Tropical Medicine and Infectious Disease最新文献

Dengue fever is a persistent public health issue in tropical regions, including Vietnam, where climate variability plays a crucial role in disease transmission dynamics. This study focuses on developing climate-based machine learning models to forecast dengue outbreaks in Ba Ria Vung Tau (BRVT) province, Vietnam, using meteorological data from 2003 to 2022. We utilized four predictive models-Negative Binomial Regression (NBR), Seasonal AutoRegressive Integrated Moving Average with Exogenous Regressors (SARIMAX), Extreme Gradient Boosting (XGBoost) v2.0.3, and long short-term memory (LSTM)-to predict weekly dengue incidence. Key climate variables, including temperature, humidity, precipitation, and wind speed, were integrated into these models, with lagged variables included to capture delayed climatic effects on dengue transmission. The NBR model demonstrated the best performance in terms of predictive accuracy, achieving the lowest Mean Absolute Error (MAE), compared to other models. The inclusion of lagged climate variables significantly enhanced the model's ability to predict dengue cases. Although effective in capturing seasonal trends, SARIMAX and LSTM models struggled with overfitting and failed to accurately predict short-term outbreaks. XGBoost exhibited moderate predictive power but was sensitive to overfitting, particularly without fine-tuning. Our findings confirm that climate-based machine learning models, particularly the NBR model, offer valuable tools for forecasting dengue outbreaks in BRVT. However, improving the models' ability to predict short-term peaks remains a challenge. The integration of meteorological data into early warning systems is crucial for public health authorities to plan timely and effective interventions. This research contributes to the growing body of literature on climate-based disease forecasting and underscores the need for further model refinement to address the complexities of dengue transmission in highly endemic regions.

Anopheles arabiensis is a highly adaptable member of the An. gambiae complex. Its flexible resting behaviour and diverse feeding habits make conventional vector control methods less effective in controlling this species. Another emerging challenge is its adaptation to breeding in polluted water, which impacts various life history traits relevant to epidemiology. The gut microbiota of mosquitoes play a crucial role in their life history, and the larval environment significantly influences the composition of this bacterial community. Consequently, adaptation to polluted breeding sites may alter the gut microbiota of adult mosquitoes. This study aimed to examine how larval exposure to metal pollution affects the gut microbial dynamics of An. arabiensis adults. Larvae of An. arabiensis were exposed to either cadmium chloride or copper nitrate, with larvae reared in untreated water serving as a control. Two laboratory strains (SENN: insecticide unselected, SENN-DDT: insecticide selected) and F₁ larvae sourced from KwaZulu-Natal, South Africa, were exposed. The gut microbiota of the adults were sequenced using the Illumina Next Generation Sequencing platform and compared. Larval metal exposure affected alpha diversity, with a more marked difference in beta diversity. There was evidence of core microbiota shared between the untreated and metal-treated groups. Bacterial genera associated with metal tolerance were more prevalent in the metal-treated groups. Although larval metal exposure led to an increase in pesticide-degrading bacterial genera in the laboratory strains, this effect was not observed in the F₁ population. In the F₁ population, Plasmodium-protective bacterial genera were more abundant in the untreated group compared to the metal-treated group. This study therefore highlights the importance of considering the larval environment when searching for local bacterial symbionts for paratransgenesis interventions.

Amphimerus, a liver fluke, is the causative agent of amphimeriasis, a foodborne disease acquired thought the consumption of infected raw or undercooked river fish-a practice embedded in traditional culinary customs. Amphimeriasis represents a significant public health issue and has been endemic in Ecuador since 2011, particularly among the Chachi Amerindians and Montubios populations residing in tropical ecoregions. By employing a mixed-methods research design, we conducted a community-based, cross-sectional study. A survey comprising of 63 questions on KAP was administrated in person to community members, health personnel, and academic staff in the two populations. Additionally, 67 semi-structured interviews were performed. Microscopy was achieved on 273 human and 80 dog fecal samples to detect Amphimerus eggs. A total of 86 questionnaires (54 Chachi) and 67 interviews (44 Chachi), out of 300 residents, were completed. Among the respondents, 31.4% were aware of Amphimerus, locally referred to as "liver worm". Although 79.1% reported not consuming raw fish, most admitted eating raw fish with lime juice and salt, a preparation known as "curtido", and 59.3% reported consuming smoked fish. Here, 86.1% of participants considered "liver worm" a serious disease, and 55.8% recognized raw or marinated fish as a potential transmission route. The Chachi showed a preference for smoked fish, whereas the Montubios favoured "curtido". The prevalence of Amphimerus infection was 23% in humans and 16.2% in dogs. Differences in KAP were observed between infected and non-infected individuals. Local health and academic personnel demonstrated insufficient knowledge about amphimeriasis. Some religious individuals refrained from participating, stating that they were "with God". Despite the high prevalence of Amphimerus infection in both humans and dogs, knowledge about the parasite, the disease, and its transmission routes remains limited. Health education initiatives should be designed to modify the population's KAP. It is crucial for national and local health authorities, as well as religious leaders, to be informed and actively involved in the prevention and control of amphimeriasis.

