Tropical Diseases, Travel Medicine and Vaccines最新文献

Objective: Acquired resistance to antifungal agents is rising among Candida species. Herbal extracts including Capsicum annum extracts have biological profits, which can be employed to overcome drug resistance in fungal species. The present study investigated the efficacy of different varieties of C. annum extracts against Candida species.

Methods: Aqueous and alcoholic extracts of three different varieties of C. annum were prepared using the succulent method. Total values for compound extracts of C. annum var. cayenne, C. annum var. cayenne cultivar sabzevari, and C. annum var. cerasiforme were 43, 42, and 38 g, respectively. The clinical Candida isolates including C. albicans (n = 13), C. dubliniensis (n = 2), C. parapsilosis (n = 2), and C. tropicalis (n = 1); and reference strains of C. albicans (TIMML 1292 and TIMML 183), C. krusei (TIMML 1321), C. parapsilosis (TIMML 2201), and C. tropicalis (TIMML 731) were examined based on the M27-A3 guideline.

Results: Aqueous and alcoholic extracts of Capsicum annum showed a minimum inhibitory concentration (MIC) range of more than 512 µg/ml against clinical and reference strains of Candida. There was no justifiable difference between the effects of these extracts on Candida species.

Conclusion: Both aqueous and alcoholic extracts of Capsicum annum could not exert a significant effective impact on clinical and reference strains of Candida. The difference in pepper spiciness did not show a significant role against Candida isolates. However, their possible effects might be different among other yeasts or filamentous fungi.

Background: In the Somali region of Ethiopia, visceral leishmaniasis (VL) is a public health concern. However, VL epidemiology and sand fly vectors have not been well studied in various areas of the regional state, including Denan district. Therefore, this study was conducted to determine the sero-prevalence, associated factors, and distribution of sand fly vectors of VL in Denan district, south-eastern Ethiopia.

Methods: A facility-based cross-sectional study was conducted from April to September 2021 among VL patients with classic signs and symptoms visiting Denan Health Center in south-eastern Ethiopia. Using a convenience sampling method, 187 blood samples were collected from individuals who visited Denan Health Center during the study period. Blood samples were subjected to Direct Agglutination Test for the detection of antibodies to VL. A pre-tested structured questionnaire was also used to gather information on risk factors and other characteristics of knowledge and attitude assessment. Sand flies were also collected from indoor, peri-domestic, mixed forest, and termite mounds using light and sticky traps to determine the fauna and abundance.

Results: The overall sero-prevalence rate was 9.63% (18/187). The sero-prevalence was significantly associated with outdoor sleeping (OR = 2.82), the presence of damp floors (OR = 7.76), and sleeping outdoor near animals (OR = 3.22). Around 53.48% of the study participants had previously heard about VL. Study participants practiced different VL control methods, including bed nets (42%), insecticide spraying (32%), smoking plant parts (14%), and environmental cleaning (8%). In total, 823 sand fly specimens, comprising 12 species in two genera (Phlebotomus and Sergentomyia), were trapped and identified. The most abundant species was Sergentomyia clydei (50.18%), followed by Phlebotomus orientalis (11.42%). Also, a higher proportion of P. orientalis was found in termite mounds (65.43%), followed by mixed forest (37.8%) and peri-domestic (20.83%) habitats.

Conclusion: The study demonstrated a 9.63% sero-positivity of VL and a remarkable gap in knowledge, attitude, and practices towards VL. P. orientalis was also detected, which could be a probable vector in this area. Thus, public education should be prioritized to improve the community's awareness of VL and its public health impact. In addition, detailed epidemiological and entomological studies are recommended.

Over the last decades, unimaginable amounts of money have gone into research and development of vector control measures, repellents, treatment, and vaccines for vector borne diseases. Technological progress and scientific breakthroughs allowed for ever more sophisticated and futuristic strategies. Yet, each year, millions of people still die or suffer from potentially serious consequences of malaria or dengue to more recent infections, such as zika or chikungunya, or of debilitating consequences of neglected tropical diseases. This does not seem value for money. In addition, all current vector control strategies and personal protection methods have shortcomings, some serious, that are either destructive to non-target species or unsatisfactory in their effectiveness. On the other hand, the rapid decline in insect populations and their predators reflects decades-long aggressive and indiscriminate vector control. This major disruption of biodiversity has an impact on human life not anticipated by the well-meaning killing of invertebrates. The objective of this paper is to re-examine current control methods, their effectiveness, their impact on biodiversity, human and animal health, and to call for scientific courage in the pursuit of fresh ideas. This paper brings together topics that are usually presented in isolation, thereby missing important links that offer potential solutions to long-standing problems in global health. First, it serves as a reminder of the importance of insects to human life and discusses the few that play a role in transmitting disease. Next, it examines critically the many currently employed vector control strategies and personal protection methods. Finally, based on new insights into insect chemo-sensation and attractants, this perspective makes a case for revisiting a previously abandoned idea, the oral repellent, and its use via currently successful methods of mass-application. The call is out for focused research to provide a powerful tool for public health, tropical medicine, and travel medicine.

