Ebola disease (EBOD) in humans is a severe disease caused by at least four related viruses in the genus Orthoebolavirus, most often by the eponymous Ebola virus. Due to human-to-human transmission and incomplete success in treating cases despite promising therapeutic development, EBOD is a high priority in public health research. Yet despite almost 50 years since EBOD was first described, the sources of these viruses remain undefined and much remains to be understood about the disease epidemiology and virus emergence and spread. One important approach to improve our understanding is detection of antibodies that can reveal past human infections. However, serosurveys routinely describe seroprevalences that imply infection rates much higher than those clinically observed. Proposed hypotheses to explain this difference include existence of common but less pathogenic strains or relatives of these viruses, misidentification of EBOD as something else, and a higher proportion of subclinical infections than currently appreciated. The work presented here maps B-cell epitopes in the spike protein of Ebola virus and describes a single epitope that is cross-reactive with an antigen seemingly unrelated to orthoebolaviruses. Antibodies against this epitope appear to explain most of the unexpected reactivity towards the spike, arguing against common but unidentified infections in the population. Importantly, antibodies of cross-reactive donors from within and outside the known EBOD geographic range bound the same epitope. In light of this finding, it is plausible that epitope mapping enables broadly applicable specificity improvements in the field of serology.

Ebola virus disease (Ebola) is a rare but severe illness in humans, with an average case fatality rate of approximately 50%. Two licensed vaccines are currently available against Orthoebolavirus zairense, the virus that causes Ebola: the 1-dose rVSVΔG-ZEBOV-GP (ERVEBO [Merck]) and the 2-dose regimen of Ad26.ZEBOV and MVA-BN-Filo (Zabdeno/Mvabea [Johnson & Johnson]). The Strategic Advisory Group of Experts on Immunization recommends the use of 1-dose ERVEBO during Ebola outbreaks, and in 2021, a global stockpile of ERVEBO was established to ensure equitable, timely, and targeted access to vaccine doses for future Ebola outbreaks. This report describes the use of Ebola vaccines and the role of the stockpile developed and managed by the International Coordinating Group (ICG) on Vaccine Provision during 2021-2023. A total of 145,690 doses have been shipped from the ICG stockpile since 2021. However, because outbreaks since 2021 have been limited and rapidly contained, most doses (139,120; 95%) shipped from the ICG stockpile have been repurposed for preventive vaccination of high-risk groups, compared with 6,570 (5%) used for outbreak response. Repurposing doses for preventive vaccination could be prioritized in the absence of Ebola outbreaks to prevent transmission and maximize the cost-efficiency and benefits of the stockpile.

Ebola disease outbreaks are major public health events because of human-to-human transmission and high mortality. These outbreaks are most often caused by Ebola virus, but at least three related viruses can also cause the disease. In 2022, Sudan virus re-emerged causing more than 160 confirmed and probable cases. This report describes generation of a recombinant Sudan virus and demonstrates its utility by quantifying antibody cross-reactivity between Ebola and Sudan virus glycoproteins after human infection or vaccination with a licensed Ebola virus vaccine.

We identified 2 fatal cases of persons infected with hantavirus in Arizona, USA, 2020; 1 person was co-infected with SARS-CoV-2. Delayed identification of the cause of death led to a public health investigation that lasted ≈9 months after their deaths, which complicated the identification of a vector or exposure.

Ebola virus disease (EVD) caused by Ebola virus species Zaire ebolavirus (EBOV) is a major global health challenge causing sporadic outbreaks with high mortality. The minimum incubation period of EBOV, or the time from infection with the virus to the development of first symptoms, is thought to be 2 days and was initially established during the first EVD investigation in 1976.1 A published observation from the investigation noted that, “in one case of the disease, the only possible source of infection was contact with a probable case 48 hours before the latter developed symptoms”, and this observation was restated in another publication.2, 3 However, concluding that the minimum incubation period for EBOV is 2 days based on these reports is flawed for several reasons. First, the presumed source of the infection was a probable case of EVD and was not laboratory-confirmed; it is therefore uncertain whether the source truly had EVD. Second, since the report describes the contact between the source and the case occurring before the source developed symptoms, this implies asymptomatic transmission, which has been established to not occur with EBOV.4, 5, 6 Finally, the report's description of 48 h refers to the time between the case's contact with the alleged source and the source's onset of symptoms, which is itself not an incubation period.