Ecuador has gone through a significant reduction in new cases from 2000 (106) to 2023 (12), suggesting a trend towards zero leprosy. An ecological spatiotemporal study design was used to describe the epidemiological distribution of the disease in the country during 2000-2023. Leprosy cases registered by the surveillance system of the Ecuadorian Ministry of Public Health were the data utilized for the study. From January 2000 to December 2023, 1539, incidence cases were diagnosed with leprosy in Ecuador. At the time of diagnosis, the median age was 54 years. Most of the cases were males (71.5%). The proportion of incidence cases in subjects over 50 years was 63% and 1.5% in children ≤ 15 years old. The yearly incidence rate ranged from 8.5/1,000,000 population in 2000 to 0.68/1,000,000 population in 2023, remaining within the low-endemic parameter. In total, 35 cantons reported newly detected leprosy cases in the year 2000. By the end of 2023, only eight cantons actively reported cases of leprosy. High-risk clusters for leprosy were detected in the tropical coastal region of Ecuador. The provinces with the highest number of cases during the study period were Guayas (44.8%) and Los Rios (15.7%), with zero cases being found in the Galapagos Islands. Our study is unique in that it documents a retrospective dataset over a two-decade timespan from a South American country that has effectively applied global guidelines for the control and elimination of leprosy.

Scabies is a worldwide parasitic dermatosis with a significant health burden on the young and the elderly. Statistics about the prevalence of scabies in Hong Kong are not available. This is a retrospective study of patients from a regional hospital cluster in Hong Kong with microscopy-documented Sarcoptes scabiei infestations from January 2018 to December 2022. The condition was categorised into classical scabies and crusted scabies upon clinical presentation. Demographic data, comorbid diseases, mobility and residential status, seasonal variability, secondary bacterial infection, treatment and outcomes were described. These were compared between classic and crusted scabies. In total, 604 patients were identified, representing 51.65 per 100,000 discharged patients during the study period. The median age was 84 years and 54.5% were male. The majority (506 or 83.8%) came from residential care homes for the elderly. The mean time from admission to diagnosis was 8.8 days for community-acquired infestation. There were 564 and 40 cases of classic and crusted scabies, respectively. The two groups of patients were comparable in terms of residence in elderly homes, co-existing chronic illnesses, mobility, and time from admission to diagnosis. Forty-five (7.5%) patients had positive blood cultures temporally associated with scabies. Patients with crusted scabies were at higher risk for bacteraemia (7/40 versus 38/564, p = 0.022). Permethrin and benzyl benzoate were the most popular treatment regimens, with treatment failure observed in 59/397 (14.4%) and 18/173 (10.4%), respectively. There were 172 (28.5%) mortalities within 30 days of scabies diagnosis. Thus, the burden of scabies infestation is significant in Hong Kong. Hospitalised patients diagnosed with scabies are mainly senior citizens living in residential care homes for the elderly, suggesting reservoirs of S. scabiei in the community. Of concern, bacteraemic illnesses are common and significant mortality is temporarily associated with infestation. With a rising elderly population, there is a pressing need to understand and control scabies in Hong Kong. Our study did not find that common medical illness, besides immunosuppressive therapy, predisposed patients to crusted scabies. The crusted form of scabies was associated with a higher risk of bacteraemia. The current study provides a better perspective of the disease load of scabies in Hong Kong.

This study aimed to determine the incidence of post-chikungunya chronic rheumatism (pCHIK-CR) and its impact on quality of life (QoL) and chronic fatigue in adults seven years after the 2014-2015 CHIKV outbreak in Piedecuesta, Colombia. We evaluated 78 adults (median age: 30 years, IQR: 21.0; women 60.3%) with confirmed CHIKV infection. In 2022, participants underwent a GALS examination and completed surveys on disability, stiffness, health status, and fatigue. A rheumatologist evaluated patients who reported arthralgia, morning stiffness, and abnormal GALS examination. Chronic fatigue was defined as fatigue persisting for over six months. Seven years after infection, 14.1% of participants were classified as pCHIK-CR cases, 41.0% as having non-inflammatory pain, likely degenerative (NIP-LD), and 44.9% without rheumatic disease (Wo-RM). Patients with pCHIK-CR and NIP-LD exhibited significantly worse QoL compared to Wo-RM cases. Chronic fatigue prevalence increased from 8.6% in Wo-RM patients to 25.0% in NIP-LD and 54.6% in pCHIK-CR cases. This study implemented a comprehensive clinical assessment to objectively estimate and characterize the incidence of chronic rheumatological disease attributed to CHIKV infection. One in seven cases with CHIKV infection develops pCHIK-CR, which impacts both QoL and chronic fatigue. This study contributes to understanding the burden of these arboviruses in the medium term.

