Enhancing Respiratory Disease Surveillance to Detect COVID-19 in Shelters for Displaced Persons, Thailand-Myanmar Border, 2020-2021

We developed surveillance guidance for COVID-19 in 9 temporary camps for displaced persons along the Thailand-Myanmar border. Arrangements were made for testing of persons presenting with acute respiratory infection, influenza-like illness, or who met the Thailand national COVID-19 Person Under Investigation case definition. In addition, testing was performed for persons who had traveled outside of the camps in outbreak-affected areas or who departed Thailand as resettling refugees. During the first 18 months of surveillance, May 2020-October 2021, a total of 6,190 specimens were tested, and 15 outbreaks (i.e., >1 confirmed COVID-19 cases) were detected in 7 camps. Of those, 5 outbreaks were limited to a single case. Outbreaks during the Delta variant surge were particularly challenging to control. Adapting and implementing COVID-19 surveillance measures in the camp setting were successful in detecting COVID-19 outbreaks and preventing widespread disease during the initial phase of the pandemic in Thailand.

Vaccine Preventable Zoonotic Diseases: Challenges and Opportunities for Public Health Progress

Zoonotic diseases represent a heavy global burden, causing important economic losses, impacting animal health and production, and costing millions of human lives. The vaccination of animals and humans to prevent inter-species zoonotic disease transmission is an important intervention. However, efforts to develop and implement vaccine interventions to reduce zoonotic disease impacts are often limited to the veterinary and agricultural sectors and do not reflect the shared burden of disease. Multisectoral collaboration, including co-development opportunities for human and animal vaccines, expanding vaccine use to include animal reservoirs such as wildlife, and strategically using vaccines to interrupt complex transmission cycles is needed. Addressing zoonoses requires a multi-faceted One Health approach, wherein vaccinating people and animals plays a critical role.

Risk factors for Ebola virus disease among household care providers, Sierra Leone, 2015

BACKGROUND

Household contacts who provide care to an Ebola virus disease (EVD) case have a 3-fold higher risk of EVD compared with contacts who do not provide care.

METHODS

We enrolled persons with confirmed EVD from December 2014 to April 2015 in Freetown, Sierra Leone, and their household contacts. Index cases and contacts were interviewed, and contacts were followed for 21 days to identify secondary cases. Epidemiological data were analysed to describe household care and to identify risk factors for developing EVD.

RESULTS

Of 838 contacts in 147 households, 156 (17%) self-reported providing care to the index case; 56 households had no care provider, 52 a single care provider and 39 multiple care providers. The median care provider age was 29 years, 68% were female and 32% were the index case's spouse. Care providers were more likely to report physical contact, contact with body fluids or sharing clothing, bed linens or utensils with an index case, compared with non-care providers (P <0.01). EVD risk among non-care providers was greater when the number of care providers in the household increased (odds ratio: 1.61; 95% confidence interval: 1.1, 2.4). In multivariable analysis, factors associated with care provider EVD risk included no piped water access and absence of index case fever, and protective factors included age <20 years and avoiding the index case.

CONCLUSIONS

Limiting the number of care providers in a household could reduce the risk of EVD transmission to both care providers and non-care providers. Strategies to protect care providers from EVD exposure are needed.

Prevalence of Crimean-Congo Hemorrhagic Fever Virus among Livestock and Ticks in Zhambyl Region, Kazakhstan, 2017

