Clinical study on the treatment of Qingfei Paidu Granules combined with nondrug therapy for asymptomatic patients with novel coronavirus.

BACKGROUND: The COVID-19 pandemic, ongoing for over 2 years with evolving viral strains, including the highly infectious Omicron variant, underscores the pivotal role of Traditional Chinese Medicine (TCM) in pandemic intervention. Qingfei Paidu Granules (QFPG) are incorporated into the national TCM diagnosis and treatment protocol. This study aims to assess the clinical effectiveness of QFPG combined with nonpharmacological interventions in asymptomatic novel coronavirus infection. MATERIALS AND METHODS: Using a full-group randomized controlled trial, asymptomatic individuals from 3 wards of Fangcang Hospital were randomly assigned to 3 groups, each comprising 150 cases: F1, the nonpharmacological treatment group, receiving only Five Elements Music Therapy and Gongfa Therapy; F2, the comprehensive treatment group, receiving QFPG treatment combined with Five Elements Music Therapy and Gongfa Therapy; and F3, the pharmacological treatment group, receiving only QFPG treatment. The treatment duration for each group was 6 days. Clinical efficacy and safety among different treatment groups were observed, including the conversion time of COVID-19 nucleic acid detection, duration of hospitalization, conversion rate from mild to moderate cases, and occurrence of adverse events. RESULTS: All 450 participants were included and completed the study. The conversion rates on the first day of treatment were 10.7%, 30%, and 11.3% for the F1, F2, and F3 groups, respectively. Compared to F1, both F2 and F3 showed shortened first conversion time and time to double negative results, with first conversion times of 1.92 days for F2 and 2.29 days for F3. Additionally, the time in F2 was shorter compared to F3. Hospitalization duration was shortened in both F2 and F3 compared to F1, with no statistically significant difference between F2 and F3. The conversion rate from mild to moderate cases was lower in both F2 and F3 compared to F1, but the difference between F2 and F3 was not significant. CONCLUSION: Combining QFPG with traditional Chinese nonpharmacological interventions effectively shortened the conversion time of COVID-19 nucleic acid detection and reduced the conversion rate from asymptomatic infection to mild/moderate cases. This treatment approach is worth promoting in the management of asymptomatic patients during pandemics. TRIAL REGISTRATION: ClinicalTrials.gov, ChiCTR2200059007.

High SARS-CoV-2 incidence and asymptomatic fraction during Delta and Omicron BA.1 waves in The Gambia.

Little is known about SARS-CoV-2 infection risk in African countries with high levels of infection-driven immunity and low vaccine coverage. We conducted a prospective cohort study of 349 participants from 52 households in The Gambia between March 2021 and June 2022, with routine weekly SARS-CoV-2 RT-PCR and 6-monthly SARS-CoV-2 serology. Attack rates of 45% and 57% were seen during Delta and Omicron BA.1 waves respectively. Eighty-four percent of RT-PCR-positive infections were asymptomatic. Children under 5-years had a lower incidence of infection than 18-49-year-olds. One prior SARS-CoV-2 infection reduced infection risk during the Delta wave only, with immunity from ≥2 prior infections required to reduce the risk of infection with early Omicron lineage viruses. In an African population with high levels of infection-driven immunity and low vaccine coverage, we find high attack rates during SARS-CoV-2 waves, with a high proportion of asymptomatic infections and young children remaining relatively protected from infection.

Subclinical tuberculosis: a meta-analysis of prevalence and scoping review of definitions, prevalence and clinical characteristics.

