COVID-19 Epidemiology during Delta Variant Dominance Period in 45 High-Income Countries, 2020-2021

The SARS-CoV-2 Delta variant, first identified in October 2020, quickly became the dominant variant worldwide. We used publicly available data to explore the relationship between illness and death (peak case rates, death rates, case-fatality rates) and selected predictors (percentage vaccinated, percentage of the population >65 years, population density, testing volume, index of mitigation policies) in 45 high-income countries during the Delta wave using rank-order correlation and ordinal regression. During the Delta-dominant period, most countries reported higher peak case rates (57%) and lower peak case-fatality rates (98%). Higher vaccination coverage was protective against peak case rates (odds ratio 0.95, 95% CI 0.91-0.99) and against peak death rates (odds ratio 0.96, 95% CI 0.91-0.99). Vaccination coverage was vital to preventing infection and death from COVID-19 during the Delta wave. As new variants emerge, public health authorities should encourage the uptake of COVID-19 vaccination and boosters.

Etiology of acute febrile illness in the peruvian amazon as determined by modular formatted quantitative PCR: a protocol for RIVERA, a health facility-based case-control study

BACKGROUND

The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI.

METHODS

A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21-28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI.

DISCUSSION

The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 h and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific prevalent pathogens as a cause of acute illness.

STUDY REGISTRATION

Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.

Etiology of Acute Febrile Illness in the Peruvian Amazon as determined by modular formatted quantitative PCR: A Protocol for RIVERA, a Health Facility-Based Case-Control Study

Background

The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI.

Methods

A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21-28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI.

Discussion

The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 hours and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific, prevalent pathogens as a cause of acute illness.

Study Registration

Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.

U.S. CDC support to international SARS-CoV-2 seroprevalence surveys, May 2020-February 2022

SARS-CoV-2 seroprevalence surveys provide critical information to assess the burden of COVID-19, describe population immunity, and guide public health strategies. Early in the pandemic, most of these surveys were conducted within high-income countries, leaving significant knowledge gaps in low-and middle-income (LMI) countries. To address this gap, the U.S. Centers for Disease Control and Prevention (CDC) is supporting serosurveys internationally. We conducted a descriptive analysis of international serosurveys supported by CDC during May 12, 2020-February 28, 2022, using an internal tracker including data on the type of assistance provided, study design, population surveyed, laboratory testing performed, and status of implementation. Since the beginning of the pandemic, CDC has supported 72 serosurveys (77 serosurvey rounds) in 35 LMI countries by providing technical assistance (TA) on epidemiologic, statistical, and laboratory methods, financial assistance (FA), or both. Among these serosurvey rounds, the majority (61%) received both TA and FA from CDC, 30% received TA only, 3% received only FA, and 5% were part of informal reviews. Fifty-four percent of these serosurveys target the general population, 13% sample pregnant women, 7% sample healthcare workers, 7% sample other special populations (internally displaced persons, patients, students, and people living with HIV), and 18% assess multiple or other populations. These studies are in different stages of implementation, ranging from protocol development to dissemination of results. They are conducted under the leadership of local governments, who have ownership over the data, in collaboration with international partners. Thirty-four surveys rounds have completed data collection. CDC TA and FA of SARS-CoV-2 seroprevalence surveys will enhance the knowledge of the COVID-19 pandemic in almost three dozen LMI countries. Support for these surveys should account for current limitations with interpreting results, focusing efforts on prospective cohorts, identifying, and forecasting disease patterns over time, and helping understand antibody kinetics and correlates of protection.

Evaluation of the collaborative integrated surveillance system (ViCo) in Guatemala: a qualitative study on lessons learned and future perspectives

Background

The collaborative integrated surveillance system known as Vigilancia Integrada Comunitaria (ViCo) was implemented in 2007 to better understand and characterize the burden of diarrheal, respiratory and febrile illnesses in Guatemala.

Methods

To evaluate the usefulness of ViCo and inform a redesign of the system and new surveillance activities in the Central American region, personnel from the United States Centers for Disease Control and Prevention (CDC) conducted thirty-nine in-depth interviews from June—December 2018 with key stakeholders responsible for the design and implementation of ViCo in Guatemala. A semi-structured questionnaire adapted from the Updated CDC Guidelines for Evaluating Public Health Surveillance Systems was used for data collection. We used a grounded theory approach to explore stakeholder perceptions of ViCo and generate recommendations for improvement. Primary qualitative findings were organized based on thematic areas using ATLAS.ti version 8 software.

