Period Of Infection Research Articles

Immulina® mitigates the development of illness when administered during the prodromal period of influenza viral infection in mice (Part 2)

BackgroundImmulina®, a dietary supplement derived from Limnospira (formerly Arthrospira), is being investigated as a potential agent to increase antiviral resilience. In our recently published manuscript, we described the effects of Immulina® on influenza when taken daily, beginning before infection (prophylaxis) or after the onset of clinical symptoms of viral illness (therapeutic). However, the benefit of Immulina® in infected individuals before the manifestation of any symptoms (prodromal) has not been investigated yet. PurposeTo evaluate Immulina®’s potential use to increase the host antiviral immune response using a prodromal therapy regime. Study DesignThe efficacy of Immulina® extract was evaluated in rodents using a prodromal protocol (test material administered prior to the emergence of viral illness symptoms). MethodsImmulina® (25, 50 and 100 mg/kg body weight) was orally administered to both genders of mice, 2 h following influenza A viral infection, and continued daily for 14 days. ResultsCompared to the infected control mice, animals fed Immulina® exhibited statistically significant reduction in the emergence of various physical symptoms of viral-induced illness and decreased viral RNA levels. The effects are likely mediated through the host immune system since the level of various cytokines (IL-6 and IFN-γ) were significantly increased in lung tissue. ConclusionThis study, together with our previous paper, indicate that Immulina® was most effective at enhancing immune antiviral resilience if administered before or soon after initial infection. The data generated can be used to guide additional research using human subjects.

Transcriptomic Profiling of Bean Aphid Megoura crassicauda upon Exposure to the Aphid-Obligate Entomopathogen Conidiobolus obscurus (Entomophthoromycotina) and Screening of CytCo-Binding Aphid Proteins through a Pull-Down Assay.

Prolonged periods of host-lethal infection by entomopathogenic fungi pose challenges to the development of biological control agents. The obligate entomopathogen C. obscurus, however, rapidly kills aphid hosts, warranting investigation. This study investigated the interaction between C. obscurus and a bean aphid Megoura crassicauda during the incubation period of infection, using transcriptome analysis to map host gene expression profiles. Results indicate C. obscurus-inoculated aphid activation of the wound healing immune responses, alongside suppression of the key molecules involved in Toll signaling, melanization, and metabolism. Furthermore, neuromotor system-related genes were upregulated, paralleling the intoxication observed in a nematode pest treated with C. obscurus-derived CytCo protein. To deepen interaction insights, a His-tag pull-down assay coupled with mass spectrometry analysis was conducted using CytCo as a bait to screen for potential aphid protein interactors. The proteins were identified based on the assembled transcriptome, and eleven transmembrane proteins were predicted to bind to CytCo. Notably, a protein of putatively calcium-transporting ATPase stood out with the highest confidence. This suggests that CytCo plays a vital role in C. obscurus killing aphid hosts, implicating calcium imbalance. In conclusion, C. obscurus effectively inhibits aphid immunity and exhibits neurotoxic potential, expediting the infection process. This finding facilitates our understanding of the complex host-pathogen interactions and opens new avenues for exploring biological pest management strategies in agroforestry.

