High-throughput quantitation of SARS-CoV-2 antibodies in a single-dilution homogeneous assay.

SARS-CoV-2 emerged in late 2019 and has since spread around the world, causing a pandemic of the respiratory disease COVID-19. Detecting antibodies against the virus is an essential tool for tracking infections and developing vaccines. Such tests, primarily utilizing the enzyme-linked immunosorbent assay (ELISA) principle, can be either qualitative (reporting positive/negative results) or quantitative (reporting a value representing the quantity of specific antibodies). Quantitation is vital for determining stability or decline of antibody titers in convalescence, efficacy of different vaccination regimens, and detection of asymptomatic infections. Quantitation typically requires two-step ELISA testing, in which samples are first screened in a qualitative assay and positive samples are subsequently analyzed as a dilution series. To overcome the throughput limitations of this approach, we developed a simpler and faster system that is highly automatable and achieves quantitation in a single-dilution screening format with sensitivity and specificity comparable to those of ELISA.

Systems, supplies, and staff: a mixed-methods study of health care workers' experiences and health facility preparedness during a large national cholera outbreak, Kenya 2015.

BACKGROUND: From December 2014 to September 2016, a cholera outbreak in Kenya, the largest since 2010, caused 16,840 reported cases and 256 deaths. The outbreak affected 30 of Kenya's 47 counties and occurred shortly after the decentralization of many healthcare services to the county level. This mixed-methods study, conducted June-July 2015, assessed cholera preparedness in Homa Bay, Nairobi, and Mombasa counties and explored clinic- and community-based health care workers' (HCW) experiences during outbreak response. METHODS: Counties were selected based on cumulative cholera burden and geographic characteristics. We conducted 44 health facility cholera preparedness checklists (according to national guidelines) and 8 focus group discussions (FGDs). Frequencies from preparedness checklists were generated. To determine key themes from FGDs, inductive and deductive codes were applied; MAX software for qualitative data analysis (MAXQDA) was used to identify patterns. RESULTS: Some facilities lacked key materials for treating cholera patients, diagnosing cases, and maintaining infection control. Overall, 82% (36/44) of health facilities had oral rehydration salts, 65% (28/43) had IV fluids, 27% (12/44) had rectal swabs, 11% (5/44) had Cary-Blair transport media, and 86% (38/44) had gloves. A considerable number of facilities lacked disease reporting forms (34%, 14/41) and cholera treatment guidelines (37%, 16/43). In FDGs, HCWs described confusion regarding roles and reporting during the outbreak, which highlighted issues in coordination and management structures within the health system. Similar to checklist findings, FGD participants described supply challenges affecting laboratory preparedness and infection prevention and control. Perceived successes included community engagement, health education, strong collaboration between clinic and community HCWs, and HCWs' personal passion to help others. CONCLUSIONS: The confusion over roles, reporting, and management found in this evaluation highlights a need to adapt, implement, and communicate health strategies at the county level, in order to inform and train HCWs during health system transformations. International, national, and county stakeholders could strengthen preparedness and response for cholera and other public health emergencies in Kenya, and thereby strengthen global health security, through further investment in the existing Integrated Disease Surveillance and Response structure and national cholera prevention and control plan, and the adoption of county-specific cholera control plans.

A population-based estimate of the economic burden of influenza in Peru, 2009-2010.

INTRODUCTION: Influenza disease burden and economic impact data are needed to assess the potential value of interventions. Such information is limited from resource-limited settings. We therefore studied the cost of influenza in Peru. METHODS: We used data collected during June 2009-December 2010 from laboratory-confirmed influenza cases identified through a household cohort in Peru. We determined the self-reported direct and indirect costs of self-treatment, outpatient care, emergency ward care, and hospitalizations through standardized questionnaires. We recorded costs accrued 15-day from illness onset. Direct costs represented medication, consultation, diagnostic fees, and health-related expenses such as transportation and phone calls. Indirect costs represented lost productivity during days of illness by both cases and caregivers. We estimated the annual economic cost and the impact of a case of influenza on a household. RESULTS: There were 1321 confirmed influenza cases, of which 47% sought health care. Participants with confirmed influenza illness paid a median of $13 [interquartile range (IQR) 5-26] for self-treatment, $19 (IQR 9-34) for ambulatory non-medical attended illness, $29 (IQR 14-51) for ambulatory medical attended illness, and $171 (IQR 113-258) for hospitalizations. Overall, the projected national cost of an influenza illness was $83-$85 millions. Costs per influenza illness represented 14% of the monthly household income of the lowest income quartile (compared to 3% of the highest quartile). CONCLUSION: Influenza virus infection causes an important economic burden, particularly among the poorest families and those hospitalized. Prevention strategies such as annual influenza vaccination program targeting SAGE population at risk could reduce the overall economic impact of seasonal influenza.

