Tropical Medicine and Infectious Disease最新文献

Background: Aedes species transmit arboviral diseases, such as dengue, chikungunya, yellow fever, and Zika. The diseases cause severe sickness, mortality, and economic losses. This study describes the biting hour and host-seeking behavior of Ae. aegypti and Ae. vittatus in three towns. Recently, chikungunya and dengue infections were reported in the study sites.

Methods: Biting hour and host-seeking behaviors of Ae. aegypti and Ae. vittatus were studied from June to September 2023, in Genda-Wuha, Kokit, and Metema-Yohannes towns, Metema district, Northwest Ethiopia. CDC-LT traps were set running indoors and outdoors for 24 h closer to humans sleeping inside unimpregnated mosquito nets. At the same time, CDC-LT traps were set running overnight closer to domestic animals' shelters located within a 50-m radius of the main residence. Mosquitoes trapped in CDC-LT were collected every hour. The study was conducted four times in each town during the wet season. A chi-square test was employed to examine biting hour and host-seeking behavior.

Results: Aedes aegypti was observed to be highly exophilic and active during the daylight hours. Aedes aegypti exhibited a peak biting rate between 07:00 and 08:00 with the biting rate of 4.5/person/hour followed by from 17:00 pm to 18:00 pm with the biting rate of 3.75/person/hour. The hourly biting rate of Ae. aegypti differed significantly. Its peak indoor biting rate was from 19:00 to 20:00 with the rate of 2.00 bites/person/hour followed by from 08:00 to 09:00 with the rate of 1.50 bites/person/hour and the biting rates differed significantly across the hours (F = 240.046; p = 0.001). Aedes vittatus also exhibited a biting rate similar to that of Ae. aegypti. Both Ae. aegypti and Ae. vittatus were abundantly collected from nearby human sleeping arrangements than from the shelters of cattle, sheep, goats, and donkeys. The highest proportions of Ae. aegypti (91.21%) and Ae. vittatus (89.87%) were unfed.

Conclusions: Aedes aegypti and Ae. vittatus exhibited peak biting rates during morning and early night hours that aligned with the active daily routine practices of the local community. This could potentially expose the inhabitants to viral diseases transmitted by Ae. aegypti and Ae. vittatus.

Human papillomavirus (HPV) infection is one of the most common sexually transmitted infections in all genders worldwide. Its association with male infertility is deeply investigated, although there are conflicting data on the role of the virus in the impairment of semen quality and reduced reproductive outcomes. In this study, we considered 335 semen samples of males (age: 37.63 ± 6.02 years) belonging to infertile couples who did not conceive a pregnancy after 12 months of unprotected intercourse. Residual semen samples, after routine sperm analysis, were used to amplify and type viral DNA. Positive or negative HPV semen samples were compared. In total, 42.51% (139/327) were positive for at least one HPV genotype, and in 54.68% (76/139), positivity was due to a high-risk (HR) genotype. The most prevalent was HPV-16 (16.55%) followed by HPV-52 (10.07%) and HPV-51 (7.91%). Overall, no significant differences emerged in terms of sperm concentration, sperm motility, and morphology between the two groups. However, a considerable reduction in sperm motility was found in the presence of HPV-51 or HPV-52. These data point to the importance of HPV screening in semen analysis to evaluate patients that might have a higher risk of infertility according to the type of HPV genotype.

Background: Human central nervous system infections due to free-living nematodes, although extremely rare, are usually fatal. Immunodeficiency has not been a feature of most of these cases, unlike the situation pertaining to disseminated Strongyloides stercoralis infection.

Case report: An elderly immunocompetent man presented with a history of tinnitus and otalgia, progressing to central nervous system involvement with confusion, weakness, and other neurological signs. Examination revealed a unilateral external auditory canal soft tissue mass and radiological evidence of ipsilateral temporal bone destruction and brain parenchymal disease. A biopsy of the ear canal mass revealed the presence of an unidentified nematode species, and treatment with anthelminthics was started. The patient's clinical condition deteriorated and he died shortly after admission to the intensive care unit. The immediate cause of death was bronchopneumonia. During the autopsy, an extensive involvement of the right middle cranial fossa was found, with destruction of the squamous and petrous parts of the temporal bone.

Results: We identified adult, larval, and egg stages of a free-living nematode in the antemortem external auditory canal tissue mass and the post-mortem brain samples. Polymerase chain reaction assays, with Sanger and whole-genome sequencing, identified Cephalobus cubaensis. This is a free-living species not previously known to be pathogenic to humans, although nematodes of the same genus have caused mastitis in horses.