#1814 Infection associated pancreatitis in peritoneal dialysis, a case report

Abstract Background and Aims Peritoneal dialysis (PD) patients seem to have a higher incidence of acute alithiasic pancreatitis. Though rare and with some suggested triggers described in the literature, this is still a poorly understood and potentially life-threatening complication. We present a 60 years old woman concluding antimicrobial therapy with an icodextrin night-dwell regimen for peritonitis presenting with epigastric pain. This work reviews our approach to cloudy effluent from non-infectious causes during an infection while managing acute pancreatitis in the PD setting. We report diagnostic difficulties and treatment considerations with a positive outcome. Method We present a 60 years old woman on PD for one year presenting to the emergency room in November of 2023 with severe epigastric pain, nausea and emesis. She suffered from stage 5 chronic kidney disease due to autosomal dominant polycystic kidney disease and had disease complications as anemia and secondary hyperthyroidism controlled within targets. She was on automated PD (APD) with glucose based solutions. She was on the 17th of 21 days antibiogram guided treatment (ceftazidime) for a Enterobacter ludwigii PD-related peritonitis with good clinical evolution and peritoneal effluent (PE) leukocyte count per μl from 1258 to 91 in 5 days. In the previous 3 months she had had 2 other infectious episodes. A bacteremic urinary tract infection to E. coli associated with peritonitis treated with antibiogram guided therapy (ceftazidime) followed by C. difficile colitis treated with oral vancomycin. During each infection period she transitioned from APD to continuous ambulatory peritoneal dialysis with an icodextrin night dwell. On admission she presented with normal vital signs, no fever, and abdominal distention with severe epigastric tenderness to palpation without muscular guarding. Her dwell exchange showed blood-tinged cloudy PE. She had hemoglobin of 11.3 g/dl, otherwise normal blood cell counts, and raised amylase (213 UI/l) and lipase (1467 UI/l). There was no elevation of transaminases, cholestatic enzymes, C-reactive protein or procalcitonin and lipidemia or hyperbilirubinemia were normal. PE cell count showed 213/μl leukocytes and 202/μl erythrocytes. Abdominal ultrasound showed no evidence of an obstructive cause. She was admitted in the surgical care unit for a conservative and watchful approach. Results On presentation we accounted for the peritonitis still under treatment, acute pancreatitis, drug therapy and recently introduced icodextrin solution. The acute alithiasic pancreatitis diagnosis was established but there was still a possible causative role of icodextrin or infection and refractory peritonitis could also not be promptly excluded. The literature suggests icodextrin and other drugs as causes for acute pancreatitis in some patients but also mentions the possibility of cloudy or hemorrhagic effluent due to abdominal inflammation processes. Considering the clinical stability, the multiple possible contributing causative agents and the differential diagnosis of refractory peritonitis we closely monitored PE cell count evolution keeping the icodextrin dwell and ceftazidime prescriptions and collected samples for bacterial and fungal culture. The cultures were negative and stability of leukocyte count and mononuclear cell predominance (Fig. 1) helped us exclude the peritonitis hypothesis and attribute the PE changes to the pancreatitis process. Conclusion Inpatient monitoring and identifying all possible causes are essential to ensure good outcomes in PD patients suffering from acute pancreatitis. Full anamnesis, physical examination and close attention to laboratory findings were key in allowing adequate antibiotic therapy and resolution of the abdominal inflammatory process at hand while maintaining an adequate PD prescription.

Mpox in children and adolescents and contact follow-up in school settings in greater Paris, France, May 2022 to July 2023.

BackgroundDuring the 2022 mpox outbreak in Europe, primarily affecting men who have sex with men, a limited number of cases among children and adolescents were identified. Paediatric cases from outbreaks in endemic countries have been associated with a higher likelihood of severe illness. Detailed clinical case descriptions and interventions in school settings before 2022 are limited.AimTo describe clinical characteristics of mpox cases among children (< 15 years) and adolescents (15-17 years) in the greater Paris area in France, and infection control measures in schools.MethodsWe describe all notified laboratory-confirmed and non-laboratory-confirmed cases among children and adolescents identified from May 2022 to July 2023, including demographic and clinical characterisation and infection control measures in school settings, i.e. contact tracing, contact vaccination, secondary attack rate and post-exposure vaccination uptake.ResultsNineteen cases were notified (13 children, 6 adolescents). Four adolescent cases reported sexual contact before symptom onset. Ten child cases were secondary cases of adult patients; three cases were cryptic, with vesicles on hands, arms and/or legs and one case additionally presented with genitoanal lesions. Five cases attended school during their infectious period, with 160 at-risk contacts identified, and one secondary case. Five at-risk contacts were vaccinated following exposure.ConclusionCases among children and adolescents are infrequent but require a careful approach to identify the source of infection and ensure infection control measures. We advocate a 'contact warning' strategy vs 'contact tracing' in order to prevent alarm and stigma. Low post-exposure vaccination rates are expected.

SIV infection and ARV treatment reshape the transcriptional and epigenetic profile of naïve and memory T cells in vivo.

