Journal of Vector Borne Diseases最新文献

Background objectives: Crimean-Congo Hemorrhagic Fever (CCHF) is a tick-borne viral infection with a wide geographic distribution globally. The clinical severity of CCHF varies, with reported mortality rates reaching up to 60%. Despite its spread to new geographic areas and its potential to cause severe and fatal disease, no approved vaccine or antiviral treatment is currently available. Studies on the use of ribavirin for CCHF have yielded conflicting results. Consequently, many physicians manage CCHF patients with supportive care. In this study, we share the positive outcomes observed in CCHF patients who were managed exclusively with supportive treatment without the use of ribavirin.

Methods: The epidemiological characteristics, laboratory results and treatment outcomes of patients with CCHF diagnosis followed up in our clinic between April 1, 2020, and September 31, 2023 were evaluated retrospectively.

Results: The study included 20 patients (5 females and 15 male) with confirmed CCHF. Based on the Severity Scoring Index (SSI) scores, 7 patients with SSI 0-2 were classified as mild cases, 12 patients with SSI 3-9 as moderate cases, and 1 patient with SSI 10-13 as a severe case. No patients received ribavirin as part of their treatment. All patients were managed with supportive care, and no mortality was observed.

Interpretation and conclusion: Supportive care remains the standard treatment for CCHF management. The effectiveness of ribavirin in CCHF remains unclear.

Background objectives: Scrub typhus (ST), a tropical infection caused by Orientia tsutsugamushi, has re-emerged as a global concern in the Asia-Pacific region. Limited data on ST in infants reveals unique presentations, complications, and severity predictors. This study was conducted to evaluate the occurrence of ST in infants, comparing clinical, laboratory and outcomes with ST in older children.

Methods: This is a prospective cohort study conducted in the Pediatrics department of a teaching hospital in South India. Children of < 12y years presenting with fever for > 5 days with serology confirmed ST using IgM ELISA for ST were included after excluding other common tropical infections.

Results: Out of 650 children, 60 (10%) were infants. Fever (100%) was the commonest presentation with mean duration of 9 days followed by cough and fast breathing. Eschar (33, 55%) was commonly seen in face (14, 23.3%) and were atypical (10, 16.6%) in appearance. Findings such as pallor, oedema, hepatosplenomegaly, lung crackles and hematological abnormalities like anemia, leukocytosis, elevated transaminases were more prevalent in infants compared to older children. Severe ST was observed in 34 (56.7%) infants, commonly presenting with pneumonia and shock. Doxycycline showed quicker defervesence with no adverse events in infants. Logistic regression identified hypoalbuminemia as a significant predictor of severe ST in infants.

Interpretation conclusion: ST in infants is common and pose diagnostic challenge due to overlapping features of other tropical infections. Timely therapy and risk stratification can improve the outcomes in resource limited setting.

Background objectives: Dengue and Japanese-B-Encephalitis (JE) are Vector-borne diseases (VBDs) that cause public health challenges in rural India with severe socio-economic challenges and health impacts. Assam, a North Eastern state of India is known for its sub-tropical hot and humid conditions that facilitate rapid transmission and survival of disease-carrying vectors. The present study employed the Socio-Economic Systems (SES) framework to explore the key determinants associated with the prevalence of Dengue and Encephalitis in state's diverse environment condition, including urban, peri-urban and rural areas. The study revealed the demographic details, housing conditions, vector control practices offered to households, and community practices in three districts of Assam. Our analysis revealed significant relationships between water supply, water storage systems, and vector breeding site among three districts.

Methods: The study involved 3600 households in three disease prone districts-Dibrugarh, Tinsukia and Karbi Anglong to see the difference in community knowledge and attributes towards Dengue and JE. Data was collected through a structured questionnaire, observation method in Open Data Kit (ODK) platform. Chi-square test was employed to determine district-wise variations.

Results: Chi-square showed significant district-wise variations in water supply in households, water storage system, vector breeding sites, mosquito control practices and socio-demographic characteristics. Despite dense vegetation cover, cases of mosquito-borne diseases recorded low in Dibrugarh and Tinsukia. However, livestock rearing in Dibrugarh poses a threat of Encephalitis cases.

Interpretation conclusion: The identified factors generated during the study can inform the development of targeted intervention strategies, ultimately aiding in the vector control and prevention of Dengue and Encephalitis in Assam's rural and peri-urban areas.

Background objectives: Scrub typhus (ST) is a serious mite-borne disease which is recently considered as under-recognized cause of acute kidney injury (AKI). The current study was undertaken to elucidate in finer details the role of inflammatory response in the pathophysiology of Scrub typhus associated AKI (STAKI).

