This article summarizes what is currently known about the 2019 novel coronavirus and offers interim guidance.

BACKGROUND: Although a human adenovirus (HAdV) vaccine is available for military use, officers-in-training are not routinely vaccinated. We describe an HAdV-associated respiratory outbreak among unvaccinated cadets at the U.S. Coast Guard Academy and its impact on cadet training. METHODS: We defined a case as a cadet with new onset cough or sore throat during August 1-October 4, 2019. We reviewed medical records and distributed a questionnaire to identify cases and to estimate impact on cadet training. We performed real-time PCR testing on patient and environmental samples and whole genome sequencing on a subset of positive patient samples. RESULTS: Among the 1,072 cadets, 378 (35%) cases were identified by medical records (n=230) or additionally by the questionnaire (n=148). Of the 230 cases identified from medical records, 138 (60%) were male and 226 (98%) had no underlying conditions. From questionnaire responses, 113/228 (50%) cases reported duty restrictions. Of cases with respiratory specimens, 36/50 (72%) were HAdV positive; all 14 sequenced specimens were HAdV-4a1. Sixteen (89%) of 18 environmental specimens from the cadet dormitory were HAdV-positive. CONCLUSIONS: The HAdV-4-associated outbreak infected a substantial number of cadets and significantly impacted cadet training. Routine vaccination could prevent HAdV respiratory outbreaks in this population.

We compared severe acute respiratory syndrome-related coronavirus-2 seroprevalence estimated from commercial laboratory residual sera and a community household survey in metropolitan Atlanta during April-May 2020 and found these two estimates to be similar (4.94% versus 3.18%). Compared with more representative surveys, commercial sera can provide an approximate measure of seroprevalence.

We assessed EV-D68 epidemiology and phylogenetics among children aged ≤9 years hospitalized with severe acute respiratory illnesses at five sites in Panama and El Salvador during 2012-2013. Respiratory specimens positive for enterovirus or rhinovirus were tested by real-time RT-PCR for EV-D68, and partial VP1 gene sequences were determined. Of 715 enrolled children, 17 from sites in both countries were EV-D68-positive and commonly had a history of asthma or wheezing. Phylogenetically, 15 of 16 sequences fell into Clade B1, and one into Clade A2. The Central American EV-D68s were closely related genetically to contemporaneous strains from North America, South America, and the Caribbean.

Molecular data are required to improve our understanding of the epidemiology of leptospirosis in Africa and to identify sources of human infection. We applied molecular methods to identify the infecting Leptospira species and genotypes among patients hospitalized with fever in Tanzania and compared these with Leptospira genotypes detected among animals in Tanzania to infer potential sources of human infection. We performed lipL32 real-time PCR to detect the presence of pathogenic Leptospira in acute-phase plasma, serum, and urine samples obtained from study participants with serologically confirmed leptospirosis and participants who had died with febrile illness. Leptospira blood culture was also performed. In positive specimens, we performed species-specific PCR and compared participant Leptospira secY sequences with Leptospira reference sequences and sequences previously obtained from animals in Tanzania. We detected Leptospira DNA in four (3.6%) of 111 participant blood samples. We detected Leptospira borgpetersenii (one participant, 25.0%), Leptospira interrogans (one participant, 25.0%), and Leptospira kirschneri (one participant, 25.0%) (one [25%] undetermined). Phylogenetic comparison of secY sequence from the L. borgpetersenii and L. kirschneri genotypes detected from participants was closely related to but distinct from genotypes detected among local livestock species. Our results indicate that a diverse range of Leptospira species is causing human infection. Although our analysis suggests a close relationship between Leptospira genotypes found in people and livestock, continued efforts are needed to obtain more Leptospira genetic material from human leptospirosis cases to help prioritize Leptospira species and genotypes for control.

Coronavirus disease 2019 (COVID-19), the respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, China and has since become pandemic. In response to the first cases identified in the United States, close contacts of confirmed COVID-19 cases were investigated to enable early identification and isolation of additional cases and to learn more about risk factors for transmission. Close contacts of nine early travel-related cases in the United States were identified and monitored daily for development of symptoms (active monitoring). Selected close contacts (including those with exposures categorized as higher risk) were targeted for collection of additional exposure information and respiratory samples. Respiratory samples were tested for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction at the Centers for Disease Control and Prevention. Four hundred four close contacts were actively monitored in the jurisdictions that managed the travel-related cases. Three hundred thirty-eight of the 404 close contacts provided at least basic exposure information, of whom 159 close contacts had ≥1 set of respiratory samples collected and tested. Across all actively monitored close contacts, two additional symptomatic COVID-19 cases (i.e., secondary cases) were identified; both secondary cases were in spouses of travel-associated case patients. When considering only household members, all of whom had ≥1 respiratory sample tested for SARS-CoV-2, the secondary attack rate (i.e., the number of secondary cases as a proportion of total close contacts) was 13% (95% CI: 4-38%). The results from these contact tracing investigations suggest that household members, especially significant others, of COVID-19 cases are at highest risk of becoming infected. The importance of personal protective equipment for healthcare workers is also underlined. Isolation of persons with COVID-19, in combination with quarantine of exposed close contacts and practice of everyday preventive behaviors, is important to mitigate spread of COVID-19.

Transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), is ongoing in many communities throughout the United States. Although case-based and syndromic surveillance are critical for monitoring the pandemic, these systems rely on persons obtaining testing or reporting a COVID-19-like illness. Using serologic tests to detect the presence of SARS-CoV-2 antibodies is an adjunctive strategy that estimates the prevalence of past infection in a population. During April 28-May 3, 2020, coinciding with the end of a statewide shelter-in-place order, CDC and the Georgia Department of Public Health conducted a serologic survey in DeKalb and Fulton counties in metropolitan Atlanta to estimate SARS-CoV-2 seroprevalence in the population. A two-stage cluster sampling design was used to randomly select 30 census blocks in each county, with a target of seven participating households per census block. Weighted estimates were calculated to account for the probability of selection and adjusted for age group, sex, and race/ethnicity. A total of 394 households and 696 persons participated and had a serology result; 19 (2.7%) of 696 persons had SARS-CoV-2 antibodies detected. The estimated weighted seroprevalence across these two metropolitan Atlanta counties was 2.5% (95% confidence interval [CI] = 1.4-4.5). Non-Hispanic black participants more commonly had SARS-CoV-2 antibodies than did participants of other racial/ethnic groups (p<0.01). Among persons with SARS-CoV-2 antibodies, 13 (weighted % = 49.9; 95% CI = 24.4-75.5) reported a COVID-19-compatible illness,* six (weighted % = 28.2; 95% CI = 11.9-53.3) sought medical care for a COVID-19-compatible illness, and five (weighted % = 15.7; 95% CI = 5.1-39.4) had been tested for SARS-CoV-2 infection, demonstrating that many of these infections would not have been identified through case-based or syndromic surveillance. The relatively low seroprevalence estimate in this report indicates that most persons in the catchment area had not been infected with SARS-CoV-2 at the time of the survey. Continued preventive measures, including social distancing, consistent and correct use of face coverings, and hand hygiene, remain critical in controlling community spread of SARS-CoV-2.

We describe the contact investigation for an early confirmed case of coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in the United States. Contacts of the case-patient were identified, actively monitored for symptoms, interviewed for a detailed exposure history, and tested for SARS-CoV-2 infection by real-time reverse transcription PCR (rRT-PCR) and ELISA. Fifty contacts were identified and 38 (76%) were interviewed, of whom 11 (29%) reported unprotected face-to-face interaction with the case-patient. Thirty-seven (74%) had respiratory specimens tested by rRT-PCR, and all tested negative. Twenty-three (46%) had ELISA performed on serum samples collected approximately 6 weeks after exposure, and none had detectable antibodies to SARS-CoV-2. Among contacts who were tested, no secondary transmission was identified in this investigation, despite unprotected close interactions with the infectious case-patient.

BACKGROUND: Human adenoviruses (HAdVs) are commonly associated with acute respiratory illness. HAdV outbreaks are well documented in congregate military training settings, but less is known about outbreaks on college campuses. During fall 2018 and spring 2019, five U.S. colleges reported increases in HAdV-associated respiratory illness. Investigations were performed to better understand HAdV epidemiology in this setting. METHODS: A case was a student at one of the five colleges with acute respiratory illness and laboratory-confirmed HAdV infection during October 2018-December 2018 or March-May 2019. Available respiratory specimens were typed by HAdV type-specific real-time PCR assays, and for a subset, whole genome sequencing was performed. We reviewed available medical records and cases were invited to complete a questionnaire, which included questions on symptom presentation, social history, and absenteeism. RESULTS: We identified 168 HAdV cases. Median age was 19 (range: 17-22) years and 102 cases (61%) were male. Eleven cases were hospitalized, 10 with pneumonia; two cases died. Among questionnaire respondents, 80% (75/94) missed >/=1 day of class because of their illness. Among those with a type identified (79%), HAdV types 4 and 7 were equally detected, with frequency of each varying by site. Genome types 4a1 and 7d were identified, respectively, by whole genome sequence analysis. CONCLUSIONS: HAdV respiratory illness was associated with substantial morbidity and missed class time among young, generally healthy adults on five U.S. college campuses. HAdVs should be considered a cause of respiratory illness outbreaks in congregate settings such as college campuses.