Human and simian immunodeficiency viruses (HIV and SIV) are lentiviruses that reverse transcribe their RNA genome with subsequent integration into the genome of the target cell. How progressive infection and administration of antiretrovirals (ARVs) longitudinally influence the transcriptomic and epigenetic landscape of particular T cell subsets, and how these may influence the genetic location of integration are unclear. Here, we use RNAseq and ATACseq to study the transcriptomics and epigenetic landscape of longitudinally sampled naïve and memory CD4+ and CD8+ T cells in two species of non-human primates prior to SIV infection, during chronic SIV infection, and after administration of ARVs. We find that SIV infection leads to significant alteration to the transcriptomic profile of all T cell subsets that are only partially reversed by administration of ARVs. Epigenetic changes were more apparent in animals with longer periods of untreated SIV infection and correlated well with changes in corresponding gene expression. Known SIV integration sites did not vary due to SIV status but did contain more open chromatin in rhesus macaque memory T cells, and the expression of proteasome-related genes at the pre-SIV timepoint correlated with subsequent viremia.IMPORTANCEChronic inflammation during progressive human and simian immunodeficiency virus (HIV and SIV) infections leads to significant co-morbidities in infected individuals with significant consequences. Antiretroviral (ARV)-treated individuals also manifest increased levels of inflammation which are associated with increased mortalities. These data will help guide rational development of modalities to reduce inflammation observed in people living with HIV and suggest mechanisms underlying lentiviral integration site preferences.

Male Reproduction and Health after Recovery from COVID-19 Infection

Objective. To study the reproductive hormones, semen quality, psychology, and sexual function of childbearing age men after recovery from Corona Virus Disease-2019 (COVID-19) infection. Materials and Methods. We recruited 387 men of childbearing age who recovered from COVID-19 infection and underwent prepregnancy health checks at the Reproductive Center of Shandong Maternal and Child Health Hospital from January to March 2023 as study subjects. Routine semen analysis and reproductive hormones were performed. The clinical symptoms, anxiety, depression, erectile function, and premature ejaculation questionnaire were investigated during the COVID-19 infection period. A control group of 226 men of childbearing age who were not infected with COVID-19 between August 2022 and October 2022 were selected based on questionnaire responses, reproductive hormones, and semen parameters. Results. The main clinical symptoms during COVID-19 infection of the 387 research subjects were fever (342/387, 88.37%), muscle pain (155/387, 40.05%), anosmia (124/387, 32.04%), cough (106/387, 27.39%), throat pain (53/387, 13.70%), nausea and vomiting (16/387, 4.13%), and testicular discomfort (5/387, 1.29%). The rates of anxiety and depression were 11.37% (44/387) and 32.82% (127/387), respectively; erectile dysfunction (ED) and premature ejaculation (PE) of the research subjects were accounted for 32.30% (125/387) and 6.98% (27/387). The IEF-5 score (P&lt;0.001) decreased significantly compared to the control group, while the PHQ-9 score (P&lt;0.001), the rate of increased ED (P&lt;0.001), and the rate of depression increased (P&lt;0.001). There were statistically significant differences in liquefaction time (P&lt;0.05), the progressive sperm motility (P&lt;0.05), total sperm motility (P&lt;0.05), the rates of progressive sperm motility &lt;32% (P&lt;0.05), and total sperm motility &lt;40% (P&lt;0.05) between the 1 month, the 2 months after recovery from COVID-19 and controls. Circular cell counts (P&lt;0.05) at 2 and 3 months were lower than in the controls. No changes in reproductive hormones before and after recovery from infection. Conclusion. COVID-19 infection exacerbates depression and ED. It has a sustained effect on sperm motility and liquefaction time in men. The effects of COVID-19 infection on semen persist for approximately 2 months, with recovery occurring in the third month. Reproductive hormone levels do not appear to be continuously affected after recovery from COVID-19.