BACKGROUND: This scoping review aimed to characterise definitions used to describe subclinical tuberculosis (TB), estimate the prevalence in different populations and describe the clinical characteristics and treatment outcomes in the scientific literature. METHODS: A systematic literature search was conducted using PubMed. We included studies published in English between January 1990 and August 2022 that defined "subclinical" or "asymptomatic" pulmonary TB disease, regardless of age, HIV status and comorbidities. We estimated the weighted pooled proportions of subclinical TB using a random-effects model by World Health Organization reported TB incidence, populations and settings. We also pooled the proportion of subclinical TB according to definitions described in published prevalence surveys. RESULTS: We identified 29 prevalence surveys and 71 other studies. Prevalence survey data (2002-2022) using "absence of cough of any duration" criteria reported higher subclinical TB prevalence than those using the stricter "completely asymptomatic" threshold. Prevalence estimates overlap in studies using other symptoms and cough duration. Subclinical TB in studies was commonly defined as asymptomatic TB disease. Higher prevalence was reported in high TB burden areas, community settings and immunocompetent populations. People with subclinical TB showed less extensive radiographic abnormalities, higher treatment success rates and lower mortality, although studies were few. CONCLUSION: A substantial proportion of TB is subclinical. However, prevalence estimates were highly heterogeneous between settings. Most published studies incompletely characterised the phenotype of people with subclinical TB. Standardised definitions and diagnostic criteria are needed to characterise this phenotype. Further research is required to enhance case finding, screening, diagnostics and treatment options for subclinical TB.

Comparison of malaria diagnostic methods for detection of asymptomatic Plasmodium infections among pregnant women in northwest Ethiopia.

BACKGROUND: Malaria in pregnancy remains a major public health problem in the globe, especially in sub-Saharan Africa. In malaria endemic areas, most pregnant women remain asymptomatic, but malaria could still cause complications on the mother and her offspring; as well as serve as reservoirs to transmit infection. Despite these effects, no attention is given to the diagnosis of asymptomatic Plasmodium infections (APIs) using highly sensitive and specific laboratory diagnostic tools in Ethiopia. Therefore, the goal of this study was to compare the performance of Rapid Diagnostic Test (RDT), microscopy and real-time polymerase chain reaction (RT-PCR) to detect APIs among pregnant women. METHODS: A health facility based cross -sectional study was conducted among pregnant women attending antenatal care at Fendeka town health facilities Jawi district, northwest Ethiopia from February to March, 2019. A total of 166 participants were enrolled by using convenient sampling technique. Socio-demographic features were collected using a semi structured questionnaire. Dried blood spot (DBS) samples were collected for molecular analysis. Asymptomatic Plasmodium infection on pregnant women was diagnosed using RDT, microscopy and RT-PCR. Descriptive statistics were used to determine the prevalence of APIs. Method comparison was performed, and Cohen's kappa coefficient (k) was used to determine the degree of agreement among the diagnostic methods. Parasite densities were also calculated. RESULTS: The prevalence of API was 9.6%, 11.4% and 18.7% using RDT, microscopy and RT-PCR, respectively. The overall proportion of API was 19.3%. Sensitivity of the RDT was 83.3% as compared with microscopy. Rapid Diagnostic Test and microscopy also showed sensitivity of 50% and 60%, respectively, as compared with RT-PCR. The mean parasite density was 3213 parasites/µl for P falciparum and 1140 parasites/µl of blood for P. vivax. CONCLUSION: Prevalence of API in the study area was high. Both RDT and microscopy had lower sensitivity when compared with RT-PCR. Therefore, routine laboratory diagnosis of API among pregnant women should be given attention and done with better sensitive and specific laboratory diagnostic tools.

Faecal shedding of SARS-CoV-2 from patients with asymptomatic and mild COVID-19 without gastrointestinal symptoms in Ghana.

OBJECTIVE: In this study, we sought to determine whether faecal shedding occurs among SARS-COV-2 positive Ghanaians, as reported elsewhere. Hence we assayed for SARS-COV-2 in the stools of 48 SARS-COV-2 confirmed patients at the Ho Municipal Hospital in Ghana. RESULTS: Of the 48 COVID-19 patients, 45 (93.8%) had positive tests for SARS-CoV-2 faecal shedding. About 60% reported no respiratory symptoms, while only 2% (1 patient) reported gastrointestinal (GI) symptoms in the form of nausea. Other symptoms reported included headache (57.9%), weakness (57.9%), cough (52.6%), blocked/runny nose (47.4%), fever (31.6%), sore throat (31.6%), and shortness of breath (21.1%). One person complained of nausea (5.3%) Semi-quantitative comparison of the SARS COV-2 viral loads in matched respiratory and faecal samples using the cycle threshold (CT) values revealed no statistical differences. Furthermore, the duration between collection of respiratory and faecal samples did not have any direct influence on the differences in the CT values. This suggests that treatment and use of sewage for environmental surveillance of SARS COV-2 could be a potential public health countermeasure.