Crimean-Congo hemorrhagic fever (CCHF) is a highly fatal zoonotic disease endemic to Kazakhstan. Previous work estimated the seroprevalence of CCHF virus (CCHFV) among livestock owners in the Zhambyl region of southern Kazakhstan at 1.2%. To estimate CCHFV seroprevalence among cattle and sheep, we selected 15 villages with known history of CCHFV circulation (endemic) and 15 villages without known circulation (nonendemic) by cluster sampling with probability proportional to livestock population size. We collected whole blood samples from 521 sheep and 454 cattle from randomly selected households within each village and collected ticks found on the animals. We tested livestock blood for CCHFV-specific IgG antibodies by ELISA; ticks were screened for CCHFV RNA by real-time reverse transcription polymerase chain reaction and CCHFV antigen by antigen-capture ELISA. We administered questionnaires covering animal demographics and livestock herd characteristics to an adult in each selected household. Overall weighted seroprevalence was 5.7% (95% CI: 3.1, 10.3) among sheep and 22.5% (95% CI: 15.8, 31.2) among cattle. CCHFV-positive tick pools were found on two sheep (2.4%, 95% CI: 0.6, 9.5) and three cattle (3.8%, 95% CI: 1.2, 11.5); three CCHFV-positive tick pools were found in nonendemic villages. Endemic villages reported higher seroprevalence among sheep (15.5% versus 2.8%, P < 0.001) but not cattle (25.9% versus 20.1%, P = 0.42). Findings suggest that the current village classification scheme may not reflect the geographic distribution of CCHFV in Zhambyl and underscore that public health measures must address the risk of CCHF even in areas without a known history of circulation.

Coronavirus Disease 2019 (COVID-19) in Americans Aboard the Diamond Princess Cruise Ship

Background

The Diamond Princess cruise ship was the site of a large outbreak of coronavirus disease 2019 (COVID-19). Of 437 Americans and their travel companions on the ship, 114 (26%) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

We interviewed 229 American passengers and crew after disembarkation following a ship-based quarantine to identify risk factors for infection and characterize transmission onboard the ship.

Results

The attack rate for passengers in single-person cabins or without infected cabinmates was 18% (58/329), compared with 63% (27/43) for those sharing a cabin with an asymptomatic infected cabinmate, and 81% (25/31) for those with a symptomatic infected cabinmate. Whole genome sequences from specimens from passengers who shared cabins clustered together. Of 66 SARS-CoV-2-positive American travelers with complete symptom information, 14 (21%) were asymptomatic while on the ship. Among SARS-CoV-2-positive Americans, 10 (9%) required intensive care, of whom 7 were ≥70 years.

Conclusion

Our findings highlight the high risk of SARS-CoV-2 transmission on cruise ships. High rates of SARS-CoV-2 positivity in cabinmates of individuals with asymptomatic infections suggest that triage by symptom status in shared quarters is insufficient to halt transmission. A high rate of intensive care unit admission among older individuals complicates the prospect of future cruise travel during the pandemic, given typical cruise passenger demographics. The magnitude and severe outcomes of this outbreak were major factors contributing to the Centers for Disease Control and Prevention’s decision to halt cruise ship travel in U.S. waters in March 2020.

Risk Factors for and Seroprevalence of Tickborne Zoonotic Diseases among Livestock Owners, Kazakhstan

Crimean-Congo hemorrhagic fever (CCHF), Q fever, and Lyme disease are endemic to southern Kazakhstan, but population-based serosurveys are lacking. We assessed risk factors and seroprevalence of these zoonoses and conducted surveys for CCHF-related knowledge, attitudes, and practices in the Zhambyl region of Kazakhstan. Weighted seroprevalence for CCHF among all participants was 1.2%, increasing to 3.4% in villages with a known history of CCHF circulation. Weighted seroprevalence was 2.4% for Lyme disease and 1.3% for Q fever. We found evidence of CCHF virus circulation in areas not known to harbor the virus. We noted that activities that put persons at high risk for zoonotic or tickborne disease also were risk factors for seropositivity. However, recognition of the role of livestock in disease transmission and use of personal protective equipment when performing high-risk activities were low among participants.

Seoul Virus Infection and Spread in United States Home-Based Ratteries: Rat and Human Testing Results From a Multistate Outbreak Investigation

BACKGROUND

During 2017, a multistate outbreak investigation occurred after 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 immunoglobulin (Ig)G and IgM serology and traditional reverse-transcription polymerase chain reaction (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; 7 reported symptoms and 3 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 laboratory-confirmed cases were significantly associated with rat IgG positivity and RT-PCR positivity (P = .03 and P = .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.