Middle East respiratory syndrome coronavirus (MERS-CoV) infection causes a spectrum of respiratory illness, from asymptomatic to mild to fatal. MERS-CoV is transmitted sporadically from dromedary camels to humans and occasionally through human-to-human contact. Current epidemiologic evidence supports a major role in transmission for direct contact with live camels or humans with symptomatic MERS, but little evidence suggests the possibility of transmission from camel products or asymptomatic MERS cases. Because a proportion of case-patients do not report direct contact with camels or with persons who have symptomatic MERS, further research is needed to conclusively determine additional mechanisms of transmission, to inform public health practice, and to refine current precautionary recommendations.

In December 2019, a cluster of cases of pneumonia emerged in Wuhan City in central China's Hubei Province. Genetic sequencing of isolates obtained from patients with pneumonia identified a novel coronavirus (2019-nCoV) as the etiology (1). As of February 4, 2020, approximately 20,000 confirmed cases had been identified in China and an additional 159 confirmed cases in 23 other countries, including 11 in the United States (2,3). On January 17, CDC and the U.S. Department of Homeland Security's Customs and Border Protection began health screenings at U.S. airports to identify ill travelers returning from Wuhan City (4). CDC activated its Emergency Operations Center on January 21 and formalized a process for inquiries regarding persons suspected of having 2019-nCoV infection (2). As of January 31, 2020, CDC had responded to clinical inquiries from public health officials and health care providers to assist in evaluating approximately 650 persons thought to be at risk for 2019-nCoV infection. Guided by CDC criteria for the evaluation of persons under investigation (PUIs) (5), 210 symptomatic persons were tested for 2019-nCoV; among these persons, 148 (70%) had travel-related risk only, 42 (20%) had close contact with an ill laboratory-confirmed 2019-nCoV patient or PUI, and 18 (9%) had both travel- and contact-related risks. Eleven of these persons had laboratory-confirmed 2019-nCoV infection. Recognizing persons at risk for 2019-nCoV is critical to identifying cases and preventing further transmission. Health care providers should remain vigilant and adhere to recommended infection prevention and control practices when evaluating patients for possible 2019-nCoV infection (6). Providers should consult with their local and state health departments when assessing not only ill travelers from 2019-nCoV-affected countries but also ill persons who have been in close contact with patients with laboratory-confirmed 2019-nCoV infection in the United States.

An outbreak of novel coronavirus (2019-nCoV) that began in Wuhan, China, has spread rapidly, with cases now confirmed in multiple countries. We report the first case of 2019-nCoV infection confirmed in the United States and describe the identification, diagnosis, clinical course, and management of the case, including the patient's initial mild symptoms at presentation with progression to pneumonia on day 9 of illness. This case highlights the importance of close coordination between clinicians and public health authorities at the local, state, and federal levels, as well as the need for rapid dissemination of clinical information related to the care of patients with this emerging infection.

OBJECTIVE: To investigate a Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak event involving multiple healthcare facilities in Riyadh, Saudi Arabia; to characterize transmission; and to explore infection control implications. DESIGN: Outbreak investigation. SETTING: Cases presented in 4 healthcare facilities in Riyadh, Saudi Arabia: a tertiary-care hospital, a specialty pulmonary hospital, an outpatient clinic, and an outpatient dialysis unit. METHODS: Contact tracing and testing were performed following reports of cases at 2 hospitals. Laboratory results were confirmed by real-time reverse transcription polymerase chain reaction (rRT-PCR) and/or genome sequencing. We assessed exposures and determined seropositivity among available healthcare personnel (HCP) cases and HCP contacts of cases. RESULTS: In total, 48 cases were identified, involving patients, HCP, and family members across 2 hospitals, an outpatient clinic, and a dialysis clinic. At each hospital, transmission was linked to a unique index case. Moreover, 4 cases were associated with superspreading events (any interaction where a case patient transmitted to >/=5 subsequent case patients). All 4 of these patients were severely ill, were initially not recognized as MERS-CoV cases, and subsequently died. Genomic sequences clustered separately, suggesting 2 distinct outbreaks. Overall, 4 (24%) of 17 HCP cases and 3 (3%) of 114 HCP contacts of cases were seropositive. CONCLUSIONS: We describe 2 distinct healthcare-associated outbreaks, each initiated by a unique index case and characterized by multiple superspreading events. Delays in recognition and in subsequent implementation of control measures contributed to secondary transmission. Prompt contact tracing, repeated testing, HCP furloughing, and implementation of recommended transmission-based precautions for suspected cases ultimately halted transmission.