Burden of Invasive Nontyphoidal Salmonella Disease in a Rural and Urban Site in Kenya, 2009-2014.

BACKGROUND: Invasive infections with nontyphoidal Salmonella (NTS) lead to bacteremia in children and adults and are an important cause of illness in Africa; however, few data on the burden of NTS bacteremia are available. We sought to determine the burden of invasive NTS disease in a rural and urban setting in Kenya. METHODS: We conducted the study in a population-based surveillance platform in a rural setting in western Kenya (Lwak), and an informal urban settlement in Nairobi (Kibera) from 2009 to 2014. We obtained blood culture specimens from participants presenting with acute lower respiratory tract illness or acute febrile illness to a designated outpatient facility in each site, or any hospital admission for a potentially infectious cause (rural site only). Incidence was calculated using a defined catchment population and adjusting for specimen collection and healthcare-seeking practices. RESULTS: A total of 12 683 and 9524 blood cultures were analyzed from Lwak and Kibera, respectively. Of these, 428 (3.4%) and 533 (5.6%) grew a pathogen; among those, 208 (48.6%) and 70 (13.1%) were positive for NTS in Lwak and Kibera, respectively. Overall, the adjusted incidence of invasive NTS disease was higher in Lwak (839.4 per 100,000 person-years of observation [PYO]) than in Kibera (202.5 per 100,000 PYO). The highest adjusted incidences were observed in children <5 years of age (Lwak 3914.3 per 100,000 PYO and Kibera 997.9 per 100,000 PYO). The highest adjusted annual incidence was 1927.3 per 100,000 PYO (in 2010) in Lwak and 220.5 per 100,000 PYO (in 2011) in Kibera; the lowest incidences were 303.3 and 62.5 per 100,000 PYO, respectively (in 2012). In both sites, invasive NTS disease incidence generally declined over the study period. CONCLUSIONS: We observed an extremely high burden of invasive NTS disease in a rural area of Kenya and a lesser, but still substantial, burden in an urban slum. Although the incidences in both sites declined during the study period, invasive NTS infections remain an important cause of morbidity in these settings, particularly among children <5 years old.

Economic Burden of Dengue Virus Infection at the Household Level Among Residents of Puerto Maldonado, Peru.

Dengue virus (DENV) was reintroduced to Peru in the 1990s and has been reported in Puerto Maldonado (population ~65,000) in the Peruvian southern Amazon basin since 2000. This region also has the highest human migration rate in the country, mainly from areas not endemic for DENV. The objective of this study was to assess the proportion of household income that is diverted to costs incurred because of dengue illness and to compare these expenses between recent migrants (RMs) and long-term residents (LTRs). We administered a standardized questionnaire to persons diagnosed with dengue illness at Hospital Santa Rosa in Puerto Maldonado from December 2012 to March 2013. We compared direct and indirect medical costs between RMs and LTRs. A total of 80 participants completed the survey, of whom 28 (35%) were RMs and 52 (65%) were LTRs. Each dengue illness episode cost the household an average of US$105 (standard deviation [SD] = 107), representing 24% of their monthly income. Indirect costs were the greatest expense (US$56, SD = 87), especially lost wages. The proportion of household income diverted to dengue illness did not differ significantly between RM and LTR households. The study highlights the significant financial burden incurred by households when a family member suffers dengue illness.

Needs, acceptability, and value of humanitarian medical assistance in remote Peruvian Amazon riverine communities.

Much debate exists regarding the need, acceptability, and value of humanitarian medical assistance. We conducted a cross-sectional study on 457 children under 5 years from four remote riverine communities in the Peruvian Amazon and collected anthropometric measures, blood samples (1-4 years), and stool samples. Focus groups and key informant interviews assessed perspectives regarding medical aid delivered by foreigners. The prevalence of stunting, anemia, and intestinal parasites was 20%, 37%, and 62%, respectively. Infection with multiple parasites, usually geohelminths, was detected in 41% of children. The prevalence of intestinal parasites both individual and polyparasitism increased with age. Participants from smaller communities less exposed to foreigners expressed lack of trust and fear of them. However, participants from all communities were positive about foreigners visiting to provide health support. Prevalent health needs such as parasitic infections and anemia may be addressed by short-term medical interventions. There is a perceived openness to and acceptability of medical assistance delivered by foreign personnel.

