ResearchPad - neglected-tropical-diseases https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Genetic diversity of <i>Echinococcus multilocularis</i> and <i>Echinococcus granulosus sensu lato</i> in Kyrgyzstan: The A2 haplotype of <i>E</i>. <i>multilocularis</i> is the predominant variant infecting humans]]> https://www.researchpad.co/article/elastic_article_13871 Analysis of the genetic variability in Echinococcus species from different endemic countries have contributed to the knowledge in the taxonomy and phylogeography of these parasites. The most important species of this genus, Echinococcus granulosus sensu lato and Echinococcus multilocularis, co-exist in Kyrgyzstan causing serious public health issues. E. granulosus s.l. causes cystic echinococcosis and E. multilocularis is the causative agent of alveolar echinococcosis. The most relevant finding of our study is the identification of the cob/nad2/cox1 A2 haplotype of E. multilocularis as the most commonly found in humans and dogs. However, it remains unknown if this variant of E. multilocularis, based on genetic differences in mitochondrial genes, presents differences in virulence which could have contributed to the emergence of alveolar echinococcosis in Kyrgyzstan. The results also show a number of non-previously described genetic variants of E. multilocularis and E. granulosus s.s.

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<![CDATA[Impacts of host gender on <i>Schistosoma mansoni</i> risk in rural Uganda—A mixed-methods approach]]> https://www.researchpad.co/article/elastic_article_13851 Globally, over 230 million people are infected with schistosomiasis, an infectious disease caused by parasitic helminths. Humans can get infected when they contact water which contains Schistosoma parasites. Although the disease can be treated with a drug, people get rapidly reinfected in certain high-transmission settings. Drug treatment alone may not be sufficient to eliminate this disease and additional interventions such as health promotion or improvements in water and sanitation need to be scaled up. To provide recommendations to these control programmes we carried out interdisciplinary research in Eastern Uganda to understand the influence of gender on schistosomiasis risk. We found that the water contact behaviour of boys and girls is quite similar, and we did not see differences in reinfection or genetic diversity of the parasite between boys and girls. Differences in water contact between genders is greater in adults, and further research is required for these individuals. In this setting, infection rates are high in school-aged children and there are no differences between genders. These results emphasise improved control efforts for all school-aged children in communities like these. Our interdisciplinary approach provided complementary findings. Such an integrated approach can therefore have more power to meaningfully inform policy on schistosomiasis control.

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<![CDATA[Assessing entomological risk factors for arboviral disease transmission in the French Territory of the Wallis and Futuna Islands]]> https://www.researchpad.co/article/elastic_article_13872 The French overseas Territory of the Wallis and Futuna Islands, located in the South Pacific, has been affected by several dengue epidemics, but did not face Zika or chikungunya outbreaks, unlike other neighboring islands. The near-exclusive presence of the Aedes polynesiensis mosquito in the islands of Wallis and Futuna confirmed the role played by this mosquito as a vector of dengue fever. A local Ae. polynesiensis population was recently shown to be able to transmit the Zika virus under experimental conditions, but its susceptibility to the chikungunya virus was still unknown, and recent data on the presence of other potential arbovirus vectors were missing. Therefore, we investigated the entomological risk factors for the transmission of arboviral diseases in the Wallis and Futuna Islands. We reported the occurrence and distribution of different Aedes species, especially the abundant presence of Ae. polynesiensis across the territory and the spread of Ae. aegypti in the island of Wallis. Our results demonstrated the ability of local Ae. polynesiensis populations to transmit the chikungunya virus. These findings highlight the risk of arbovirus transmission in the Wallis and Futuna Islands and provide relevant data to guide prevention and vector control strategies in the territory.

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<![CDATA[Amino acids serve as an important energy source for adult flukes of <i>Clonorchis sinensis</i>]]> https://www.researchpad.co/article/elastic_article_13829 Clonorchiasis, closely related to cholangiocarcinoma and hepatocellular carcinoma, has led to a negative socioeconomic impact in global areas especially some Asian endemic regions. Owing to the emergence of drug resistance and hypersensitivity reactions after the massive and repeated use of praziquantel as well as the lack of effective vaccines, searching for new strategies that prevent and treat clonorchiasis has become an urgent matter. Clonorchis sinensis, the causative agent of clonorchiasis, long-term inhabits the microaerobic and limited-glucose environment of the bile ducts. Adequate nutrients are essential for adult flukes to resist the adverse condition and survive in the crowed habitat. Studies on energy metabolism of adult flukes are beneficial for further exploring host-parasite interactions and developing novel anti-parasitic drugs. Our results suggest that gluconeogenesis probably plays a vital role in energy metabolism of Clonorchis sinensis and exogenous amino acids might be an essential energy source for adult flukes to successfully survive in the host. Our foundational study opens a new avenue for explaining energy metabolism of Clonorchis sinensis and provides a valuable strategy that the gluconeogenesis pathway will be a potential and novel target for the prevention and treatment of clonorchiasis.