Monkeypox (mpox) cases in the 2022 outbreak have primarily occurred among adult gay, bisexual, and other men who have sex with men (MSM); however, other populations have also been affected (1). To date, data on mpox in cisgender women and pregnant persons have been limited. Understanding transmission in these populations is critical for mpox prevention. In addition, among pregnant persons, Monkeypox virus can be transmitted to the fetus during pregnancy or to the neonate through close contact during or after birth (2-5). Adverse pregnancy outcomes, including spontaneous abortion and stillbirth, have been reported in previous mpox outbreaks (3). During May 11-November 7, 2022, CDC and U.S. jurisdictional health departments identified mpox in 769 cisgender women aged ≥15 years, representing 2.7% of all reported mpox cases.(†) Among cases with available data, 44% occurred in cisgender women who were non-Hispanic Black or African American (Black), 25% who were non-Hispanic White (White), and 23% who were Hispanic or Latino (Hispanic). Among cisgender women with available data, 73% reported sexual activity or close intimate contact as the likely route of exposure, with mpox lesions most frequently reported on the legs, arms, and genitals. Twenty-three mpox cases were reported in persons who were pregnant or recently pregnant(§); all identified as cisgender women based on the mpox case report form.(¶) Four pregnant persons required hospitalization for mpox. Eleven pregnant persons received tecovirimat, and no adverse reactions were reported. Continued studies on mpox transmission risks in populations less commonly affected during the outbreak, including cisgender women and pregnant persons, are important to assess and understand the impact of mpox on sexual, reproductive, and overall health.

BACKGROUND: In June 2019, the Bolivian Ministry of Health reported a cluster of cases of hemorrhagic fever that started in the municipality of Caranavi and expanded to La Paz. The cause of these cases was unknown. METHODS: We obtained samples for next-generation sequencing and virus isolation. Human and rodent specimens were tested by means of virus-specific real-time quantitative reverse-transcriptase-polymerase-chain-reaction assays, next-generation sequencing, and virus isolation. RESULTS: Nine cases of hemorrhagic fever were identified; four of the patients with this illness died. The etiologic agent was identified as Mammarenavirus Chapare mammarenavirus, or Chapare virus (CHAPV), which causes Chapare hemorrhagic fever (CHHF). Probable nosocomial transmission among health care workers was identified. Some patients with CHHF had neurologic manifestations, and those who survived had a prolonged recovery period. CHAPV RNA was detected in a variety of human body fluids (including blood; urine; nasopharyngeal, oropharyngeal, and bronchoalveolar-lavage fluid; conjunctiva; and semen) and in specimens obtained from captured small-eared pygmy rice rats (Oligoryzomys microtis). In survivors of CHHF, viral RNA was detected up to 170 days after symptom onset; CHAPV was isolated from a semen sample obtained 86 days after symptom onset. CONCLUSIONS: M. Chapare mammarenavirus was identified as the etiologic agent of CHHF. Both spillover from a zoonotic reservoir and possible person-to-person transmission were identified. This virus was detected in a rodent species, O. microtis. (Funded by the Bolivian Ministry of Health and others.).

BACKGROUND: Long-term persistence of Ebola virus (EBOV) in immunologically-privileged sites has been implicated in recent outbreaks of Ebola Virus Disease (EVD) in Guinea and the Democratic Republic of Congo. This study was designed to understand how the acute course of EVD, convalescence, and host immune and genetic factors may play a role in prolonged viral persistence in semen. METHODS: A cohort of 131 male EVD survivors in Liberia were enrolled in a case-case study. "Early clearers" were defined as those with two consecutive negative EBOV semen tests by real-time reverse transcriptase polymerase chain reaction (rRT-PCR) at least two weeks apart within 1 year after discharge from the Ebola Treatment Unit (ETU) or acute EVD. "Late clearers" had detectable EBOV RNA by rRT-PCR over one year following ETU discharge or acute EVD. Retrospective histories of their EVD clinical course were collected by questionnaire, followed by complete physical exams and blood work. RESULTS: Compared to early clearers, late clearers were older (median 42.5 years, p = 0.0001) and experienced fewer severe clinical symptoms (median 2, p = 0.006). Late clearers had more lens opacifications (OR 3.9, 95%CI 1.1-13.3, p = 0.03), after accounting for age, higher total serum IgG3 titers (p = 0.007) and increased expression of the HLA-C*03:04 allele (OR 0.14, 95% CI 0.02-0.70, p = 0.007). CONCLUSIONS: Older age, decreased illness severity, elevated total serum IgG3 and HLA-C*03:04 allele expression may be risk factors for the persistence of EBOV in the semen of EVD survivors. EBOV persistence in semen may also be associated with its persistence in other immunologically protected sites, such as the eye.

