High Attack Rate Research Articles

Narrow transmission bottlenecks and limited within-host viral diversity during a SARS-CoV-2 outbreak on a fishing boat.

The long-term evolution of viruses is ultimately due to viral mutants that arise within infected individuals and transmit to other individuals. Here, we use deep sequencing to investigate the transmission of viral genetic variation among individuals during a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak that infected the vast majority of crew members on a fishing boat. We deep-sequenced nasal swabs to characterize the within-host viral population of infected crew members, using experimental duplicates and strict computational filters to ensure accurate variant calling. We find that within-host viral diversity is low in infected crew members. The mutations that did fix in some crew members during the outbreak are not observed at detectable frequencies in any of the sampled crew members in which they are not fixed, suggesting that viral evolution involves occasional fixation of low-frequency mutations during transmission rather than persistent maintenance of within-host viral diversity. Overall, our results show that strong transmission bottlenecks dominate viral evolution even during a superspreading event with a very high attack rate.

Ecological Constraints on the Evolution of Consumer Functional Responses

Intrinsically generated oscillations are a defining feature of consumer-resource interactions. They can have important consequences for the evolution of consumer functional responses. Functional response traits that maximize resource fitness (low attack rate and long handling time) and consumer fitness (high attack rate and short handling time) generate high-amplitude oscillations that can predispose species to extinction during periods of low abundances. This suggests that the ecological consequences of consumer-resource oscillations may impede evolutionary outcomes that maximize fitness. Data suggest this to be a strong possibility. Time series analyses reveal consumer-resource cycles to be infrequent in real communities, and functional response studies show a preponderance of low attack rates and/or short handling times that preclude oscillations but maximize neither species' fitness. Here I present a mathematical model to address this tension between ecological dynamics and the evolution of functional response traits. I show that the empirically observed attack rate-handling time distributions emerge naturally from the interplay between individual-level selection and the population-level constraint of oscillation-induced extinction. Extinction at low abundances curtails stabilizing selection toward trait values that maximize fitness but induce large-amplitude oscillations. As a result, persistent interactions are those in which the mean attack rate is low and/or the mean handling time is short. These findings emphasize the importance of incorporating oscillation-induced extinction into models that link food web topology to community persistence.

High Attack Rate of Severe Acute Respiratory Syndrome Coronavirus 2 B.1.1.529 Among 2-Dose Vaccinated Populations in 2 Indoor Entertainment Setting Outbreaks.

We estimated attack rates of SARS-CoV-2 B.1.1.529 (Omicron) infection among people attending a nightclub and a graduation ball where >95% had at least 2 vaccine doses. Attack rates were 295/535(55.1%) and 102/189(54.0%) respectively (mean: 5 days post-event). At the ball, attack rates increased with time since vaccination: 12.5% among those vaccinated 1-2 months previously; 68.0% among those vaccinated 3 + months previously; such differences were not found at the nightclub. Recent vaccination prevents Omicron infection, but is time and setting-dependent, emphasising the importance of non-pharmaceutical public health measures in addition to vaccine booster doses to maximise protection in high-risk contexts.

Brote nosocomial de COVID-19 en una planta de medicina interna: probable transmisión aérea

Background and objectivesDespite the increasing evidence supporting the importance of airborne transmission in SARS-CoV-2 infection, it has not been considered relevant in the vast majority of reported nosocomial outbreaks of COVID-19. The aim of this study is to describe a nosocomial outbreak of SARS-CoV-2 infection whose features suggest that aerosol transmission had an important role. MethodsThis is a descriptive analysis of a nosocomial outbreak of SARS-CoV-2 infection in an internal medicine ward that occurred in December 2020. All cases were confirmed by a positive PCR test for SARS-CoV-2. ResultsFrom December 5 to December 17, 21 patients and 44 healthcare workers developed a nosocomial SARS-CoV-2 infection. Fifty-one of the 65 cases (78.5%) were diagnosed between December 6 and 9. The attack rate in patients was 80.8%. Among workers, the attack rate was higher in those who had worked at least one full working day in the ward (56.3%) than in those who had occasionally been in the ward (25.8%, p=0.005). Three days before the first positive case was detected, 2extractor fans were found to be defective, affecting the ventilation of 3rooms. Sixteen cases were asymptomatic, 48 cases had non-severe symptoms, and 2 cases required admission to the intensive care unit. All patients eventually recovered. ConclusionThe high attack rate, the explosive nature of the outbreak, and the coincidence in time with the breakdown in air extractors in some rooms of the ward suggest that airborne transmission played a key role in the development of the outbreak.

