Tropical Diseases, Travel Medicine and Vaccines最新文献

Background: Malaria still remains one of the leading causes of death, especially in Africa, with one of the major struggles associated with eradication being resistance to antimalarial medications. Imatinib, a selective tyrosine kinase inhibitor used to treat chronic myeloid leukemia, has emerged as a potential pharmacological approach for malaria management.

Methods: This review synthesizes studies from the inception of the databases of PubMed, Scopus, Google Scholar, Cochrane, Web of Science, and Embase to February 2025, identifying key clinical trials and invitro studies conducted to assess the efficacy and safety of Imatinib in malaria.

Results: With varying sample sizes, dosage and follow-up data, the studies reported a decline in parasite density, pyrexia, parasite growth inhibition, and synergism with other anti-malarial medications like Artesunate. Across the nine (9) studies reviewed, Imatinib showed a favorable safety profile with no adverse drug-related events reported.

Conclusions: We discuss the potential advantages and challenges of repurposing Imatinib for treating malaria, its pharmacokinetic profile, and its use in other patient populations, such as children and pregnant women. Future studies should focus on randomized controlled trials with larger sample sizes and possible combination therapies with other antimalarial medications.

Background: Hypersensitivity reactions (HSR) to the COVID-19 vaccine have been reported. Despite these reactions, revaccination remains essential.

Objective: This study aims to explore the potential outcomes of COVID-19 revaccination in individuals with prior vaccine-related adverse reactions.

Methods: A retrospective study was employed with a sample of 225 patients, with HSR regarding COVID-19 vaccines, who were referred to a university hospital. Demographic data, vaccine types and HSR were collected.

Results: Seventy-seven percent (175/225) of patients were revaccinated post HSR. Out of the 175 patients, 57.1%, 34.2% and 8.5% had a history of HSR in connection to inactivated vaccines, viral vector vaccines, and mRNA vaccines, respectively. Sixty percent were revaccinated with the same type of vaccine and 63.4% received antihistamines and/or anti-leukotriene premedication. After revaccination, 89.1% did not have adverse reactions, while 10.9% had mild reactions. When comparing patients who experienced HSR following COVID-19 revaccination with those who did not exhibit reactions, a significant association among patients with revaccination adverse effects were a revaccination with inactivated vaccines; Sinovac-CoronaVac (P < 0.001), a history of any allergic diseases (P < 0.001) and underlying allergic rhinitis (P = 0.003). Premedication or change of vaccine type did not have an effect to the rate of adverse reactions reported post revaccinations.

Conclusions: In this study, COVID-19 revaccination in patients with a history of COVID-19 vaccine-related HSRs was generally safe, with most patients tolerating it well. However, individuals with underlying allergic conditions, particularly allergic rhinitis, exhibited a higher incidence of mild reactions, especially following revaccination with an inactivated vaccine.

Introduction: Enteric diseases are a leading cause of mortality in developing countries, yet are highly preventable. Typhoid vaccines remain underutilized, and diagnostic capacity constraints impede treatment and prevention. Wastewater monitoring could provide a more accurate picture of disease burden if detection and quantification of Salmonella Typhi in wastewater are advanced. To motivate why countries should invest to improve wastewater testing methods, we conducted a cost-benefit analysis, quantifying the value this approach could yield.

Methods: We estimated benefits that could accrue if wastewater data informed the early launch of a theoretical typhoid vaccine campaign in Cox's Bazar, Bangladesh. After empirically estimating the lead-time advantage of wastewater data over clinical data to flag case upticks, we simulated changes in case counts from a 1- to 14-day early campaign launch, using ordinary differential equation modeling. We quantified benefits resulting from averted cases (from preserved caregiver time, school days, and wages), hospitalizations (from savings to public funds), and deaths (using the value of statistical life). We then calculated how cumulative benefits, costs, and the ratio of the two varied by campaign launch timing scenario over a five-year period.

Results: Wastewater concentrations of Salmonella Typhi upticked up to 13 days before case counts. Cumulative benefits varied by year and launch timing. With a 13-day early launch, every $100 spent on wastewater monitoring could yield $295 in societal benefits by year 5. Cumulative benefits roughly equaled cumulative costs with a 5-day early launch and outweighed costs when the campaign was launched even earlier.

Conclusion: If wastewater data can be advanced to reliably provide early warnings of new typhoid outbreaks, governments could reap large benefits that more than justify spending on program implementation. Our findings could generalize to other high-aid countries that, like Bangladesh, experience routine enteric disease outbreaks and have strong operational networks.