On December 19, 2019, the Food and Drug Administration (FDA) approved rVSVΔG-ZEBOV-GP Ebola vaccine (ERVEBO, Merck) for the prevention of Ebola virus disease (EVD) caused by infection with Ebola virus, species Zaire ebolavirus, in adults aged ≥18 years. In February 2020, the Advisory Committee on Immunization Practices (ACIP) recommended preexposure vaccination with ERVEBO for adults aged ≥18 years in the United States who are at highest risk for potential occupational exposure to Ebola virus because they are responding to an outbreak of EVD, work as health care personnel at federally designated Ebola treatment centers in the United States, or work as laboratorians or other staff members at biosafety level 4 facilities in the United States (1).

After a pilot study, we tested 443 cadavers using OraQuick Ebola rapid diagnostic tests during surveillance after the 10th Ebola outbreak in the Democratic Republic of the Congo. No false negative and 2% false-positive results were reported. Quickly returning results and engaging the community enabled timely public health actions.

OBJECTIVES: To describe the characteristics of cases of Ebola virus disease (EVD) nosocomial infections (NIs) in the Democratic Republic of the Congo, July 2018-May 2020, to inform future interventions. METHODS: We identified cases of NI during EVD outbreak response surveillance, and conducted a retrospective analysis of cases according to demographic characteristics and health facility (HF) type. RESULTS: Of 3481 cases of EVD, 579 (16.6%) were NIs, 332 of which occurred in women (57.3%). Patients and visitors accounted for 419 cases (72.4%), of which 79 (18.9%) were aged from 6 to ≤ 18 years and 108 (25.8%) were aged ≤ 5 years. Health workers (HWs) accounted for the remaining 160 (27.6%) NI cases. Case fatality rate (CFR) among HWs (66/160; 41.3%) was significantly lower than among patients and visitors (292/419; 69.7%) (p < 0.001). CFR was higher among those aged 6-18 years (54/79; 68.4%) and ≤ 5 years (89/108; 82.4%). Referral HFs (> 39 beds) had the highest prevalence of EVD NI (148/579; 25.6%). Among HFs with at least one case of NI, 50.0% (98/196) were privately owned. CONCLUSIONS: nurses and traditional healers should be targeted for IPC training, and supportive supervision provided to HFs to mitigate EVD transmission.

BACKGROUND: Tick-borne encephalitis (TBE) is an arboviral disease that is focally endemic in parts of Europe and Asia. TBE cases among US travellers are rare, with previous reports of only six cases among civilian travellers through 2009 and nine military-related cases through 2020. A TBE vaccine was licenced in the USA in August 2021. Understanding TBE epidemiology and risks among US travellers can help with the counselling of travellers going to TBE-endemic areas. METHODS: Diagnostic testing for TBE in the USA is typically performed at the Centers for Disease Control and Prevention (CDC) because no commercial testing is available. Diagnostic testing for TBE at CDC since 2010 was reviewed. For individuals with evidence of TBE virus infection, information was gathered on demographics, clinical presentations and risk factors for infection. RESULTS: From 2010-20, six patients with TBE were identified. Cases occurred among both paediatric and adult travellers and all were male. Patients were diagnosed with meningitis (n = 2) or encephalitis (n = 4); none died. Cases had travelled to various countries in Europe or Russia. Three cases reported visiting friends or relatives. Activities reported included hiking, camping, trail running, or working outdoors, and two cases had a recognized tick bite. CONCLUSIONS: TBE cases among US travellers are uncommon, with these six cases being the only known TBE cases among civilian travellers during this 11-year period. Nonetheless, given potential disease severity, pre-travel counselling for travellers to TBE-endemic areas should include information on measures to reduce the risk for TBE and other tick-borne diseases, including possible TBE vaccine use if a traveller's itinerary puts them at higher risk for infection. Clinicians should consider the diagnosis of TBE in a patient with a neurologic or febrile illness recently returned from a TBE-endemic country, particularly if a tick bite or possible tick exposure is reported.