Early surveillance of rice bakanae disease using deep learning and hyperspectral imaging

Bakanae disease, caused by Fusarium fujikuroi, poses a significant threat to rice production and has been observed in most rice-growing regions. The disease symptoms caused by different pathogens may vary, including elongated and weak stems, slender and yellow leaves, and dwarfism, as example. Bakanae disease is likely to cause necrosis of diseased seedlings, and it may cause a large area of infection in the field through the transmission of conidia. Therefore, early disease surveillance plays a crucial role in securing rice production. Traditional monitoring methods are both time-consuming and labor-intensive and cannot be broadly applied. In this study, a combination of hyperspectral imaging technology and deep learning algorithms were used to achieve in situ detection of rice seedlings infected with bakanae disease. Phenotypic data were obtained on the 9th, 15th, and 21st day after rice infection to explore the physiological and biochemical performance, which helps to deepen the research on the disease mechanism. Hyperspectral data were obtained over these same periods of infection, and a deep learning model, named Rice Bakanae Disease-Visual Geometry Group (RBD-VGG), was established by leveraging hyperspectral imaging technology and deep learning algorithms. Based on this model, an average accuracy of 92.2% was achieved on the 21st day of infection. It also achieved an accuracy of 79.4% as early as the 9th day. Universal characteristic wavelengths were extracted to increase the feasibility of using portable spectral equipment for field surveillance. Collectively, the model offers an efficient and non-destructive surveillance methodology for monitoring bakanae disease, thereby providing an efficient avenue for disease prevention and control.

Impact of the Transboundary Interference Inhibitor on RNAi and the Baculovirus Expression System in Insect Cells.

RNA interference inhibitors were initially discovered in plant viruses, representing a unique mechanism employed by these viruses to counteract host RNA interference. This mechanism has found extensive applications in plant disease resistance breeding and other fields; however, the impact of such interference inhibitors on insect cell RNA interference remains largely unknown. In this study, we screened three distinct interference inhibitors from plant and mammal viruses that act through different mechanisms and systematically investigated their effects on the insect cell cycle and baculovirus infection period at various time intervals. Our findings demonstrated that the viral suppressors of RNA silencing (VSRs) derived from plant and mammal viruses significantly attenuated the RNA interference effect in insect cells, as evidenced by reduced apoptosis rates, altered gene regulation patterns in cells, enhanced expression of exogenous proteins, and improved production efficiency of recombinant virus progeny. Further investigations revealed that the early expression of VSRs yielded superior results compared with late expression during RNA interference processes. Additionally, our results indicated that dsRNA-binding inhibition exhibited more pronounced effects than other modes of action employed by these interference inhibitors. The outcomes presented herein provide novel insights into enhancing defense mechanisms within insect cells using plant and mammal single-stranded RNA virus-derived interference inhibitors and have potential implications for expanding the scope of transformation within insect cell expression systems.

Unraveling tuberculosis patient cluster transmission chains: integrating WGS-based network with clinical and epidemiological insights.

Tuberculosis remains a global health threat, and the World Health Organization reports a limited reduction in disease incidence rates, including both new and relapse cases. Therefore, studies targeting tuberculosis transmission chains and recurrent episodes are crucial for developing the most effective control measures. Herein, multiple tuberculosis clusters were retrospectively investigated by integrating patients' epidemiological and clinical information with median-joining networks recreated based on whole genome sequencing (WGS) data of Mycobacterium tuberculosis isolates. Epidemiologically linked tuberculosis patient clusters were identified during the source case investigation for pediatric tuberculosis patients. Only M. tuberculosis isolate DNA samples with previously determined spoligotypes identical within clusters were subjected to WGS and further median-joining network recreation. Relevant clinical and epidemiological data were obtained from patient medical records. We investigated 18 clusters comprising 100 active tuberculosis patients 29 of whom were children at the time of diagnosis; nine patients experienced recurrent episodes. M. tuberculosis isolates of studied clusters belonged to Lineages 2 (sub-lineage 2.2.1) and 4 (sub-lineages 4.3.3, 4.1.2.1, 4.8, and 4.2.1), while sub-lineage 4.3.3 (LAM) was the most abundant. Isolates of six clusters were drug-resistant. Within clusters, the maximum genetic distance between closely related isolates was only 5-11 single nucleotide variants (SNVs). Recreated median-joining networks, integrated with patients' diagnoses, specimen collection dates, sputum smear microscopy, and epidemiological investigation results indicated transmission directions within clusters and long periods of latent infection. It also facilitated the identification of potential infection sources for pediatric patients and recurrent active tuberculosis episodes refuting the reactivation possibility despite the small genetic distance of ≤5 SNVs between isolates. However, unidentified active tuberculosis cases within the cluster, the variable mycobacterial mutation rate in dormant and active states, and low M. tuberculosis genetic variability inferred precise transmission chain delineation. In some cases, heterozygous SNVs with an allelic frequency of 10-73% proved valuable in identifying direct transmission events. The complex approach of integrating tuberculosis cluster WGS-data-based median-joining networks with relevant epidemiological and clinical data proved valuable in delineating epidemiologically linked patient transmission chains and deciphering causes of recurrent tuberculosis episodes within clusters.