Background: Vietnam experiences a significant occurrence of fascioliasis infection, largely due to the common practice of consuming raw vegetables. Diagnosing the fascioliasis infection remains difficult, and patients endure various long-term consequences. The purpose of this study is to describe the clinical and laboratory features, along with the treatment approaches for fascioliasis patients in Vietnam.

Methods: The study included 31 patients diagnosed with fascioliasis in Northern Vietnam between 2019 and 2023. Blood ELISA testing, fresh stool microscopy, ultrasonography, and magnetic resonance imaging were all used to evaluate the patients. The patients received triclabendazole, and the efficacy of treatment was assessed three months later.

Results: All patients infected with Fasciola reported having raw vegetables and exhibited typical clinical symptoms of right hypochondriac pain (61%), epigastric pain (58%), exhaustion, and anorexia (42%). All patients presented with a hepatic lesion, with an average abscess measuring of 5.5 ± 2.8 cm. Increased eosinophil levels were noted in 77% and 68% of the patients, whereas only 13%, 36%, and 19% showed decreased red blood cell counts, elevated white blood cell counts, and increased liver enzyme levels, respectively. Following three months of treatment with triclabendazole, 81% of patients achieved cure, while 19% (6 patients) remained uncured. The patients who did not respond to the initial treatment received an additional dose of triclabendazole (20 mg/kg body weight) and were monitored for another three months; all of these patients were cured.

Conclusions: The functional symptoms associated with fascioliasis include right hypochondriac pain, epigastric pain, fatigue, anorexia, weight loss, and fever. However, observable physical symptoms such as enlarged liver, jaundice, and yellow eyes are uncommon. Patients may exhibit liver lesions and an increase in eosinophils, but they rarely present with elevated liver enzymes or anemia. Treatment using triclabendazole is highly effective; however, an additional dose of triclabendazole is necessary to reach optimal effectiveness.

Non-ulcerated cutaneous leishmaniasis (NUCL) is an atypical clinical form of leishmaniasis first described, in 1988, by Ponce and collaborators, in Honduras, Central America, characterized by isolated or disseminated closed skin lesions appearing as papules, nodules, or infiltrated plaques, primarily in adolescents and young adults. Leishmania (L.) chagasi was then identified as the causal agent of both NUCL and American visceral leishmaniasis (AVL) in Honduras, though NUCL has been reported as more prevalent. However, due to the uncertain taxonomic classification of the NUCL-causing parasite, especially since L. (L.) chagasi has not been associated to this form of the disease in South America, this study conducted a comprehensive taxonomic review incorporating phenotypic (biological and clinical-immunopathological) and genotypic (genomic/molecular) analyses. Biologically, Honduran parasite-LPG does not have Gal (β1,4) Man (α1)-PO4 side chains common to all Leishmania LPGs. From a clinical-pathogenic perspective, NUCL is unique, it does not ulcerate like cutaneous leishmaniasis due to L. (L.) chagasi or L. (L.) infantum. Molecular findings showed that the Honduran parasite is more ancestral than all known viscerotropic Leishmania species, exhibited an unprecedented structural variation on chromosome 17 with the highest frequency of genomic SNPs, formed a distinct phylogenetic lineage, and displayed a homozygous SNP profile typical of a parental (non-hybrid) parasite. Building on these findings, a new species, Leishmania (Leishmania) poncei n. sp. (Kinetoplastea: Trypanosomatidae), is proposed in honor of Professor Carlos Ponce, who first described NUCL in Honduras. This study formally classifies L. (L.) poncei n. sp. as a novel Leishmania species responsible for both NUCL and AVL in Honduras, Central America.

Background: Spontaneous abortion (SA) associated with infectious pathogens such as Toxoplasma gondii during pregnancy poses a substantial health risk for pregnant women and is linked to transplacental infection of the fetus. This study was conducted to investigate the serological and molecular aspects of T. gondii genotyping in women who have experienced SA at various gestational ages. These women were admitted to the Obstetrics and Gynecology Department of Ali Ibn Abi Talib Zahedan Hospital between September 2021 and May 2024.

Methods: This study examined 163 women with a history of abortion. Blood samples were tested for specific anti-Toxoplasma IgM and IgG antibodies using ELISA. In contrast, tissue samples from their aborted placentas were analyzed for molecular examination using nested PCR targeting the GRA6 gene.

