The COVID-19 pandemic has exposed weaknesses in disease surveillance in nearly all countries. Early identification of COVID-19 cases and clusters for rapid containment was hampered by inadequate diagnostic capacity, insufficient contact tracing, fragmented data systems, incomplete data insights for public health responders, and suboptimal governance of all these elements. Once SARS-CoV-2 became widespread, interventions to control community transmission were undermined by weak surveillance of cases and insufficient national capacity to integrate data for timely adjustment of public health measures.1, 2 Although some countries had little or no reliable data, others did not share data consistently with their own populations and with WHO and other multilateral agencies. The emergence of SARS-CoV-2 variants has highlighted inadequate national pathogen genomic sequencing capacities in many countries and led to calls for expanded virus sequencing. However, sequencing without epidemiological and clinical surveillance data is insufficient to show whether new SARS-CoV-2 variants are more transmissible, more lethal, or more capable of evading immunity, including vaccine-induced immunity.3, 4

The covid-19 pandemic reminds us yet again of the critical importance of an effective field epidemiology workforce to safeguard and promote the health of countries' citizens, prevent the spread of infectious disease, and strengthen global health security. For the past 4 decades, field epidemiology training programs (FETPs)1,2 have worked to address precisely this need in countries throughout the world. FETPs are service-based, hands-on programs that emphasize learning by doing. They are designed to develop skilled and experienced field epidemiologists who can detect, investigate, and control disease outbreaks; conduct surveillance; analyze epidemiological data; measure the impact of interventions; and carry out applied epidemiological studies. Today, more than 85 FETPs are providing invaluable field epidemiology services to ministries of health in more than 165 countries and territories,3 and, as cases surge, the COVID-19 pandemic offers myriad examples of impactful contributions of FETP trainees and graduates to the response around the globe.4

During 2013, the Maryland Department of Health and Mental Hygiene in Baltimore, MD, USA, received report of 2 Maryland residents whose surgical sites were infected with rapidly growing mycobacteria after cosmetic procedures at a clinic (clinic A) in the Dominican Republic. A multistate investigation was initiated; a probable case was defined as a surgical site infection unresponsive to therapy in a patient who had undergone cosmetic surgery in the Dominican Republic. We identified 21 case-patients in 6 states who had surgery in 1 of 5 Dominican Republic clinics; 13 (62%) had surgery at clinic A. Isolates from 12 (92%) of those patients were culture-positive for Mycobacterium abscessus complex. Of 9 clinic A case-patients with available data, all required therapeutic surgical intervention, 8 (92%) were hospitalized, and 7 (78%) required ≥3 months of antibacterial drug therapy. Healthcare providers should consider infection with rapidly growing mycobacteria in patients who have surgical site infections unresponsive to standard treatment.

CDC's response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa was the largest in the agency's history and occurred in a geographic area where CDC had little operational presence. Approximately 1,450 CDC responders were deployed to Guinea, Liberia, and Sierra Leone since the start of the response in July 2014 to the end of the response at the end of March 2016, including 455 persons with repeat deployments. The responses undertaken in each country shared some similarities but also required unique strategies specific to individual country needs. The size and duration of the response challenged CDC in several ways, particularly with regard to staffing. The lessons learned from this epidemic will strengthen CDC's ability to respond to future public health emergencies. These lessons include the importance of ongoing partnerships with ministries of health in resource-limited countries and regions, a cadre of trained CDC staff who are ready to be deployed, and development of ongoing working relationships with U.S. government agencies and other multilateral and nongovernment organizations that deploy for international public health emergencies. CDC's establishment of a Global Rapid Response Team in June 2015 is anticipated to meet some of these challenges. 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).

In August 2013, the Maryland Department of Health and Mental Hygiene (MDHMH) was notified of two persons with rapidly growing nontuberculous mycobacterial (RG-NTM) surgical-site infections. Both patients had undergone surgical procedures as medical tourists at the same private surgical clinic (clinic A) in the Dominican Republic the previous month. Within 7 days of returning to the United States, both sought care for symptoms that included surgical wound abscesses, clear fluid drainage, pain, and fever. Initial antibiotic therapy was ineffective. Material collected from both patients' wounds grew Mycobacterium abscessus exhibiting a high degree of antibiotic resistance characteristic of this organism.