A deterministic mathematical model with non-linear least squares method for investigating the transmission dynamics of lumpy skin disease

Lumpy skin disease (LSD) is an economically significant viral disease of cattle caused by the lumpy disease virus (LSDV) which is primarily spread mechanically by blood feeding vectors such as particular species in flies, mosquitoes and ticks. Despite efforts to control its spread, LSD has been expanding geographically, posing challenges for effective control measures. This study develops a Susceptible–Exposed–Infectious–Recovered–Susceptible (SEIRS) model that incorporates cattle and vector populations to investigate LSD transmission dynamics. The model considers the waning rate of natural active immunity in recovered cattle, disease-induced mortality, and the biting rate. Using a standard dynamical system approach, we conducted a qualitative analysis of the model, defining the invariant region, establishing conditions for solution positivity, computing the basic reproduction number, and examining the stability of disease-free and endemic equilibria. We employ a non-linear least squares method for model calibration, fitting it to a synthetic dataset. We subsequently test it with actual infectious cases data. Results from the calibration and testing phases demonstrate the model’s validity and reliability for diverse settings. Local and global sensitivity analyses were conducted to determine the model’s robustness to parameter values. The biting rate emerged as the most significant parameter, followed by the probabilities of infection from either population and the recovery rate. Additionally, the waning rate of LSD infection-induced immunity gained positive significance in LSD prevalence from the beginning of the infectious period onward. Simulation results suggest reducing the biting rate as the most effective LSD control measure, which can be achieved by applying vector repellents in cattle farms/herds, thereby mitigating the disease’s prevalence in both cattle and vector populations and reducing the chances of infection from either population. Furthermore, measures aiming to boost LSD infection-induced immunity upon recovery are recommended to preserve the immune systems of the cattle population.

Novel estimation of African swine fever transmission parameters within smallholder villages in Lao P.D.R

African Swine Fever (ASF) disease transmission parameters are crucial for making response and control decisions when faced with an outbreak, yet they are poorly quantified for smallholder and village contexts within Southeast Asia. Whilst disease-specific factors − such as latent and infectious periods − should remain reasonably consistent, host, environmental and management factors are likely to affect the rate of disease spread. These differences are investigated using Approximate Bayesian Computation with Sequential Monte-Carlo methods to provide disease parameter estimates in four naïve pig populations in villages of Lao People’s Democratic Republic. The villages represent smallholder pig farmers of the Northern province of Oudomxay and the Southern province of Savannakhet, and the model utilised field mortality data to validate the transmission parameter estimates over the course of multiple model generations. The basic reproductive number between-pigs was estimated to range from 3.08 to 7.80, whilst the latent and infectious periods were consistent with those published in the literature for similar genotypes in the region (4.72 to 6.19 days and 2.63 to 5.50 days, respectively). These findings demonstrate that smallholder village pigs interact similarly to commercial pigs, however the spread of disease may occur slightly slower than in commercial study groups. Furthermore, the findings demonstrated that despite diversity across the study groups, the disease behaved in a consistent manner. This data can be used in disease control programs or for future modelling of ASF in smallholder contexts.

Why aphid virus retention needs more attention: modelling aphid behaviour and virus manipulation in non-persistent plant virus transmission.