Functional response of the predatory mite, Typhlodromus bagdasarjani (Acari: Phytoseiidae) to protonymphs of Eotetranychus frosti (Acari: Tetranychidae) on four apple cultivars

The functional response of natural enemies and their interactions may be affected by host plant characters. Functional response of the adult females of the predatory mite, Typhlodromus bagdasarjani Wainstein and Arutunjan to protonymphs of Eotetranychus frosti (McGregor) on four apple cultivars Imperial Gala, Kohanz Golab, Granny Smith and Lebanon Red was investigated. The protonymphs of E. frosti were offered to the adult female of the predator at densities of 2, 4, 8, 16, 32, 64 and 128 on apple leaf discs (4 cm<sup>2</sup>). The number and length of trichomes on the lower surface of each apple cultivar were measured. The highest and lowest number of trichomes were observed in Granny Smith and Kohanz Golab, respectively. Typhlodromus bagdasarjani adult females exhibited the type II functional response on E. frosti protonymphs regardless of apple cultivars. Also, the values of attack rate (a) and handling time (T<sub>h</sub>) were determined using the Rogers's type II model. Adult females of T. bagdasarjani had the highest attack rate (a) (0.0747 h<sup>1</sup>) and the shortest handling time (0.7005 h) on Kohanz Golab, and the lowest attack rate (0.0334 h<sup>1</sup>) and the longest handling time (1.1189 h) was on Granny Smith. The theoretical maximum predation rate (T/T<sub>h</sub>) on Kohanz Golab, Imperial Gala, Lebanon Red and Granny Smith were 34.26, 33.79, 26.85 and 21.45 prey/day, respectively. The estimated value of a/T<sub>h</sub> indicated that T. bagdasarjani was most effective against E. frosti on Kohanz Golab with lowest number of trichomes. The finding of this study shows that the predation and searching activity of the predator was affected by trichome density and length of the apple leaves.

An in-depth statistical analysis of the COVID-19 pandemic’s initial spread in the WHO African region

During the first wave of the COVID-19 pandemic, sub-Saharan African countries experienced comparatively lower rates of SARS-CoV-2 infections and related deaths than in other parts of the world, the reasons...

Reassessing Reported Deaths and Estimated Infection Attack Rate during the First 6 Months of the COVID-19 Epidemic, Delhi, India.

India reported >10 million coronavirus disease (COVID-19) cases and 149,000 deaths in 2020. To reassess reported deaths and estimate incidence rates during the first 6 months of the epidemic, we used a severe acute respiratory syndrome coronavirus 2 transmission model fit to data from 3 serosurveys in Delhi and time-series documentation of reported deaths. We estimated 48.7% (95% credible interval 22.1%–76.8%) cumulative infection in the population through the end of September 2020. Using an age-adjusted overall infection fatality ratio based on age-specific estimates from mostly high-income countries, we estimated that just 15.0% (95% credible interval 9.3%–34.0%) of COVID-19 deaths had been reported, indicating either substantial underreporting or lower age-specific infection-fatality ratios in India than in high-income countries. Despite the estimated high attack rate, additional epidemic waves occurred in late 2020 and April–May 2021. Future dynamics will depend on the duration of natural and vaccine-induced immunity and their effectiveness against new variants.

Risk factors associated with an outbreak of COVID-19 in a meat processing plant in southern Germany, April to June 2020

Meat processing plants have been prominent hotspots for coronavirus disease (COVID-19) outbreaks around the world. We describe infection prevention measures and risk factors for infection spread at a meat processing plant in Germany with a COVID-19 outbreak from April to June 2020. We analysed a cohort of all employees and defined cases as employees with either a PCR or ELISA positive result. Of 1,270 employees, 453 (36%) had evidence of SARS-CoV-2 infection. The highest attack rates were observed in meat processing and slaughtering areas. Multivariable analysis revealed that being a subcontracted employee (adjusted risk ratio (aRR)): 1.43, 95% CI: 1.06–1.96), working in the meat cutting area (aRR: 2.44, 95% CI: 1.45–4.48), working in the slaughtering area (aRR: 2.35, 95% CI: 1.32–4.45) and being a veterinary inspector (aRR: 4.77, 95% CI: 1.16–23.68) increased infection risk. Sharing accommodation or transportation were not identified as risk factors for infection. Our results suggest that workplace was the main risk factor for infection spread. These results highlight the importance of implementing preventive measures targeting meat processing plants. Face masks, distancing, staggering breaks, increased hygiene and regular testing for SARS-CoV2 helped limit this outbreak, as the plant remained open throughout the outbreak.