Methods: This prospective study was carried out on patients admitted to the Department of Nephrology, SCB Medical College and Hospital, Cuttack, a tertiary care hospital of the state. All sera were tested for O. tsutsugamushi using IgM ELISA kit (In Bios International, Inc., Seattle, WA, USA) and PCR assay. The serum level cytokines were detected by using commercially available ELISA kits.

Results: The study reveals that 31.4% of the hospitalized AKI samples were positive for scrub typhus. IL-33, IL-17, TNF-α, IFN-γ and Angio-2were significantly high in both scrub typhus associated febrile patients and STAKI patients. However, IL-17, TNF-α and Ang-2 were found to be significantly high in STAKI patients in comparison to scrub typhus associated febrile patients. However, significantly high expression of IL-10 was observed in both groups of scrub typhus patients with and without AKI.

Interpretation conclusion: Significantly high levels of IL-17, TNF-α and Ang-2 levels in STAKI patients showed the dysregulated inflammatory response during pathogenesis and can be used as potential biomarkers for monitoring disease progression. However, more studies are needed to shed light on delineating the mechanism which will help in developing future therapeutic target for the management of this neglected tropical disease.

Background objectives: Leptospirosis, a zoonotic disease caused by Leptospira, is prevalent in tropical areas like Brazil. This study aimed to describe the demographics, outcomes, and mortality risk factors in leptospirosis patients in Brazil.

Methods: We conducted a retrospective cohort study using data from the Brazilian DATASUS database (2001-2020) to evaluate outcomes in individuals diagnosed with leptospirosis. Cases were confirmed through clinical and laboratory criteria. Risk factors for mortality were assessed using both univariate and multivariate regression analyses.

Results: Of 64,963 patients, 80.2% were male, and 10.6% experienced all-cause mortality. Some of the risk factors for mortality included respiratory symptoms (OR 3.23), age >60 (OR 2.07), jaundice (OR 1.75), and renal insufficiency (OR 2.07).

Interpretation conclusion: Leptospirosis remains a significant health burden in Brazil, especially for young adult males. This study highlights critical risk and protective factors, which may inform targeted interventions and public health policies. Future research should explore non-binary classifications of variables to improve the understanding of leptospirosis mortality determinants.

Background objectives: Sound plays an important role in mosquito foraging and sexual interactions. Mosquitoes utilize acoustic signals for host location, sexual recognition, and mating, which is achieved through the rhythmic beating of their wings to generate distinct sounds characterized by specific flight tone frequencies.

Methods: In this study, electronic music (Tremor by Dimitri Vegas, Martin Garrix and Like Mike) and country music (Country Road by John Denver) were played in high and low volumes to investigate the influence of different genres of music on the blood feeding and mating responses of Aedes aegypti . The observations encompassed monitoring the landing attempts, blood-feeding endeavors, and mating behavior of Ae. aegypti.

Results: High-volume electronic and country music with elevated pitch and amplitude significantly reduced host attacks and blood-feeding attempts by female mosquitoes compared to low-volume or music-off conditions.

Interpretation conclusion: However, significant reduction of successful copula was only observed in Ae. aegypti mosquitoes exposed under electronic music with high volume. As transmission of dengue is through blood feeding and mating, this discovery may open new possibilities for developing music-based control strategies against mosquito-borne diseases.

The epidemiology of dengue has been demonstrating significant changes in recent years, with rising incidence of infection in countries with known endemicity and occurrence of fresh outbreaks in previously unaffected territories. India, which has been a traditional hotspot dengue virus (DENV) transmission in the endemic south-east Asian region, has been affected by the sweeping changes in dengue epidemiology. Two remarkable developments characterize the alterations witnessed by India from 2011-2017. First, all parts of the country have witnessed abrupt replacement of existing DENV lineages with emerging novel strains. Second, co-circulation of multiple serotypes of DENV have been reported from all across the country from 2011-2017; thereby hinting at the transition of the country towards hyper-endemicity. Considering the potential clinical implications of such epidemiological transformation in terms of increasing involvement of pediatric patients and growing predisposition to serious complications, the present review provides an update on the serotypic and genotypic profile of dengue outbreaks that have been witnessed by different zones of India between 2011 and 2017. Dividing the country into northern, southern, eastern, western, central and north-eastern zones, we describe discrete zone-specific distribution patterns of DENV serotypes and genotypes and observe simultaneous circulation of different DENV strains in different parts of the country. Random shifts in the genetic characteristics of the circulating strains and widespread co-circulation of all four serotypes underscore the need for undertaking continuous and representative molecular surveillance of the circulating DENV strains across the country for prompt identification of emerging strains and novel mutants; gain insights into the formulation of dengue vaccines and develop a clearer understanding of the molecular basis of immune evasion, disease epidemiology and pathogenesis.