Abstract Plant viruses threaten food security and are often transmitted by insect vectors. Non-persistently transmitted (NPT) plant viruses are transmitted almost exclusively by aphids. Because virions attach to the aphid's stylet (mouthparts) and are acquired and inoculated via brief epidermal probes, the aphid-virus interaction is highly transient, with a very short aphid virus retention time. Many NPT viruses manipulate their host plant's phenotype to change aphid behaviour to optimise virus transmission. Epidemiological models of this have overlooked a key feature of aphid NPT virus retention: probing or feeding on a plant causes aphids to lose the virus. Additionally, experimental studies suggest aphids could possibly inoculate multiple healthy plants within one infective period. However, consequences of this for virus manipulation of host plant phenotype have not been explored. Our new compartmental epidemiological model includes both behaviour-based aphid dispersal and infectivity loss rates, and the ability of infective aphids to probe more than one plant before virus loss. We use our model to explore how NPT virus-induced host phenotypes affect epidemic outcomes, comparing these results to representative previous models. We find that previous models behave fundamentally differently and underestimate the benefit of an 'attract-and-deter' phenotype, where the virus induces increased aphid attraction to infected plants but deters them from prolonged feeding. Our results also highlight the importance of characterising NPT virus retention upon the aphid during probing. Allowing for multiple infective probes increases disease incidence and the effectiveness of virus manipulation, with implications for epidemic prediction and control.

Epidemiology of cutaneous leishmaniasis in children of Khyber Pakhtunkhwa, Pakistan.

In Pakistan, cutaneous leishmaniasis is an emerging tropical disease and a very high number (>70%) of children are afflicted by this marring infection. This study aimed to scrutinise the prevalence, spatial distribution and socio-demographic and behavioural risk factors associated with cutaneous leishmaniasis in children aged <5-15 years in Khyber Pakhtunkhwa. A total of 1, 559 clinically confirmed records of children diagnosed with cutaneous leishmaniasis (January-December) from 2020 and 2022 were obtained from selected district hospitals. In addition, a risk factors-related questionnaire was administered to 1, 011 households (400 in 2020 and 611 in 2022) in nine districts during a household survey. The maximum number of cutaneous leishmaniasis cases was recorded in 2022 (n = 877, 56.25%) as compared to 2020 (n = 682, 43.75%). The hospital records showed a greater number of male patients in the 2022 cohort (n = 603, 68.76%). The highest number of cases were observed in children aged 5-9 years in 2022 (n = 282, 32.16%) and 2020 (n = 255, 37.39%). In 2020 and 2022, cutaneous leishmaniasis cases showed peak aggregation in March (n = 118, 17.3%) and January (n = 322, 36.72%). From a spatial analysis, the maximum number of cutaneous leishmaniasis cases was recorded at 59-1700 m elevation in various land-use/land-cover and climatic regions with quaternary alluvium rock formations. A multivariate logistic regression model analysis of risk factors from the households survey suggested that age group, socio-economic status, construction materials of the house, use of insect repellents, Afghan refugee camps in the village/district, knowledge and biting times of sand flies, frequent use of mosquito bed nets, presence of domestic animals in the house, knowledge of the transmission period and peak month of leishmaniasis infection increased the risk of acquiring cutaneous leishmaniasis (p value < 0.05). Our analysis demonstrated that cutaneous leishmaniasis in children is influenced by a variety of environmental, socio-demographic and behavioural risk factors in Khyber Pakhtunkhwa. The increase in recorded cases of cutaneous leishmaniasis in children in 2022 compared to 2020 suggests that the infection likely extended to new foci in the province.

Physiological response of chestnuts (Castanea mollissima Blume) infected by pathogenic fungi and their correlation with fruit decay

The postharvest decay of chestnuts (Castanea mollissima Blume) limits their industrial utilization, and pathogenic fungi are the main cause for chestnut decay. In this study, the physiological changes and their correlation with the rotting degree of chestnuts were investigated during single or mixed infection by Fusarium proliferatum, Penicillium crustosum, and Alternaria alternata. During the infection period, the activities of cell wall degrading enzymes (CWDEs) and antioxidant enzymes firstly increased and then decreased, the contents of nutrients decreased, but the levels of physiological indexes increased. The mycelium and spores of pathogenic fungi colonized the intercellular space, and then the mycelium covered the entire tissue surface of chestnuts, leading to the disappearance of cell structure. Notably, the most prominent changes in physiological indexes and ultrastructure were observed in chestnuts infected with three pathogenic fungi. Furthermore, the rotting degree of chestnuts was positively correlated with the levels of CWDEs, antioxidant enzymes and malondialdehyde.

