Journal of Tropical Medicine最新文献

The isolation of nucleic acids is a critical and limiting step for molecular assays, which prompted the arrival in Colombia of automated purification instruments during the SARS-CoV-2 pandemic. The local application of this technology in the study of tropical diseases, such as dengue and zika, is beginning to be tested. We evaluated the efficiency of the automated extraction of viral RNA for studies of pediatric dengue and zika. Clinical samples of children with dengue that were well characterized through RNA isolation by silica columns and serotype-specific nested RT-PCR (DENV-1 n = 7, DENV-2 n = 5, and negatives n = 8) in addition to 40 pediatric plasma samples spiked with ZIKV (strain PRVA BC59) and 209 from negative pre-epidemic children were analyzed. RNA from patients was extracted by two automated standard and high-throughput protocols on the KingFisher™ Flex instrument. The isolated RNA was evaluated for concentration and purity by spectrophotometry, for structural and functional integrity by electrophoresis and expression of the RNase P gene, and usefulness in serotype-specific DENV detection by conventional and real-time RT-PCR. For the evaluation of ZIKV RNA, the commercial TaqMan Triplex® assay was used, along with a well-tested in-house RT-qPCR assay. The concentration of RNA (5.2 vs. 7.5 ng/μL, P=0.03) and the number of integral bands (9 vs. 11) were higher with the high-throughput protocol. However, the number of specimens serotyped for DENV by RT-qPCR was comparable for both protocols. The cycle thresholds of the TaqMan Triplex® commercial kit and the in-house assay for the detection of plasma ZIKV RNA isolated with the standard protocol showed a strong association (r = 0.93, P < 0.0001) and a Cohen Kappa index of 0.98 when all 249 samples were analyzed. These preliminary results suggest that automated instruments could be used in studies of cocirculating flaviviruses that have represented a public health problem in recent decades in Colombia. They boast advantages such as efficiency, precision, time savings, and lower risk of cross-contamination.

Background: Vegetable and fruit consumptions are important for health as they are good sources of carbohydrates, vitamins, minerals, and fiber. However, contamination of vegetables and fruits is indicated as the main contributing factor to parasitic contamination.

Objective: This study aims to assess the prevalence and associated factors of intestinal parasites among fruits and vegetables collected from local markets in Bule Hora Town, Southeast Ethiopia.

Methods: A cross-sectional assessment was carried out on 391 raw fruits and vegetables from the market in Bule Hora Town from July 29 to August 17, 2022. After being soaked in physiological saline and vigorously shaken for 15 minutes with the help of a mechanical shaker, a total of 391 samples taken from various fruits and vegetables were evaluated using the sedimentation concentration technique. Software SPSS version 25 was used to analyze the data after it had been entered using EpiData version 3.1. To assess various associated factors, binary and multivariable logistic regression was employed.

Results: 142 (36.3%) of the 391 samples analyzed had at least one species of parasite. The parasite Ascaris lumbricoides (40.1%) was found the most frequently, whereas Strongyloides spp. was found the least frequently. Variables such as fingernail trimming (AOR = 1.99; 95% CI: 1.274-3.108), hand washing habit with soap after using toilet (AOR = 2.912; CI: 1.896-4.47), and eating raw vegetables or fruits (AOR = 0.604; CI: 0.394-0.925) were associated with parasitic contamination.

Conclusions: The results of this study show that eating vegetables that are raw in the study area carries a potentially significant risk of contracting parasitic illnesses. Therefore, the appropriate bodies should make an effort to lower the rate of product contamination with intestinal parasites by educating vendors and the general public.

Objectives: We aimed to model and predict the changes in the trend of vector-borne diseases (VBDs) before and after the COVID-19 pandemic in a high-risk area of Iran.

Methods: This case-series study was conducted in Fars province, south of Iran, between April 2016 and July 2021. All referred cases of VBDs were considered during the five years to investigate the effect of the lockdown on the epidemiological profile of these diseases. We used time-series autoregressive integrated moving average (ARIMA) and seasonal ARIMA (SARIMA) models.

Results: Pediculosis incidence trend was rising with a peak of 1,146 per 100,000 in 2018, followed by a dramatic decrease reached to the minimum amount of 157.8 per 100,000 in 2021. In contrast, malaria and scabies had a smooth decreasing trend ranging from 2.2 per 100,000 and 7.3 per 100,000 in 2016 to a minimum of 0.2 per 100,000 in 2021, respectively. Likewise, leishmaniasis had a falling trend, with a maximum rate of 82.9 per 100,000 in 2016 to the lowest rate of 9.4 per 100,000 in 2021. However, the difference between observed and expected values revealed that the consequences of the COVID-19 pandemic had increased the number of leishmaniasis cases.