Considering potential roles of selected MicroRNAs in evaluating subclinical mastitis and Milk quality in California mastitis test (+) and infected bovine milk.

This study investigates the relationships between subclinical mastitis and milk quality with selected microRNAs in cow milk. California Mastitis Test (CMT)-positive (n = 20) and negative (n = 20) samples were compared (Experiment I). Additionally, samples with CMT-positive but microbiological-negative, as well as positive for only Staphylococcus subspecies (Staph spp.) and only Streptococcus subspecies (Strep spp.) were examined (Experiment II). Four groups were formed in Experiment II: Group I (CMT and microbiological-negative) (n = 20), Group II (CMT-positive but microbiological-negative) (n = 10), Group III (Staph spp.) (n = 5), Group IV (Strep spp.) (n = 5). While electrical conductivity, somatic cell count (SCC), malondialdehyde (MDA) increased, miR-27a-3p and miR-223 upregulated and miR-125b downregulated in the CMT-positive group in Experiment I. SCC and MDA were higher in CMT-positive groups. miR-27a-3p and miR-223 upregulated in Groups III and IV. While miR-155 is upregulated, miR-125b downregulated in Group IV. Milk fat is positively correlated with miR-148a and miR-223. As miR-27a-3p positively correlated with SCC and MDA, miR-125b negatively correlated with electrical conductivity and SCC. miR-148a and MDA were positively correlated. miR-155 was correlated with fat-free dry matter, protein, lactose, and freezing point. miR-223 was positively correlated with SCC and miR-148a. Results particularly highlight miR-27a-3p and miR-223 as potential biomarkers in subclinical mastitis, especially those caused by Staph spp. and Strep spp., while miR-148a, miR-155, and miR-223 stand out in determining milk quality.

Impaired Cardiorespiratory Fitness of Elite Athletes after Asymptomatic or Mild SARS-CoV-2 Infection.

Background and Objectives: The aim of the study was to evaluate the health status of professional athletes after recovering from COVID-19 and the impact that SARS-CoV-2 had on their overall cardiorespiratory fitness, which was done by conducting cardiopulmonary exercise testing (CPET). Materials and Methods: A total of twenty-seven professional basketball players (Euroleague Basketball and the ABA League) participated in the study. CPET was performed before (as part of their regular preparticipation exam, during the pre-season period), as well as after SARS-CoV-2 infection (after two weeks of home isolation, during the competitive part of the season). CPET was performed on a treadmill, while cardiovascular, respiratory, and metabolic functions were evaluated by using a breath-by-breath analysis technique (Quark CPET system manufactured by Cosmed, Rome, Italy). Results: Maximal oxygen consumption and aerobic efficiency were significantly reduced after SARS-CoV-2 infection (p = 0.000). An obvious decrease in oxygen pulse was observed during CPET after recovering from COVID-19 (p = 0.001), as was deterioration of ventilatory efficiency. Internal respiration was the most negatively affected. An early transition from aerobic to anaerobic mechanisms of creating energy for work and intensive metabolic fatigue were obvious after SARS-CoV-2 infection. Conclusions: Although it was believed that SARS-CoV-2 only affects the cardiopulmonary status of the elderly population and people with associated comorbidities, it is clear from this research that professional athletes can also be at certain risk. Even though no pathological cardiovascular and respiratory changes were found in athletes after COVID-19, results showed significantly decreased cardiorespiratory fitness, with an emphasis on internal respiration.

The Hidden Hand of Asymptomatic Infection Hinders Control of Neglected Tropical Diseases: A Modeling Analysis.