Because of widespread distribution of the influenza A (H1N1) 2009 monovalent vaccine (pH1N1 vaccine) and the prior association between Guillain-Barre syndrome (GBS) and the 1976 H1N1 influenza vaccine, enhanced surveillance was implemented to estimate the magnitude of any increased GBS risk following administration of pH1N1 vaccine. The authors conducted active, population-based surveillance for incident cases of GBS among 45 million persons residing at 10 Emerging Infections Program sites during October 2009-May 2010; GBS was defined according to published criteria. The authors determined medical and vaccine history for GBS cases through medical record review and patient interviews. The authors used vaccine coverage data to estimate person-time exposed and unexposed to pH1N1 vaccine and calculated age- and sex-adjusted rate ratios comparing GBS incidence in these groups, as well as age- and sex-adjusted numbers of excess GBS cases. The authors received 411 reports of confirmed or probable GBS. The rate of GBS immediately following pH1N1 vaccination was 57% higher than in person-time unexposed to vaccine (adjusted rate ratio = 1.57, 95% confidence interval: 1.02, 2.21), corresponding to 0.74 excess GBS cases per million pH1N1 vaccine doses (95% confidence interval: 0.04, 1.56). This excess risk was much smaller than that observed during the 1976 vaccine campaign and was comparable to some previous seasonal influenza vaccine risk assessments.

BACKGROUND: Human parainfluenza viruses (HPIVs) are an important cause of acute respiratory illness in young children but little is known about their epidemiology in the tropics. METHODS: From 2003-2007, we conducted surveillance for hospitalized respiratory illness in rural Thailand. We performed reverse-transcriptase polymerase chain reaction on nasopharyngeal specimens and enzyme immunoassay on paired sera. RESULTS: Of 10,097 patients enrolled, 573 (5%) of all ages and 370 (9%) of children <5 years of age had evidence of HPIV infection (HPIV1=189, HPIV2=54, HPIV3=305, untyped=27). Average adjusted annual incidence of HPIV-associated hospitalized respiratory illness was greatest in children aged <1 year (485 per 100,000 person years). CONCLUSIONS: In Thailand, HPIV caused substantial illnesses requiring hospitalization in young children.

INTRODUCTION: Mortality data provide essential evidence on the health status of populations in crisis-affected and resource-poor settings and to guide and assess relief operations. Retrospective surveys are commonly used to collect mortality data in such populations, but require substantial resources and have important methodological limitations. We evaluated the feasibility of an alternative method for rapidly quantifying mortality (the informant method). The study objective was to assess the economic feasibility of the informant method. METHODS: The informant method captures deaths through an exhaustive search for all deaths occurring in a population over a defined and recent recall period, using key community informants and next-of-kin of decedents. Between July and October 2008, we implemented and evaluated the informant method in: Kabul, Afghanistan; Mae La camp for Karen refugees, Thai-Burma border; Chiradzulu District, Malawi; and Lugufu and Mtabila refugee camps, Tanzania. We documented the time and cost inputs for the informant method in each site, and compared these with projections for hypothetical retrospective mortality surveys implemented in the same site with a 6 month recall period and with a 30 day recall period. FINDINGS: The informant method was estimated to require an average of 29% less time inputs and 33% less monetary inputs across all four study sites when compared with retrospective surveys with a 6 month recall period, and 88% less time inputs and 86% less monetary inputs when compared with retrospective surveys with a 1 month recall period. Verbal autopsy questionnaires were feasible and efficient, constituting only 4% of total person-time for the informant method's implementation in Chiradzulu District. CONCLUSIONS: The informant method requires fewer resources and incurs less respondent burden. The method's generally impressive feasibility and the near real-time mortality data it provides warrant further work to develop the method given the importance of mortality measurement in such settings.

Population incidence of Guillain-Barre syndrome (GBS) is required to assess changes in GBS epidemiology, but published estimates of GBS incidence vary greatly depending on case ascertainment, definitions, and sample size. We performed a meta-analysis of articles on GBS incidence by searching Medline (1966-2009), Embase (1988-2009), Cinahl (1981-2009) and CABI (1973-2009) as well as article bibliographies. We included studies from North America and Europe with at least 20 cases, and used population-based data, subject matter experts to confirm GBS diagnosis, and an accepted GBS case definition. With these data, we fitted a random-effects negative binomial regression model to estimate age-specific GBS incidence. Of 1,683 nonduplicate citations, 16 met the inclusion criteria, which produced 1,643 cases and 152.7 million person-years of follow-up. GBS incidence increased by 20% for every 10-year increase in age; the risk of GBS was higher for males than females. The regression equation for calculating the average GBS rate per 100,000 person-years as a function of age in years was exp[-12.0771 + 0.01813(age in years)] x 100,000. Our findings provide a robust estimate of background GBS incidence in Western countries. Our regression model may be used in comparable populations to estimate the background age-specific rate of GBS incidence for future studies.