A Framework to Monitor Changes in Transmission and Epidemiology of Emerging Pathogens: Lessons From Nipah Virus

It is of uttermost importance that the global health community develops the surveillance capability to effectively monitor emerging zoonotic pathogens that constitute a major and evolving threat for human health. In this study, we propose a comprehensive framework to measure changes in (1) spillover risk, (2) interhuman transmission, and (3) morbidity/mortality associated with infections based on 6 epidemiological key indicators derived from routine surveillance. We demonstrate the indicators' value for the retrospective or real-time assessment of changes in transmission and epidemiological characteristics using data collected through a long-standing, systematic, hospital-based surveillance system for Nipah virus in Bangladesh. We show that although interhuman transmission and morbidity/mortality indicators were stable, the number and geographic extent of spillovers varied significantly over time. This combination of systematic surveillance and active tracking of transmission and epidemiological indicators should be applied to other high-risk emerging pathogens to prevent public health emergencies.

Use of US Public Health Travel Restrictions during COVID-19 Outbreak on Diamond Princess Ship, Japan, February-April 2020

Public health travel restrictions (PHTR) are crucial measures during communicable disease outbreaks to prevent transmission during commercial airline travel and mitigate cross-border importation and spread. We evaluated PHTR implementation for US citizens on the Diamond Princess during its coronavirus disease (COVID-19) outbreak in Japan in February 2020 to explore how PHTR reduced importation of COVID-19 to the United States during the early phase of disease containment. Using PHTR required substantial collaboration among the US Centers for Disease Control and Prevention, other US government agencies, the cruise line, and public health authorities in Japan. Original US PHTR removal criteria were modified to reflect international testing protocols and enable removal of PHTR for persons who recovered from illness. The impact of PHTR on epidemic trajectory depends on the risk for transmission during travel and geographic spread of disease. Lessons learned from the Diamond Princess outbreak provide critical information for future PHTR use.

Ebola Patient Virus Cycle Threshold and Risk of Household Transmission of Ebola Virus

BACKGROUND

Identifying risk factors for household transmission of Ebola virus (EBOV) is important to guide preventive measures during Ebola outbreaks.

METHODS

We enrolled all confirmed persons with EBOV disease who were the first case patient in a household from December 2014 to April 2015 in Freetown, Sierra Leone, and their household contacts. Index patients and contacts were interviewed, and contacts were followed up for 21 days to identify secondary cases. Epidemiologic data were linked to EBOV real-time reverse-transcription polymerase chain reaction cycle threshold (Ct) data from initial diagnostic specimens obtained from enrolled index case patients.

RESULTS

Ct data were available for 106 (71%) of 150 enrolled index patients. Of the Ct results, 85 (80%) were from blood specimens from live patients and 21 (20%) from oral swab specimens from deceased patients. The median Ct values for blood and swab specimens were 21.0 and 24.0, respectively (P = .007). In multivariable analysis, a Ct value from blood specimens in the lowest quintile was an independent predictor of both increased risk of household transmission (P = .009) and higher secondary attack rate among household contacts (P = .03), after adjustment for epidemiologic factors.

CONCLUSIONS

Our findings suggest the potential to use Ct values from acute EBOV diagnostic specimens for index patients as an early predictor of high-risk households and high-risk groups of contacts to help prioritize EBOV disease investigation and control efforts.

A retrospective cohort investigation of seroprevalence of Marburg virus and ebolaviruses in two different ecological zones in Uganda

BACKGROUND

Uganda has experienced seven Ebola Virus Disease (EVD) outbreaks and four Marburg Virus Disease (MVD) outbreaks between 2000 and 2019. We investigated the seroprevalence and risk factors for Marburg virus and ebolaviruses in gold mining communities around Kitaka gold mine in Western Uganda and compared them to non-mining communities in Central Uganda.

METHODS

A questionnaire was administered and human blood samples were collected from three exposure groups in Western Uganda (gold miners, household members of miners, non-miners living within 50 km of Kitaka mine). The unexposed controls group sampled was community members in Central Uganda far away from any gold mining activity which we considered as low-risk for filovirus infection. ELISA serology was used to analyse samples, detecting IgG antibodies against Marburg virus and ebolaviruses (filoviruses). Data were analysed in STATA software using risk ratios and odds ratios.

