Average Infection Rate Research Articles

Comparison of catheter-related bloodstream infection rates in pediatric patients receiving parenteral nutrition with soybean oil-based intravenous fat emulsion versus a mixed oil fat emulsion.

To compare rates of catheter-related bloodstream infections (CR-BSI) in pediatric patients who received parenteral nutrition (PN) with either soybean oil-based intravenous fat emulsion (SO-IFE) or mixed oil-IFE (MO-IFE). We hypothesized that the use of MO-IFE would be independently associated with reduced infection rates compared with SO-IFE. Retrospective cohort study. Tertiary referral children's hospital and its associated gastrointestinal rehabilitation clinic (01 January, 2015-31 July, 2019). Days of IFE exposure were counted for patients aged <18 years on IFE initiated during the review period, who had a central venous catheter (CVC) placed for PN administration, received IFE at least three times weekly, and for at least 7 days. The primary outcome included total and categorical CR-BSI rates expressed as the average with standard error (SE) number of infections per 1000 fat emulsion days. The following categories were specified: Candida albicans, non-albicans Candida spp., coagulase-negative Staphylococcus (CoNS), Enterobacterales, methicillin-resistant S. aureus, methicillin-susceptible S. aureus, and Pseudomonadales. Average infection rate comparisons were quantified as incidence rate ratios (IRR) using generalized linear mixed modeling with a Poisson distribution. Seven hundred and forty-three SO-IFE and 450 MO-IFE exposures were reviewed from 1131 patients, totaling 37,599 and 19,796 days of therapy, respectively. From those found significantly different, the average rate of infections with CoNS was 3.58 (SE 0.5)/1000 days of SO-IFE and 1.39 (SE 0.45)/1000 days of MO-IFE (IRR [95% confidence interval, CI]: 0.27 [0.16-0.46]; p < 0.01). Total average rates of infection were 7.33 (SE 0.76)/1000 days of SO-IFE and 4.52 (SE 0.75)/1000 days of MO-IFE (IRR [95% CI]: 0.60 [0.44-0.81]; p < 0.01). Other factors associated with higher infection rates include female gender, neonatal age, and inpatient-only IFE exposure. Receipt of MO-IFE was associated with lower rates of CoNS and total CR-BSIs compared with SO-IFE in pediatric patients. These findings could have major implications on IFE selection for pediatric patients receiving PN.

Molecular Detection of Southern Tomato Amalgavirus Prevalent in Tomatoes and Its Genomic Characterization with Global Evolutionary Dynamics.

Southern tomato amalgavirus (STV) is a cryptic pathogen that is abundant in tomato production fields and intensifies the resurgence of tomato yellow stunt disease (ToYSD), together with other phytoviruses. Here, we mapped the geographical and genomic diversity, phylogenetics, and evolutionary dynamics of STV. We found that STV prevailed across China and Pakistan, with a maximum average rate of infection of 43.19% in Beijing, China, and 40.08% in Punjab, Pakistan. Subsequently, we amplified, cloned, and annotated the complete genome sequences of STV isolates from Solanum lycopersicum L. in China (OP548653 and OP548652) and Pakistan (MT066231) using Sanger and next-generation sequencing (NGS). These STV isolates displayed close evolutionary relationships with others from Asia, America, and Europe. Whole-genome-based molecular diversity analysis showed that STV populations had 33 haplotypes with a gene diversity (Hd) of 0.977 and a nucleotide diversity (π) of 0.00404. The genetic variability of RNA-dependent RNA-polymerase (RdRp) was higher than that of the putative coat protein (CP) p42. Further analysis revealed that STV isolates were likely to be recombinant but with a lower-to-moderate level of confidence. With a variable distribution pattern of positively and negatively selected sites, negative selection pressure predominantly acted on p42 and RdRp. These findings elaborated on the molecular variability and evolutionary trends among STV populations across major tomato-producing regions of the world.