COVID-19 Prevention Practices Among Prisoners, in Southern Ethiopia.

BackgroundCoronavirus disease-19 (COVID-19) is a highly contagious disease with high attack and case fatality rate. Since WHO’s declaration of disease as pandemic in March 2020, the unprecedented global crises have been happening. To curb and reduce such crises, multi-dimensional international efforts have been made, particularly, infection prevention measures has been developed. However, there was a wide gap of implementing COVID-19 prevention measures from rural to urban, from institution to institution and from person to person. Therefore, the aim of this study was to measure the level of prevention practice towards COVID 19 and associated factors in prison, in Sidama National Regional State, Ethiopia.MethodsA cross-sectional study using quantitative method of data collection was conducted in November, 2020 among 422 prisoners in two prisons. Data were collected by trained nurses using structured questionnaires. We analyzed data using SPSS version 24 software. Descriptive statistics and bivariable and multivariable logistic regression analyses were employed to identify factors associated with prevention practices of COVID-19.ResultsMore than one-fifth (22%; 95% CI: 19%, 26%) of respondents had good preventive practice. Participants who had a history of alcohol intake were 1.79 times less likely to implement good preventive practice for COVID-19 (AOR = 1.79; 95% CI; 1.09, 2.93). The respondents who had negative attitude towards COVID-19 infection were 1.69 times more likely to have poor prevention practice (AOR = 1.69; 95% CI: 1.02, 2.81).Conclusion and RecommendationIn this study, COVID-19 prevention practice among prisoners was very low. Negative attitude and previous alcohol taking history were factors associated with poor prevention practice. Accordingly, the researchers recommends to the concerned body to design educational intervention to change the attitude towards COVID-19 and other infectious diseases and behaviors of the prisoners.

Chickenpox Outbreak Investigation in Assabain District, Sana’a City, Yemen, January to February 2019

Background Varicella zoster virus (VZV) causes chickenpox. The epidemiological profile of chickenpox varies considerably across countries, health care systems, and immunization policies. In Yemen, chickenpox remains an important public health issue and outbreaks are not uncommon since vaccination is not universal. On February 23, 2019, a medical doctor from the Al Kafji area of the Assabain district notified the Ministry of Public Health and Population of a chickenpox infection among his family members and neighbors. Objective The aim of this study was to confirm the existence of a chickenpox outbreak, describe the epidemiological characteristics of the outbreak, and recommend prevention and control measures. Methods A door-to-door search was performed for case finding and line listing with detailed epidemiological, clinical, and vaccination history collected. Four blood samples were collected and sent for laboratory confirmation by enzyme-linked immunosorbent assay. Data were analyzed with Epi info 7.2. Results A total of 26 cases met the case definition. The outbreak started on January 19, 2019, at one house and was then transmitted to the 2nd and 3rd neighboring houses. The Epi curve showed three peaks, with one peak for each affected house. The index case was an 11-year-old male. The overall attack rate was 34% and the highest attack rate of 56% was found in the 3rd house. More than half (58%) of cases were females and 46% were found in children in the age group of 10-14 years. All cases included symptoms of a rash with itching, 46% of cases had vesicular lesions, and 42% had <50 lesions. Overall, 8% of the cases had complications (ie, pneumonia). Approximately 25% of samples were IgM-positive. All cases were in unvaccinated individuals. Conclusions A chickenpox outbreak in the Al Kafji area of the Assabain district was confirmed. Females were more affected than males. Introducing the chickenpox vaccine as part of routine immunizations, and increasing community awareness about the mode of transmission and control measures for prevention are recommended.

Functional Responses and Additive Multiple Predator Effects of Two Common Wetland Fish