Sub-Saharan Africa bears the largest public health burden of Kaposi sarcoma (KS), a leading cause of cancer mortality. Quality of life (QOL) assessments in cancer patients can provide information on prognosis beyond traditional biomarkers or biological measures. The prognostic value of QOL measures in patients with HIV-KS was evaluated. Prognostic associations of baseline QOL scores (by quartiles or thresholds for clinical importance) and changes in QOL scores (using minimum important difference) over the first 3 months of therapy were evaluated in 112 participants with HIV-KS randomised to receive ART, with or without chemotherapy. Cox's regression analysis assessed the prognostic contribution of QOL scores from the EORTC QLQ-C30 questionnaire. Survival curves were generated using the Kaplan-Meier method. Baseline QOL scores did not predict overall survival. The change in the 3-month QOL scores for the global health scale, fatigue, and pain domains was prognostic; the hazard ratios were 3.88 (95% CI 1.32-11.38, p = 0.01), 3.72 (95% CI 1.61-8.62, p = 0.00) and 5.96 (95% CI 2.46-14.43, p = 0.00), respectively. QOL assessments can provide useful prognostic information in patients with HIV-KS. Patients lacking meaningful improvement early into treatment represent a population at high risk of death.

Schistosomiasis, which affects a large number of people worldwide, is among the most overlooked parasitic diseases. The disease is mainly prevalent in sub-Saharan Africa, southeast Asian countries, and South America due to the lack of adequate sanitation. The disease is mainly associated with poor hygiene, sanitation, and contaminated water, so it is also known as a disease of poverty. Three Schistosoma species (S. mansoni, S. japonicum, and S. haematobium) cause significant human infections. Co-infections with Schistosoma and other parasites are widely common. All these parasites may cause intestinal or urogenital schistosomiasis, where the disease may be categorized into the acute, sensitized, and chronic phases. The disease is more prevalent among school children, which may cause anemia and reduce development. Chronic infections frequently cause significant liver, intestinal, and bladder damage. Women exposed to contaminated water while performing normal duties like washing clothes might acquire urogenital schistosomiasis (UGS), which can cause tissue damage and raise the risk of blood-borne disease transmission, including human immunodeficiency virus (HIV) transmission. Praziquantel (PZQ) is the World Health Organization (WHO)-prescribed treatment for individuals who are known to be infected, but it does not prevent further re-infections with larval worms. Vaccine development and new molecular-based diagnosis techniques have promised to be a reliable approach to the diagnosis and prevention of schistosomiasis. The current review emphasizes the recent advancement in the diagnosis of schistosomiasis by molecular techniques and the treatment of schistosomiasis by combined and alternative regimes of drugs. Moreover, this review has also focused on the recent outbreak of schistosomiasis, the development of vaccines, and their clinical trials.

Chromobacterium violaceum is a Gram-negative, facultative anaerobe proteobacterium. Its natural habitat is water and soil in tropical and subtropical regions. Human infections are characterized by rapid dissemination that can lead to high fatality rates. Here, we describe the first case of a C. violaceum infection reported from Germany. A German national with permanent residence in French Guyana contracted a C. violaceum infection presumably while bathing in a barrier lake in Brazil. The patient presented with a high fever and a crusty, erythematous skin lesion at an emergency department in Hamburg, Germany. Ultrasound and a CT scan of the abdomen revealed multiple liver abscesses. C. violaceum was detected in blood and from aspirates of the liver abscesses, using traditional culture methods and modern molecular assays. Prolonged treatment with meropenem and ciprofloxacin led to full recovery. Rapid pathogen detection and treatment initiation are of high importance in C. violaceum infections as mortality rates are overall declining but have still tended to reach up to 25% in recent years in systemic infections. Due to its broad natural drug resistance, antibiotic treatment is challenging. Increased travel activities may lead to more frequent presentation of patients with environmental pathogens of the tropics such as C. violaceum.

Persistent HPV infection is a major risk factor for the subsequent development of cervical cancer. LAMP is simple and suitable for field detection in the resource-limited settings. In this study, hydroxy naphthol blue (HNB)-based visual LAMP and evagreen-based fluorescent LAMP coupled with a microfluidic chip (LAMP-chip) were established for the field detection of seven subtypes of HPV. The analytical sensitivity was 19-233 copies/reaction. The overall clinical sensitivity was 97.35% for visual LAMP and 98.23% for LAMP-chip. Both LAMP assays exhibited 100% specificity and were completed in less than 50 min. Additionally, both assays did not require complicated nucleic acid extraction and purification steps. A complete quality control monitoring system (including internal control, positive quality control and negative control) in the LAMP assays further ensured the credibility of the results. Our findings demonstrated that the proposed LAMP assays have the potential to be applied in the testing of common HPV DNA in field investigations (visual LAMP) or within communities and primary health centers (LAMP-chip).