Background objectives: A hike in dengue cases was recorded in last two years, resulting from both single and multiple-serotypes of dengue virus (DENV) and secondary infections, culminating in significant hospitalizations and deaths in India. This study focuses on evaluating symptomatic and haematological parameters in acute dengue patients of the northern part of West Bengal to predict disease severity early on and to analyze the correlation between circulating DENV serotypes with severity.

Methods: Dengue patients (N=540) diagnosed as NS1 positives were categorized into 13.7% severe DHF (N=74) and 86.3% mild DF (N=466) and prediction of risk was done using logistic regression. DENV RNA was isolated from blood, converted to cDNA, and detected/serotyped via RT-qPCR by using DENV specific primers.

Results: Only 14.48% (N=11) patients showed single serotypic (DENV2 or DENV3) infection of dengue. In contrast, multi-serotypic infections (N=65) with the prevalence of DENV-2 and DENV-3 co-infections were found among the dengue patients, affecting severe changes in the most critical haematological parameters such as haematocrit and platelet count. The multivariate binary logistic regression model revealed that only six parameters viz., age (p=0.032), presence of joint pain (p=0.015), Haemoglobin level (p<0.001), total RBC count (p=0.024), total WBC count (p=0.003), lymphocyte% (p=0.019) were found to be significantly associated with the risk of DHF.

Interpretation conclusion: Most prevalent DENV-2 and DENV-3 infections significantly impact haematocrit and platelet counts in the study region. Our prediction model, incorporating age, joint pain, haemoglobin, RBC, WBC, and lymphocyte, may effectively predict dengue severity.

Dengue hemorrhagic fever (DHF) typically presents with various bleeding manifestations such as epistaxis, gum bleeding, and gastrointestinal bleeding. However, spontaneous large muscle hematoma formation is a rare complication. This case report discusses a patient with DHF who developed bilateral psoas muscle hematomas, a very uncommon presentation. The patient experienced acute abdominal pain and was diagnosed with psoas muscle hematomas complicated by bacterial infection. Conservative treatment, including fluid management, blood transfusions, and antibiotics, led to the patient's full recovery. This case highlights the importance of suspecting muscle hematomas in DHF patients who present with sudden abdominal or flank pain, especially in the context of dropping hemoglobin and platelet counts. Imaging techniques such as ultrasonography and CT scans are critical for diagnosis. Early diagnosis, close monitoring, and appropriate conservative management are essential for preventing serious outcomes. Prompt treatment of any secondary infections is crucial for patient recovery. This case report reminds clinicians to consider a rare complication.

Background objectives: A 2.5-year placebo-controlled double-blind trial was conducted to investigate the safety and efficacy of AYUSH-SL, a poly-herbal ayurvedic formulation on filarial lymphedema in different endemic areas of India. Lymphatic filariasis (LF) is caused by parasitic nematodes from Wuchereria bancrofti, Brugia malayi, or B. timori that are transmitted through mosquitoes. In Ayurveda, LF has been elaborately narrated under the heading Shlipada and literature also includes detailed therapeutic measures.

Methods: The multicenter, prospective, parallel group interventional study in which 180 participants were recruited within the duration through competitive enrollment. Diagnosed cases of Grade I and Grade II filarial lymphedema of Grade I and Grade II (lower extremities) were included in the trial. The study group was treated with mass drug administration and AYUSH-SL or its placebo tablet.

Results: The control group had received mass drug administration and a matching placebo. The primary outcome measure was the reduction in edema calculated for analysis by percentage reduction from baseline at the 4 th , 12 th and 24 th week. Secondary outcome measures included improved quality of life (QoL), which was assessed using the Lymphatic Filariasis Specific QoL Questionnaire, and prevention of recurrence of acute episodes, which was evaluated by investigating the presence and severity of episodes in the past four weeks. The water displacement method for the evaluation of the efficacy of the intervention was shown to be highly significant compared to the baseline value (right leg; 3071.60±970.482, 2828.40±829.339, p<0.001and left leg; 3158.69±1136.391, 2890.73±1077.475, p<0.001).

Interpretation conclusion: There was significant improvement of Quality of Life in the LF QoL Questionnaire (p<0.001) at each follow-up visit in both groups. Safety estimations on hematologic and biochemical parameters were within limits and or changes were not significant. The results revealed that AYUSH-SL is safe and effective for lymphatic filariasis due to its comprehensive anti-inflammatory, antimicrobial, and anti-allergic activities.