IMPACT OF SOCIAL DISTANCING DURING THE SARS-COV-2 PANDEMIC ON THE ASSOCIATION BETWEEN VIRAL RESPIRATORY ILLNESS AND CARDIOVASCULAR-RELATED EVENTS

IMPACT OF SOCIAL DISTANCING DURING THE SARS-COV-2 PANDEMIC ON THE ASSOCIATION BETWEEN VIRAL RESPIRATORY ILLNESS AND CARDIOVASCULAR-RELATED EVENTS

Pathogens in Ixodes persulcatus and Ixodes ricinus ticks (Acari, Ixodidae) in Karelia (Russia)

Ixodid ticks (Acarina, Ixodidae) are vectors of dangerous human infections. The main tick species that determine the epidemiological situation for tick-borne diseases in northern Europe are Ixodes ricinus and Ixodes persulcatus. In recent years, significant changes in the number and distribution of these species have been observed, accompanied by an expansion of the sympatric range. This work summarizes the data of long-term studies carried out in Karelia since 2007 on the infection of I. persulcatus and I. ricinus ticks with various pathogens, including new viruses with unclear pathogenic potential. As a result, tick-borne encephalitis virus (TBEV, Siberian genotype), Alongshan virus, several representatives of the family Phenuiviridae, Borrelia afzelii, Borrelia garinii, Ehrlichia muris, Candidatus Rickettsia tarasevichiae and Candidatus Lariskella arthropodarum were identified. Data were obtained on the geographical and temporal variability of tick infection rates with these main pathogens. The average infection rates of I. persulcatus with TBEV and Borrelia burgdorferi sensu lato were 4.4% and 23.4% and those of I. ricinus were 1.1% and 11.9%, respectively. We did not find a correlation between the infection rate of ticks with TBEV, B. burgdorferi s.l. and Ehrlichia muris/chaffeensis with the sex of the vector. In general, the peculiarities of the epidemiological situation in Karelia are determined by the wide distribution and high abundance of I. persulcatus ticks and by their relatively high infection rate with TBEV and B. burgdorferi s.l. in most of the territory, including the periphery of the range.

Assess transmissibility of different influenza subtypes: Based on a SEIABR model.

Influenza is a worldwide public health problem which causes a serious economic and health burden. In order to provide a scientific basis for improving the prevention and control level of influenza, using dynamic model to evaluate the infection rates of influenza different subtypes from 2010 to 2019 in China. This article established SEIABR model based on influenza cases reported by China National Influenza Center from 2010 to 2019. And calculated the transmission rate and Re by combined the natural birth rate, natural death rate, infectious rate, proportion of asymptomatic patients, proportion of untreated patients, recovery rate and fatality rate. The average infection rate of influenza was (2.38±0.59)×10-10, and influenza A was (2.24±0.51)×10-10, influenza B was (2.21±0.68)×10-10. And average Re were 1.60, 1.51, 1.49. In addition, the infection rates of A /H1N1, A/H3N2, B/Yamagata and B/Victoria were (2.47±0.51)×10-10, (2.25±0.48)×10-10, (2.15±0.61)×10-10, and (2.30±0.66)×10-10 and average Re were 1.67, 1.52, 1.44, 1.56. Between each year, flu transmission capacity had fluctuation. Influenza A was more transmissible than influenza B, and during the major subtypes, influenza A/H1N1 was the most transmissible.

Geographical distribution and phylogenetic analysis of Jingmen tick virus in China

SummaryJingmen tick virus (JMTV) is a novel tick-borne segmented RNA virus that is closely related to un-segmental RNA virus in evolution. It has been confirmed that JMTV could be a causative agent of human disease. In this study, a total of 3658 ticks were sampled from 7 provinces of China and then divided into 545 pools according to the location and species. QRT-PCR and nested PCR were performed to confirm the presence of JMTV. The results showed JMTV was identified in 5 out of 7 provinces with an average infection rate of 1.4% (51/3658). Phylogenetic analysis indicated that all JMTV strains identified in this study were closely related to each other and formed a well-supported sub-lineage. Our results provide molecular evidence of JMTV in different species of ticks from endemic and non-endemic regions and demonstrate that JMTV, as a natural foci pathogen, may be widely distributed all over China.