Results

Emergent themes relevant to the usefulness of ViCo were organized across strengths, weaknesses, and recommendations pertaining to the: (1) Size and Complexity of ViCo, (2) Stakeholder Expectations About the Objectives of ViCo, (3) Data Management and Structure of the Information System, (4) Local Control of Data, (5) Integration of ViCo within the Ministry of Health, and, (6) Improvement of the Operational and Design Aspects of ViCo across System, Process, and Output levels.

Conclusions

Stakeholders perceived ViCo to be useful. They recommended measures to improve system performance and quality, including simplifying the surveillance system, routine data analysis and feedback, and channeling efforts towards integrating surveillance data into the national health information system. To create a well-performing surveillance system and achieve the intended objective of surveillance for public health action, ongoing evaluation and assessment of surveillance activities are necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12719-7.

Incidence and etiology of infectious diarrhea from a facility-based surveillance system in Guatemala, 2008-2012

BACKGROUND

Diarrhea is a major cause of morbidity and mortality, yet incidence and etiology data are limited. We conducted laboratory-based diarrhea surveillance in Guatemala.

METHODS

A diarrhea case was defined as ≥3 loose stools in a 24-h period in a person presenting to the surveillance facilities. Epidemiologic data and stool specimens were collected. Specimens were tested for bacterial, parasitic, and viral pathogens. Yearly incidence was adjusted for healthcare seeking behaviors determined from a household survey conducted in the surveillance catchment area.

RESULTS

From November 2008 to December 2012, the surveillance system captured 5331 diarrhea cases; among these 1381 (26%) had specimens tested for all enteric pathogens of interest. The adjusted incidence averaged 659 diarrhea cases per 10,000 persons per year, and was highest among children aged < 5 years, averaging 1584 cases per 10,000 children per year. Among 1381 (26%) specimens tested for all the pathogens of interest, 235 (17%) had a viral etiology, 275 (20%) had a bacterial, 50 (4%) had parasites, and 86 (6%) had co-infections. Among 827 (60%) specimens from children aged < 5 years, a virus was identified in 196 (23%) patients; 165 (20%) had norovirus and 99 (12%) rotavirus, including co-infections. Among 554 patients aged ≥5 years, 103 (19%) had a bacterial etiology, including diarrheagenic Escherichia coli in 94 (17%) cases, Shigella spp. in 31 (6%), Campylobacter spp. in 5 (1%), and Salmonella spp. in 4 (1%) cases. Detection of Giardia and Cryptosporidium was infrequent (73 cases; 5%).

CONCLUSIONS

There was a substantial burden of viral and bacterial diarrheal diseases in Guatemala, highlighting the importance of strengthening laboratory capacity for rapid detection and control and for evaluation of public health interventions.

Statistical adjustment of culture-independent diagnostic tests for trend analysis in the Foodborne Diseases Active Surveillance Network (FoodNet), USA

Background

Culture-independent diagnostic tests (CIDTs) are increasingly used to diagnose Campylobacter infection in the Foodborne Diseases Active Surveillance Network (FoodNet). Because CIDTs have different performance characteristics compared with culture, which has been used historically and is still used to diagnose campylobacteriosis, adjustment of cases diagnosed by CIDT is needed to compare with culture-confirmed cases for monitoring incidence trends.

Methods

We identified the necessary parameters for CIDT adjustment using culture as the gold standard, and derived formulas to calculate positive predictive values (PPVs). We conducted a literature review and meta-analysis to examine the variability in CIDT performance and Campylobacter prevalence applicable to FoodNet sites. We then developed a Monte Carlo method to estimate test-type and site-specific PPVs with their associated uncertainties.

Results

The uncertainty in our estimated PPVs was largely derived from uncertainty about the specificity of CIDTs and low prevalence of Campylobacter in tested samples. Stable CIDT-adjusted incidences of Campylobacter cases from 2012 to 2015 were observed compared with a decline in culture-confirmed incidence.

Conclusions

We highlight the lack of data on the total numbers of tested samples as one of main limitations for CIDT adjustment. Our results demonstrate the importance of adjusting CIDTs for understanding trends in Campylobacter incidence in FoodNet.