RESULTS

Miners in western Uganda were 5.4 times more likely to be filovirus seropositive compared to the control group in central Uganda (RR = 5.4; 95% CI 1.5-19.7) whereas people living in high-risk areas in Ibanda and Kamwenge districts were 3.6 more likely to be seropositive compared to control group in Luweeero district (RR = 3.6; 95% CI 1.1-12.2). Among all participants, filovirus seropositivity was 2.6% (19/724) of which 2.3% (17/724) were reactive to Sudan virus only and 0.1% (1/724) to Marburg virus. One individual seropositive for Sudan virus also had IgG antibodies reactive to Bundibugyo virus. The risk factors for filovirus seropositivity identified included mining (AOR = 3.4; 95% CI 1.3-8.5), male sex (AOR = 3.1; 95% CI 1.01-9.5), going inside mines (AOR = 3.1; 95% CI 1.2-8.2), cleaning corpses (AOR = 3.1; 95% CI 1.04-9.1) and contact with suspect filovirus cases (AOR = 3.9, 95% CI 1.04-14.5).

CONCLUSIONS

These findings indicate that filovirus outbreaks may go undetected in Uganda and people involved in artisan gold mining are more likely to be exposed to infection with either Marburg virus or ebolaviruses, likely due to increased risk of exposure to bats. This calls for active surveillance in known high-risk areas for early detection and response to prevent filovirus epidemics.

Household Transmission of Ebola Virus: Risks and Preventive Factors, Freetown, Sierra Leone, 2015

Background

Knowing risk factors for household transmission of Ebola virus is important to guide preventive measures during Ebola outbreaks.

Methods

We enrolled all confirmed persons with Ebola who were the first case in a household, December 2014-April 2015, in Freetown, Sierra Leone, and their household contacts. Cases and contacts were interviewed, contacts followed prospectively through the 21-day incubation period, and secondary cases confirmed by laboratory testing.

Results

We enrolled 150 index Ebola cases and 838 contacts; 83 (9.9%) contacts developed Ebola during 21-day follow-up. In multivariable analysis, risk factors for transmission included index case death in the household, Ebola symptoms but no reported fever, age <20 years, more days with wet symptoms; and providing care to the index case (P < .01 for each). Protective factors included avoiding the index case after illness onset and a piped household drinking water source (P < .01 for each).

Conclusions

To reduce Ebola transmission, communities should rapidly identify and follow-up all household contacts; isolate those with Ebola symptoms, including those without reported fever; and consider closer monitoring of contacts who provided care to cases. Households could consider efforts to minimize risk by designating one care provider for ill persons with all others avoiding the suspected case.

Active Ebola Virus Replication and Heterogeneous Evolutionary Rates in EVD Survivors

Following cessation of continuous Ebola virus (EBOV) transmission within Western Africa, sporadic EBOV disease (EVD) cases continued to re-emerge beyond the viral incubation period. Epidemiological and genomic evidence strongly suggests that this represented transmission from EVD survivors. To investigate whether persistent infections are characterized by ongoing viral replication, we sequenced EBOV from the semen of nine EVD survivors and a subset of corresponding acute specimens. EBOV evolutionary rates during persistence were either similar to or reduced relative to acute infection rates. Active EBOV replication/transcription continued during convalescence, but decreased over time, consistent with viral persistence rather than viral latency. Patterns of genetic divergence suggest a moderate relaxation of selective constraints within the sGP carboxy-terminal tail during persistent infections, but do not support widespread diversifying selection. Altogether, our data illustrate that EBOV persistence in semen, urine, and aqueous humor is not a quiescent or latent infection.