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<![CDATA[Integrating testing for chronic strongyloidiasis within the Indigenous adult preventive health assessment system in endemic communities in the Northern Territory, Australia: An intervention study]]> https://www.researchpad.co/article/elastic_article_13848 Strongyloidiasis is a neglected tropical disease that is endemic in some Aboriginal communities in the Northern Territory. This study asks if the number and proportion of persons tested for chronic strongyloidiasis can be increased by incorporating a Strongyloides serology test into the existing routine Indigenous adult preventive health assessment system in remote endemic communities. This study demonstrated that integrating Strongyloides serology test within the Indigenous adult preventive health assessment system does increase the number and proportion of people tested in endemic communities. This intervention means that life-threatening clinical complications of strongyloidiasis can be prevented by early detection and treatment. Primary health care services have an important role in increased testing in this high-risk population. Primary health care clinicians incorporated chronic strongyloidiasis with other preventable chronic and infectious diseases. The sustainable population health systems-based approach successfully increased coverage by integrating testing for chronic strongyloidiasis into the adult preventive health assessment in health services in remote Indigenous Australian endemic communities, utilising the electronic health record system. The Strongyloides report developed to measure the change in clinical practice would be replicable in other health services with high risk populations.

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<![CDATA[A systematic review of alternative surveillance approaches for lymphatic filariasis in low prevalence settings: Implications for post-validation settings]]> https://www.researchpad.co/article/elastic_article_13802 Lymphatic filariasis (LF) is a mosquito-borne disease, which can result in complications including swelling affecting the limbs (lymphoedema) or scrotum (hydrocele). LF can be eliminated by mass drug administration (MDA) which involves whole communities taking drug treatment at regular intervals. After MDA programmes, country programmes conduct the Transmission Assessment Survey (TAS), which tests school children for LF. It is important to continue testing for LF after elimination because there can be a 10-year period between becoming infected and developing symptoms, but it is thought that the use of TAS in such settings is likely to be too expensive and also not sensitive enough to detect low-level infections. Our study assesses the results from 44 studies in areas of low LF prevalence that have investigated methods of surveillance for LF which differ from the standardised TAS approach. These include both human and mosquito studies. Results show that there is currently no standardised approach to testing, but that surveillance can be made more sensitive through the use of new diagnostic tests, such as antibody testing, and also by targeting higher risk populations. However, further research is needed to understand whether these approaches work in a range of settings and whether they are affordable on the ground.

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<![CDATA[Investigating barriers and challenges to the integrated management of neglected tropical skin diseases in an endemic setting in Nigeria]]> https://www.researchpad.co/article/elastic_article_13828 Community perceptions of causation of neglected tropical diseases (NTDs) of the skin may play an important role in access to or utilization of health services. The World Health Organization (WHO) has recommended empowerment of populations affected by or at risk of NTDs in control interventions. Furthermore, the WHO recommends that social mobilisation needs to be maintained in order to create demand for integrated management of skin NTDs and to address specific community aspects and concerns related to the diseases. There are no studies on community knowledge, attitudes and practices (KAP) on skin NTDs co-occurring in the same community in Nigeria. We surveyed community members and health workers and also held group discussions with community members, health workers and individuals with lymphatic filariasis and Buruli ulcer in order to assess their understanding of the causes, treatment and effects of the skin NTDs (leprosy, Buruli ulcer and lymphatic filariasis) which were all occurring in the study communities. There was a shared understanding that these NTDs were caused by germ/infection or through witchcraft/curse/poison. Also, a substantial proportion of the community believed that these conditions are not amenable to treatment. The focus group discussions reinforced these findings.