Linking human health and livestock health: a "one-health" platform for integrated analysis of human health, livestock health, and economic welfare in livestock dependent communities.

BACKGROUND: For most rural households in sub-Saharan Africa, healthy livestock play a key role in averting the burden associated with zoonotic diseases, and in meeting household nutritional and socio-economic needs. However, there is limited understanding of the complex nutritional, socio-economic, and zoonotic pathways that link livestock health to human health and welfare. Here we describe a platform for integrated human health, animal health and economic welfare analysis designed to address this challenge. We provide baseline epidemiological data on disease syndromes in humans and the animals they keep, and provide examples of relationships between human health, animal health and household socio-economic status. METHOD: We designed a study to obtain syndromic disease data in animals along with economic and behavioral information for 1500 rural households in Western Kenya already participating in a human syndromic disease surveillance study. Data collection started in February 2013, and each household is visited bi-weekly and data on four human syndromes (fever, jaundice, diarrhea and respiratory illness) and nine animal syndromes (death, respiratory, reproductive, musculoskeletal, nervous, urogenital, digestive, udder disorders, and skin disorders in cattle, sheep, goats and chickens) are collected. Additionally, data from a comprehensive socio-economic survey is collected every 3 months in each of the study households. FINDINGS: Data from the first year of study showed 93% of the households owned at least one form of livestock (55%, 19%, 41% and 88% own cattle, sheep, goats and chickens respectively). Digestive disorders, mainly diarrhea episodes, were the most common syndromes observed in cattle, goats and sheep, accounting for 56% of all livestock syndromes, followed by respiratory illnesses (18%). In humans, respiratory illnesses accounted for 54% of all illnesses reported, followed by acute febrile illnesses (40%) and diarrhea illnesses (5%). While controlling for household size, the incidence of human illness increased 1.31-fold for every 10 cases of animal illness or death observed (95% CI 1.16-1.49). Access and utilization of animal source foods such as milk and eggs were positively associated with the number of cattle and chickens owned by the household. Additionally, health care seeking was correlated with household incomes and wealth, which were in turn correlated with livestock herd size. CONCLUSION: This study platform provides a unique longitudinal dataset that allows for the determination and quantification of linkages between human and animal health, including the impact of healthy animals on human disease averted, malnutrition, household educational attainment, and income levels.

Challenges in responding to the ebola epidemic - four rural counties, Liberia, August-November 2014.

The first cases of Ebola virus disease (Ebola) in West Africa were identified in Guinea on March 22, 2014. On March 30, the first Liberian case was identified in Foya Town, Lofa County, near the Guinean border. Because the majority of early cases occurred in Lofa and Montserrado counties, resources were concentrated in these counties during the first several months of the response, and these counties have seen signs of successful disease control. By October 2014, the epidemic had reached all 15 counties of Liberia. During August 27-September 10, 2014, CDC in collaboration with the Liberian Ministry of Health and Social Welfare assessed county Ebola response plans in four rural counties (Grand Cape Mount, Grand Bassa, Rivercess, and Sinoe, to identify county-specific challenges in executing their Ebola response plans, and to provide recommendations and training to enhance control efforts. Assessments were conducted through interviews with county health teams and health care providers and visits to health care facilities. At the time of assessment, county health teams reported lacking adequate training in core Ebola response strategies and reported facing many challenges because of poor transportation and communication networks. Development of communication and transportation network strategies for communities with limited access to roads and limited means of communication in addition to adequate training in Ebola response strategies is critical for successful management of Ebola in remote areas.

Assessment of ebola virus disease, health care infrastructure, and preparedness - four counties,Southeastern Liberia, august 2014.

Ebola virus disease (Ebola) is a multisystem disease caused by a virus of the genus Ebolavirus. In late March 2014, Ebola cases were described in Liberia, with epicenters in Lofa County and later in Montserrado County. While information about case burden and health care infrastructure was available for the two epicenters, little information was available about remote counties in southeastern Liberia. Over 9 days, August 6-14, 2014, Ebola case burden, health care infrastructure, and emergency preparedness were assessed in collaboration with the Liberian Ministry of Health and Social Welfare in four counties in southeastern Liberia: Grand Gedeh, Grand Kru, River Gee, and Maryland. Data were collected by health care facility visits to three of the four county referral hospitals and by unstructured interviews with county and district health officials, hospital administrators, physicians, nurses, physician assistants, and health educators in all four counties. Local burial practices were discussed with county officials, but no direct observation of burial practices was conducted. Basic information about Ebola surveillance and epidemiology, case investigation, contact tracing, case management, and infection control was provided to local officials.