Background: Dengue virus (DENV) infection is a global economic and public health concern, particularly in tropical and subtropical countries where it is endemic. Saudi Arabia has seen an increase in DENV infections, especially in the western and southwestern regions. This study aims to investigate the genetic variants of DENV-2 that were circulating during a serious outbreak in Jazan region in 2019.

Methods: A total of 482 serum samples collected during 2019 from Jazan region were tested with reverse transcription-polymerase chain reaction (RT-PCR) to detect and classify DENV; positive samples underwent sequencing and bioinformatics analyses.

Results: Out of 294 positive samples, type-specific RT-PCR identified 58.8% as DENV-2 but could not identify 41.2%. Based on sequencing and bioinformatics analyses, the samples tested PCR positive in the first round but PCR negative in the second round were found to be imported genetic variant of DENV-2. The identified DENV-2 imported variant showed similarities to DENV-2 sequences reported in Malaysia, Singapore, Korea and China. The results revealed the imported genetic variant of DENV-2 was circulating in Jazan region that was highly prevalent and it was likely a major factor in this outbreak.

Conclusions: The emergence of imported DENV variants is a serious challenge for the dengue fever surveillance and control programmes in endemic areas. Therefore, further investigations and continuous surveillance of existing and new viral strains in the region are warranted.

Background: Despite being first identified in 1947, Zika virus-related outbreaks were first described starting from 2007 culminating with the 2015 Latin American outbreak. Hypotheses indicate that the virus has been circulating in Asia for decades, but reports are scarce.

Methods: We performed serological analysis and screened placental samples isolated in 2008 for the presence of Zika virus from pregnant women in Ho Chi Minh City (Vietnam).

Results: None of the placental samples was positive for Zika virus. Four serum samples out of 176 (2.3%) specifically inhibited Zika virus, with variable degrees of cross-reactivity with other flaviviruses. While one of the four samples inhibited only Zika virus, cross-reactivity with other flaviviruses not included in the study could not be ruled out.

Conclusion: Our results support the conclusion that the virus was not present among pregnant women in the Vietnamese largest city during the initial phases of the epidemic wave.

Background: We aimed to investigate the aetiology and outcomes of illnesses in patients presenting to an emergency department after travelling to a malaria-endemic country, in order to raise awareness of both tropical and cosmopolitan diseases.

Methods: A retrospective chart review was performed for all patients who underwent blood smear testing for malaria at the Emergency Department of the University Hospitals Leuven from 2017 to 2020. Patient characteristics, results of laboratory and radiological examinations, diagnoses, disease course and outcome were collected and analysed.

Results: A total of 253 patients were included in the study. The majority of ill travellers returned from Sub-Saharan Africa (68.4%) and Southeast Asia (19.4%). Their diagnoses fell into three major syndrome categories: systemic febrile illness (30.8%), inflammatory syndrome of unknown origin (23.3%) and acute diarrhoea (18.2%). Malaria (15.8%) was the most common specific diagnosis in patients with systemic febrile illness, followed by influenza (5.1%), rickettsiosis (3.2%), dengue (1.6%), enteric fever (0.8%), chikungunya (0.8%) and leptospirosis (0.8%). The presence of hyperbilirubinemia and thrombocytopenia increased the probability of malaria, with a likelihood ratio of 4.01 and 6.03, respectively. Seven patients (2.8%) were treated in the intensive care unit, and none died.

Conclusion: Systemic febrile illness, inflammatory syndrome of unknown origin and acute diarrhoea were the three major syndromic categories in returning travellers presenting to our emergency department after a stay in a malaria-endemic country. Malaria was the most common specific diagnosis in patients with systemic febrile illness. None of the patients died.