Molecular characterization and zoonotic potential of Enterocytozoon bieneusi in ruminants in northwest China

This study was conducted to examine the molecular characteristics and assess the zoonotic potential of Enterocytozoon bieneusi in ruminants in northwest China. A total of 1581 fresh fecal samples were collected from eight categories of ruminants. The E. bieneusi was screened and genotyped via nested polymerase chain reaction (PCR) amplification targeting the internal transcribed spacer (ITS) of the small subunit rRNA (ssu rRNA) gene. The result indicated that the average infection rate of E. bieneusi in ruminants was 16.0% (253/1581), with infection rates of E. bieneusi in Mongolian sheep, Mongolian goats, Chifeng cattle, red deer, alpine musk deer, and blue sheep at 21.8% (169/777), 8.2% (46/561), 25.9% (28/108), 13.2% (5/38), 20.0% (4/20), and 6.3% (1/16), respectively. The infections of E. bieneusi varied by different categories. For the different age groups, the infection rates in lambs (29.3%, 108/369) and calves (57.1%, 8/14) were significantly higher than that in ewes (21.1%, 215/1020) and cows (21.3%, 20/94). For the molecular characterization, diverse E. bieneusi ITS genotypes were identified, with a total of 13 genotypes were observed, including 10 known genotypes (BEB6, COS-I, J, CHC8, I, CHG1, BEB4, CHG3, CHS7, and NCF2) and 3 novel genotypes (CNR1 to CNR3). Genotype BEB6 was predominant (59.7%, 151/253). Phylogenetic analysis revealed that most E. bieneusi ITS genotypes clustered into group 2 and only one (NCF2) genotype belonged to group 1. The zoonotic genotypes identified in ruminants in the present study indicated the zoonotic potential of E. bieneusi. In addition, simultaneous identification of genotypes, such as BEB6, COS-I, and BEB4, in the same eco-geographical system indicated some host multiplicity transmission potential of E. bieneusi.

Urban monitoring, evaluation and application of COVID-19 listed vaccine effectiveness: a health code blockchain study

Urban monitoring, evaluation and application of COVID-19 listed vaccine effectiveness: a health code blockchain study

Are High-Altitude Residents More Susceptible to Covid-19 in India? Findings and Potential Implications for Research and Policy

In this paper, we study the incidence of COVID-19 and the associated fatality with altitude using high frequency, district level data from India. To understand the implications of the nationwide lockdown after the outbreak, we use data for about four months- two from the lockdown period starting from March 25 till May 31, 2020 and about two months after unlocking was initiated (June 1-July 26, 2020). The multivariate regression result indicates slower growth in average rate of infection during the lockdown period in hilly regions, the gains of which attenuated after the unlocking was initiated. Despite these early gains, the rate of fatalities is significantly higher during the lockdown period in comparison to the plains. The findings remain robust to multiple alternative specifications and methods including one that accounts for confounding possibilities via unobservable and provides consistent estimates of bias adjusted treatment effects. The evidence supports the need for provisioning of public health services and infrastructure upgradation, especially maintenance of adequate stock of life support devices, in high altitude regions. It also underscores the necessity for strengthening and revising the existing Hill Areas Development Programme and integrating important aspects of public health as part of this policy.

HIV and AIDS-defining opportunistic illnesses in the state of Qatar: A cohort population-based retrospective study covering 17 years (2000-2016)

Background and introductionHuman immune deficiency virus (HIV) infection remains a major health problem since discovery of the virus in 1981. Globally, since introduction of antiretroviral therapy, AIDS-related mortality was reduced by 47% since 2010. Also, HIV-related opportunistic infections (OIs) became less common, especially with use of prophylaxis to prevent such infections. In this study, we aim to assess the incidence of HIV infection and related OIs in Qatar for 17-year period, and to assess the spectrum of these infections, risk factors and treatment outcomes. MethodsThis is a retrospective cohort study for all HIV infected patients registered in the state of Qatar from 2000 to 2016. Incidence of HIV infection and related opportunistic illness was calculated per 100,000 population. Demographic and Clinical characteristic were compared between two groups of patients with and without opportunistic illness. Resultsof 167 cases with HIV infection 54 (32.3%) had opportunistic illness. The average incidence rate of HIV infection over 17 years is 0.69 per 100,000 population, and the incidence rate for opportunistic illness is 0.27 per 100,000 population. The most common opportunistic illness is pneumocystis jirovecii pneumonia (PCP) which constituted 25% of cases, followed by cytomegalovirus (CMV) retinitis 7.2%, Tuberculosis 5.4%, Toxoplasmosis 4.2% and, less than 2% for each of Kaposi sarcoma, lymphoma and cryptococcal infection.The outcome of treatment of cases with opportunistic illness showed cure rates of 59.3%, one year relapse rates of 8.76% and overall, 90-day mortality of 3.7% however, 33.4% of patients left the country before completion of therapy.Most of our patients in both groups were of young age, majority males, and almost half of them were Qatari. The CD4 count, CD4%, CD4/CD8 ratio and viral load were statistically significant risk factors in cases with opportunistic illness with a p value < 0.05, however presence of comorbidities was lower in patients with opportunistic illness P value of 0.032. ConclusionQatar has a low prevalence rate for HIV infection and related opportunistic illness. Early diagnosis and use of antiretroviral therapy are important measures to decrease the rate of opportunistic illness.