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During persistence, EBOV exhibits heterogeneous evolutionary rates

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Active EBOV transcription and replication occurs during persistence

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RNA hyper-editing observed during viral persistence

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No evidence for significant selective pressure during persistence

Comprehensive Clinical and Laboratory Follow-up of a Female Patient With Ebola Virus Disease: Sierra Leone Ebola Virus Persistence Study

The clinical, virologic, and immunologic findings in a female Ebola virus disease patient are described. During the long-term follow-up, Ebola virus RNA was detectable in vaginal fluid before 36 days after symptom onset, with nearly an identical genome sequence as in acute phase blood. Ebola-specific T cells retained activation at 56 days after disease onset.

LB7. Contract Tracing Investigation Following First Case of Andes Virus in the United States

Background

In January 2018, a patient admitted to a Delaware hospital tested positive for New World hantavirus by IgM and IgG ELISA. Subsequent testing by CDC’s Viral Special Pathogens Branch (VSPB) confirmed Andes virus (ANDV) by reverse transcription polymerase chain reaction (RT-PCR) and sequencing. ANDV is transmitted to humans through contact with long-tailed rice rats endemic to Argentina and Chile. Unlike other hantavirus species, ANDV can be transmitted person to person, but transmission is typically limited to close contacts of ill persons. Because of this risk, a contact tracing investigation was initiated by CDC, state and county health departments.

Method

A suspect case was defined as a person with close contact with the traveler who became ill within the maximum incubation period (42 days) following last contact. A high-risk contact was defined as a person with exposure to the traveler’s body fluids. A low-risk contact was defined as a person who had provided care or in-flight service to, or was seated near the traveler for at least 1 hour, in the absence of exposure to body fluids. All contacts were advised to self-monitor their temperature daily for 42 days from last contact, and to seek medical care for any of the specified symptoms. Contacts that developed symptoms were tested for ANDV by RT-PCR and serology by VSPB.

Result

Fifty-three contacts were identified in six states; 51 were successfully reached. Of these, 28 were healthcare workers, 15 were airline contacts, seven were acquaintances of the traveler, and one was a hospital roommate. Two high-risk contacts were identified, both of whom remained asymptomatic. Six low-risk contacts reported influenza-like illness, diarrhea, or mild rhinitis during the incubation period. All six symptomatic low-risk contacts tested negative for ANDV by PCR, IgM, and IgG. The remaining low-risk contacts remained asymptomatic.

Conclusion

Hospitalized patients with ANDV should be managed with standard, contact, and droplet precautions. While the risk of human-to-human transmission is low, contact tracing should be considered to identify potential cases and limit additional exposures. Health providers should consider ANDV in returning travelers with a nonspecific febrile or acute respiratory illness who have traveled to the Andes region of Argentina or Chile in the preceding 6 weeks.

Disclosures

All authors: No reported disclosures.

Care of Ebola Survivors and Factors Associated With Clinical Sequelae-Monrovia, Liberia

Background

The Eternal Love Winning Africa (ELWA) Clinic was the first clinic to provide free, comprehensive care to Ebola virus disease (EVD) survivors in Liberia. The objectives of this analysis were to describe the demographics and symptoms of EVD survivors at ELWA from January 2015 through March 2017 and to identify risk factors for development of sequelae.

Methods

Patients' demographic and clinical information was collected by chart review in June 2016 and March 2017. Associations with clinical sequelae were analyzed using the chi-square test, t test, and multivariate logistic regression.

Results

From January 2015 to March 2017, 329 EVD survivors were evaluated at ELWA. Most survivors experienced myalgia/arthralgia (73%; n = 239) and headache (53%; n = 173). The length of time from Ebola Treatment Unit (ETU) discharge to first clinic visit ranged from 0 to 30 months. Many visits (30%) occurred 24 or more months after ETU discharge. The proportion of visits for headache, weight loss, joint pain, visual problems, insomnia, fatigue, memory loss, decreased libido, depression, and uveitis decreased over time. More men than women had visits for depression; however, these differences were not significant. Symptom prevalence differed in adults and children; significantly more adults experienced myalgia/arthralgia (77% vs 44%), visual problems (41% vs 12%), post-EVD-related musculoskeletal pain (42% vs 15%), and insomnia (17% vs 2%).