Ebola Surveillance - Guinea, Liberia, and Sierra Leone

Developing a surveillance system during a public health emergency is always challenging but is especially so in countries with limited public health infrastructure. Surveillance for Ebola virus disease (Ebola) in the West African countries heavily affected by Ebola (Guinea, Liberia, and Sierra Leone) faced numerous impediments, including insufficient numbers of trained staff, community reticence to report cases and contacts, limited information technology resources, limited telephone and Internet service, and overwhelming numbers of infected persons. Through the work of CDC and numerous partners, including the countries' ministries of health, the World Health Organization, and other government and nongovernment organizations, functional Ebola surveillance was established and maintained in these countries. CDC staff were heavily involved in implementing case-based surveillance systems, sustaining case surveillance and contact tracing, and interpreting surveillance data. In addition to helping the ministries of health and other partners understand and manage the epidemic, CDC's activities strengthened epidemiologic and data management capacity to improve routine surveillance in the countries affected, even after the Ebola epidemic ended, and enhanced local capacity to respond quickly to future public health emergencies. However, the many obstacles overcome during development of these Ebola surveillance systems highlight the need to have strong public health, surveillance, and information technology infrastructure in place before a public health emergency occurs. Intense, long-term focus on strengthening public health surveillance systems in developing countries, as described in the Global Health Security Agenda, is needed.The activities summarized in this report would not have been possible without collaboration with many U.S and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Clinical outcomes of nalidixic acid, ceftriaxone, and multidrug-resistant nontyphoidal salmonella infections compared with pansusceptible infections in FoodNet sites, 2006-2008

BACKGROUND

Nontyphoidal Salmonella causes an estimated 1.2 million infections, 23,000 hospitalizations, and 450 deaths annually in the United States. Most illnesses are self-limited; however, treatment with antimicrobial agents can be life-saving for invasive infections.

METHODS

The Foodborne Diseases Active Surveillance Network and the National Antimicrobial Resistance Monitoring System collaborated on a prospective cohort study of patients with nontyphoidal Salmonella bloodstream and gastrointestinal infections to determine differences in the clinical outcomes of resistant compared with pansusceptible infections. Interviews were conducted within 85 days of specimen collection date.

RESULTS

Of 875 nontyphoidal Salmonella isolates, 705 (81%) were pansusceptible, 165 (19%) were resistant to at least 1 agent, and 5 (0.6%) had only intermediate resistance. The most common pattern, found in 51 (31%) of resistant isolates, was resistance to at least ampicillin, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline (ACSSuT); 88% of isolates with this pattern were serotype Typhimurium or Newport. Fourteen (52%) of the 27 ceftriaxone-resistant isolates were also ACSSuT resistant. Adjusted for age and serotype, bloodstream infection was significantly more common among patients infected with strains resistant to only two, only three, or only five antimicrobial classes, to ACSSuT with or without other agents, to ACSSuT only, or to nalidixic acid with or without other agents than among patients with pansusceptible isolates. Adjusted for age, serotype, and bloodstream infection, hospitalization was significantly more common among patients infected with strains resistant to only three agents or to ceftriaxone (all ceftriaxone-resistant isolates were resistant to other agents) than among patients with pansusceptible isolates.

CONCLUSION

This study extends evidence that patients with antimicrobial-resistant nontyphoidal Salmonella infections have more severe outcomes. Prevention efforts are needed to reduce unnecessary antimicrobial use in patient care settings and in food animals to help prevent the emergence of resistance and infections with resistant nontyphoidal Salmonella.

Burden of laboratory-confirmed Campylobacter infections in Guatemala 2008-2012: results from a facility-based surveillance system

INTRODUCTION

Campylobacteriosis is one of the leading causes of gastroenteritis worldwide. This study describes the epidemiology of laboratory-confirmed Campylobacter diarrheal infections in two facility-based surveillance sites in Guatemala.

METHODS

Clinical, epidemiologic, and laboratory data were collected on patients presenting with acute diarrhea from select healthcare facilities in the departments of Santa Rosa and Quetzaltenango, Guatemala, from January 2008 through August 2012. Stool specimens were cultured for Campylobacter and antimicrobial susceptibility testing was performed on a subset of isolates. Multidrug resistance (MDR) was defined as resistance to ≥3 antimicrobial classes.