A New Generalized Modified Weibull Model: Simulating and Modeling the Dynamics of the COVID-19 Pandemic in Saudi Arabia and Egypt

The flare-up of coronavirus disease 2019 (COVID-19) was first identified in China and then spread worldwide. The concerning articles are significant because of their increasing average infection rate. The exact scientific anatomy of this circumstance remains to be discussed. Nevertheless, it is important for governments and all responsible organizations to have sound statistics and analysis to decide on possible necessary actions. This article compares the dynamics of the COVID-19 pandemic between Saudi Arabia and Egypt. We provide an appropriate process of convergence of facts that can be useful for both administrations to implement appropriate quarantine procedures. In addition, the new generalized modified Weibull distribution is provided to provide the preferred description about COVID-19 total cases, daily new cases, total deaths, and daily death statistics of Saudi Arabia and Egypt.

TRICHINELLOSIS OF WOLVES FROM THE EUROPEAN PART OF RUSSIA

The research purpose was to identify the prevalence and intensity of Trichinella infection in the Eurasian wolf. The work on the diagnosis of trichinellosis and on the larvae isolation was performed in 2020–2022. Carcasses of wolves were brought from the territories of hunting farms of various regions in the European part of Russia. Muscle sections were examined by the compression method to detect Trichinella larvae. The Gastros apparatus was used to isolate Trichinella larvae. Peptolysis of muscle tissue using artificial gastric juice was performed using ACROS pepsin (Belgium, USA). Twelve animals were studied during the reporting period. The results of the in-house studies showed significant invasion in this animal species. Trichinella larvae were found in 58.3% of animals. The animals aged 1–3 years were the most infected by helminths. The least infected animals were 3–5 years old. The average intensity of Trichinella invasion was 29 larvae in one g of muscle tissue. These groups of animals were obtained by sport hunters in the Chuvash Republic and the Republic of Dagestan. The average rate of Trichinella infection in carnivores were in wolves up to one year old. The prevalence of infection in this group was 60.0% with an average intensity of 32 larvae in one g of muscles. Animals obtained on the hunting farms in the Tver and Ryazan Regions and the Republic of Karelia were free from the infection.

Identification and Validation of Quantitative Trait Loci for Wheat Dwarf Virus Resistance in Wheat (Triticum spp.).

Wheat dwarf virus (WDV) is transmitted by the leafhopper Psammotettix alienus. As a major pathogen in wheat and other cereals, WDV causes high yield losses in many European countries. Due to climate change, insect-transmitted viruses will become more important and the restrictions in the use of insecticides efficient against P. alienus renders growing of WDV resistant/tolerant varieties the only effective strategy to control WDV. So far, there is little information about the possible sources of resistance and no known information about the genome regions responsible for the resistance. In a screening for WDV resistance using artificial inoculation in gauze houses, a panel of 500 wheat accessions including cultivars, gene bank accessions, and wild relatives of wheat was phenotyped for virus titer, infection rate, as well as plant height and yield parameters relative to healthy controls of the same genotype. Additionally, 85 T. aestivum-Ae. tauschii intogression lines were tested for WDV resistance in the greenhouse. A subset of 250 hexaploid wheat accessions was genotyped with the 15k iSelect SNP Chip. By genome-wide association study (GWAS), the quantitative trait loci (QTL) for partial WDV resistance were identified. Within these studies, one cultivar was identified showing an average infection rate of only 5.7%. By analyzing single seed descent (SSD) and doubled haploid (DH) populations comprising 153 and 314 individuals for WDV resistance and by genotyping these with the 25k iSelect SNP Chip, QTL for yield per plant, thousand-grain weight, and relative virus titer were validated on chromosomes 1B, 2B, 3B, 4B, 4A, 5A, 6A, and 7A. These results will be the basis for marker-assisted selection for WDV resistance to replacing the laborious, time-consuming, and technically challenging phenotyping with WDV bearing leafhoppers.