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<![CDATA[Forecasting the monthly incidence rate of brucellosis in west of Iran using time series and data mining from 2010 to 2019]]> https://www.researchpad.co/article/elastic_article_13811 The identification of statistical models for the accurate forecast and timely determination of the outbreak of infectious diseases is very important for the healthcare system. Thus, this study was conducted to assess and compare the performance of four machine-learning methods in modeling and forecasting brucellosis time series data based on climatic parameters.MethodsIn this cohort study, human brucellosis cases and climatic parameters were analyzed on a monthly basis for the Qazvin province–located in northwestern Iran- over a period of 9 years (2010–2018). The data were classified into two subsets of education (80%) and testing (20%). Artificial neural network methods (radial basis function and multilayer perceptron), support vector machine and random forest were fitted to each set. Performance analysis of the models were done using the Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Root Error (MARE), and R2 criteria.ResultsThe incidence rate of the brucellosis in Qazvin province was 27.43 per 100,000 during 2010–2019. Based on our results, the values of the RMSE (0.22), MAE (0.175), MARE (0.007) criteria were smaller for the multilayer perceptron neural network than their values in the other three models. Moreover, the R2 (0.99) value was bigger in this model. Therefore, the multilayer perceptron neural network exhibited better performance in forecasting the studied data. The average wind speed and mean temperature were the most effective climatic parameters in the incidence of this disease.ConclusionsThe multilayer perceptron neural network can be used as an effective method in detecting the behavioral trend of brucellosis over time. Nevertheless, further studies focusing on the application and comparison of these methods are needed to detect the most appropriate forecast method for this disease. ]]> <![CDATA[New estimates of the Zika virus epidemic attack rate in Northeastern Brazil from 2015 to 2016: A modelling analysis based on Guillain-Barré Syndrome (GBS) surveillance data]]> https://www.researchpad.co/article/elastic_article_7754 The mandatory reporting of the Zika virus (ZIKV) disease began region-wide in February 2016, and it is believed that ZIKV cases could have been highly under-reported before that. Given the Guillain-Barré syndrome (GBS) is relatively well reported, the GBS surveillance data has the potential to act as a reasonably reliable proxy for inferring the true ZIKV epidemics. We developed a mathematical model incorporating weather effects to study the ZIKV-GBS epidemics and estimated the key epidemiological parameters. It was found that the attack rate of ZIKV was likely to be lower than 33% over the two epidemic waves. The risk rate from symptomatic ZIKV case to develop GBS was estimated to be approximately 0.0061%. The analysis suggests that it would be difficult for another ZIKV outbreak to appear in Northeastern Brazil in the near future.

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<![CDATA[Gene Conversion Transfers the GAF-A Domain of Phosphodiesterase TbrPDEB1 to One Allele of TbrPDEB2 of Trypanosoma brucei]]> https://www.researchpad.co/article/5989da89ab0ee8fa60b9d706

Background

Chromosome 9 of Trypanosoma brucei contains two closely spaced, very similar open reading frames for cyclic nucleotide specific phosphodiesterases TbrPDEB1 and TbrPDEB2. They are separated by 2379 bp, and both code for phosphodiesterases with two GAF domains in their N-terminal moieties and a catalytic domain at the C-terminus.

Methods and Findings

The current study reveals that in the Lister427 strain of T. brucei, these two genes have undergone gene conversion, replacing the coding region for the GAF-A domain of TbrPDEB2 by the corresponding region of the upstream gene TbrPDEB1. As a consequence, these strains express two slightly different versions of TbrPDEB2. TbrPDEB2a represents the wild-type phosphodiesterase, while TbrPDEB2b represents the product of the converted gene. Earlier work on the subcellular localization of TbrPDEB1 and TbrPDEB2 had demonstrated that TbrPDEB1 is predominantly located in the flagellum, whereas TbrPDEB2 partially locates to the flagellum but largely remains in the cell body. The current findings raised the question of whether this dual localization of TbrPDEB2 may reflect the two alleles. To resolve this, TbrPDEB2 of strain STIB247 that is homozygous for TbrPDEB2a was tagged in situ, and its intracellular localization was analyzed.

Conclusions

The results obtained were very similar to those found earlier with Lister427, indicating that the dual localization of TbrPDEB2 reflects its true function and is not simply due to the presence of the two different alleles. Notably, the gene conversion event is unique for the Lister427 strain and all its derivatives. Based on this finding, a convenient PCR test has been developed that allows the stringent discrimination between Lister-derived strains that are common in many laboratories and other isolates. The technique is likely very useful to resolve questions about potential mix-ups of precious field isolates with the ubiquitous Lister strain.