RESULTS

Campylobacter was isolated from 306 (6.0%) of 5137 stool specimens collected. For children <5 years of age, annual incidence was as high as 1288.8 per 100,000 children in Santa Rosa and 185.5 per 100,000 children in Quetzaltenango. Among 224 ambulatory care patients with Campylobacter, 169 (75.5%) received metronidazole or trimethoprim-sulfamethoxazole, and 152 (66.7%) received or were prescribed oral rehydration therapy. Antimicrobial susceptibilities were tested in 96 isolates; 57 (59.4%) were resistant to ciprofloxacin and 12 (12.5%) were MDR.

CONCLUSION

Campylobacter was a major cause of diarrhea in children in two departments in Guatemala; antimicrobial resistance was high, and treatment regimens in the ambulatory setting which included metronidazole and trimethoprim-sulfamethoxazole and lacked oral rehydration were sub-optimal.

Development of a virtual reality haptic Veress needle insertion simulator for surgical skills training

The Veress needle is the most commonly used technique for creating the pneumoperitoneum at the start of a laparoscopic surgical procedure. Inserting the Veress needle correctly is crucial since errors can cause significant harm to patients. Unfortunately, this technique can be difficult to teach since surgeons rely heavily on tactile feedback while advancing the needle through the various layers of the abdominal wall. This critical step in laparoscopy, therefore, can be challenging for novice trainees to learn without adequate opportunities to practice in a safe environment with no risk of injury to patients. To address this issue, we have successfully developed a prototype of a virtual reality haptic needle insertion simulator using the tactile feedback of 22 surgeons to set realistic haptic parameters. A survey of these surgeons concluded that our device appeared and felt realistic, and could potentially be a useful tool for teaching the proper technique of Veress needle insertion.

Sporadic campylobacter infection in infants: a population-based surveillance case-control study

BACKGROUND

Campylobacter is an important cause of foodborne illness in infants (younger than 1 year of age), but little is known about the sources of infection in this age group.

METHODS

Eight sites in the Foodborne Diseases Active Surveillance Network (FoodNet) participated in a 24-month population-based case-control study conducted in 2002-2004. Cases were infants with laboratory-confirmed Campylobacter infection ascertained through active laboratory surveillance, and controls were infants in the community.

RESULTS

We enrolled 123 cases and 928 controls. Infants 0-6 months of age with Campylobacter infection were less likely to be breast-fed than controls [odds ratio (OR); 0.2; 95% confidence interval (CI), 0.1-0.6]. Risk factors for infants 0-6 months of age included drinking well water (OR 4.4; CI, 1.4-14) and riding in a shopping cart next to meat or poultry (OR 4.0; CI, 1.2-13.0). Risk factors for infants 7-11 months of age included visiting or living on a farm (OR 6.2; CI, 2.2-17), having a pet with diarrhea in the home (OR 7.6; CI, 2.1-28) and eating fruits and vegetables prepared in the home (OR 2.5, CI 1.2-4.9). Campylobacter infection was associated with travel outside the United States at all ages (OR 19.3; CI, 4.5-82.1).

CONCLUSIONS

Several unique protective and risk factors were identified among infants, and these risk factors vary by age, suggesting that prevention measures be targeted accordingly. Breast-feeding was protective for the youngest infants and should continue to be encouraged.

Race- and age-dependent alterations in global methylation of DNA in squamous cell carcinoma of the lung (United States)

OBJECTIVE

The current study investigated the race- and age-dependent alterations in global DNA methylation on the development and progression of squamous cell carcinomas (SCCs) of the lung.

METHODS

Methylation status was evaluated in SCC and in the associated uninvolved bronchial mucosa (UBM) and epithelial hyperplasia (EH) of 53 Whites and 23 African Americans by using an antibody specific for 5-methylcytosine (5-mc). A low 5-mc score indicates global hypomethylation of DNA.

RESULTS

5-mc scores of SCC were significantly lower compared to 5-mc scores of UBM and EH in Whites (p < 0.05). In African Americans, 5-mc scores of SCCs were not significantly different from 5-mc scores of UBM and EH, suggesting an involvement of methylation in the development of SCCs in Whites, but not in African Americans. 5-mc scores were lower in younger subjects compared to older subjects in Whites. Since cancers in younger subjects tend to be more aggressive than cancers in older subjects, these observations may suggest that hypomethylation may have contributed to aggressiveness cancers of younger Whites. Hypomethylation of SCCs in White men was associated with shorter survival from the disease.

CONCLUSIONS

These preliminary results suggest that the methylation status of DNA may affect the development, aggressiveness, and prognosis of SCCs in Whites.