San Antonio, Texas, was one of the first metropolitan areas where 2009 pandemic influenza A (H1N1) virus (pH1N1) was detected. Identification of laboratory-confirmed pH1N1 in 2 students led to a preemptive 8-day closure of their high school. We assessed transmission of pH1N1 and changes in adoption of nonpharmaceutical interventions (NPIs) within households of students attending the affected school. Household | secondary attack rates were 3.7% overall and 9.1% among those 0-4 years of age. Widespread adoption of NPIs was reported among household members. Respondents who viewed pH1N1 as very serious were more likely to adopt certain NPIs than were respondents who viewed pH1N1 as not very serious. NPIs may complement influenza vaccine prevention programs or be the only line of defense when pandemic vaccine is unavailable. The 2009 pandemic provided a unique opportunity to study NPIs, and these real-world experiences provide muchneeded | data to inform pandemic response policy.

Clinicians frequently use influenza rapid antigen tests for diagnostic testing. We tested nasal wash samples from 1 April to 7 June 2009 from 1538 patients using the QuickVue Influenza A1B (Quidel) rapid influenza antigen test and compared the results with real-time reverse transcription polymerase chain reaction (rRTPCR) assay (gold standard). The prevalence of 2009 pandemic influenza A (pH1N1) was 1.98%, seasonal influenza type A .87%, and seasonal influenza type B 2.07%. The sensitivity and specificity of the rapid test for pH1N1 was 20% (95% CI, 8-39) and 99% (95% CI, 98-99), for seasonal influenza type A 15% (95% CI, 2-45) and 99% (95% CI, 98-99), and for influenza type B was 31% (95% CI, 9-61) and 99% (95% CI, 98-99.7). Rapid influenza antigen tests were of limited use at a time when the prevalence of pH1N1 and seasonal influenza in the United States was low. Clinicians should instead rely on clinical impression and laboratory diagnosis by rRT-PCR.

A critical issue during the 2009 influenza A (H1N1) pandemic was determining the appropriate duration of time individuals with influenza-like illness (ILI) should remain isolated to reduce onward transmission while limiting societal disruption. Ideally this is based on knowledge of the relative infectiousness of ill individuals at each point during the course of the infection. Data on 261 clinically apparent pH1N1 infector-infectee pairs in households, from 7 epidemiological studies conducted in the United States early in 2009, were analyzed to estimate the distribution of times from symptom onset in an infector to symptom onset in the household contacts they infect (mean, 2.9 days, not correcting for tertiary transmission). Only 5% of transmission events were estimated to take place .3 days after the onset of clinical symptoms among those ill with pH1N1 virus. These results will inform future recommendations on duration of isolation of individuals with ILI.

Knowledge from early outbreaks is limited regarding the virus detection and illness duration of the 2009 pandemic influenza A (H1N1) infections. During the period from April to May 2009 in Texas, we collected serial nasopharyngeal (NP) and stool specimens from 35 participants, testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) and culture. The participants were aged 2 months to 71 years; 25 (71%) were under 18. The median duration of measured fever was 3.0 days and of virus detection in NP specimens was 4.2 days; however, few specimens were collected between days 5-9. The duration of virus detection (4.2 days) was similar to the duration of fever (3.5 days) (RR, 1.14; 95% CI, .66-1.95; P=.8), but was shorter than the duration of cough (11.0 days) (RR, .41; 95% CI, .24-.68; P.001). We detected viral RNA in two participants' stools. All cultures were negative. This investigation suggests that the duration of virus detection was likely similar to the seasonal influenza virus.

