Journal of Tropical Medicine最新文献

Background: A diverse range of pollutants, including heavy metals, agrochemicals, pharmaceutical residues, illicit drugs, personal care products, and other anthropogenic contaminants, pose a significant threat to aquatic ecosystems. The Winam Gulf of Lake Victoria, heavily impacted by surrounding human activities, faces potential contamination from these pollutants. However, studies exploring the presence of antibiotic resistance genes (ARGs) in the lake remain limited. In the current study, a shotgun metagenomics approach was employed to identify ARGs and related pathways. Genomic DNA was extracted from water and sediment samples and sequenced using the high-throughput Illumina NovaSeq platform. Additionally, phenotypic antibiotic resistance was assessed using the disk diffusion method with commonly used antibiotics. Results: The analysis of metagenomes sequences from the Gulf ecosystem and Comprehensive Antibiotic Resistance Database (CARD) revealed worrying levels of ARGs in the lake. The study reported nine ARGs from the 37 high-risk resistant gene families previously documented by the World Health Organization (WHO). Proteobacteria had the highest relative abundance of antibiotic resistance (53%), Bacteriodes (4%), Verrucomicrobia (2%), Planctomycetes Chloroflexi, Firmicutes (2%), and other unclassified bacteria (39%). Genes that target protection, replacement, change, and antibiotic-resistant efflux were listed in order of dominance. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed antibiotic resistance to beta-lactamase and vancomycin. Phenotypic resistance to vancomycin, tetracycline, sulfamethoxazole, erythromycin, trimethoprim, tetracycline, and penicillin was reported through the zone of inhibition. Conclusions: This study highlights that the Winam Gulf of Lake Victoria in Kenya harbors a diverse array of antibiotic-resistant genes, including those conferring multidrug resistance. These findings suggest that the Gulf could be serving as a reservoir for more antibiotic-resistant genes, posing potential risks to both human health and aquatic biodiversity. The insights gained from this research can guide policy development for managing antibiotic resistance in Kenya.

Malaria remains a significant global health challenge, with the deadliest infections caused by Plasmodium falciparum. In light of the escalating drug resistance and the limited effectiveness of available vaccines, innovative treatment approaches are urgently needed. This study explores the potential of the probiotic Limosilactobacillus fermentum YZ01, isolated from traditionally fermented kindirmo milk, to modify host responses to Plasmodium berghei ANKA infection. Twenty-five male BALB/c mice were grouped and administered various treatments, including probiotic-enriched yogurt alone or in combination with antibiotics. Parameters assessed included gut lactic acid bacteria (LAB) composition, parasitaemia progression, survival rates, and immune response dynamics over a 21-day postinfection period. The probiotic treatment significantly altered gut microbiota, evidenced by increased LAB counts and modulated immune responses, notably enhancing IgM and IL-4 production while reducing IFN-γ levels. Mice receiving prolonged probiotic treatment exhibited delayed parasitaemia onset, reduced mortality rates, and a more robust immune response compared to control groups. These outcomes suggest that probiotic intervention not only tempers the pathological effects of malaria but also enhances host resilience against infection. This study underscores the role of gut microbiota in infectious disease pathogenesis and supports probiotics as a promising adjunct therapy for malaria management.