Conclusions: Microscopic appearance and the invasive behaviour of the pathogen evoked a putative diagnosis of Halicephalobus gingivalis, the most frequently reported free-living nematode infecting humans. However, this nematode's size and anatomical features, and the clinical presentation and duration of illness, prompted the consideration of an alternative species. We speculate that an initial bacterial otitis externa provided the opportunity for colonization by the nematode from an environmental source and subsequent invasion.

Aedes albopictus, one of the most rapidly spreading invasive mosquito species, has expanded from Asia to establish populations on every continent except Antarctica, showcasing exceptional adaptability, particularly in island environments. This study provides the first molecular characterization of Ae. albopictus in the Canary Islands, Spain. Genotyping was conducted using rDNA 5.8S-ITS2 and mtDNA cox1 sequencing, with haplotype analysis and phylogenetic network assessment. Among 49 sequences, 28 distinct 5.8S-ITS2 haplotypes were identified, with individual specimens containing 5 to 17 haplotypes (mean, 10.6). Most haplotypes (26/28; 92.85%) were unique to Tenerife, while only two (7.14%) were shared with other regions. H1 was the most frequent haplotype, shared with Valencia and China, while H2, a short-length haplotype, was shared with Mallorca. For cox1, only two haplotypes were detected: cox1-H1, reported in Europe, China, and Brazil, and a novel haplotype, cox1-H28. This genetic diversity suggests the species' potential capacity to colonize new environments. The findings provide a foundation for further research in the Canary Islands and globally, particularly in regions with high tourism and arbovirus risks, emphasizing the importance of ongoing surveillance and genetic studies to understand the dynamics and public health impacts of invasive mosquito species.

Viruses are a frequent cause of self-limited diarrhea, with more severe outcomes in immunocompromised patients. This study aimed to compare the performance of Real-Time RT-PCR to chromatographic immunoassays (CIAs) for detecting the major gastrointestinal viruses in human stool. This study was conducted at the University Hospital of Split, Croatia, from October 2023 to May 2024. Stool samples were simultaneously analyzed with CIA (Acro Biotech Rotavirus and Adenovirus Combo Rapid Test Cassette, USA and JusChek Norovirus Rapid Test Cassette, China) and Real-Time RT-PCR (AccuPower Diarrhea V1&V2 Real-Time RT-PCR, Bioneer, Republic of Korea), according to the manufacturers' instructions. Positive percent agreement (PPA), negative percent agreement (NPA), and overall percent agreement (OPA) were calculated. For norovirus, CIA had a low PPA (25%), indicating that it missed 75% of norovirus-positive cases identified by RT-PCR. Adenovirus detection by CIA showed poor agreement with RT-PCR (PPA 0%; NPA 100%). Rotavirus detection presented a relatively better performance with CIA (PPA 90.9% and OPA 84.13%). However, the presence of false positives (15.8%) highlights the need for confirmatory RT-PCR testing. One specimen was sapovirus-RT-PCR-positive, marking the first documented case from human specimens in Croatia. Although CIA provided rapid results, limitations regarding reliability highlight the value of RT-PCR, particularly in the case of ambiguous clinical cases with negative antigenic test results and newly emerged viruses. A two-step diagnostic approach, with initial CIA screening followed by confirmatory RT-PCR, could balance cost-effectiveness with diagnostic accuracy.

Background: Dengue has emerged as a significant public health concern in Sao Tome and Principe, with the first documented outbreak occurring between 2022 and 2024. This study examined the epidemiological patterns, environmental determinants, and demographic characteristics of dengue transmission during this period.

Methods: We conducted a comprehensive retrospective analysis of laboratory-confirmed dengue cases using national surveillance data, clinical records, and environmental monitoring data. Statistical analyses included demographic profiling, temporal trend assessment, and environmental correlation studies using multiple regression modeling.

Results: Among 1264 laboratory-confirmed cases, we observed distinct age-specific vulnerability patterns, with the highest incidence rate in the 70-79 age group (829.6 per 100,000) despite most cases occurring in younger adults. Rainfall emerged as the strongest predictor of dengue transmission (r = 0.96, p < 0.001), explaining 92% of case variance in the regression model. Case distribution showed marked temporal variation, with 91.9% of cases reported in 2022, coinciding with exceptional rainfall (3205 mm). The overall case fatality rate was 0.71% (95% CI: 0.33-1.35), with significant quarterly variations. Geographical analysis revealed concentration in the Água Grande district (68.2% of cases).

Conclusions: This first comprehensive analysis of dengue in Sao Tome and Principe demonstrates the crucial role of rainfall in disease transmission and reveals important age-specific vulnerability patterns. These findings provide an evidence base for developing targeted interventions, particularly during high-rainfall periods, and suggest the need for age-stratified clinical protocols in similar island settings.