BACKGROUND: Neglected tropical diseases are responsible for considerable morbidity and mortality in low-income populations. International efforts have reduced their global burden, but transmission is persistent and case-finding-based interventions rarely target asymptomatic individuals. METHODS: We develop a generic mathematical modeling framework for analyzing the dynamics of visceral leishmaniasis in the Indian sub-continent (VL), gambiense sleeping sickness (gHAT), and Chagas disease and use it to assess the possible contribution of asymptomatics who later develop disease (pre-symptomatics) and those who do not (non-symptomatics) to the maintenance of infection. Plausible interventions, including active screening, vector control, and reduced time to detection, are simulated for the three diseases. RESULTS: We found that the high asymptomatic contribution to transmission for Chagas and gHAT and the apparently high basic reproductive number of VL may undermine long-term control. However, the ability to treat some asymptomatics for Chagas and gHAT should make them more controllable, albeit over relatively long time periods due to the slow dynamics of these diseases. For VL, the toxicity of available therapeutics means the asymptomatic population cannot currently be treated, but combining treatment of symptomatics and vector control could yield a quick reduction in transmission. CONCLUSIONS: Despite the uncertainty in natural history, it appears there is already a relatively good toolbox of interventions to eliminate gHAT, and it is likely that Chagas will need improvements to diagnostics and their use to better target pre-symptomatics. The situation for VL is less clear, and model predictions could be improved by additional empirical data. However, interventions may have to improve to successfully eliminate this disease.

Beyond Symptoms: Radiologic identification of asymptomatic Mycobacterium avium complex pulmonary infections.

BACKGROUND: Although international nontuberculous mycobacterial pulmonary disease (NTM-PD) guidelines highlight symptom presence at diagnosis, the clinical characteristics of asymptomatic Mycobacterium avium complex pulmonary infection (MAC-PI) patients remain understudied. We clarified the clinical characteristics and course of asymptomatic MAC-PI patients. METHODS: We retrospectively analyzed 200 consecutive patients with MAC-PIs and adequate available data who newly met the microbiological and radiological criteria for NTM-PD at Fukujuji Hospital from January 2018 to June 2020. We compared the clinical characteristics and course of asymptomatic patients with symptomatic patients and evaluated factors influencing treatment initiation through multivariate analysis. RESULTS: 111 patients were symptomatic and 89 were asymptomatic at diagnosis. While the proportion was significantly lower than that in the symptomatic group (28.8 %), 15.7 % of asymptomatic group patients had cavitary lesions (P = 0.042). In the asymptomatic group, treatments were initiated in 38 (42.7 %) patients, and cavitary lesions, a positive acid-fast bacilli smear, and younger age were independent risk factors for treatment initiation. Among 22 (57.9 %) patients who experienced disease progression necessitating treatment during follow-up, 13 (34.2 %) displayed radiological progression without any worsening of symptoms. Agents used for treatment were consistent across the groups, with no significant differences in culture conversion, microbiological recurrence rates, or spontaneous culture conversion rates. CONCLUSION: Routine health checkups and radiological examinations can detect clinically important MAC-PIs even in the absence of symptoms. Considering that the clinical course of asymptomatic MAC-PI patients is largely similar to that of symptomatic patients, timely and appropriate management and intervention are essential for all MAC-PI patients.

Antimicrobial resistance of Enterobacteriaceae and Staphylococcus spp. isolated from raw cow's milk from healthy, clinical and subclinical mastitis udders.

Mastitis is the most common disease of dairy cattle and can be manifested in clinical and subclinical forms. The overuse of antimicrobials in the treatment and prevention of mastitis favours antimicrobial resistance and milk can be a potential route of dissemination. This study aimed to evaluate the biological quality of bulk tank milk (BTM) and the microbiological quality and signs of mastitis of freshly milked raw milk. In addition, to evaluate antimicrobial resistance in Enterobacteriaceae and Staphylococcus spp. isolated from freshly milked raw milk. None of the farms were within the official Brazilian biological quality limits for BTM. Freshly milked raw milk with signs of clinical (CMM), subclinical (SCMM) and no signs (MFM) of mastitis were detected in 6.67%, 27.62% and 65.71% samples, respectively. Most samples of freshly milked raw milk showed acceptable microbiological quality, when evaluating the indicators total coliforms (78.10%), Escherichia coli (88.57%) and Staphylococcus aureus (100%). Klebsiella oxytoca and S. aureus were the most prevalent microorganisms in SCMM and MFM samples. Antimicrobial resistance and multidrug resistance (MDR) were observed in 65.12% and 13.95% of Enterobacteriaceae and 84.31% and 5.88% of Staphylococcus spp., respectively, isolated from both SCMM and MFM samples. Enterobacteriaceae resistant to third-generation cephalosporin (3GCR) (6.98%) and carbapenems (CRE) (6.98%) and methicillin-resistant S. aureus (MRSA) (4.88%) were observed. Antimicrobial-resistant bacteria can spread resistance genes to previously susceptible bacteria. This is a problem that affects animal, human and environmental health and should be evaluated within the one-health concept.