BACKGROUND: Data on mortality rates are crucial to guide health interventions in crisis-affected and resource-poor settings. The methods currently available to collect mortality data in such settings feature important methodological limitations. We developed and validated a new method to provide near real-time mortality estimates in such settings. METHODS: We selected four study sites: Kabul, Afghanistan; Mae La refugee camp, Thailand; Chiradzulu District, Malawi; and Lugufu and Mtabila refugee camps, Tanzania. We recorded information about all deaths in a 60-day period by asking key community informants and decedents' next of kin to refer interviewers to bereaved households. We used the total number of deaths and population estimates to calculate mortality rates for 60- and 30-day periods. For validation we compared these rates with a best estimate of mortality using capture-recapture analysis with two further independent lists of deaths. RESULTS: The population covered by the new method was 76,476 persons in Kabul, 43,794 in Mae La camp, 54,418 in Chiradzulu District and 80,136 in the Tanzania camps. The informant method showed moderate sensitivity (55.0% in Kabul, 64.0% in Mae La, 72.5% in Chiradzulu and 67.7% in Tanzania), but performed better than the active surveillance system in the Tanzania refugee camps. CONCLUSIONS: The informant method currently features moderate sensitivity for accurately assessing mortality, but warrants further development, particularly considering its advantages over current options (ease of implementation and analysis and near-real estimates of mortality rates). Strategies should be tested to improve the performance of the informant method.

After recreational exposure to river water in Uganda, 12 (17%) of 69 persons had evidence of schistosome infection. Eighteen percent self-medicated with praziquantel prophylaxis immediately after exposure, which was not appropriate. Travelers to schistosomiasis-endemic areas should consult a travel medicine physician.

To assess household transmission of pandemic (H1N1) 2009 in San Antonio, Texas, USA, during April 15-May 8, 2009, we investigated 77 households. The index case-patient was defined as the household member with the earliest onset date of symptoms of acute respiratory infection (ARI), influenza-like illness (ILI), or laboratory-confirmed pandemic (H1N1) 2009. Median interval between illness onset in index and secondary case-patients was 4 days (range 1-9 days); the index case-patient was likely to be < or =18 years of age (p = 0.034). The secondary attack rate was 4% for pandemic (H1N1) 2009, 9% for ILI, and 13% for ARI. The secondary attack rate was highest for children <5 years of age (8%-19%) and lowest for adults > or =50 years of age (4%-12%). Early in the outbreak, household transmission primarily occurred from children to other household members and was lower than the transmission rate for seasonal influenza.

BACKGROUND: Severe illness due to 2009 pandemic A(H1N1) infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1), independent of chronic medical conditions considered by the Advisory Committee on Immunization Practices (ACIP) to increase the risk of influenza-related complications. METHODOLOGY/PRINCIPAL FINDINGS: We used a case-cohort design to compare cases of hospitalizations and deaths from 2009 pandemic A(H1N1) influenza occurring between April-July, 2009, with a cohort of the U.S. population estimated from the 2003-2006 National Health and Nutrition Examination Survey (NHANES); pregnant women and children <2 years old were excluded. For hospitalizations, we defined categories of relative weight by body mass index (BMI, kg/m(2)); for deaths, obesity or morbid obesity was recorded on medical charts, and death certificates. Odds ratio (OR) of being in each BMI category was determined; normal weight was the reference category. Overall, 361 hospitalizations and 233 deaths included information to determine BMI category and presence of ACIP-recognized medical conditions. Among >or=20 year olds, hospitalization was associated with being morbidly obese (BMI>or=40) for individuals with ACIP-recognized chronic conditions (OR = 4.9, 95% CI 2.4-9.9) and without ACIP-recognized chronic conditions (OR = 4.7, 95%CI 1.3-17.2). Among 2-19 year olds, hospitalization was associated with being underweight (BMI<or=5(th) percentile) among those with (OR = 12.5, 95%CI 3.4-45.5) and without (OR = 5.5, 95%CI 1.3-22.5) ACIP-recognized chronic conditions. Death was not associated with BMI category among individuals 2-19 years old. Among individuals aged >or=20 years without ACIP-recognized chronic medical conditions death was associated with obesity (OR = 3.1, 95%CI: 1.5-6.6) and morbid obesity (OR = 7.6, 95%CI 2.1-27.9). CONCLUSIONS/SIGNIFICANCE: Our findings support observations that morbid obesity may be associated with hospitalization and possibly death due to 2009 pandemic H1N1 infection. These complications could be prevented by early antiviral therapy and vaccination.