OBJECTIVES: Hantavirus is endemic in the Four Corners region of Arizona, Colorado, New Mexico, and Utah, and hantavirus cardiopulmonary syndrome (HCPS) disproportionately affects the Navajo Nation. We describe the application of a rapid screening tool for identification of HCPS. METHODS: A rapid screening tool for HCPS was implemented at Tséhootsooí Medical Center (TMC) in collaboration with academic partners. RESULTS: Since its implementation in 2016, 20 TMC staff members have been trained to perform this test, and 189 screens for HCPS have been reported. Although hantavirus infection is rare even in high-risk areas, use of this tool resulted in the identification of 4 acute cases of hantavirus infection. CONCLUSIONS: The results demonstrate the successful implementation of a 5-point screening tool for hantavirus infection in an endemic setting by a laboratory in a small community hospital.

OBJECTIVES: Navajo Nation is disproportionately affected by hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease that can quickly progress to respiratory failure and cardiogenic shock. The initial signs and symptoms of HCPS are indistinguishable from coronavirus disease 2019 (COVID-19). However, this distinction is critical, as the disease course differs greatly, with most patients with COVID-19 experiencing mild to moderate illness. We set out to determine if the evaluation of peripheral blood smears for five hematopathologic criteria previously identified as hallmarks of hantavirus infection, or "the hantavirus 5-point screen," could distinguish between COVID-19 and HCPS. METHODS: The hantavirus 5-point screen was performed on peripheral blood smears from 139 patients positive for COVID-19 seeking treatment from Tséhootsooí Medical Center and two Emory University hospitals. RESULTS: Of these 139 individuals, 136 (98%) received a score of 3/5 or below, indicating low suspicion for HCPS. While thrombocytopenia, one of the key signs of HCPS, was seen in the patients with COVID-19, it was generally mild and remained stable on repeat specimens collected 12 to 24 hours later. CONCLUSIONS: Given these findings, the 5-point screen remains a useful rapid screening tool for potential HCPS cases and may be useful to distinguish early HCPS from COVID-19 in HCPS endemic regions.

During an Ebola virus disease (EVD) outbreak, calculating the exposure window of a confirmed case can assist field investigators in identifying the source of infection and establishing chains of transmission. However, field investigators often have difficulty calculating this window. We developed a bilingual (English/French), smartphone-based field application to assist field investigators in determining the exposure window of an EVD case. The calculator only requires the reported date of symptoms onset and the type of symptoms present at onset or the date of death. Prior to the release of this application, there was no similar electronic capability to enable consistent calculation of EVD exposure windows for field investigators. The Democratic Republic of the Congo Ministry of Health endorsed the application and incorporated it into trainings for field staff. Available for Apple and Android devices, the calculator continues to be downloaded even as the eastern DRC outbreak resolved. We rapidly developed and implemented a smartphone application to estimate the exposure window for EVD cases in an outbreak setting.

This report summarizes the recommendations of the Advisory Committee on Immunization Practices (ACIP) for use of the rVSVΔG-ZEBOV-GP Ebola vaccine (Ervebo) in the United States. The vaccine contains rice-derived recombinant human serum albumin and live attenuated recombinant vesicular stomatitis virus (VSV) in which the gene encoding the glycoprotein of VSV was replaced with the gene encoding the glycoprotein of Ebola virus species Zaire ebolavirus. Persons with a history of severe allergic reaction (e.g., anaphylaxis) to rice protein should not receive Ervebo. This is the first and only vaccine currently licensed by the Food and Drug Administration for the prevention of Ebola virus disease (EVD). These guidelines will be updated based on availability of new data or as new vaccines are licensed to protect against EVD.ACIP recommends preexposure vaccination with Ervebo for adults aged ≥18 years in the U.S. population who are at highest risk for potential occupational exposure to Ebola virus species Zaire ebolavirus because they are responding to an outbreak of EVD, work as health care personnel at federally designated Ebola treatment centers in the United States, or work as laboratorians or other staff at biosafety level 4 facilities in the United States. Recommendations for use of Ervebo in additional populations at risk for exposure and other settings will be considered and discussed by ACIP in the future.