Kinetics of Hepatitis E Virus Infections in Asymptomatic Persons.

To determine the kinetics of hepatitis E virus (HEV) in asymptomatic persons and to evaluate viral load doubling time and half-life, we retrospectively tested samples retained from 32 HEV RNA-positive asymptomatic blood donors in Germany. Close-meshed monitoring of viral load and seroconversion in intervals of ≈4 days provided more information about the kinetics of asymptomatic HEV infections. We determined that a typical median infection began with PCR-detectable viremia at 36 days and a maximum viral load of 2.0 × 104 IU/mL. Viremia doubled in 2.4 days and had a half-life of 1.6 days. HEV IgM started to rise on about day 33 and peaked on day 36; IgG started to rise on about day 32 and peaked on day 53. Although HEV IgG titers remained stable, IgM titers became undetectable in 40% of donors. Knowledge of the dynamics of HEV viremia is useful for assessing the risk for transfusion-transmitted hepatitis E.

Global seroprevalence of Zika virus in asymptomatic individuals: A systematic review.

BACKGROUND: Zika virus (ZIKV) has spread to five of the six World Health Organization (WHO) regions. Given the substantial number of asymptomatic infections and clinical presentations resembling those of other arboviruses, estimating the true burden of ZIKV infections is both challenging and essential. Therefore, we conducted a systematic review and meta-analysis of seroprevalence studies of ZIKV IgG in asymptomatic population to estimate its global impact and distribution. METHODOLOGY/PRINCIPAL FINDINGS: We conducted extensive searches and compiled a collection of articles published from Jan/01/2000, to Jul/31/2023, from Embase, Pubmed, SciELO, and Scopus databases. The random effects model was used to pool prevalences, reported with their 95% confidence interval (CI), a tool to assess the risk of study bias in prevalence studies, and the I2 method for heterogeneity (PROSPERO registration No. CRD42023442227). Eighty-four studies from 49 countries/territories, with a diversity of study designs and serological tests were included. The global seroprevalence of ZIKV was 21.0% (95%CI 16.1%-26.4%). Evidence of IgG antibodies was identified in all WHO regions, except for Europe. Seroprevalence correlated with the epidemics in the Americas (39.9%, 95%CI:30.0-49.9), and in some Western Pacific countries (15.6%, 95%CI:8.2-24.9), as well as with recent and past circulation in Southeast Asia (22.8%, 95%CI:16.5-29.7), particularly in Thailand. Additionally, sustained low circulation was observed in Africa (8.4%, 95%CI:4.8-12.9), except for Gabon (43.7%), and Burkina Faso (22.8%). Although no autochthonous transmission was identified in the Eastern Mediterranean, a seroprevalence of 16.0% was recorded. CONCLUSIONS/SIGNIFICANCE: The study highlights the high heterogeneity and gaps in the distribution of seroprevalence. The implementation of standardized protocols and the development of tests with high specificity are essential for ensuring a valid comparison between studies. Equally crucial are vector surveillance and control methods to reduce the risk of emerging and re-emerging ZIKV outbreaks, whether caused by Ae. aegypti or Ae. albopictus or by the Asian or African ZIKV.

Reducing Treatment of Asymptomatic Bacteriuria: What Works?

Asymptomatic bacteriuria is common, but usually benign. Inappropriate antimicrobial treatment of asymptomatic bacteriuria contributes to negative antimicrobial outcomes. Optimizing antimicrobial use for bacteriuria is a component of antimicrobial stewardship programs and includes key practices of dissemination and implementation of guidelines, laboratory practices which support stewardship, and programs to monitor and implement optimal antimicrobial treatment for urinary infection. These activities vary in their effectiveness, costs, and complexity to institute. Stewardship strategies targeting unique populations with a high prevalence of bacteriuria and for whom symptom assessment is not straightforward need to be further developed and evaluated to support optimal stewardship.