Developing an incident management system to support Ebola response -- Liberia, July-August 2014.

The ongoing Ebola virus disease (Ebola) outbreak in West Africa is the largest and most sustained Ebola epidemic recorded, with 6,574 cases. Among the five affected countries of West Africa (Liberia, Sierra Leone, Guinea, Nigeria, and Senegal), Liberia has had the highest number cases (3,458). This epidemic has severely strained the public health and health care infrastructure of Liberia, has resulted in restrictions in civil liberties, and has disrupted international travel. As part of the initial response, the Liberian Ministry of Health and Social Welfare (MOHSW) developed a national task force and technical expert committee to oversee the management of the Ebola-related activities. During the third week of July 2014, CDC deployed a team of epidemiologists, data management specialists, emergency management specialists, and health communicators to assist MOHSW in its response to the growing Ebola epidemic. One aspect of CDC's response was to work with MOHSW in instituting incident management system (IMS) principles to enhance the organization of the response. This report describes MOHSW's Ebola response structure as of mid-July, the plans made during the initial assessment of the response structure, the implementation of interventions aimed at improving the system, and plans for further development of the response structure for the Ebola epidemic in Liberia.

Control of Ebola virus disease - firestone district, liberia, 2014.

On March 30, 2014, the Ministry of Health and Social Welfare (MOHSW) of Liberia alerted health officials at Firestone Liberia, Inc. (Firestone) of the first known case of Ebola virus disease (Ebola) inside the Firestone rubber tree plantation of Liberia. The patient, who was the wife of a Firestone employee, had cared for a family member with confirmed Ebola in Lofa County, the epicenter of the Ebola outbreak in Liberia during March-April 2014. To prevent a large outbreak among Firestone's 8,500 employees, their dependents, and the surrounding population, the company responded by 1) establishing an incident management system, 2) instituting procedures for the early recognition and isolation of Ebola patients, 3) enforcing adherence to standard Ebola infection control guidelines, and 4) providing differing levels of management for contacts depending on their exposure, including options for voluntary quarantine in the home or in dedicated facilities. In addition, Firestone created multidisciplinary teams to oversee the outbreak response, address case detection, manage cases in a dedicated unit, and reintegrate convalescent patients into the community. The company also created a robust risk communication, prevention, and social mobilization campaign to boost community awareness of Ebola and how to prevent transmission. During August 1-September 23, a period of intense Ebola transmission in the surrounding areas, 71 cases of Ebola were diagnosed among the approximately 80,000 Liberians for whom Firestone provides health care (cumulative incidence = 0.09%). Fifty-seven (80%) of the cases were laboratory confirmed; 39 (68%) of these cases were fatal. Aspects of Firestone's response appear to have minimized the spread of Ebola in the local population and might be successfully implemented elsewhere to limit the spread of Ebola and prevent transmission to health care workers (HCWs).

The role of disease surveillance in achieving IHR compliance by 2012.

The World Health Organization's revised International Health Regulations (IHR (2005)) call for member state compliance by mid-2012. Variation in disease surveillance and core public health capacities will affect each member state's ability to meet this deadline. We report on topics presented at the preconference workshop, "The Interaction of Disease Surveillance and the International Health Regulations," held at the 2010 International Society for Disease Surveillance conference in Park City, Utah. Presenters were from the Pan American Health Organization (PAHO), the U.S. Department of Health and Human Services (HHS), the Centers for Disease Control and Prevention (CDC), the Armed Forces Health Surveillance Center, U.S. Naval Research Unit Six, the Philippines' National Epidemiologic Center, and the French armed forces. The topics addressed were: an overview of the revised IHRs; disease surveillance systems implemented in Peru, the Philippines, and by the French armed forces; the capacity building efforts of the CDC; partnerships and contributions to IHR compliance from HHS; and the application of the IHRs to special populations. Results from the meeting evaluation indicate that many participants found the information useful in better understanding current efforts of the U.S. government and international organizations, areas for collaboration, and how the IHRs apply to their countries' public health systems. Topics to address at future workshops include progress and challenges to IHR implementation across all member states and additional examples of how disease surveillance supports the IHRs in resource-constrained countries. The preconference workshop provided the opportunity to convene public health experts from all regions of the world. Stronger collaborations and support to better detect and respond to public health events through building sustainable disease surveillance systems will not only help member states to meet IHR compliance by 2012, but will also improve pandemic preparedness and global health security.