INTRODUCTION: Ebola virus (EBOV), species Zaire ebolavirus, may persist in the semen of male survivors of Ebola Virus Disease (EVD). We conducted a study of male survivors of the 2014-2016 EVD outbreak in Liberia and evaluated their immune responses to EBOV. We report here findings from the serologic testing of blood for EBOV-specific antibodies, molecular testing for EBOV in blood and semen, and serologic testing of peripheral blood mononuclear cells (PBMCs) in a subset of study participants. METHODS: We tested for EBOV RNA in blood by qRT-PCR, and for anti-EBOV-specific IgM and IgG antibodies by enzyme-linked immunosorbent assay (ELISA) for 126 study participants. We performed peripheral blood mononuclear cell (PBMC) analysis on a subgroup of 26 IgG-negative participants. RESULTS: All 126 participants tested negative for EBOV RNA in blood by qRT-PCR. The blood of 26 participants tested negative for EBOV-specific IgG antibodies by ELISA. PBMCs were collected from 23/26 EBOV IgG-negative participants. Of these, 1/23 participants had PBMCs which produced anti-EBOV-specific IgG antibodies upon stimulation with EBOV-specific GP and NP antigens. DISCUSSION: The blood of EVD survivors, collected when they did not have symptoms meeting the case definition for acute or relapsed EVD, is unlikely to pose a risk for EBOV transmission. We identified one IgM/IgG negative participant who had PBMCs which produced anti-EBOV-specific antibodies upon stimulation. Immunogenicity following acute EBOV infection may exist along a spectrum and absence of antibody response should not be exclusionary in determining an individual's status as a survivor of EVD.

BACKGROUND: During 2017, a multi-state outbreak investigation occurred following the confirmation of Seoul virus (SEOV) infections in people and pet rats. A total of 147 humans and 897 rats were tested. METHODS: In addition to IgG and IgM serology and traditional RT-PCR, novel quantitative RT-PCR primers/probe were developed, and whole genome sequencing was performed. RESULTS: Seventeen people had SEOV IgM, indicating recent infection; seven reported symptoms and three were hospitalized. All patients recovered. Thirty-one facilities in 11 US states had SEOV infection, and among those with >/=10 rats tested, rat IgG prevalence ranged 2-70% and SEOV RT-PCR positivity ranged 0-70%. Human lab-confirmed cases were significantly associated with rat IgG positivity and RT-PCR positivity (p=0.03 and p=0.006, respectively). Genomic sequencing identified >99.5% homology between SEOV sequences in this outbreak, and these were >99% identical to SEOV associated with previous pet rat infections in England, the Netherlands, and France. Frequent trade of rats between home-based ratteries contributed to transmission of SEOV between facilities. CONCLUSIONS: Pet rat owners, breeders, and the healthcare and public health community should be aware and take steps to prevent SEOV transmission in pet rats and to humans. Biosecurity measures and diagnostic testing can prevent further infections.

Lassa virus is a rodentborne arenavirus responsible for human cases of Lassa fever, a viral hemorrhagic fever, in West Africa and in travelers arriving to non-Lassa-endemic countries from West Africa. We describe a retrospective review performed through literature search of clinical and epidemiologic characteristics of all imported Lassa fever cases worldwide during 1969-2016. Our findings demonstrate that approximately half of imported cases had distinctive clinical features (defined as fever and >1 of the following: pharyngitis, sore throat, tonsillitis, conjunctivitis, oropharyngeal ulcers, or proteinuria). Delays in clinical suspicion of this diagnosis were common. In addition, no secondary transmission of Lassa fever to contacts of patients with low-risk exposures occurred, and infection of high-risk contacts was rare. Future public health investigations of such cases should focus on timely recognition of distinctive clinical features, earlier treatment of patients, and targeted public health responses focused on high-risk contacts.