COVID-19 response in a long-term care facility for people with epilepsy.

OBJECTIVE: To assess asymptomatic rates and severity of SARS-CoV-2 infection in people with epilepsy and their healthcare workers in a long-term care facility which had implemented weekly surveillance testing between April 2020 and June 2022. METHODS: Questionnaires focused on objective and subjective COVID-19 symptoms for people with epilepsy residing in and their healthcare workers at the Chalfont Centre for Epilepsy in June 2022. Demographic information, comorbidities, and seizure frequency were gathered from medical records. We also collected responses on objective and subjective COVID-19 symptoms from healthcare workers who participated in a prospective study assessing the reaction to COVID-19 vaccinations (SAFER). RESULTS: Fifty-five out of 89 (62%) residents tested positive at least once on weekly PCR testing for SARS-CoV-2 during the period of interest; 20 of those (37%) were asymptomatic. In comparison, of those 63 healthcare workers who tested positive at least once on weekly testing during the same period, only four (6%) were asymptomatic. Of the 159 healthcare workers who also participated in the SAFER study, 41 tested positive at least once, and seven (17%) were completely asymptomatic during infection with SARS-CoV-2. SIGNIFICANCE: People with epilepsy living in a long-term care facility were more likely to present with asymptomatic SARS-CoV-2 infections than healthcare workers at the same facility. Despite possible bias in the reporting of subjective symptoms due to management-by-proxy, there is no evidence that vulnerable people living in an epilepsy long-term care facility showed reduced resilience towards infections. PLAIN LANGUAGE SUMMARY: People with epilepsy living in care home facilities had a surprisingly high degree of asymptomatic infections with SARS-CoV-2. Very few residents had severe or fatal outcomes. This is in stark contrast to the widely reported bad outcomes for people without epilepsy in other care homes. People with epilepsy reported significantly less symptoms than their healthcare workers. No changes in seizure frequency during or after infection were observed.

Deletions of Histidine-Rich Protein 2/3 Genes in Natural Plasmodium falciparum Populations from Cameroon and India: Role of Asymptomatic and Submicroscopic Infections.

The bulk of malaria rapid diagnostic tests (RDTs) target histidine-rich protein 2 of Plasmodium falciparum, the deadliest malaria species. The WHO considers pfhrp2/3 deletions as one of the main threats to successful malaria control and/or elimination; as such, parasites that lack part or all of the pfhrp2 gene are missed by pfHRP2-targeting RDTs. Such deletions have been reported in several African and Asian countries, but little is known in Cameroon and India. Blood samples were collected from individuals living in four areas of Cameroon (Douala, Maroua, Mayo-Oulo, Pette) and India (Mewat, Raipur, Ranchi, Rourkela). Deletions in pfhrp2/3 genes were confirmed if samples 1) had ≥100 parasites/µL by quantitative polymerase chain reaction (PCR), 2) PCR negative for pfhrp2/3, and 3) PCR positive for at least two single-copy genes. The overall proportion of pfhrp2 and pfhrp3 deletions in Cameroon was 13.5% and 3.1%. In India, the overall proportion was 8% for pfhrp2 and 4% for pfhrp3. The overall proportions of samples with both gene deletions (pfhrp2-/3-) were 3.1% in Cameroon and 1.3% in India. In Cameroon, pfhrp2-/3+ and pfhrp2-/3- deletions were common in Maroua (P = 0.02), in asymptomatic parasitemia (P = 0.006) and submicroscopic parasitemia (P <0.0001). In both countries, pfhrp2/3 deletions, including pfhrp2-/3- deletions, were mainly seen in monoclonal infections. This study outlines that double deletions that result in false negative RDTs are uncommon in our settings, and highlights the importance of active molecular surveillance for pfhrp2/3 deletions in Cameroon and India.

Asymptomatic Leishmania infantum infection in dogs and dog owners in an endemic area in southeast France.