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<![CDATA[Gender norms and mass deworming program access in Comé, Benin: A qualitative assessment of gender-associated opportunities and challenges to achieving high mass drug administration coverage]]> https://www.researchpad.co/article/N0cbc3c85-9c5e-43fe-983c-4afc7d1b8db3

The World Health Organization’s Neglected Tropical Disease Roadmap has accelerated progress towards eliminating select neglected tropical diseases (NTDs). This momentum has catalyzed research to determine the feasibility of interrupting transmission of soil-transmitted helminths (STH) using community-wide mass drug administration (MDA). This study aims to identify potential gender-specific facilitators and barriers to accessing and participating in community-wide STH MDA, with the goal of ensuring programs are equitable and maximize the probability of interrupting STH transmission. This research was conducted prior to the launch of community-wide MDA for STH in Comé, Benin. A total of 10 focus group discussions (FGDs) were conducted separately among 40 men, 38 women, and 15 community drug distributors (CDDs). Salient themes included: both men and women believe that community-wide MDA would reduce the financial burden associated with self-treatment, particularly for low income adults. Community members believe MDA should be packaged alongside water, sanitation, and other health services. Women feel past community-wide programs have been disorganized and are concerned these distributions will be similar. Women also expressed interest in increased engagement in the implementation of future community-based public health programs. Men often did not perceive themselves to be at great risk for STH infection and did not express a high demand for treatment. Finally, the barriers discussed by CDDs generally did not align with gender-specific concerns, but rather represented concerns shared by both genders. A door-to-door distribution strategy for STH MDA is preferred by women in this study, as this platform empowers women to participate as health decision makers for their family. In addition, involving women in planning and implementation of community-wide programs may help to increase treatment coverage and compliance.

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<![CDATA[Identification of cholera hotspots in Zambia: A spatiotemporal analysis of cholera data from 2008 to 2017]]> https://www.researchpad.co/article/Nb4ea4681-5c5d-42bd-a1ce-642b56a34f03

The global burden of cholera is increasing, with the majority (60%) of the cases occurring in sub-Saharan Africa. In Zambia, widespread cholera outbreaks have occurred since 1977, predominantly in the capital city of Lusaka. During both the 2016 and 2018 outbreaks, the Ministry of Health implemented cholera vaccination in addition to other preventative and control measures, to stop the spread and control the outbreak. Given the limitations in vaccine availability and the logistical support required for vaccination, oral cholera vaccine (OCV) is now recommended for use in the high risk areas (“hotspots”) for cholera. Hence, the aim of this study was to identify areas with an increased risk of cholera in Zambia. Retrospective cholera case data from 2008 to 2017 was obtained from the Ministry of Health, Department of Public Health and Disease Surveillance. The Zambian Central Statistical Office provided district-level population data, socioeconomic and water, sanitation and hygiene (WaSH) indicators. To identify districts at high risk, we performed a discrete Poisson-based space-time scan statistic to account for variations in cholera risk across both space and time over a 10-year study period. A zero-inflated negative binomial regression model was employed to identify the district level risk factors for cholera. The risk map was generated by classifying the relative risk of cholera in each district, as obtained from the space-scan test statistic. In total, 34,950 cases of cholera were reported in Zambia between 2008 and 2017. Cholera cases varied spatially by year. During the study period, Lusaka District had the highest burden of cholera, with 29,080 reported cases. The space-time scan statistic identified 16 districts to be at a significantly higher risk of having cholera. The relative risk of having cholera in these districts was significantly higher and ranged from 1.25 to 78.87 times higher when compared to elsewhere in the country. Proximity to waterbodies was the only factor associated with the increased risk for cholera (P<0.05). This study provides a basis for the cholera elimination program in Zambia. Outside Lusaka, the majority of high risk districts identified were near the border with the DRC, Tanzania, Mozambique, and Zimbabwe. This suggests that cholera in Zambia may be linked to movement of people from neighboring areas of cholera endemicity. A collaborative intervention program implemented in concert with neighboring countries could be an effective strategy for elimination of cholera in Zambia, while also reducing rates at a regional level.

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<![CDATA[Feasibility of establishing an HIV vaccine preparedness cohort in a population of the Uganda Police Force: Lessons learnt from a prospective study]]> https://www.researchpad.co/article/Ne890bb8a-5661-4c39-82f7-6f40a2e69675

Background

Members of uniformed armed forces are considered to be at high risk for HIV infection and have been proposed as suitable candidates for participation in HIV intervention studies. We report on the feasibility of recruitment and follow up of individuals from the community of the Uganda Police Force (UPF) for an HIV vaccine preparedness study.