Conclusion: Tropical regions of Iran, including Fars province, are the favorite destinations for travelers. During COVID-19 outbreaks, some reasons, such as quarantine, movement restrictions, and social distancing, reduced human-vector contact and finally led to the reduction of VBDs in this area.

The present study was done to evaluate the prevalence of intestinal parasitic infections (IPIs) in patients with COVID-19 in health care centers (Imam Reza and Golestan hospitals), Tehran, capital of Iran. By designing a matched case-control study, 200 fecal samples were collected for each of the COVID-19 patients and healthy individuals. Nasopharyngeal/oropharyngeal swab samples were collected from all participants for the diagnosis of COVID-19. RNA extraction was performed, and then real time reverse-transcription polymerase chain reaction (rRT-PCR) assay was applied to detect viral RNA. Considering the lung complications, 25%> lung complications was detected in 49 patients, 25-49% in 42 patients, and 50%≤ in 109 patients. Fecal samples were examined using different parasitological techniques. After nested-PCR, sequencing was applied to identify Cryptosporidium spp. and microsporidia spp. A relatively lower prevalence of IPIs was detected among control group (7.5%), than in COVID-19 patients (13%), though not significant (P=0.13). The most prevalent parasite among patients was Blastocystis sp. (6%). Also, 13.76% of IPIs were detected in inpatients with more than 50% lung complication. As well, a remarkably significant difference in IPIs was observed among diarrheic COVID-19 patients, in comparison with nondiarrheic patients (P < 0.00001). Moreover, the isolated sequences in the present study belonged to C. parvum subtype IIa and Enterocytozoon bieneusi genotypes D and Peru 8. In conclusion, more epidemiological and clinical research studies are needed to better understand the status and interaction of IPI in COVID-19 in Iran and other countries.

Cutaneous Mycobacterium marinum infection is an increasingly infectious disease presenting unique diagnostic and therapeutic challenges. The aim of this study was to evaluate the differences in time to treatment among patients with different types of skin lesions and who were treated with single or multidrug therapies. In addition, the clinical characteristics of M. marinum infection were explored and the mechanism of the host immune responses was investigated. The electronic medical records of 35 patients with M. marinum infection were reviewed. The clinical characteristics, histopathological and laboratory data, and treatment outcomes were analyzed. Immunohistochemical analysis was performed to clarify the immune mechanisms induced by M. marinum infection in 9 patients and 5 healthy controls. Of the 35 patients, 25 (71.4%) had lesions with sporotrichoid patterns. The duration of patients with sporotrichoid lesions or treatment with multiple drugs was longer, although differences were not significant, possibly due to the small cohort. However, this trend was also observed in previous studies, making it worthy of further attention. Expression levels of cytokines (IFN-γ, IL-4, IL-9, and FOXP3) were significantly upregulated in the patient specimens, whereas there were no significant differences in IL-17 and IL-22 expression levels between the patient and control groups.

Background: Soil-transmitted helminths are parasitic nematodes found in the intestine. They are more prevalent in the tropics and subtropics, including Ethiopia. However, low-sensitive direct wet mount microscopy fails to detect soil-transmitted helminths among infected cases. Therefore, more sensitive and cost-effective diagnostic methods are urgently needed to minimize soil-transmitted helminthiasis morbidity.

Objective: This study aimed to compare and evaluate the performance of diagnostic methods for soil-transmitted helminths against the "gold" standard.

Methods: An institution-based cross-sectional study was conducted among 421 schoolchildren from May to July, 2022 in the Amhara Region. Study participants were selected using a systematic random sampling technique. Stool samples were processed via Kato-Katz, McMaster, and spontaneous tube sedimentation techniques. Data were entered into epi-data version 3.1 and analyzed using SPSS version 25. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated against the combined result as a "gold" standard. The strength of agreement between the diagnostic methods was determined by the Kappa value.