Conclusions

EVD survivors frequented ELWA for EVD-related symptoms many months after ETU discharge, indicating a long-term need for care. Reported symptoms changed over time, which may reflect eventual resolution of some sequelae.

Sensitivity and Specificity of Suspected Case Definition Used during West Africa Ebola Epidemic

Rapid early detection and control of Ebola virus disease (EVD) is contingent on accurate case definitions. Using an epidemic surveillance dataset from Guinea, we analyzed an EVD case definition developed by the World Health Organization (WHO) and used in Guinea. We used the surveillance dataset (March-October 2014; n = 2,847 persons) to identify patients who satisfied or did not satisfy case definition criteria. Laboratory confirmation determined cases from noncases, and we calculated sensitivity, specificity and predictive values. The sensitivity of the defintion was 68.9%, and the specificity of the definition was 49.6%. The presence of epidemiologic risk factors (i.e., recent contact with a known or suspected EVD case-patient) had the highest sensitivity (74.7%), and unexplained deaths had the highest specificity (92.8%). Results for case definition analyses were statistically significant (p<0.05 by χ² test). Multiple components of the EVD case definition used in Guinea contributed to improved overall sensitivity and specificity.

A Case of Lassa Fever Diagnosed at a Community Hospital-Minnesota 2014

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.

Rift valley fever viral load correlates with the human inflammatory response and coagulation pathway abnormalities in humans with hemorrhagic manifestations

Rift Valley fever virus is an arbovirus that affects both livestock and humans throughout Africa and in the Middle East. Despite its endemicity throughout Africa, it is a rare event to identify an infected individual during the acute phase of the disease and an even rarer event to collect serial blood samples from the affected patient. Severely affected patients can present with hemorrhagic manifestations of disease. In this study we identified three Ugandan men with RVFV disease that was accompanied by hemorrhagic manifestations. Serial blood samples from these men were analyzed for a series of biomarkers specific for various aspects of human pathophysiology including inflammation, endothelial function and coagulopathy. There were significant differences between biomarker levels in controls and cases both early during the illness and after clearance of viremia. Positive correlation of viral load with markers of inflammation (IP-10, CRP, Eotaxin, MCP-2 and Granzyme B), markers of fibrinolysis (tPA and D-dimer), and markers of endothelial function (sICAM-1) were all noted. However, and perhaps most interesting given the fact that these individuals exhibited hemorrhagic manifestations of disease, was the finding of a negative correlation between viral load and P-selectin, ADAMTS13, and fibrinogen all of which are associated with coagulation pathways occurring on the endothelial surface.

Prevalence and risk factors of Rift Valley fever in humans and animals from Kabale district in Southwestern Uganda, 2016

Background

Rift Valley fever (RVF) is a zoonotic disease caused by Rift Valley fever virus (RVFV) found in Africa and the Middle East. Outbreaks can cause extensive morbidity and mortality in humans and livestock. Following the diagnosis of two acute human RVF cases in Kabale district, Uganda, we conducted a serosurvey to estimate RVFV seroprevalence in humans and livestock and to identify associated risk factors.

Methods

Humans and animals at abattoirs and villages in Kabale district were sampled. Persons were interviewed about RVFV exposure risk factors. Human blood was tested for anti-RVFV IgM and IgG, and animal blood for anti-RVFV IgG.

Principal findings

655 human and 1051 animal blood samples were collected. Anti-RVFV IgG was detected in 78 (12%) human samples; 3 human samples (0.5%) had detectable IgM only, and 7 (1%) had both IgM and IgG. Of the 10 IgM-positive persons, 2 samples were positive for RVFV by PCR, confirming recent infection. Odds of RVFV seropositivity were greater in participants who were butchers (odds ratio [OR] 5.1; 95% confidence interval [95% CI]: 1.7–15.1) and those who reported handling raw meat (OR 3.4; 95% CI 1.2–9.8). No persons under age 20 were RVFV seropositive. The overall animal seropositivity was 13%, with 27% of cattle, 7% of goats, and 4% of sheep seropositive.