Enteric fever is a significant health problem in developing countries caused by Salmonella enterica serovars Typhi and Paratyphi. Unfortunately, the burden of the disease remains high not only because of the complications related to the disease but also, especially, because of the spread of the strains of Salmonella resistant to antibiotics. The aim of the present study was to evaluate the antibiotic resistance patterns of Salmonella Typhi and Paratyphi clinical isolates as well as the risk factors associated with infection. This cross-sectional study was conducted from June 2020 to September 2021. One thousand and seventy-six patients in the age range (1- ≥ 50 years) were recruited including 423 (39.31%) infected with S. Typhi, 115 (10.68%) infected with S. Paratyphi, and 538 (50%) noninfected after obtaining their informed consent using a face-to-face interview and questionnaire. The stool samples were collected in clean and sterile boxes reserved for this purpose and were cultured. Demographic parameters such as sex, age, occupation, water source, level of education, as well as clinical signs and symptoms were obtained. The resistance profile determination was carried out by the disk diffusion method. A multivariate logistic regression analysis was performed to identify factors associated with infection. Results of multivariate logistic regression analysis showed positive and significant associations (OR > 1; p < 0.05) between enteric fever and women among the age groups: 1-10 years, 11-20 years, and 21-30 years. These positive associations were also noted in patients who ate shellfish, salads, fruits, and vegetables; in patients who consumed ice cubes; as well as those who consumed food and drinks offered by ambulant merchants. This indicated that they are more likely to be infected by S. enterica than others. The level of multidrug-resistant (MDR) S. enterica to first-line antimicrobial agents ampicillin, chloramphenicol, and co-trimoxazole was high and selectively distributed according to age groups, marital status, profession, level of education, source of water, and lifestyle. The results highlighted the emergence of MDR S. enterica isolated in the study population, demonstrating resistance to first-line drugs, fluoroquinolones, and third-generation cephalosporins. Further studies with large-scale samples are needed to validate the present results and to monitor MDR S. Typhi and S. Paratyphi serovars in other parts of Cameroon.

Snakebites are a significant health issue, especially in tropical and subtropical regions. Envenomation from snakebites is a clinical emergency requiring prompt treatment. Recently, a new species of blunt-nosed viper, Macrovipera razii, was identified in central and southern Iran through morphological and molecular studies. This large, dangerous viper can deliver substantial amounts of venom. Following reports to the Faculty of Health at Shiraz University of Medical Science (SUMS), the identification of venomous snakes involved in envenomation cases in Fars province was undertaken. Approximately 20 snakes were captured and presented by locals, while others provided photos. Despite some information being photo-based, the data highlighted the significant role of this viper in envenomation cases. Macrovipera razii is now recorded from 12 counties in Fars province. One incident involved a male bitten in Shiraz, and another case led to a male needing limb amputation. This study emphasizes the importance of this newly described viper in recent snakebite envenomations in the region and reviews its distribution within the Fars province.

Background: Visceral leishmaniasis (VL) is one of the public health issues in some areas of Ethiopia, and over 3.2 million people are at risk with an estimated 4000 new cases occurring each year in the country. This study was conducted to determine the prevalence of VL and its associated risk factors in Addis Zemen Health Center, Northwest Ethiopia. Methods: Data were collected from Addis Zemen Health Center and meteorological office in Addis Ababa from 2012 to 2016. Univariate and multivariate analyses were conducted to identify the determinants of VL. According to the result obtained from the retrospective data analysis, a total of 4100 suspected VL patients diagnosed by rk39 in Addis Zemen Health Center from Libokemkem and nearby districts. Results: The overall prevalence of VL among study participants were 30% (1230/4100). Of this, the prevalence of VL among male and female study participants was 86.8% and 13.2%, respectively. The proportion of sex infected by VL was 3.26 times higher in male than female (AOR = 3.26, 95% CI: 2.42-4.40). The risk of acquiring VL in those people living in rural area was 62% more likely than those residing in urban (AOR = 1.62, 95% CI: 1.29-2.04). People that were traveled to the endemic area of VL were 18.44 times more likely to be affected than the people who have not traveled once (AOR = : 18.44, 95% CI: 14.49-23.47). Age, sex, residence, season, travel history to endemic areas, and mean monthly precipitation were found to be statistically significant for VL at 5% significance level. Conclusion and Recommendation: The prevalence of VL in the present study was high with the highest prevalence in the rural areas. Therefore, there is a need of the immediate establishment of sound control and prevention program in rural areas.

