min from vial retrieval to administration (aOR = 26.90, 95% CI: 4.20, 247.00). Vaccine supply, distribution, and storage met standards, but vaccine campaign registration and waiting time processes require improvement. Conclusion: MMR-related mumps infections were confirmed during PNS mass vaccination campaign. Potential risk factors include a history of prior MMR vaccination and delay time from vial retrieval to vaccine administration. Improvements are needed in vaccination campaigns, particularly in the registration system and expediting vaccination process flow.

Soil-transmitted helminth (STH) infections are the most common parasitic infections worldwide, particularly in tropical regions. There are currently no reports on the prevalence of STH infections among children in Koh Yao District of Phang Nga Province, Thailand. Therefore, this study aims to assess the prevalence of STH infections and associated risk factors among primary schoolchildren. A school-based cross-sectional study was conducted among 243 schoolchildren aged 7 to 12 years from 12 rural primary schools across three subdistricts. Demographic data and associated risk factors were collected and analyzed. Stool samples were collected and examined for parasites using the formalin-ethyl acetate sedimentation concentration and the modified Kato-Katz methods. A multivariate logistic regression analysis was used to determine the strength of the relationship between risk variables and STH infections. Of the 243 participants (mean age: 8.99 ± 1.57 years), 12 (4.94%, 95% CI: 2.60%-8.50%) were infected with STH. The most common STH infection was hookworm (4.11%), followed by Trichuris trichiura (1.65%). More than 80% (n = 10, 83.33%) had a single intestinal parasite, while two (16.67%) were coinfected with two parasitic species. Infections were more prevalent among males (66.67%) compared to females (33.33%). Multiple regression analyses revealed that children above Grade 3 had a significantly higher prevalence of STH infections compared to those below Grade 3 (adjusted odds ratio [AOR] = 10.54; 95% CI: 1.24-89.14, p = 0.031). Open defecation was also statistically associated with STH infections (AOR = 22.66; 95% CI: 1.18-433.58, p = 0.038). This study highlights a low prevalence of STH infections in the study area, with hookworm being the most common. The potential risk factors identified were linked to educational level and open defecation practices. Improving sanitation and enhancing health education to raise public awareness about hygiene are essential strategies for controlling STH infections among primary schoolchildren in remote areas.

Background: Antimicrobial resistance (AMR) is a major global threat to public health and development. The emergence of drug-resistant pathogens compromises the effectiveness of current treatments and necessitates the discovery of new antimicrobial agents. Objective: This study aims to evaluate the antimicrobial potential of Toxocara canis adult and larval somatic and excretory-secretory (ES) antigens against common bacterial pathogens, including Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Salmonella enterica. Methods: Adult Toxocara canis worms were collected and dissected to obtain somatic antigenic proteins. Larval somatic and ES antigenic proteins were prepared from hatched eggs. The antimicrobial activity of these antigens was evaluated using susceptibility assays and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. High-performance liquid chromatography (HPLC) was used to investigate the possible bactericidal properties in comparison with standard tetracycline antibiotics. Results: The somatic antigenic proteins of adult and larval T. canis worms and larval ES antigens showed effective antimicrobial potential against Staphylococcus aureus, but not against the other 3 bacteria. HPLC analysis suggested that the bactericidal properties of these proteins may be close to that of tetracycline antibiotics because of the similar retention time. Conclusion: The preliminary study provides evidence of the antimicrobial properties of different stages of T. canis antigens, offering potential new solutions to combat AMR. Further research is needed to elucidate the mechanisms of action and assess the clinical applications of these antigenic proteins.

Background: Utilization of video capsule endoscopy (VCE) for the evaluation of small bowel disease is limited in Africa. The predominant causes of gastrointestinal disease in this region are infectious, but the prevalence of inflammatory bowel disease and malignancies is rising. We sought to evaluate the indications and outcomes of VCE in sub-Saharan Africa. Methods: We conducted a retrospective study at an outpatient gastroenterology center in Nairobi, Kenya. Data collected included demographics of the study population, procedure indication, prior investigations, findings, and complications of VCE. Descriptive statistics were used to analyze the results, and statistical analysis of association was performed using Fischer's exact test; a p value of less than 0.05 was considered significant. Results: A total of 72 patients underwent VCE from January 2017 to April 2022. The mean age was 59.1 years (range: 15-91); 61.7% were males. A total of 97.2% of the patients had a preceding upper and lower endoscopy. The indications were obscure gastrointestinal bleeding (GIB) in 51.4%, anemia (15.5%), abdominal pain (25.4%), altered bowel habits (23.9%), weight loss (9.9%), and suspected Crohn's disease (7.0%). The overall diagnostic yield was 77.1% and included angiodysplasia (14%), duodenitis (10.7%), mass/polyps (8.9%), suspected intestinal tuberculosis (7.1%), and helminths (2.8%). Angiodysplasia was the most common cause of GIB, accounting for 35.3% and 35.0% of occult and overt bleeding, respectively. Capsule retention occurred in 2 patients (2.8%). Conclusions: There are similarities in indications and preceding workup in our cohort compared to existing literature from Western and Asian countries. Infectious causes of GIB were unique to our study.

[This corrects the article DOI: 10.1155/2021/6273954.].