Understanding trophic interactions is essential for the prediction and measurement of structure and function in aquatic environments. Communities in these ecosystems may be shaped by variables such as predator diversity, prey density and emergent multiple predator effects (MPEs), which are likely to influence trophic dynamics. In this study, we examined the effect of key predatory fish in floodplain wetlands, namely Oreochromis mossambicus and Enteromius paludinosus, towards Chironomidae prey, using a comparative functional response (FR) approach. We used single predator species as well as intra- and interspecific paired species to contrast FRs under multiple predator scenarios. Attack rate and handling time estimates from single predator FRs were used to predict multiple predators’ feeding rates, which were compared to observe multiple predators’ feeding rates to quantify potential MPEs. From single fish trials, each species displayed a significant Type II FR, characterized by high feeding rates at low prey densities. Oreochromis mossambicus had a steeper (initial slope, i.e., higher attack rate) and higher (asymptote of curve, i.e., shorter handling time and higher maximum feeding rate) FR, whereas E. paludinosus exhibited lower-magnitude FRs (i.e., lower attack rate, longer handling time and lower feeding rate). In multiple predator scenarios, feeding rates were well-predicted by those of single predators, both in conspecific and interspecific pairs, and thus we did not find evidence for antagonistic or synergistic MPEs. Predator–prey interactions in wetland systems can have significant consequences on the structure and dynamics of ecological communities. In turn, this could have destabilizing effects on resources in tropical wetlands. These results, although experimental, help us understand how trophic interaction among conspecific or interspecific fish species in Austral tropical wetlands might influence their aquatic prey species. This will help us to understand food web dynamics better.

Cheryl Cohen—promoting evidence-based health policy

Cheryl Cohen—promoting evidence-based health policy

High attack rate in a Tong Lau house outbreak of COVID-19 with subdivided units in Hong Kong.

Poor housing conditions are known to be associated with infectious diseases such as high Coronavirus disease 2019 (COVID-19) incidences. Transmission causes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in poor housing conditions can be complex. An understanding of the exact mechanism of transmission can help to pinpoint contributing environmental issues. Here, we investigated a Hong Kong COVID-19 outbreak in early 2021 in four traditional Tong Lau houses with subdivided units. There are more than 80 subdivided units of less than 20 m2 floor area each on average. With a total of 34 confirmed COVID-19 cases, the outbreak had an attack rate of 25.4%, being one of the highest attack rates observed in Hong Kong, and ranked among the highest attack rates in reported outbreaks internationally. Tracer gas leakage and decay measurements were performed in the drainage system and in the subdivided units to determine the transport of infectious aerosols by the owner-modified sophisticated wastewater drainage pipe networks and the poor ventilation conditions in some subdivided units. The results show that the outbreak was probably due to multiple transmission routes, i.e. by the drainage pipe spread of stack aerosols, which is enhanced by poor ventilation in the subdivided units.

Seroprevalence of anti-SARS-CoV-2 antibodies in Colombia, 2020: A population-based study

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to cause very high morbidity and mortality throughout Latin American countries. However, few population-based seroprevalence surveys have been conducted to quantify attack rates and characterize drivers of transmission.MethodsWe conducted a population-based cross-sectional study to assess the seroprevalence of antibodies against SARS-CoV-2 in ten cities in Colombia between September and December 2020. The study involved multi-stage cluster sampling at each city. Participants provided a serum sample and answered a demographic and risk factor questionnaire. Prior infection by SARS-CoV-2 was ascertained using the "SARS-CoV-2 Total (COV2T) Advia Centaur - Siemens" chemiluminescence assay.FindingsA total of 17863 participants from 7320 households participated in the study. Seroprevalence varied substantially between cities, ranging from 26% (95%CI 23–29 %) in Medellín to 68% (95%CI 62–74 %) in Guapi. There were no differences in seroprevalence by sex, but seropositivity was higher in certain ethnic groups. There was substantial heterogeneity in seroprevalence within cities, driven to a large extent by a strong association between socioeconomic stratum and seropositivity.InterpretationColombia has been one of the Latin American countries most affected by the COVID-19 pandemic. This study documented very high attack rates in several Colombian cities by the end of 2020 and identified key drivers of heterogeneities including ethnicity and socioeconomic stratum. Few studies of seroprevalence of SARS-CoV-2 have been conducted in Latin America, and therefore this study contributes to the fundamental understanding of the pandemic in the region.FundingThe study was sponsored by, Ministerio de Ciencia y Tecnología e Innovación –CT361/2020, Ministerio de Salud y Protección Social, Fundación Universitaria del Norte, Imperial College of London, Universidad Nacional de Colombia (Sede Medellín), Universidad de Córdoba, California University, Unidad Nacional de Gestión del Riesgo, Centro de Atención y Diagnóstico de Enfermedades Infecciosas -CDI-, Centro Internacional de Entrenamiento e Investigaciones Médicas -CIDEIM-, Departamento Administrativo Nacional de Estadística - DANE, Fondo Nacional de Turismo -FONTUR-, Secretarías de Salud Departamentales, Distritales y Municipales and Instituto Nacional de Salud.