Malaria remains a critical global health issue, particularly in tropical and subtropical regions. The disease, caused by Plasmodium parasites, is transmitted by Anopheles mosquitoes and can lead to severe complications and death if untreated. The emergence of drug-resistant strains highlights the urgent need for new antimalarial agents. Gnetum gnemon, a plant native to Southeast Asia, has shown promise due to its rich bioactive compounds. This study aims to evaluate the suppressive, curative, and prophylactic antimalarial potential of Gnetum gnemon leaf extract (GGE) against Plasmodium berghei in mice. GGE was prepared using a combination of hot water extraction and microwave-assisted heating. Acute toxicity tests revealed no significant adverse effects at a dose of 3000 mg/kg. The doses of 100, 200, and 400 mg/kg were selected based on preliminary toxicity assessments to systematically investigate the dose-dependent antimalarial efficacy of the extract. Suppressive tests showed that GGE at doses of 100, 200, and 400 mg/kg significantly reduced parasitemia levels, with the highest dose achieving a 63.97% inhibition. In these tests, GGE also increased the mean survival time (MST) of treated mice compared to untreated controls. However, GGE did not exhibit significant curative effects, as parasitemia levels in the treated groups were similar to the untreated control group. Prophylactic tests indicated that GGE pretreatment did not significantly reduce parasitemia levels or improve MST compared to controls, unlike chloroquine (CQ), which demonstrated potent prophylactic efficacy with a significant increase in MST. These findings suggest that while GGE has notable suppressive antimalarial activity, it does not exhibit strong curative or prophylactic effects at the tested doses. This study contributes to the understanding of plant-based antimalarial agents and underscores the importance of continued exploration of natural products for malaria treatment.

Cholera, an intestinal infection caused by Vibrio cholerae, poses a severe threat to public health, particularly in developing countries. This narrative review discusses drivers for cholera outbreaks, challenges and viable alternatives, in Zimbabwe. A literature search was conducted using electronic databases notably ScienceDirect, Google Scholar and PubMed, as well as thesis and conference papers. Evidence indicates that the epidemiology, as well as risk factors, includes (1) extreme droughts; (2) political meddling in health issues and water supply; (3) natural disasters; (4) migration; (5) problems with water and sanitation; and (6) the endemic nature of the causative agent as well as its development of drug resistance. Reliable supply of clean water and proper sanitation and hygiene as the main key to prevention is emphasised. The use of antibiotics and vaccines for therapy, as well as the use of medicinal plants in traditional medicine, is discussed. Kirkia acuminata and Ziziphus mucronata root and stem bark infusions or decoctions were revealed to be the most common folklore treatments for cholera in rural communities. The potential of medicinal plants as anti-Vibrio cholerae remedies based on their positive antibacterial assays, and mechanism of action is also presented. Finally, the development of innovative anti-Vibrio cholerae therapeutics based on natural leads and compounds and adapted for use in resource-constrained cholera-prone areas is viewed as a potential option, to complement cholera prevention and treatment, particularly in resource-limited endemic areas.

Strongyloides stercoralis is a soil-transmitted helminth which is distributed predominately throughout tropical and subtropical regions and is considered a neglected tropical disease. Due to low larval output, traditional microscopic methods lack sensitivity, especially in areas of low endemicity. Serological assays present an opportunity to study the epidemiology of S. stercoralis in areas of low endemicity such as Jamaica. The current study evaluated the seroprevalence of S. stercoralis in a selected subpopulation in Jamaica. An analysis was conducted on 311 archived serum samples previously submitted for investigating viral infections during a fever epidemic between 2014 and 2015. Randomly selected, anonymized sera were tested for the presence of S. stercoralis IgG antibodies using the AccuDiag Strongyloides IgG ELISA Kit. Data including age, sex, clinical diagnosis, and the geographic location of sample submission were recorded to delineate trends in demographic variables. The seropositivity rate of S. stercoralis was 15.43%. The rate among females and males was 16.45% and 14.47%, respectively (χ ² = 0.2339, p=0.629). The highest rate was found in middle adulthood (31-50 years) (26.53%; 13/49). The seroprevalence of S. stercoralis was significantly highest in a rural Regional Health Authority (33.33%; 14/42) and least within an urban Health Authority (9.71%; 17/175). Exposure to S. stercoralis appears to be highest in the rural Regional Health Authorities with an island-wide exposure rate of 15.43%. The rapid ELISA testing method for the detection of IgG antibodies to S. stercoralis used in this study may be useful as part of a combined approach to elucidate the epidemiology of this soil-transmitted parasite in Jamaica.