In a multivariate logistic regression, cattle species (OR 9.1; 95% CI 4.1–20.5), adult age (OR 3.0; 95% CI 1.6–5.6), and female sex (OR 2.1; 95%CI 1.0–4.3) were significantly associated with animal seropositivity. Individual human seropositivity was significantly associated with animal seropositivity by subcounty after adjusting for sex, age, and occupation (p < 0.05).

Conclusions

Although no RVF cases had been detected in Uganda from 1968 to March 2016, our study suggests that RVFV has been circulating undetected in both humans and animals living in and around Kabale district. RVFV seropositivity in humans was associated with occupation, suggesting that the primary mode of RVFV transmission to humans in Kabale district could be through contact with animal blood or body fluids.

Viral hemorrhagic fevers are known to cause high morbidity and mortality and pose a serious threat to human and animal populations in endemic countries. An outbreak of Rift Valley fever was detected in Kabale district in March, 2016 and identified the first human cases in Uganda since 1968. There was a need to perform a rapid assessment of the burden of Rift valley fever in Kabale district, identify undetected acute cases, identify risk factors associated with human disease, identify areas at high-risk or future infections, and to determine if this was a newly emerging infection or an endemic disease. Our study found the seroprevalence to be as high as 28% in humans and 36% in animals within some subcounties of Kabale district. Human seropositivity correlated with animal seropositivity, suggesting that animal to human transmission may be the predominant mode of virus spread. Our findings also suggest that this virus may have been endemic for many years prior to these human cases being identified.

Rift Valley Fever: A survey of knowledge, attitudes, and practice of slaughterhouse workers and community members in Kabale District, Uganda

Background

Rift Valley Fever virus (RVF) is a zoonotic virus in the Phenuiviridae family. RVF outbreaks can cause significant morbidity and mortality in humans and animals. Following the diagnosis of two RVF cases in March 2016 in southern Kabale district, Uganda, we conducted a knowledge, attitudes and practice (KAP) survey to identify knowledge gaps and at-risk behaviors related to RVF.

Methodology/Principal findings

A multidisciplinary team interviewed 657 community members, including abattoir workers, in and around Kabale District, Uganda. Most participants (90%) had knowledge of RVF and most (77%) cited radio as their primary information source. Greater proportions of farmers (68%), herdsmen (79%) and butchers (88%) thought they were at risk of contracting RVF compared to persons in other occupations (60%, p<0.01). Participants most frequently identified bleeding as a symptom of RVF. Less than half of all participants reported fever, vomiting, and diarrhea as common RVF symptoms in either humans or animals. The level of knowledge about human RVF symptoms did not vary by occupation; however more farmers and butchers (36% and 51%, respectively) had knowledge of RVF symptoms in animals compared to those in other occupations (30%, p<0.01). The use of personal protective equipment (PPE) when handling animals varied by occupation, with 77% of butchers using some PPE and 12% of farmers using PPE. Although most butchers said that they used PPE, most used gumboots (73%) and aprons (60%) and less than 20% of butchers used gloves or eye protection when slaughtering.

Conclusions

Overall, knowledge, attitudes and practice regarding RVF in Kabale District Uganda could be improved through educational efforts targeting specific populations.

Rift Valley Fever (RVF) virus is transmitted to humans from contact with infected livestock and through mosquito bites. Several human cases of RVF were diagnosed in Kabale District, Uganda in March 2016, over 40 years after the last RVF case was identified in Uganda. We administered a knowledge, attitudes, and practice survey to people living in Kabale District, near where the cases occurred. Survey results demonstrated that knowledge, attitudes and practice surrounding RVF could be improved within the community.

Ebola RNA Persistence in Semen of Ebola Virus Disease Survivors - Final Report

BACKGROUND

Ebola virus has been detected in the semen of men after their recovery from Ebola virus disease (EVD). We report the presence of Ebola virus RNA in semen in a cohort of survivors of EVD in Sierra Leone.