An improved deep bagging convolutional neural network classifier for efficient intrusion detection system

In the current trend, the network-based system has substantial jobs, and they have become the targets of attackers. When an intrusion occurs, the security of a computer system is compromised. As a result, we must seek out the best methods for ensuring frameworks. A crucial component of the security management architecture is the intrusion detection system (IDS). To maintain effective network security, the design and implementation of IDS remain an important assessment topic. For intrusion detection, the previous system created an enhanced relevance vector machine (ERVM) classifier. However, intrusion detection is not robust for large-scale intrusion datasets, resulting in a high attack rate. The suggested work developed an improved deep bagging based convolutional neural network (DBCNN) for intrusion detection to address this issue. Preprocessing, feature selection, and classification are three processes included in the proposed framework. The KDD dataset is preprocessed in this stage using the kalman filter method. The feature selection is then carried out using the inertia weight based dragonfly method (IWDA). Finally, the DBCNN classifier successfully identifies interruption assaults. The KDD dataset is used to test the new model. The test results show that the proposed work accomplishes better execution contrasted and the current framework as far as accuracy, precision, recall and f-measure.

Measles Outbreak Investigation in Guradamole District of Bale Zone, South Eastern Ethiopia, 2021.

BackgroundMeasles is a highly contagious viral illness and globally, 142,300 people died from measles in 2018. On 25 March 2021, an outbreak of measles was reported from Guradamole district Bale Zone Southeast Ethiopia. Hence, we investigated to determine existence of the outbreak and to identify the associated factors.MethodDescriptive and 1:2 unmatched case–control study was done in Guradamole district from March 25 to April 9/2021. For the descriptive study, a total of 98 cases were used. To identify the factor associated with the outbreak, 60 cases were selected by computer-generated simple random method by using line list as a sampling frame and 120 controls were studied. Active cases were identified through home-to-home searching in affected kebeles and controls were selected from neighbors of cases. Five serum samples were taken and an IgM test was done to confirm cases. Cases were any person who developed fever, maculopapular rash and cough, coryza or conjunctivitis while controls were without such diagnosis. We collected data by using a structured questionnaire, cases were described by time, place, and person; logistic regression was used to identify factors associated with measles. In the multivariable analysis P-value <0.05 was declared statistical significance.ResultsOverall, 98 cases were identified with an overall attack rate of 12/1000 population and a case fatality rate (CFR) of 7%. The highest attack rate (38/1000 population) and CFR (57%) were among children aged <59 months. Vaccination efficacy was calculated to be 82.6%. Being unvaccinated (adjusted odds ratio/AOR=5.66, 95% confidence interval, CI: 1.24–25.81), contact with patient (AOR=3.24, 95%CI: 1.03–10.17), moderate malnutrition (AOR=4.34, 95%CI: 2.14–8.814), distance from health facility (AOR=4.58, 95%CI: 1.39–15.19) and history of travel to affected area (AOR=3.99, 95%CI: 1.31–12.19) were shown significant associated with measles infection.ConclusionThe attack and fatality rate of the investigation were high. Being unvaccinated, distant from the health facility, malnutrition, and history of contact with measles case were associated with the outbreak. We recommend conducting vaccination campaigns, interventions to malnutrition, and strengthening routine immunization programs to reduce future measles outbreaks.

Epidemiological analysis of the emergence and disappearance of the SARS-CoV-2 Kappa variant within a region of British Columbia, Canada.

The Kappa variant is designated as a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of interest (VOI). We identified 195 Kappa variant cases in a region of British Columbia, Canada-the largest published cluster in North America. To describe the epidemiology of the Kappa variant in relation to other circulating SARS-CoV-2 variants of concern (VOC) in the region to determine if the epidemiology of the Kappa variant supports a VOI or VOC status. Clinical specimens testing positive for SARS-CoV-2 collected between March 10 and May 2, 2021, were screened for the detection of known circulating VOCs; approximately 50% of specimens were subsequently selected for whole genome sequencing (WGS). Epidemiological analysis was performed comparing the characteristics of Kappa cases to the main circulating variants in the region (Alpha and Gamma) and to non-VOC/VOI cases. A total of 2,079 coronavirus disease 2019 (COVID-19) cases were reported in the region during the study period, of which 54% were selected for WGS. The 1,131 sequenced cases were categorized into Kappa, Alpha, Gamma and non-VOC/VOI. While Alpha and Gamma cases were found to have a significantly higher attack rate among household contacts compared to non-VOI/VOC cases, Kappa was not. Epidemiological analysis supports the designation of Kappa as a VOI and not a VOC. The Alpha and Gamma variants were found to be more transmissible, explaining their subsequent dominance in the region and the rapid disappearance of the Kappa variant. Variant surveillance strategies should focus on both detection of established VOCs and detection of potential new VOCs.