Various techniques have been used for the molecular identification of Mycobacterium leprae (M. leprae). The aim of this review was to identify the relationship between the molecular presence of M. leprae and the process of infection and/or illness of contact of leprosy cases. A systematic review was carried out by searching the Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane Library, Embase, Scopus, Web of Science and the Latin American and Caribbean Health Sciences Literature (LILACS) databases in January 2024. The studies were selected by two pairs of reviewers. Observational cross-sectional, case-control and cohort studies were included. A descriptive synthesis of the results by category was carried out. A total of 443 studies were identified, and 36 were included in the review. Twelve molecular targets were tested to identify the presence of the bacillus. A relationship was established between the identification of M. leprae DNA and factors related to the index case, housing characteristics, living conditions, epidemiology and anti-PGL-1 serology. None of the studies identified evaluated the molecular viability of M. leprae among contacts. The detection of M. leprae DNA alone does not necessarily predict the development of infection or clinical illness among contacts.

Culex pipiens quinquefasciatus is a notorious vector transmitting severe diseases such as Zika virus and West Nile virus to humans worldwide. Vermistatin is a type of funicon-like compound and was first isolated from Penicillin vermiculatum in the 1970s. Vermistatin has shown promising activity against Cx. p. quinquefasciatus larvae in our previous research. Here, we conducted a transcriptomic analysis of Cx. p. quinquefasciatus larvae treated with a median lethal concentration of 28.13 mg/L vermistatin. Differential expression analysis identified 1055 vermistatin-responsive genes, with 477 downregulated and 578 upregulated. Gene Ontology annotation and enrichment analysis revealed the metabolic process to be the most significantly affected biological process, the membrane to be the most significantly affected cellular component, and catalytic activity to be the most significantly affected molecular function. Kyoto Encyclopedia of Genes and Genomes pathway analysis classified the differential expression genes into six major categories, with metabolism and organismal systems being the most enriched. Fifty-five pathways were significantly enriched, with the hematopoietic cell lineage, renin-angiotensin system, cholesterol metabolism, and peroxisome proliferator-activated receptor signaling pathways among the top altered pathways. Furthermore, 32 potential detoxification-related genes were differentially expressed, with 3 cytochrome P450s, 2 ABC transporters, and 1 UGT induced by vermistatin. This study provides insights into the molecular mechanisms of vermistatin's action against Cx. p. quinquefasciatus larvae, highlighting potential targets for novel mosquito control strategies.

Schistosomiasis japonica is an infectious parasitic disease caused by infection with the blood fluke Schistosoma japonicum, which is endemic in China, small pockets of Indonesia, and the Philippines. Of the three countries, the prevalence of infection is the highest in the Philippines, despite decades of mass drug administration (MDA). As a zoonosis with 46 potential mammalian definitive hosts and a snail intermediate host, the control and eventual elimination of S. japonicum requires management of these animal hosts in addition to new interventions for the human hosts, including health education and water, sanitation, and hygiene (WASH) infrastructure. In this review we examine the status and epidemiology of S. japonicum in the Philippines with an overview of the current control program there and what needs to be accomplished in the future to control and eliminate this disease in the country.

Management of severe dengue remains a clinical challenge. This retrospective study evaluated clinical features and laboratory biomarkers associated with severe dengue at Hospital Sultanah Aminah Johor Bahru from 1 January 2022 to 31 March 2023. Records of 99 patients, categorized into ICU (51) and non-ICU (48) groups, were identified and analyzed using SPSS version 28.0. Sociodemographic details, clinical features and laboratory biomarkers were collected. Patients aged 50 and older, those with obesity, and those with pre-existing comorbidities were significantly more likely to be admitted to the ICU. The four most common warning signs in both cohorts were lethargy/restlessness/confusion, abdominal pain, persistent vomiting, and diarrhea. Fever, or history of fever, and thrombocytopenia were the two most common severe dengue criteria present in both cohorts. ICU patients exhibited more signs of plasma leakage and abnormal laboratory findings, including normal white cell count, hypoalbuminemia, hyperbilirubinemia, and elevated creatine kinase. In contrast, leukopenia and normal albumin, bilirubin, and creatine kinase levels were more common in non-ICU patients. Hyponatremia and raised lactate dehydrogenase were seen in both groups. This study highlighted key differences and similarities in clinical features and laboratory biomarkers between ICU and non-ICU patients, emphasizing the need for further research to develop a comprehensive risk assessment tool for predicting severe dengue that resulted in ICU admission.