The prevalence of asymptomatic leishmaniasis in dogs and their owners in the main endemic areas of France has not been studied to date. The objective of this study was to quantify asymptomatic Leishmania infantum infection in southeast France in healthy people and their dogs using molecular and serological screening techniques. We examined the presence of parasitic DNA using specific PCR targeting kinetoplast DNA (kDNA) and specific antibodies by serology (ELISA for dogs and Western blot for humans) among immunocompetent residents and their dogs in the Alpes-Maritimes. Results from 343 humans and 607 dogs were included. 46.9% (n = 161/343) of humans and 18.3% (n = 111/607) of dogs were PCR positive; 40.2% of humans (n = 138/343) and 9.9% of dogs (n = 60/607) were serology positive. Altogether, 66.2% of humans (n = 227) and 25.7% of dogs (n = 156) had positive serologies and/or positive PCR test results. Short-haired dogs were more frequently infected (71.8%, n = 112) than long-haired dogs (12.2%, n = 19) (p = 0.043). Dogs seemed to be more susceptible to asymptomatic infection according to their breed types (higher infection rates in scenthounds, gun dogs and herding dogs) (p = 0.04). The highest proportion of dogs and human asymptomatic infections was found in the Vence Region, corresponding to 28.2% (n = 20/71) of dogs and 70.5% (n = 31/44) of humans (4.5/100,000 people). In conclusion, the percentage of infections in asymptomatic humans is higher than in asymptomatic dogs in the studied endemic area. It is questionable whether asymptomatic infection in humans constitutes a risk factor for dogs.

Title: Infection asymptomatique à Leishmania infantum chez les chiens et propriétaires de chiens dans une zone endémique du sud-est de la France. Abstract: La prévalence de la leishmaniose asymptomatique chez les chiens et leurs propriétaires dans les principales zones d'endémie françaises n'a pas été étudiée à ce jour. L'objectif de cette étude était de quantifier l'infection asymptomatique à Leishmania infantum dans le sud-est de la France chez des personnes saines et leurs chiens à l'aide de techniques de dépistage moléculaire et sérologique. Nous avons examiné chez des résidents immunocompétents et leurs chiens dans les Alpes-Maritimes la présence d'ADN parasitaire par PCR spécifique ciblant l'ADN du kinétoplaste (ADNk) et d'anticorps spécifiques par sérologie (ELISA pour le chien et Western Blot pour l'homme). Les résultats de 343 humains et 607 chiens ont été inclus; 46,9 % (n = 161/343) des humains et 18,3 % (n = 111/607) des chiens étaient positifs à la PCR et 40,2 % des humains (n = 138/343) et 9,9 % des chiens (n = 60/607) avaient une sérologie positive. Au total, 66,2 % des humains (n = 227) et 25,7 % des chiens (n = 156) avaient des sérologies positives et/ou des résultats de tests PCR positifs. Les chiens à poils courts étaient plus fréquemment infectés (71,8 %, n = 112) que les chiens à poils longs (12,2 %, n = 19) (p = 0,043). Les chiens semblaient plus sensibles à l'infection asymptomatique selon leurs races (taux supérieurs chez les chiens de chasse et chiens de berger) (p = 0,04). La plus forte proportion d'infections asymptomatiques chez les chiens et les humains a été observée dans la Région de Vence, correspondant à 28,2 % (n = 20/71) des chiens et 70,5 % (n = 31/44) des humains (4,5/100 000). personnes). En conclusion, le pourcentage d'infections chez les humains asymptomatiques est plus élevé que chez les chiens asymptomatiques dans la zone d'endémie étudiée. On peut se demander si une infection asymptomatique chez l'homme constitue un facteur de risque pour les chiens.

Prevalence of non-falciparum malaria infections among asymptomatic individuals in four regions of Mainland Tanzania.

BACKGROUND: Recent studies point to the need to incorporate the detection of non-falciparum species into malaria surveillance activities in sub-Saharan Africa, where 95% of the world's malaria cases occur. Although malaria caused by infection with Plasmodium falciparum is typically more severe than malaria caused by the non-falciparum Plasmodium species P. malariae, P. ovale spp. and P. vivax, the latter may be more challenging to diagnose, treat, control and ultimately eliminate. The prevalence of non-falciparum species throughout sub-Saharan Africa is poorly defined. Tanzania has geographical heterogeneity in transmission levels but an overall high malaria burden. METHODS: To estimate the prevalence of malaria species in Mainland Tanzania, we randomly selected 1428 samples from 6005 asymptomatic isolates collected in previous cross-sectional community surveys across four regions and analyzed these by quantitative PCR to detect and identify the Plasmodium species. RESULTS: Plasmodium falciparum was the most prevalent species in all samples, with P. malariae and P. ovale spp. detected at a lower prevalence (< 5%) in all four regions; P. vivax was not detected in any sample. CONCLUSIONS: The results of this study indicate that malaria elimination efforts in Tanzania will need to account for and enhance surveillance of these non-falciparum species.