Methods

HIV-negative volunteers aged 18–49 years, were identified from UPF facilities situated in Kampala and Wakiso districts through community HIV counselling and testing. Potential volunteers were referred to the study clinic for screening, enrolment and quarterly visits for one year. HIV incidence, retention rates were estimated and expressed as cases per 100 person years of observation (PYO). Rate ratios were used to determine factors associated with retention using Poisson regression models.

Results

We screened 560 to enroll 500 volunteers between November 2015 and May 2016. One HIV seroconversion occurred among 431 PYO, for an incidence rate of 0.23/100 PYO (95% confidence interval [CI]: 0.03–1.64). Overall, retention rate was 87% at one year, and this was independently associated with residence duration (compared to <1 year, 1 to 5 years adjusted rate ratio (aRR) = 1.19, 95%CI: 1.00–1.44); and >5 years aRR = 1.34, 95%CI: 0.95–1.37); absence of genital discharge in the last 3 months (aRR = 1.97, 95% CI: 1.38–2.83, absence of genital ulcers (aRR = 1.90, 95%CI: 1.26–2.87, reporting of new sexual partner in the last month (aRR = 0.57, 95%CI: 0.45–0.71, being away from home for more than two nights (aRR = 1.27, 95%CI: 1.04–1.56, compared to those who had not travelled) and absence of knowledge on HIV prevention (aRR = 2.67, 95%CI: 1.62–4.39).

Conclusions

While our study demonstrates the feasibility of recruiting and retaining individuals from the UPF for HIV research, we did observe lower than anticipated HIV incidence, perhaps because individuals at lower risk of HIV infection may have been the first to come forward to participate or participants followed HIV risk reduction measures. Our findings suggest lessons for recruitment of populations at high risk of HIV infection.

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<![CDATA[Antibiotic use for Australian Aboriginal children in three remote Northern Territory communities]]> https://www.researchpad.co/article/N999fa4e6-a15c-456a-862e-2e1ce88316a9

Objective

To describe antibiotic prescription rates for Australian Aboriginal children aged <2 years living in three remote Northern Territory communities.

Design

A retrospective cohort study using electronic health records.

Setting

Three primary health care centres located in the Katherine East region.

Participants

Consent was obtained from 149 mothers to extract data from 196 child records. There were 124 children born between January 2010 and July 2014 who resided in one of the three chosen communities and had electronic health records for their first two years of life.

Main outcome measures

Antibiotic prescription rates, factors associated with antibiotic prescription and factors associated with appropriate antibiotic prescription.

Results

There were 5,675 Primary Health Care (PHC) encounters for 124 children (median 41, IQR 25.5, 64). Of the 5,675 PHC encounters, 1,542 (27%) recorded at least one infection (total 1,777) and 1,330 (23%) had at least one antibiotic prescription recorded (total 1,468). Children had a median five (IQR 2, 9) prescriptions in both their first and second year of life, with a prescription rate of 5.99/person year (95% CI 5.35, 6.63). Acute otitis media was the most common infection (683 records, 38%) and Amoxycillin was the most commonly prescribed antibiotic (797 prescriptions, 54%). Of the 1,468 recorded prescriptions, 398 (27%) had no infection recorded and 116 (8%) with an infection recorded were not aligned with local treatment guidelines.

Conclusion

Prescription rates for Australian Aboriginal children in these communities are significantly higher than that reported nationally for non-Aboriginal Australians. Prescriptions predominantly aligned with treatment guidelines in this setting where there is a high burden of infectious disease.

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<![CDATA[Will COVID-19 become the next neglected tropical disease?]]> https://www.researchpad.co/article/N3ea3a36c-f707-4121-8cab-1c306bbb1993 ]]> <![CDATA[Ivermectin as an adjuvant to anti-epileptic treatment in persons with onchocerciasis-associated epilepsy: A randomized proof-of-concept clinical trial]]> https://www.researchpad.co/article/N2a703e18-6320-408f-bd4d-1f677396d877

Introduction

Recent findings from onchocerciasis-endemic foci uphold that increasing ivermectin coverage reduces the epilepsy incidence, and anecdotal evidence suggests seizure frequency reduction in persons with onchocerciasis-associated epilepsy, when treated with ivermectin. We conducted a randomized clinical trial to assess whether ivermectin treatment decreases seizure frequency.