Effectiveness of Prophylactic Human Cytomegalovirus Hyperimmunoglobulin in Preventing Cytomegalovirus Infection following Transplantation: A Systematic Review and Meta-Analysis.

Cytomegalovirus (CMV) is a common infection occurring in patients undergoing solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT). CMV-specific hyperimmunoglobulin (CMVIG) has been used for the past four decades and is typically administered either prophylactically or pre-emptively. The present meta-analysis evaluated CMV infection rates in SOT patients who received prophylactic CMVIG. PubMed and the Cochrane Library were searched for studies published up to October 2021. The primary endpoint was CMV infection rate. Thirty-two SOT studies were identified (n = 1521 CMVIG-treated and n = 1196 controls). Prophylactic CMVIG treatment was often associated with a lower risk of CMV infection in transplant recipients. The average CMV infection rate was 35.8% (95% confidence interval [CI]: 33.4–38.2%) in patients treated prophylactically with CMVIG and 41.4% (95% CI: 38.6–44.2%) in the control group not receiving CMVIG (p = 0.003). Similar results were observed in analyses limited to publications evaluating currently available CMVIG products (Cytotect CP and Cytogam; p < 0.001). In combination with the established safety profile for CMVIG, these results suggest that prophylactic CMVIG treatment in patients undergoing solid organ transplantation may be beneficial, particularly in those at high risk of CMV infection or disease.

Selection of Monitoring points for the Number and Infectivity of the Main Vectors of West Nile Virus in the Volgograd Region

Relevance. Since 1999, the incidence of West Nile fever has been recorded in the Volgograd region. The main vectors of West Nile virus in Russia are Cx mosquitoes. pipiens L. and Cx. modestus Fic. An objective assessment of the entomological situation and infection rate of these species within the framework of epidemiological surveillance of West Nile fever is possible only in biotopes with sufficiently high numbers of mosquitoes; therefore, the choice of sampling points is an urgent task. Purpose of the study. Analysis of the West Nile virus main vectors - mosquitoes Cx. pipiens L. and Cx. modestus Fic. average number, occurrence and infection rate at the various open biotopes of the Volgograd region to justify the choice of optimal points for entomological monitoring. Materials and methods. The catching and accounting of the mosquitoes’ number was carried out in 2015–2019 from May to August in the third decade of each month in a floodplain forest, at a personal plot, a summer cottage and on bank of water body. To catch mosquitoes, automatic traps Mosquito Magnet Executive and LovKom-1 were used. The accounting unit was the number of mosquitoes collected in both traps per trap-night. The average number, the index of occurrence and infection rate were determined by generally accepted methods. Detection of West Nile virus RNA in samples of mosquito pool suspensions was performed by RT-PCR using the AmpliSense WNV-FL reagent kit. The results were statistically processed using Microsoft Excel 2016 (Microsoft Corporation, USA). Results. In the 2015-2019 period, 17468 mosquitoes of the genus Culex: 8258 species – Cx. pipiens L., 9210 species – Cx. modestus Fic. were collected in over than 80 trap nights at the selected stationary points of the Volgograd region. Average number of Cx. pipiens L. was: in the floodplain forest – 4.6 individuals per 1 trap-night; at the personal plot – 183.9; at the summer cottage – 30.2; on the bank of water body – 194.3. Average number of Cx. modestus Fic. was: in the floodplain forest – 5.2 individuals per 1 trapnight; at the personal plot – 8.3; at the summer cottage – 2.5;on the bank of water body – 444.6. Occurrence index Cx. pipiens L. was highon the bank of water body and at the personal plot (47.1% and 44.5%, respectively), much lower – at the summer cottage (7.3%) and in the floodplain forest (1.1%). Level of WNV infection among Cx. pipiens L.on a personal plot was 5.4%, on a summer cottage – 3.6%,on the bank of water body – 2.2%. No infected samples were found among Cx. pipiens L. collected from the floodplain forest. WNV RNA in samples from mosquitoes Cx. modestus Fic. found only in individuals caughton the bank of water body. Their infection rate was 1.2%. Discussion. Ecological plasticity of Cx. pipiens L. mosquitoes allows them to live in settlements and near water bodies. Mosquitoes of the species Cx. modestus Fic. do not fly away from ponds, breeding places. Conclusion. High numbers and occurrence of the Cx. pipiens L. mosquitoes were observed at a personal plot within the city andon the bank of water body, Cx. modestus Fic. –on the bank of water body. WNV RNA positive samples were detected from mosquitoes collected at the personal plot, the summer cottage andon the bank of water body. To monitor the number and infection rate among Cx. pipiens L., points of registration and sampling should be placed in open stationson personal plots in settlements, banks of water bodies and summer cottages. We recommend to carry entomological monitoring for Cx. modestus Fic. out onlyon the banks of water bodies along the water's edge in reed thickets. The placement of the main WNV vectors number and infection rate monitoring points in the floodplain forest is not advisable.