In January 2018, a woman admitted to a Delaware hospital tested positive for New World hantavirus immunoglobulin M (IgM) and immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA). Subsequent testing by CDC’s Viral Special Pathogens Branch detected New World hantavirus by nested reverse transcription–polymerase chain reaction (RT-PCR) and Andes virus by nucleic acid sequencing. This case represents the first confirmed importation of Andes virus infection into the United States; two imported cases have also been reported in Switzerland (1). Before her illness, the patient had traveled to the Andes region of Argentina and Chile from December 20, 2017, to January 3, 2018. She stayed in cabins and youth hostels in reportedly poor condition. No rodent exposures were reported. After returning to the United States on January 10, she developed fever, malaise, and myalgias on January 14. On January 17, while ill, she traveled on two commercial domestic flights. She was hospitalized during January 20–25 in Delaware and discharged to her home after clinical recovery.

In November 2017, CDC confirmed Sin Nombre virus (SNV) infection in a previously healthy man aged 47 years who was admitted to a hospital in Israel. The patient had traveled with his family on vacation to the southwestern United States (Arizona, Nevada, and Utah) during October 3–9, 2017. During this time, he and his family hiked and biked the southern rim of the Grand Canyon and Zion National Park and took a guided tour through Antelope Cave. On November 7, approximately 3 weeks after his return to Israel, he was hospitalized with fever, cough, and shortness of breath requiring bilevel positive airway pressure. A chest radiograph indicated diffuse reticulonodular infiltrates with consolidations at the right costophrenic angle and in the retrocardiac space. Based upon the patient’s travel history and clinical findings, hantavirus pulmonary syndrome was suspected. A blood specimen collected on November 9 tested positive for SNV using nested reverse transcription–polymerase chain reaction; he had an immunoglobulin M titer of ≥1:6,400 and an immunoglobulin G titer of ≥1:6,400. Hantavirus pulmonary syndrome has a mortality rate of approximately 36%.* The patient was treated with supportive care and discharged from the hospital on November 19. No illness was reported in any family member who traveled with him.

Human Ebola virus disease can be caused by four viruses: Sudan virus, Tai Forest virus, Bundibugyo virus, and Ebola virus (EBOV, species Zaire ebolavirus). The 2014 outbreak of EBOV in West Africa was the worst ever, with more than 28,000 cases and more than 11,000 deaths in Liberia, Guinea, Sierra Leone, Nigeria, and Mali. Investigational studies undertaken during the latter stages of the response, however, have led to progress in the development and use of biologic and chemical compounds to treat EBOV and Ebola virus disease (EVD). Recommendations to study vaccines and therapeutics and evaluate their benefit in the context of Ebola responses have been issued by a panel of the National Academies of Sciences, Engineering, and Medicine and by the World Health Organization (WHO) in the form of an EVD Blueprint.1,2

Background: In April 2014, a 46-year-old returning traveler from Liberia was transported by emergency medical services to a community hospital in Minnesota with fever and altered mental status. Twenty-four hours later, he developed gingival bleeding. Blood samples tested positive for Lassa fever RNA by reverse transcriptase polymerase chain reaction. Methods: Blood and urine samples were obtained from the patient and tested for evidence of Lassa fever virus infection. Hospital infection control personnel and health department personnel reviewed infection control practices with health care personnel. In addition to standard precautions, infection control measures were upgraded to include contact, droplet, and airborne precautions. State and federal public health officials conducted contract tracing activities among family contacts, health care personnel, and fellow airline travelers. Results: The patient was discharged from the hospital after 14 days. However, his recovery was complicated by the development of near complete bilateral sensorineural hearing loss. Lassa virus RNA continued to be detected in his urine for several weeks after hospital discharge. State and federal public health authorities identified and monitored individuals who had contact with the patient while he was ill. No secondary cases of Lassa fever were identified among 75 contacts. Conclusions: Given the nonspecific presentation of viral hemorrhagic fevers, isolation of ill travelers and consistent implementation of basic infection control measures are key to preventing secondary transmission. When consistently applied, these measures can prevent secondary transmission even if travel history information is not obtained, not immediately available, or the diagnosis of a viral hemorrhagic fever is delayed.