Background: Rat lung worm disease (RLWD) has several clinical forms including eosinophilic meningitis (EOM) and two severe forms, eosinophilic meningoencephalitis (EOME) and eosinophilic radiculomyelitis (EORM). It remains unclear whether transmission sources are associated with severe forms of RLWD. This study aimed to evaluate if transmission factors are related to the severity of RLWD among travelers by using a scoping review of case reports.

Methods: This was a review using five databases to retrieve case reports and case series of travelers with RLWD. Clinical data and transmission sources of reported cases diagnosed as RLWD were retrieved. The outcome of the study was occurrence of severe forms of RLWD defined as EOME, EORM, and combined EOME/EORM.

Results: We retrieved 1,326 articles from five databases and 31 articles were included in the analysis. There were 84 cases eligible from 15 countries. Four cases were excluded. Seventy cases were in EOM group and 10 cases had EOME or EORM. Compared with the EOM group, the EOME, EORM, and combination EOME/EORM group had similar age, sex, and risk factors of consumptions of apple snails, shrimp and prawn, and salad/vegetables. The EOME group had higher proportion of consumption of African snails than the EOM group (60% vs 13.8%). However, only one study reported the consumption of African snails and the heterogeneity between studies and the small sample size impeded direct comparisons between groups.

Conclusions: RLWD in travelers can be found in most continents and mostly get infected from endemic countries of RLWD. Further studies are required to evaluate the association between transmission vectors and severity of RLWD.

Background: Yellow fever is a viral hemorrhagic fever caused by yellow fever virus, a mosquito-borne flavivirus. Despite an effective vaccine, major outbreaks continue to occur around the world. Even though it is not a proven neurotropic virus, neurological symptoms in more severe clinical forms are frequent. The understanding of this apparent paradox is still rarely addressed in literature.

Methods: The brains of thirty-eight patients with yellow fever confirmed by RT-PCR, who underwent autopsy, were analyzed morphologically to identify and characterize neuropathological changes. The data were compared with brains collected from individuals without the disease, as a control group. Both cases and controls were subdivided according to the presence or absence of co-concurrent septic shock, to exclude changes of the sepsis associated encephalopathy. To verify possible morphological differences between the yellow fever cases groups, between the control groups, and between the cases and the controls, we applied the statistical tests Fisher's exact test and chi-square, with p values < 0.05 considered statistically significant.

Results: All cases and controls presented, at least focally, neuropathological changes, which included edema, meningeal and parenchymal inflammatory infiltrate and hemorrhages, and perivascular inflammatory infiltrate. We did not find an unequivocal aspect of encephalitis. The only parameter that, after statistical analysis, can be attributed to yellow fever was the perivascular inflammatory infiltrate.

Conclusions: The neuropathological findings are sufficient to justify the multiple clinical neurologic disturbances detected in the YF cases. Since most of the parameters evaluated did not show statistically significant difference between cases and controls, an explanation for most of the neuropathological findings may be the vascular changes, consequent to shock induced endotheliopathy, associated with stimulation of the immune system inherent to systemic infectious processes. The statistical difference obtained in yellow fever cases regarding perivascular infiltrate can be can be explained by the immune activation inherent to the condition.

Background: Hump-nosed vipers (HNV; Hypnale spp) are one of the medically important venomous snakes in Sri Lanka and South-Western regions of India. The haemostatic dysfunction due to HNV bites is poorly characterized by standard diagnostic tests performed to identify coagulopathy. We aimed to determine the usefulness of rotational thromboelastometry (ROTEM) parameters compared to 20-minute whole blood clotting test (WBCT20) and prothrombin time (PT) in understanding the coagulopathy of HNV bites.

Methods: Twenty-three HNV snakebite patients in a prospective study of 127 consecutive snakebites were recruited. After recording details of the clinical presentation, PT/international normalized ratio (INR), WBCT20 and ROTEM delta were performed at presentation.

Results: In this preliminary study, none of the patients had clinically apparent bleeding. Coagulopathy was detected by either WBCT20, INR or ROTEM in 13 HNV patients. Eleven had a coagulopathy detectable by ROTEM (either abnormal EXTEM-CT, INTEM-CT or FIBTEM-MCF) but with negative WBCT20. Of them, only two had prolonged INR values. Two patients had positive WBCT20 but with normal ROTEM and INR values. The remaining 10 patients did not show any coagulopathy either by INR, ROTEM or WBCT20.

Conclusion: In this preliminary study with small number of sample size, ROTEM parameters appeared to be more sensitive to subtle changes in coagulation compared to WBCT20. The clinical utility of detecting these changes and their usefulness in managing snakebite should be explored further in a larger study.