The Epidemiological and Clinical Characteristics of 2019 Novel Corona Virus Disease (COVID-19) in Balochistan, Pakistan

Background: The unprecedented outbreak of 2019 novel coronavirus disease (COVID-19) drastically spread worldwide. The study was aimed to articulate the findings of a descriptive and clinical characteristic, also to access the potential risk factors link with the spread of COVID-19. Method: The COVID-19 cases reported through April 30, 2020, were extracted from Balochistan’s COVID-19 Electronic Dashboard. All cases from March to April 2020 were included. The results of the laboratory finding as well as data acquired through COVID-19 Dashboard were cleaned; descriptive exploratory analysis and chi-square were calculated to demonstrate the association using Epi- Info. Results: A total of 1381 patient records extracted and screened. Of these, 1218 suspected cases and 1049 confirmed cases contributed to the analysis. Among confirmed cases, 77% (811) were male. The most affected age group was 60 – 69 years (attack rate 1.90/10,000), mean age was 36 ±17.11 SD with age range 2 months-94 years. District Quetta 82% (864) and district Pishin 5% (55) remained the epi-center for high attack rates. Among confirmed cases, a total of 14 deaths occurred for an overall Case fatality rate of 1.33%. The epi surge was peaked around March 19, April 5, and April 24, 2020. Among high-risk personals, those who had contact with infected individuals’ showed a high association of 97% (323/333) than without any contact 87% (221/254). Those who had travel history showed a prevalence of 86% (87/101) than in those who did not 59% (60/104) while those admitted in hospital with comorbid conditions showed a prevalence of 70% (26/37) than in those who did not 13% (6/46). Conclusion: COVID-19 epidemic has spread rapidly in the province. A series of multidimensional public health interventions, a cost-effective surveillance system, and the adoption of safe working practice, awareness sessions are necessary to control the COVID-19 outbreak

Risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission Among Healthcare Workers Dining in Hospital Staff Cafeterias.

BackgroundPreventive measures are needed to reduce the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among healthcare workers (HCWs). Notably, hospital staff are usually exposed when they are unmasked. There are limited data on the risk of transmission during mealtimes at hospital staff cafeterias. We aimed to evaluate the risk of transmission in cafeterias.MethodsFrom January 2020 through September 2021, we analyzed the risk of SARS-CoV-2 transmission through closed-circuit television and radio-frequency identification tracking and follow-up testing when 33 HCWs, who were eventually diagnosed as coronavirus disease 2019 (COVID-19), ate in staff cafeterias during the infectious period. The seats were arranged so the HCWs would sit on either side without facing each other. There were no plastic barriers installed, and HCWs were encouraged not to talk during meals.ResultsThree of the 119 individuals who ate at seats next (about 30 cm) to index during the period of transmission and underwent follow-up SARS-CoV-2 polymerase chain reaction tests were diagnosed with COVID-19 (2.5%; 95% confidence interval, 0.5–7.4%). Among the 98 HCWs who were investigated about talking during meals, there was a higher attack rate among those who spoke with each other than among those who did not (12.5% [3/24] vs. 0% [0/74], P = 0.013).ConclusionThe risk of transmission in a hospital’s employee cafeterias is not high with side-by-side seating, especially in the absence of conversation.

Influence of the Season on Armyworm (Spodoptera frugiperda J.E. Smith) Attacks on Some Bio-fortified maize (Zea mays L.) Varieties Introduced in Kisangani Eco-region (Democratic Republic of the Congo)

The present study was conducted in the Kisangani region of the northeastern Democratic Republic of Congo in 2018-2019. The objective was to evaluate the influence of the seasons in the face of armyworm attacks on the behavior of three new biofortified maize varieties being introduced in the Tshopo Province. These trials were conducted using a split plot design with three replications and the results were analyzed using R Studio version 3.6 statistical software. The results at (p&lt;0.05) show that all three varieties were attacked by armyworms. The overall average incidence was significantly similar to that of the control. During two cropping seasons, the maize varieties tested showed variable armyworm attack rates: Yellow Plata (14.16%) SAM4 VITA/A (18.05%) SAM4 VITA/B (16.44%) and PVA SYN- 18 F2'' (14.66%). As for the variation of attack between seasons, the results of the statistical analysis showed that season B had a higher attack rate (25.54%) than season A (6.11%).