Newly Developed COVID-19 Bundle Greatly Reduces the Infection Fatality Rate for a Highly Vulnerable Nursing Home Population.

This performance improvement initiative used a bundle designed to reduce the COVID-19 infection fatality rate (IFR) by ≥33% and the new infection rate (IR) to <1% among nursing home (NH) residents over a 3-month period at a large public NH in New York City. Participants were all NH residents, newly testing COVID-19 PCR positive between March 1, 2020 and June 30, 2020. Key bundle components involved close observation of all residents with vital signs taken once/shift, including O2 saturation, frequent clinical team follow-up visits for those symptomatic, and ramped-up COVID-19 PCR testing. From April to June, average IFR was 12.3%, a 49.6% reduction from the March baseline (P < 0.05), and average new IR was 5.4%, a 29.9% reduction from baseline (P < 0.05). In the 2 follow-up months, no deaths occurred with a new IR < 1%, indicating sustained improvement. Because of its simplicity, this bundle or components of it could be readily applied elsewhere after appropriate assessment.

First detection and genotyping of Enterocytozoon bieneusi in pet golden hamsters (Mesocricetus auratus) and Siberian hamsters (Phodopus sungorus) in China.

Enterocytozoon bieneusi, a common opportunistic pathogen, has been detected in humans and a wide range of animals worldwide. However, no information on the prevalence and molecular characterization of E. bieneusi in hamsters is available worldwide. In this study, fecal specimens were collected from 175 golden hamsters and 175 Siberian hamsters purchased from pet shops in three provinces of China. The average infection rate of E. bieneusi was 12.0% (42/350), with 14.9% (26/175) in pet golden hamsters and 9.1% (16/175) in pet Siberian hamsters. Four genotypes were identified in pet golden hamsters, including three known genotypes (D, Henan-II, and SHW5) and one novel genotype (named Ebph1). Five genotypes were found in pet Siberian hamsters, including one known genotype (D) and four novel genotypes (named Ebph2 to Ebph5). Genotypes D and Ebph2 were the dominant genotype in pet golden hamsters (23/26, 88.5%) and Siberian hamsters (9/16, 56.3%), respectively. Phylogenetic analysis showed that the E. bieneusi isolates clustered into two groups: Group 1 (D, Henan-II, SHW5, and Ebph1) and Group 3 (Ebph2 to Ebph5). To the best of our knowledge, this is the first report of E. bieneusi infection in golden hamsters and Siberian hamsters worldwide. The identification of four genotypes belonging to Group 1 of high zoonotic potential suggests that pet hamsters especially golden hamsters can be potential sources of human microsporidiosis.

Entomological surveillance of Chagas disease in the East of Minas Gerais region, Brazil.