Methods

A proof-of-concept randomized clinical trial was conducted in the Logo health zone in the Ituri province, Democratic Republic of Congo, to compare seizure frequencies in onchocerciasis-infected persons with epilepsy (PWE) randomized to one of two treatment arms: the anti-epileptic drug phenobarbital supplemented with ivermectin, versus phenobarbital alone. The primary endpoint was defined as the probability of being seizure-free at month 4. A secondary endpoint was defined as >50% reduction in seizure frequency at month 4, compared to baseline. Both endpoints were analyzed using multiple logistic regression. In longitudinal analysis, the probability of seizure freedom during the follow-up period was assessed for both treatment arms by fitting a logistic regression model using generalized estimating equations (GEE).

Results

Ninety PWE enrolled between October and November 2017 were eligible for analysis. A multiple logistic regression analysis showed a borderline association between ivermectin treatment and being seizure-free at month 4 (OR: 1.652, 95% CI 0.975–2.799; p = 0.062). There was no significant difference in the probability of experiencing >50% reduction of the seizure frequency at month 4 between the two treatment arms. Also, treatment with ivermectin did not significantly increase the odds of being seizure-free during the individual follow-up visits.

Conclusion

Whether ivermectin has an added value in reducing the frequency of seizures in PWE treated with AED remains to be determined. A larger study in persons with OAE on a stable AED regimen and in persons with recent epilepsy onset should be considered to further investigate the potential beneficial effect of ivermectin treatment in persons with OAE.

Trial registration

Registration: www.clinicaltrials.gov; NCT03052998.

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<![CDATA[Crystal structures of Triosephosphate Isomerases from Taenia solium and Schistosoma mansoni provide insights for vaccine rationale and drug design against helminth parasites]]> https://www.researchpad.co/article/N340e3046-cb91-4c84-8d1b-fb2a65cf4cdb

Triosephosphate isomerases (TPIs) from Taenia solium (TsTPI) and Schistosoma mansoni (SmTPI) are potential vaccine and drug targets against cysticercosis and schistosomiasis, respectively. This is due to the dependence of parasitic helminths on glycolysis and because those proteins elicit an immune response, presumably due to their surface localization. Here we report the crystal structures of TsTPI and SmTPI in complex with 2-phosphoglyceric acid (2-PGA). Both TPIs fold into a dimeric (β-α)8 barrel in which the dimer interface consists of α-helices 2, 3, and 4, and swapping of loop 3. TPIs from parasitic helminths harbor a region of three amino acids knows as the SXD/E insert (S155 to E157 and S157 to D159 in TsTPI and SmTPI, respectively). This insert is located between α5 and β6 and is proposed to be the main TPI epitope. This region is part of a solvent-exposed 310–helix that folds into a hook-like structure. The crystal structures of TsTPI and SmTPI predicted conformational epitopes that could be used for vaccine design. Surprisingly, the epitopes corresponding to the SXD/E inserts are not the ones with the greatest immunological potential. SmTPI, but not TsTPI, habors a sole solvent exposed cysteine (SmTPI-S230) and alterations in this residue decrease catalysis. The latter suggests that thiol-conjugating agents could be used to target SmTPI. In sum, the crystal structures of SmTPI and TsTPI are a blueprint for targeted schistosomiasis and cysticercosis drug and vaccine development.

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<![CDATA[Prediction model for dengue fever based on interactive effects between multiple meteorological factors in Guangdong, China (2008–2016)]]> https://www.researchpad.co/article/Nfe4e2064-ca0a-4d6d-a8b7-4f75eb296e9a

Introduction

In order to improve the prediction accuracy of dengue fever incidence, we constructed a prediction model with interactive effects between meteorological factors, based on weekly dengue fever cases in Guangdong, China from 2008 to 2016.

Methods

Dengue fever data were derived from statistical data from the China National Notifiable Infectious Disease Reporting Information System. Daily meteorological data were obtained from the China Integrated Meteorological Information Sharing System. The minimum temperature for transmission was identified using data fitting and the Ross-Macdonald model. Correlations and interactive effects were examined using Spearman’s rank correlation and multivariate analysis of variance. A probit regression model to describe the incidence of dengue fever from 2008 to 2016 and forecast the 2017 incidence was constructed, based on key meteorological factors, interactive effects, mosquito-vector factors, and other important factors.