Ebola virus is known to persist in semen of male survivors of Ebola virus disease (EVD). However, maximum duration of, or risk factors for, virus persistence are unknown. We report an EVD survivor with preexisting HIV infection, whose semen was positive for Ebola virus RNA 565 days after recovery from EVD.

The largest Ebola virus disease epidemic in history, the 2014 west African outbreak, left more than 17 000 survivors. Previously, Ebola virus RNA has been detected in semen by RT-PCR up to 101 days and infectious particles via culture up to 82 days after illness onset.1 As such, all male survivors of Ebola virus disease were advised to abstain from sex or use condoms for 3 months after recovery. In May 2015, genomic and epidemiological data provided evidence of sexual transmission of Ebola virus from a Liberian man who had detectable virus RNA 199 days after illness onset.2 This led WHO to recommend semen testing for all male survivors or safe sex practices for at least 6 months after illness onset if semen testing is not available.3 More recently, ongoing semen testing programmes in west Africa and USA have detected virus RNA in semen up to 290 days after disease onset and up to 565 days after disease recovery.4, 5 | Like Ebola virus disease, Zika virus has been found to persist in semen—RT-PCR has identified presence of virus 93 days after symptom onset,5 as has virus isolation 24 days after.6 As with Ebola virus, reported sexual transmission of Zika virus has led to changes in recommendations for safe sex practices. Condom use is recommended for asymptomatic men for 8 weeks after return from an area with ongoing local Zika virus transmission, and for symptomatic men, use for 6 months after onset of symptoms is advised.7

According to World Health Organization (WHO) data, the Ebola virus disease (Ebola) outbreak that began in West Africa in 2014 has resulted in 28,603 cases and 11,301 deaths. In March 2015, epidemiologic investigation and genetic sequencing in Liberia implicated sexual transmission from a male Ebola survivor, with Ebola virus detected by reverse transcription-polymerase chain reaction (RT-PCR) 199 days after symptom onset, far exceeding the 101 days reported from an earlier Ebola outbreak. In response, WHO released interim guidelines recommending that all male survivors, in addition to receiving condoms and sexual risk reduction counseling at discharge from an Ebola treatment unit (ETU), be offered semen testing for Ebola virus RNA by RT-PCR 3 months after disease onset, and every month thereafter until two consecutive semen specimens collected at least 1 week apart test negative for Ebola virus RNA. Male Ebola survivors should also receive counseling to promote safe sexual practices until their semen twice tests negative. When these recommendations were released, testing of semen was not widely available in Liberia. Challenges in establishing and operating the first nationwide semen testing and counseling program for male Ebola survivors included securing sufficient resources for the program, managing a public health semen testing program in the context of ongoing research studies that were also collecting and screening semen, identification of adequate numbers of trained counselors and appropriate health communication messages for the program, overcoming Ebola survivor-associated stigma, identification and recruitment of male Ebola survivors, and operation of mobile teams.