ABSTRACTBackground: After decentralizing the actions of the Chagas Disease Control Program (CDCP) in Brazil, municipalities were now responsible for control measures against this endemic, supervised by the Regional Health Superintendencies (RHS). We aimed to evaluate the recent entomological surveillance of Chagas disease in the Regional Health Superintendence of Governador Valadares (RHS/GV) from 2014 to 2019. Methods: Triatomines captured by residents during entomological surveillance were sent to the reference laboratory, where the species and evolutionary stages were identified, place of capture, and presence of Trypanosoma cruzi. A database was created, and the following were calculated: the rate of infection by T. cruzi (overall rate and rate by species), monthly seasonality, spatial distribution of species, number of captures, and infected triatomines/health microregions. Results: We identified 1,708 insects; 1,506 (88.2%) were triatomines, most were adult instars (n=1,469), and few were nymphs (n=37). The identified species were Triatoma vitticeps, Panstrongylus megistus, Panstrongylus diasi, Rhodnius neglectus, and Panstrongylus geniculatus. The first three were most frequently captured and distributed throughout the study area. Most bugs were captured intradomicile (72.5%), mainly in the second semester, between September and November, with an average infection rate of 41.5% (predominantly T. vitticeps, 49.2%). All municipalities sent triatomines, especially in the microregions of Governador Valadares. Conclusions: These data reinforce the need and importance of improving Chagas disease control measures in the region to establish active and participatory entomological surveillance.

Interspecies Phylogenetic Analysis of Clonorchis sinensis in High-incidence Areas of Hunan Province, China

ObjectiveThis study aims to investigate the infection of Clonorchis sinensis (C. sinensis) in high-incidence areas of Hunan Province, China. The phylogenetic analysis of the C. sinensis species in the highly infected areas was carried out. MethodInfection of the definitive human host and intermediate fish host by C. sinensis was investigated, and the mitochondrial genes cox1 and Nad1 were used as genetic markers for phylogenetic analysis. ResultsIn 2016–2020, the average population infection rate of Hunan was 1.38%, while in Tongdao County the rate was up to 26.90%, and the highest fish infection rate was detected in Qiyang County (99.44% in the dorsal fin of crucian carp). High genetic sequence similarity was observed in the samples from Qiyang and Lengshuitan which exhibited high homology with those from Guangdong and Gansu, whereas the parasitic species from Tongdao was highly homologous with those located in high-latitude areas. Moreover, no significant difference was found in the gene sequence of the parasitic species in definitive hosts dogs and cats. ConclusionThe systematically study of C. sinensis infection in the high-incidence areas will contribute greatly to the prevention and effectively controlling the spread of Clonorchis sinensis in Hunan Province The endemic of C. sinensis infection in Hunan Province is the result of co-action of local and foreign parasite species.

Dengue epidemiological characteristic in Kuala Lumpur and Selangor, Malaysia

In the last few decades, dengue remains a leading public health problem in Malaysia. The problem persists with increasing trend of cases despite implementation of various interventions by the Ministry of Health Malaysia. The difficulty in eradicating dengue disease throughout the world is related to the complexity of the dengue phenomena. With no access to a safe, effective and affordable dengue vaccine, the only intervention strategy is to control the mosquito vector. In reality, data on mosquitoes is limited, and in most cases, the dynamic of mosquito is unobservable. In this study, based on the dengue incidence data in Malaysia−Kuala Lumpur and Selangor−from the year 2011 to 2014, a transmission model of type SI-SIR is constructed. Transmission rates in the two locations are estimated from the data fitting of the dynamic of infected human to dengue incidence. The average infection rate and the estimated average reproduction number for Selangor are estimated to be 0.1674 week−1 and 1.025, respectively. An enclave in Selangor, the capital city Kuala Lumpur has slightly lower average dengue infection rate of 0.1656 week−1 and estimated average reproduction number of 1.014. Further sensitivity analysis indicated that the dengue infection rate is the critical parameter of dengue transmission in Kuala Lumpur and Selangor. This implies that dengue control strategies should focus on reducing the dengue infection rate. Numerical simulations are also performed to validate the estimated dengue infection rate, to illustrate the dengue dynamics and to determine the effects of dengue control strategies in the two selected locations. The predictive test results of this method also provide good results in capturing the pattern of dengue cases both in Kuala Lumpur and in Selangor. Numerical simulations on instantaneous reproduction number reveal that the instantaneous reproduction number of Kuala Lumpur varies between 0.8 and 1.28 while the instantaneous reproduction number of Selangor varies between 0.7 and 1.2. The insights and results presented in this paper are useful to the relevant authorities in analyzing the effect of mosquito intervention for reducing the prevalence of dengue in Malaysia.