Results

We found the minimum temperature suitable for dengue transmission was ≥18°C, and as 97.91% of cases occurred when the minimum temperature was above 18 °C, the data were used for model training and construction. Epidemics of dengue are related to mean temperature, maximum/minimum and mean atmospheric pressure, and mean relative humidity. Moreover, interactions occur between mean temperature, minimum atmospheric pressure, and mean relative humidity. Our weekly probit regression prediction model is 0.72. Prediction of dengue cases for the first 41 weeks of 2017 exhibited goodness of fit of 0.60.

Conclusion

Our model was accurate and timely, with consideration of interactive effects between meteorological factors.

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<![CDATA[The validity, reliability and minimal clinically important difference of the patient specific functional scale in snake envenomation]]> https://www.researchpad.co/article/5c8823c4d5eed0c484638faf

Objective

Valid, reliable, and clinically relevant outcome measures are necessary in clinical studies of snake envenomation. The aim of this study was to evaluate the psychometric (validity and reliability) and clinimetric (minimal clinically important difference [MCID]) properties of the Patient-Specific Functional Scale (PSFS) in snakebite envenomation.

Methods

We performed a secondary analysis of two existing snakebite trials that measured clinical outcomes using the PSFS as well as other quality of life and functional assessments. Data were collected at 3, 7, 10, and 17 days. Reliability was determined using Cronbach’s alpha for internal consistency and the intraclass correlation coefficient (ICC) for temporal stability at 10 and 17 days. Validity was assessed using concurrent validity correlating with the other assessments. The MCID was evaluated using the following criteria: (1) the distribution of stable patients according to both standard error of measurement (SEM) and responsiveness techniques, and (2) anchor-based methods to compare between individuals and to detect discriminant ability of a positive change with a receiver operator characteristic (ROC) curve and optimal cutoff point.

Results

A total of 86 patients were evaluated in this study. The average PSFS scores were 5.37 (SD 3.23), 7.95 (SD 2.22), and 9.12 (SD 1.37) at 3, 7, and 10 days, respectively. Negligible floor effect was observed (maximum of 8% at 3 days); however, a ceiling effect was observed at 17 days (25%). The PSFS showed good reliability with an internal consistency of 0.91 (Cronbach’s alpha) (95% CI 0.88, 0.95) and a temporal stability of 0.83 (ICC) (95% CI 0.72, 0.89). The PSFS showed a strong positive correlation with quality of life and functional assessments. The MCID was approximately 1.0 for all methods.

Conclusions

With an MCID of approximately 1 point, the PSFS is a valid and reliable tool to assess quality of life and functionality in patients with snake envenomation.

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<![CDATA[Cutaneous leishmaniasis and co-morbid major depressive disorder: A systematic review with burden estimates]]> https://www.researchpad.co/article/5c7d95d9d5eed0c484734dd0

Background

Major depressive disorder (MDD) associated with chronic neglected tropical diseases (NTDs) has been identified as a significant and overlooked contributor to overall disease burden. Cutaneous leishmaniasis (CL) is one of the most prevalent and stigmatising NTDs, with an incidence of around 1 million new cases of active CL infection annually. However, the characteristic residual scarring (inactive CL) following almost all cases of active CL has only recently been recognised as part of the CL disease spectrum due to its lasting psychosocial impact.

Methods and findings

We performed a multi-language systematic review of the psychosocial impact of active and inactive CL. We estimated inactive CL (iCL) prevalence for the first time using reported WHO active CL (aCL) incidence data that were adjusted for life expectancy and underreporting. We then quantified the disability (YLD) burden of co-morbid MDD in CL using MDD disability weights at three severity levels. Overall, we identified 29 studies of CL psychological impact from 5 WHO regions, representing 11 of the 50 highest burden countries for CL. We conservatively calculated the disability burden of co-morbid MDD in CL to be 1.9 million YLDs, which equalled the overall (DALY) disease burden (assuming no excess mortality in depressed CL patients). Thus, upon inclusion of co-morbid MDD alone in both active and inactive CL, the DALY burden was seven times higher than the latest 2016 Global Burden of Disease study estimates, which notably omitted both psychological impact and inactive CL.

Conclusions

Failure to include co-morbid MDD and the lasting sequelae of chronic NTDs, as exemplified by CL, leads to large underestimates of overall disease burden.

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