Results: The overall prevalence of soil-transmitted helminths was 32.8% (95% CI: 28.2-37.8%) using a combination of methods. The detection rates of Kato-Katz, McMaster, and spontaneous tube sedimentation were 28.5% (95% CI: 24.2-33.2%), 30% (95% CI: 25.6-34.8%), and 30.5% (95% CI: 26.1-35.3%), respectively. Sensitivity and negative predictive values were 87.1% (95% CI: 80.2-92.3%) and 95.1% (95% CI: 92.6-96.8%) for Kato-Katz; 91.7% (95% CI: 85.6-95.6%) and 96.5% (95% CI: 94.1-98.0%) for McMaster; and 93.2% (95% CI: 87.5-96.8%) and 97.1% (95% CI: 94.7-98.4%) for spontaneous tube sedimentation. Kappa values of Kato-Katz, McMaster, and spontaneous tube sedimentation for the diagnosis of soil-transmitted helminths were 0.901, 0.937, and 0.948, respectively.

Conclusion: Kato-Katz, McMaster, and spontaneous tube sedimentation techniques had comparable sensitivity with almost perfect agreement for the detection of soil-transmitted helminths. Therefore, the spontaneous tube sedimentation technique can be used as an alternative diagnostic method for soil-transmitted helminth infections in endemic countries.

Background: The current study aimed to evaluate the therapeutic features and complications of liver hydatid cyst in patients who underwent surgery for cystic echinococcosis (CE) in Fars province, southern Iran.

Methods: A total of 293 patients who underwent surgery for liver hydatid cyst from 2004 to 2018 in Fars province, southern Iran, were retrospectively evaluated. The clinical records of patients were reviewed, and the demographic and clinical characteristics of each patient were assessed.

Results: Of the total of 293 cases, 178 (60.9%) were females and 115 (39.1%) were males. The mean age of the subjects was 37.22 (±20.55) years. The mean size of the liver hydatid cyst was 9.18 (±4.365) cm. Of the 293 patients studied, 227 (77.4%) had hydatid cysts only in the liver, while 55 (9.4%) had both liver and lung cysts. More than half of the liver cysts (65.9%) were located in the right portion of the liver (segment 5 to 8). Of the 293 cases, 52 (17.7%) underwent radical surgery, while 241 (82.3%) underwent conservative surgery. Recurrence of hydatid cyst was recorded in 46 (15%) of cases. Patients who were treated with radical surgery in comparison with those who had conservative surgery had a lower recurrence rate but a longer duration of hospital stay (P < 0.05).

Conclusion: Recurrence remains as one of the major challenges in the management of hydatid cyst. Radical surgery reduces the chance of recurrence, although this procedure increases the length of hospital stay.

Materials and methods: Salvadora persica stem bark was extracted with two different solvents, i.e., ethyl acetate and water, and preliminary phytochemical screening was performed. Two behavioral models were used: an elevated plus maze test (EPM) and the light and dark model test for anxiolytic parameters, and a forced swim test (FST) for antidepressant effects. Healthy mice weighing 18-40 gms were treated orally in four groups (n = 6), i.e., negative control treated with normal saline and positive control with 1 mg/kg diazepam (EPM) and 30 mg/kg fluoxetine (FST), and the test groups were treated with 500 mg/kg of aqueous and ethyl acetate Sp extract. The number of entries and duration spent in the open arm for 5 minutes were the parameters for evaluating the anxiolytic activity (EPM). Duration of immobility was measured for 5 min in the FST model.

Results: In EPM, both the Sp extracts significantly (p < 0.005) increased the number of entries and the time spent in the open arms and was much similar to those of diazepam. Similarly, these extracts and fluoxetine significantly (p < 0.005) decreased the immobility time in FST.

Conclusion: The results suggest the therapeutic potential of Salvadora persica an alternative in the management of comorbid anxiety and depression.

Snakebite is a global public health concern, which often occurs in tropical and subtropical underdeveloped areas, but it is often neglected. In the southern China, Naja naja atra (Chinese cobra) is a common venomous snake that causes swelling and necrosis of local tissues, even amputation and death. Currently, the main therapy is the administration of Naja atra antivenom, which greatly reduces mortality. However, the antivenom is not particularly effective in the improvement of local tissue necrosis. Clinically, antivenom is mainly administered intravenously. We speculated that the method of injection influences the efficacy of antivenom. In this study, the rabbit model was used to explore the effects of different antivenom injection methods on systemic and local poisoning symptoms. If topical injection of antivenom contributes to ameliorate tissue necrosis, then we need to reconsider the use of Naja atra antivenom.