Low Rate of Asymptomatic Dengue Infection Detected in Coastal Kenya Using Pooled Polymerase Chain Reaction Testing.

Asymptomatic dengue virus (DENV) infections have important public health implications but are challenging to identify. We performed a cross-sectional study of reverse transcription quantitative polymerase chain reaction on pooled sera of asymptomatic individuals from the south coast of Kenya at two time periods to identify cases of asymptomatic viremia. Among 2,460 samples tested in pools of 9 or 10, we found only one positive case (0.04% incidence). Although pooling of samples has the potential to be a cost-effective and time-efficient method for asymptomatic DENV detection, mass cross-sectional pooled testing may not provide accurate data on rates of asymptomatic infection, likely owing to a decrease in the sensitivity with pooling of samples, a short period of viremia, or testing in the absence of an outbreak.

Asymptomatic Enteric Virus Infections and Association with the Gut Microbiome in Rural Residents of Northern Laos.

Viral gastrointestinal infections are an important public health concern, and the occurrence of asymptomatic enteric virus infections makes it difficult to prevent and control their spread. This study aimed to determine the prevalence of and factors associated with asymptomatic enteric virus infection in adults in northern Laos. Fecal samples were collected from apparently healthy participants who did not report diarrhea or high fever at the time of the survey in northern Laos, and enteric viruses were detected using polymerase chain reaction (PCR) and reverse transcription (RT)-PCR. Individual characteristics, including the gut microbiome, were compared between asymptomatic carriers and noncarriers of each enteric virus. Of the participants (N = 255), 12 (4.7%) were positive for norovirus genogroup I (GI), 8 (3.1%) for human adenovirus, and 1 (0.4%) for norovirus GII; prevalence tended to be higher in less-modernized villages. Gut microbial diversity (evaluated by the number of operational taxonomic units) was higher in asymptomatic carriers of norovirus GI or human adenovirus than in their noncarriers. Gut microbiome compositions differed significantly between asymptomatic carriers and noncarriers of norovirus GI or human adenovirus (permutational analysis of variance, P <0.05). These findings imply an association between asymptomatic enteric virus infection and modernization and/or the gut microbiome in northern Laos.

Challenges for maintaining post elimination phase of visceral leishmaniasis control programme in India: A field-based study.

BACKGROUND: India is going through the maintenance phase of VL elimination programme which may be threatened by the persistence of hidden parasite pools among asymptomatic leishmanial infection (ALI) and PKDL. The present work was designed to determine the burden of VL, PKDL, and ALI and to assess the role of treatment of ALI in maintaining post-elimination phase. METHODS AND FINDING: The study was undertaken in Malda district, West Bengal, India during October 2016 to September 2021. Study areas were divided into 'Study' and 'Control' arms. VL and PKDL cases of both the arms were diagnosed by three active mass surveys with an interval of one year and treated as per National guideline. ALI of 'Study' arm was treated like VL. ALI of 'Control' arm was followed up to determine their fate. Fed sand-fly pools were analysed for parasitic DNA. No significant difference was noted between the incidence of VL and PKDL in both the arms. Incidence of ALI declined sharply in 'Study' arm but an increasing trend was observed in 'Control' arm. Significantly higher rate of sero-conversion was noted in 'Control' arm and was found to be associated with untreated ALI burden. Parasitic DNA was detected in 22.8% ALI cases and 2.2% sand-fly pools. CONCLUSION: Persistence of a significant number of PKDL and ALI and ongoing transmission, as evidenced by new infection and detection of leishmanial DNA in vector sand-flies, may threaten the maintenance of post-elimination phase. Emphasis should be given for elimination of pathogen to prevent resurgence of VL epidemics.