Results: The results indicated that the women in the study ranged in age from 18 to 39 years, with 16% testing positive for anti-Toxoplasma antibodies: 9% had IgG, 4% had IgM, and 3% had both IgM and IgG. Subsequent nested PCR analysis of the placental tissue revealed that 7 cases (4.29%) were positive for the 529 bp fragment of T. gondii. Our data confirmed that five isolates belonged to type I, and two belonged to type II of T. gondii.

Discussion: The findings of this study suggest that screening programs for T. gondii significantly elevate the risk of miscarriage among pregnant women. Examining placental tissue for the molecular epidemiology and genetic variants of T. gondii linked to abortion is advisable to improve detection sensitivity.

Background: Vaccination is one of the most effective strategies in mitigating the severity of SARS-CoV-2 infection. While a connection between poor nutritional status and diminished immune responses to vaccination has been noted, comprehensive reviews elucidating this association have been scarce. To address this gap, we conducted a scoping review to characterise the relationship between nutritional status (specifically, body mass index (BMI) or micronutrient deficiencies) and the responses to COVID-19 vaccination, encompassing efficacy, effectiveness, and immunogenicity.

Method: We searched PubMed, OVID-Medline, Scopus, Cochrane Covid Register, LitCovid, and WHO COVID-19 research databases for studies that reported the association between nutritional status and responses to the COVID-19 vaccines (published between December 20, 2019, and December 30, 2023). Two reviewers independently screened the articles, and disagreements were resolved through consensus or by a third reviewer.

Results: Seventy-three out of 1,853 identified articles were included in this review, predominantly featuring cohort designs (72%). Among these studies, 63% reported BMI, 30% focused on micronutrients (specifically vitamin D, selenium, iron, zinc), and 6% examined both. Most studies (84%) focused on vaccine immunogenicity. The most frequently studied vaccines were BNT162b2 (Pfizer, 74%), ChAdOx (AstraZeneca, 23%), and mRNA-1273 (Moderna, 14%). High BMI significantly reduced COVID-19 vaccine immunogenicity in 23 studies, while adequate vitamin D was associated with increased vaccine response in seven studies.

Conclusion: Overnutrition and micronutrient deficiencies (vitamin D, iron, selenium and zinc) have been observed to attenuate the potency of COVID-19 vaccines. Future strategies aimed at prioritizing vaccination in obese and overweight individuals, or enhancing their vaccine response, may involve identifying measures such as the provision of booster doses. Additionally, efforts should ensure micronutrient adequacy, including improving vitamin D status through strategies like increased sun exposure or supplementation, particularly for deficient individuals.

Introduction: Artemether-lumefantrine (AL) is an effective drug combination that is used to treat uncomplicated falciparum malaria worldwide including travellers. Although this treatment is regarded as highly effective, recrudescence of falciparum malaria may occur in the weeks after treatment with AL. The occurrence of recrudescence and its potential (risk) factors in travellers remain poorly investigated.

Methods: This retrospective cohort study included falciparum malaria cases treated with AL at a tertiary referral hospital in the Netherlands, between January 1, 2010, and July 1, 2024. The primary outcome was the proportion of recrudescence cases among falciparum malaria cases who completed treatment with AL. Recrudescence was defined as a negative microscopy result for Plasmodium falciparum at least once after AL treatment, followed by a subsequent positive result without intercurrent travel to malaria-endemic areas. Secondary outcomes included the proportion of recrudescence cases that experienced secondary treatment failures (recrudescence after retreatment with AL or other malaria therapies) and factors associated with recrudescence. In addition to our cohort study, we performed a literature review on studies reporting on falciparum recrudescence cases after AL treatment among travellers.

Results: Of 391 falciparum malaria cases identified, 270 were treated with AL and thus included in this study. Among these, eight (3%; 95% confidence interval [CI]: 1-6%) recrudescence cases were identified. Diarrhoea was a risk factor for recrudescence in our cohort (unadjusted OR 4.9 95%; CI: 1.14-21.06). In the literature, 19 studies reported on 61 recrudescence cases amongst a total of 1,770 malaria cases (3%). No secondary treatment failures occurred in recrudescence cases treated with AL from our cohort or the literature (0/19), whereas secondary treatment with atovaquone-proguanil failed in 2/28 (7%) of cases.

Interpretation: Recrudescence after AL treatment is rare among travellers, and was associated with diarrhoea, which might cause malabsorption. When recrudescence occurs, retreatment with AL is effective.