Contribution of parasite and host genotype to immunopathology of schistosome infections

BackgroundThe role of pathogen genotype in determining disease severity and immunopathology has been studied intensively in microbial pathogens including bacteria, fungi, protozoa and viruses but is poorly understood in parasitic helminths. The medically important blood fluke Schistosoma mansoni is an excellent model system to study the impact of helminth genetic variation on immunopathology. Our laboratory has demonstrated that laboratory schistosome populations differ in sporocyst growth and cercarial production in the intermediate snail host and worm establishment and fecundity in the vertebrate host. Here, we (i) investigate the hypothesis that schistosome genotype plays a significant role in immunopathology and related parasite life history traits in the vertebrate mouse host and (ii) quantify the relative impact of parasite and host genetics on infection outcomes.MethodsWe infected BALB/c and C57BL/6 mice with four different laboratory schistosome populations from Africa and the Americas. We quantified disease progression in the vertebrate host by measuring body weight and complete blood count (CBC) with differential over a 12-week infection period. On sacrifice, we assessed parasitological (egg and worm counts, fecundity), immunopathological (organ measurements and histopathology) and immunological (CBC with differential and cytokine profiles) characteristics to determine the impact of parasite and host genetics.ResultsWe found significant variation between parasite populations in worm numbers, fecundity, liver and intestine egg counts, liver and spleen weight, and fibrotic area but not in granuloma size. Variation in organ weight was explained by egg burden and intrinsic parasite factors independent of egg burden. We found significant variation between infected mouse lines in cytokine levels (IFN-γ, TNF-α), eosinophils, lymphocytes and monocyte counts.ConclusionsThis study showed that both parasite and host genotype impact the outcome of infection. While host genotype explains most of the variation in immunological traits, parasite genotype explains most of the variation in parasitological traits, and both host and parasite genotypes impact immunopathology outcomes.Graphical

Vaccine effectiveness against emerging COVID-19 variants using digital health data

BackgroundParticipatory surveillance of self-reported symptoms and vaccination status can be used to supplement traditional public health surveillance and provide insights into vaccine effectiveness and changes in the symptoms produced by an infectious disease. The University of Maryland COVID Trends and Impact Survey provides an example of participatory surveillance that leveraged Facebook’s active user base to provide self-reported symptom and vaccination data in near real-time.MethodsHere, we develop a methodology for identifying changes in vaccine effectiveness and COVID-19 symptomatology using the University of Maryland COVID Trends and Impact Survey data from three middle-income countries (Guatemala, Mexico, and South Africa). We implement conditional logistic regression to develop estimates of vaccine effectiveness conditioned on the prevalence of various definitions of self-reported COVID-like illness in lieu of confirmed diagnostic test results.ResultsWe highlight a reduction in vaccine effectiveness during Omicron-dominated waves of infections when compared to periods dominated by the Delta variant (median change across COVID-like illness definitions: −0.40, IQR[−0.45, −0.35]. Further, we identify a shift in COVID-19 symptomatology towards upper respiratory type symptoms (i.e., cough and sore throat) during Omicron periods of infections. Stratifying COVID-like illness by the National Institutes of Health’s (NIH) description of mild and severe COVID-19 symptoms reveals a similar level of vaccine protection across different levels of COVID-19 severity during the Omicron period.ConclusionsParticipatory surveillance data alongside methodologies described in this study are particularly useful for resource-constrained settings where diagnostic testing results may be delayed or limited.

Prevalence and antimicrobial resistant &lt;i&gt;Escherichia coli&lt;/i&gt; and &lt;i&gt;Klebsiella&lt;/i&gt; sp among individuals with urinary tract infection from hospital and community settings in Ado-Ekiti, Nigeria

The antibiotic resistance of urinary pathogens has been varying over the period of years, in community and healthcare-associated infections. The study provided the current prevalence and antimicrobial-resistant Escherichia coli and Klebsiella sp among individuals with urinary tract infections from hospital and community settings in Ado-Ekiti, Nigeria. Midstream urine samples were collected and studied using standard microbiological techniques. Information for the factors associated with UTIs was obtained using questionnaires. An agar disc diffusion technique was used to test for antibiotic susceptibility. The chi-square test and Poisson regression was used to express associations among descriptive variables of UTI. The study revealed females are more susceptible to UTIs than males. Bacterial isolates showed a low prevalence of UTI with 122(8.5%). The age-wise distribution shows that the Incidence is more common in age bracket 51-60 and 21to 30 years. Gender and risk factors among the individuals had a significant relationship with UTIs. Overall, the bacterial strains showed the highest resistance to amoxicillin-clavulanate 43(91.5%) and most susceptible to imipenem 40(85.1%). The bacteria isolates also showed high multiple resistance with 0.6 MAR index. Appropriate diagnosis and management of UTI are aimed at treating the acute occurrence as well as preventing recurrences of this infection.