BACKGROUND: Ebola virus has been detected in semen of Ebola virus disease survivors after recovery. Liberia's Men's Health Screening Program (MHSP) offers Ebola virus disease survivors semen testing for Ebola virus. We present preliminary results and behavioural outcomes from the first national semen testing programme for Ebola virus. METHODS: The MHSP operates out of three locations in Liberia: Redemption Hospital in Montserrado County, Phebe Hospital in Bong County, and Tellewoyan Hospital in Lofa County. Men aged 15 years and older who had an Ebola treatment unit discharge certificate are eligible for inclusion. Participants' semen samples were tested for Ebola virus RNA by real-time RT-PCR and participants received counselling on safe sexual practices. Participants graduated after receiving two consecutive negative semen tests. Counsellors collected information on sociodemographics and sexual behaviours using questionnaires administered at enrolment, follow up, and graduation visits. Because the programme is ongoing, data analysis was restricted to data obtained from July 7, 2015, to May 6, 2016. FINDINGS: As of May 6, 2016, 466 Ebola virus disease survivors had enrolled in the programme; real-time RT-PCR results were available from 429 participants. 38 participants (9%) produced at least one semen specimen that tested positive for Ebola virus RNA. Of these, 24 (63%) provided semen specimens that tested positive 12 months or longer after Ebola virus disease recovery. The longest interval between discharge from an Ebola treatment unit and collection of a positive semen sample was 565 days. Among participants who enrolled and provided specimens more than 90 days since their Ebola treatment unit discharge, men older than 40 years were more likely to have a semen sample test positive than were men aged 40 years or younger (p=0.0004). 84 (74%) of 113 participants who reported not using a condom at enrolment reported using condoms at their first follow-up visit (p<0.0001). 176 (46%) of 385 participants who reported being sexually active at enrolment reported abstinence at their follow-up visit (p<0.0001). INTERPRETATION: Duration of detection of Ebola virus RNA by real-time RT-PCR varies by individual and might be associated with age. By combining behavioural counselling and laboratory testing, the Men's Health Screening Program helps male Ebola virus disease survivors understand their individual risk and take appropriate measures to protect their sexual partners. FUNDING: World Health Organization and the US Centers for Disease Control and Prevention.

Health care personnel (HCP) caring for patients with Ebola virus disease (EVD) are at increased risk for infection with the virus. In 2014, a Texas hospital became the first U.S. community hospital to care for a patient with EVD; 2 nurses were infected while providing care. This article describes infection control measures developed to strengthen the hospital's capacity to safely diagnose and treat patients with EVD. After admission of the first patient with EVD, a multidisciplinary team from the Centers for Disease Control and Prevention (CDC) joined the hospital's infection preventionists to implement a system of occupational safety and health controls for direct patient care, handling of clinical specimens, and managing regulated medical waste. Existing engineering and administrative controls were strengthened. The personal protective equipment (PPE) ensemble was standardized, HCP were trained on donning and doffing PPE, and a system of trained observers supervising PPE donning and doffing was implemented. Caring for patients with EVD placed substantial demands on a community hospital. The experiences of the authors and others informed national policies for the care of patients with EVD and protection of HCP, including new guidance for PPE, a rapid system for deploying CDC staff to assist hospitals ("Ebola Response Team"), and a framework for a tiered approach to hospital preparedness. The designation of regional Ebola treatment centers and the establishment of the National Ebola Training and Education Center address the need for HCP to be prepared to safely care for patients with EVD and other high-consequence emerging infectious diseases.

BACKGROUND: Live animal markets have been implicated in transmission of influenza A viruses (IAVs) from animals to people. We sought to characterize IAVs at two live animal markets in Minnesota to assess potential routes of occupational exposure and risk for interspecies transmission. METHODS: We implemented surveillance for IAVs among employees, swine, and environment (air and surfaces) during a 12-week period (October 2012-January 2013) at two markets epidemiologically associated with persons with swine-origin IAV (variant) infections. Real-time reverse transcription polymerase chain reaction (rRT-PCR), viral culture, and whole genome sequencing were performed on respiratory and environmental specimens, and serology on sera from employees at beginning and end of surveillance. RESULTS: Nasal swabs from 11 (65%) of 17 employees tested positive for IAVs by rRT-PCR; seven employees tested positive on multiple occasions and one employee reported influenza-like illness. Eleven (73%) of 15 employees had baseline hemagglutination-inhibition antibody titers ≥40 to swine-origin IAVs, but only one demonstrated a 4-fold titer increase to both swine-origin, and pandemic A/Mexico/4108/2009 IAVs. IAVs were isolated from swine (72/84), air (30/45) and pen railings (5/21). Whole genome sequencing of 122 IAVs isolated from swine and environmental specimens revealed multiple strains and subtype codetections. Multiple gene segment exchanges among and within subtypes were observed, resulting in new genetic constellations and reassortant viruses. Genetic sequence similarities of 99%-100% among IAVs of one market customer and swine indicated interspecies transmission. CONCLUSIONS: At markets where swine and persons are in close contact, swine-origin IAVs are prevalent and potentially provide conditions for novel IAV emergence.