Cryptosporidium infection is highly prevalent among immunocompromised patients with Acquired Immunodeficiency Syndrome, cancer, primary immunodeficiency, and organ transplant recipients. Comprehensive knowledge about Cryptosporidium infection provides the means for efficient diagnosis, treatment, and prevention. Therefore, with the objective of providing an in-depth analysis of Cryptosporidiosis in immunocompromised patients, this review presents a comprehensive understating of the prevalence, risk factors, pathophysiology of Cryptosporidium infection, clinical presentation in the immunocompromised, the immune response of the host, diagnostic methods performed in laboratory settings, possible treatments, and prevention methods, which can be used for further studies. Peer-reviewed, published, original articles on cryptosporidiosis in immunocompromised patients were searched using specific key-words on PubMed, ResearchGate, Google Scholar, and ScienceDirect databases. Articles which were accessible to the date of 18^th of August 2023, were included in this comprehensive review. We analyzed reports on Cryptosporidium in immunocompromised patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), cancer, primary immunodeficiency, and organ transplant recipients. 134 Articles describing epidemiology, related risk factors, clinical presentation, diagnosis, and possible treatments in the light of pathogenesis, pathophysiology, and virulence factors of Cryptosporidium and immunology of the host are summarized in this study. Effective treatments to be administered, importance, and ways of prevention were identified. Cryptosporidium infection was found to be highly prevalent among immunocompromised in Asia, Africa, Europe, and North America. The immunity of the host and the decrease in CD4⁺ T-cell count were found to the main factors which decide the susceptibility and the severity of infection. Drugs that activate host immunity and suppress Cryptosporidium growth, along with supportive therapy, is an effective treatment. But prevention is the most effective strategy for immunocompromised patients; thus, a better understanding about the disease would lead to effective prevention.

Background: Rapid diagnostic tests (RDTs) targeting pfhistidine-rich protein 2 (Pfhrp2) are widely used for diagnosis of Plasmodium falciparum infections in resource-limited malaria endemic countries. However, test results are affected by deletions of the Pfhrp2, Pfhrp3, and flanking genes and associated negative results from rapid diagnostic devices were previously reported. Therefore, the aim of this study was to reveal the existing genetic profile of Pfhrp2 and Pfhrp3 genes of P. falciparum-infected patients in northwestern Ethiopia. Methods: A total number of 302 blood samples were collected from children at Chilga (Aykel, Negade Bahir), and Sanja health centers in northwestern Ethiopia. Thirty-three (10.9%) samples tested positive for P. falciparum malaria. The Pfhrp2, Pfhrp3, and flanking genes (MAL7P1_228 and MAL7P1_230 for Pfhrp2, and MAL13P1_475 and MAL13P1_485 for Pfhrp3) were amplified using standard nested-PCR. Results: Pfhrp2 and both of its flanking genes were found to be present in 12 (36.4%) out of the 33 samples. Twenty-one (63.6%) samples tested negative for the Pfhrp2 gene and 19 samples (57.6%) tested positive for at least one of the flanking genes. Five (15.2%) samples gave positive results for the Pfhrp3 gene and both of its flanking genes, whereas 16 (48.5%) tested negative for all three. Conclusions: Our study provides widespread deletions in the Pfhrp2 and Pfhrp3 genes in Ethiopia, thereby confirming anecdotal reports of diagnostic failure with Pfhrp2-based RDTs in the region. The implications of our finding for the current diagnostic paradigm, which relies on the detection of P. falciparum by Pfhrp2-based RDTs in remote areas, may need rethinking.