Using Passive Surveillance to Maintain Elimination as a Public Health Problem for Neglected Tropical Diseases: A Model-Based Exploration.

Great progress is being made toward the goal of elimination as a public health problem for neglected tropical diseases such as leprosy, human African trypanosomiasis, Buruli ulcer, and visceral leishmaniasis, which relies on intensified disease management and case finding. However, strategies for maintaining this goal are still under discussion. Passive surveillance is a core pillar of a long-term, sustainable surveillance program. We use a generic model of disease transmission with slow epidemic growth rates and cases detected through severe symptoms and passive detection to evaluate under what circumstances passive detection alone can keep transmission under control. Reducing the period of infectiousness due to decreasing time to treatment has a small effect on reducing transmission. Therefore, to prevent resurgence, passive surveillance needs to be very efficient. For some diseases, the treatment time and level of passive detection needed to prevent resurgence is unlikely to be obtainable. The success of a passive surveillance program crucially depends on what proportion of cases are detected, how much of their infectious period is reduced, and the underlying reproduction number of the disease. Modeling suggests that relying on passive detection alone is unlikely to be enough to maintain elimination goals.

The dynamic risk factors of cardiovascular disease among people living with HIV: a real-world data study

BackgroundThis study aims to investigate the incidence and dynamic risk factors for cardiovascular diseases (CVD) among people living with HIV (PLWH).MethodsIn this population-based statewide cohort study, we utilized integrated electronic health records data to identify adult (age ≥ 18) who were diagnosed with HIV between 2006 and 2019 and were CVD event-free at the HIV diagnosis in South Carolina. The associations of HIV-related factors and traditional risk factors with the CVD incidence were investigated during the overall study period, and by different follow-up periods (i.e., 0-5yrs, 6-10yrs 11-15yrs) using multivariable logistic regression models.ResultsAmong 9,082 eligible participants, the incidence of CVD was 18.64 cases per 1000 person-years. Overall, conventional risk factors, such as tobacco use, hypertension, obesity, chronic kidney disease (CKD), were persistently associated with the outcome across all three groups. While HIV-related factors, such as recent CD4 count (e.g., > 350 vs. <200 cells/mm3: adjusted odds ratio [aOR] range: 0.18–0.25), and percent of years in retention (e.g., 31–75% vs. 0–30%: aOR range: 0.24–0.57) were associated with lower odds of CVD incidence regardless of different follow up periods. The impact of the percent of days with viral suppression gradually diminished as the follow-up period increased.ConclusionsMaintaining an optimal viral suppression might prevent CVD incidence in the short term, whereas restoring immune recovery may be beneficial for reducing CVD risk regardless of the duration of HIV diagnosis. Our findings suggest the necessity of conducting more targeted interventions during different periods of HIV infection.

Investigation on KAP Model of Urban Residents in Prevention and Control of COVID-19

Objective: To investigate the knowledge, attitude and practice of the residents in Changxing community in the prevention and control of novel coronavirus pneumonia, and put forward targeted suggestions for formulating epidemic prevention and control measures. Methods: Convenience sampling method was used to invite residents to fill in the self-designed questionnaire online. Results: Total of 294 valid questionnaires were obtained. Among them, the awareness rates of the infectious source, transmission route, incubation period and epidemic situation of COVID-19 were 84.7%, 94.2%, 90.1% and 83.0% respectively. The proportions of judging that COVID-19 has high infectious characteristics, low mortality and high cure rate were 89.5%, 40.1% and 62.6%. The proportions of mastering the knowledge of preventive behaviors such as wearing masks, avoiding family and friends' gatherings, and washing hands correctly were 98.0%, 96.6% and 90.8%; The level of attitude towards epidemic prevention and control measures and awareness of prevention behavior exceeded 90%. Conclusion: The knowledge, attitude and practice of residents in Changxing community on COVID-19 are good.