There is paucity of data regarding the geographical distribution, incidence, and phylogenetics of multi-drug resistant (MDR) Salmonella Typhi in sub-Saharan Africa. Here we present a phylogenetic reconstruction of whole genome sequenced 249 contemporaneous S. Typhi isolated between 2008-2015 in 11 sub-Saharan African countries, in context of the 2,057 global S. Typhi genomic framework. Despite the broad genetic diversity, the majority of organisms (225/249; 90%) belong to only three genotypes, 4.3.1 (H58) (99/249; 40%), 3.1.1 (97/249; 39%), and 2.3.2 (29/249; 12%). Genotypes 4.3.1 and 3.1.1 are confined within East and West Africa, respectively. MDR phenotype is found in over 50% of organisms restricted within these dominant genotypes. High incidences of MDR S. Typhi are calculated in locations with a high burden of typhoid, specifically in children aged <15 years. Antimicrobial stewardship, MDR surveillance, and the introduction of typhoid conjugate vaccines will be critical for the control of MDR typhoid in Africa.

Background: An outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) in Jordan in 2015 involved a variant virus that acquired distinctive deletions in the accessory open reading frames. We conducted a molecular and seroepidemiologic investigation to describe the deletion variant's transmission patterns and epidemiology. Methods: We reviewed epidemiologic and medical chart data and analyzed viral genome sequences from respiratory specimens of MERS-CoV cases. In early 2016, sera and standardized interviews were obtained from MERS-CoV cases and their contacts. Sera were evaluated by nucleocapsid and spike protein enzyme immunoassays and microneutralization. Results: Among 16 cases, 11 (69%) had health care exposure and 5 (31%) were relatives of a known case; 13 (81%) were symptomatic, and 7 (44%) died. Genome sequencing of MERS-CoV from 13 cases revealed 3 transmissible deletions associated with clinical illness during the outbreak. Deletion variant sequences were epidemiologically clustered and linked to a common transmission chain. Interviews and sera were collected from 2 surviving cases, 23 household contacts, and 278 health care contacts; 1 (50%) case, 2 (9%) household contacts, and 3 (1%) health care contacts tested seropositive. Conclusions: The MERS-CoV deletion variants retained human-to-human transmissibility and caused clinical illness in infected persons despite accumulated mutations. Serology suggested limited transmission beyond that detected during the initial outbreak investigation.

During July-August 2015, the number of cases of Middle East respiratory syndrome (MERS) reported from Saudi Arabia increased dramatically. We reviewed the 143 confirmed cases from this period and classified each based upon likely transmission source. We found that the surge in cases resulted predominantly (90%) from secondary transmission largely attributable to an outbreak at a single healthcare facility in Riyadh. Genome sequencing of MERS coronavirus from 6 cases demonstrated continued circulation of the recently described recombinant virus. A single unique frameshift deletion in open reading frame 5 was detected in the viral sequence from 1 case.

BACKGROUND: Salmonella enterica serovar Typhi is a predominant cause of bloodstream infections in sub-Saharan Africa (SSA). Increasing numbers of S. Typhi with resistance to ciprofloxacin have been reported from different parts of the world. However, data from SSA are limited. In this study, we aimed to measure the ciprofloxacin susceptibility of S. Typhi isolated from patients with febrile illness in SSA. METHODS: Febrile patients from 9 sites within 6 countries in SSA with a body temperature of ≥38.0 degrees C were enrolled in this study. Blood samples were obtained for bacterial culture, and Salmonella isolates were identified biochemically and confirmed by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility of all Salmonella isolates was performed by disk diffusion test, and minimum inhibitory concentrations (MICs) against ciprofloxacin were measured by Etest. All Salmonella isolates with reduced susceptibility to ciprofloxacin (MIC > 0.06 microg/mL) were screened for mutations in quinolone resistance-determining regions in target genes, and the presence of plasmid-mediated quinolone resistance (PMQR) genes was assessed by PCR. RESULTS: A total of 8161 blood cultures were performed, and 100 (1.2%) S. Typhi, 2 (<0.1%) Salmonella enterica serovar Paratyphi A, and 27 (0.3%) nontyphoid Salmonella (NTS) were isolated. Multidrug-resistant S. Typhi were isolated in Kenya (79% [n = 38]) and Tanzania (89% [n = 8]) only. Reduced ciprofloxacin-susceptible (22% [n = 11]) S. Typhi were isolated only in Kenya. Among those 11 isolates, all had a Glu133Gly mutation in the gyrA gene combined with either a gyrA (Ser83Phe) or gyrB mutation (Ser464Phe). One Salmonella Paratyphi A isolate with reduced susceptibility to ciprofloxacin was found in Senegal, with 1 mutation in gyrA (Ser83Phe) and a second mutation in parC (Ser57Phe). Mutations in the parE gene and PMQR genes were not detected in any isolate. CONCLUSIONS: Salmonella Typhi with reduced susceptibility to ciprofloxacin was not distributed homogenously throughout SSA. Its prevalence was very high in Kenya, and was not observed in other study countries. Continuous monitoring of antimicrobial susceptibility is required to follow the potential spread of antimicrobial-resistant isolates throughout SSA.