METHODS

We enrolled a convenience sample of 220 adult male survivors of EVD in Sierra Leone, at various times after discharge from an Ebola treatment unit (ETU), in two phases (100 participants were in phase 1, and 120 in phase 2). Semen specimens obtained at baseline were tested by means of a quantitative reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay with the use of the target sequences of NP and VP40 (in phase 1) or NP and GP (in phase 2). This study did not evaluate directly the risk of sexual transmission of EVD.

RESULTS

Of 210 participants who provided an initial semen specimen for analysis, 57 (27%) had positive results on quantitative RT-PCR. Ebola virus RNA was detected in the semen of all 7 men with a specimen obtained within 3 months after ETU discharge, in 26 of 42 (62%) with a specimen obtained at 4 to 6 months, in 15 of 60 (25%) with a specimen obtained at 7 to 9 months, in 4 of 26 (15%) with a specimen obtained at 10 to 12 months, in 4 of 38 (11%) with a specimen obtained at 13 to 15 months, in 1 of 25 (4%) with a specimen obtained at 16 to 18 months, and in no men with a specimen obtained at 19 months or later. Among the 46 participants with a positive result in phase 1, the median baseline cycle-threshold values (higher values indicate lower RNA values) for the NP and VP40 targets were lower within 3 months after ETU discharge (32.4 and 31.3, respectively; in 7 men) than at 4 to 6 months (34.3 and 33.1; in 25), at 7 to 9 months (37.4 and 36.6; in 13), and at 10 to 12 months (37.7 and 36.9; in 1). In phase 2, a total of 11 participants had positive results for NP and GP targets (samples obtained at 4.1 to 15.7 months after ETU discharge); cycle-threshold values ranged from 32.7 to 38.0 for NP and from 31.1 to 37.7 for GP.

CONCLUSIONS

These data showed the long-term presence of Ebola virus RNA in semen and declining persistence with increasing time after ETU discharge. (Funded by the World Health Organization and others.).

Development of risk reduction behavioral counseling for Ebola virus disease survivors enrolled in the Sierra Leone Ebola Virus Persistence Study, 2015-2016

Background

During the 2014–2016 West Africa Ebola Virus Disease (EVD) epidemic, the public health community had concerns that sexual transmission of the Ebola virus (EBOV) from EVD survivors was a risk, due to EBOV persistence in body fluids of EVD survivors, particularly semen. The Sierra Leone Ebola Virus Persistence Study was initiated to investigate this risk by assessing EBOV persistence in numerous body fluids of EVD survivors and providing risk reduction counseling based on test results for semen, vaginal fluid, menstrual blood, urine, rectal fluid, sweat, tears, saliva, and breast milk. This publication describes implementation of the counseling protocol and the key lessons learned.

Methodology/Principal findings

The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol was developed from a framework used to prevent transmission of HIV and other sexually transmitted infections. The framework helped to identify barriers to risk reduction and facilitated the development of a personalized risk-reduction plan, particularly around condom use and abstinence. Pre-test and post-test counseling sessions included risk reduction guidance, and post-test counseling was based on the participants’ individual test results. The behavioral counseling protocol enabled study staff to translate the study’s body fluid test results into individualized information for study participants.

Conclusions/Significance

The Ebola Virus Persistence Risk Reduction Behavioral Counseling Protocol provided guidance to mitigate the risk of EBOV transmission from EVD survivors. It has since been shared with and adapted by other EVD survivor body fluid testing programs and studies in Ebola-affected countries.

The 2014–2016 West Africa Ebola Virus Disease (EVD) epidemic was large and widespread, affecting thousands of people across Guinea, Liberia, and Sierra Leone. Prior to this epidemic, there were limited data on persistence of Ebola virus in body fluids of EVD survivors and the potential risk that viral persistence may pose for Ebola virus transmission, including possible sexual transmission. This paper documents the development and implementation of a behavioral counseling protocol to facilitate adoption of risk reduction behaviors among male and female EVD survivors enrolled in the Sierra Leone Ebola Virus Persistence Study. This behavioral counseling protocol, composed of pre-test, delivery of results, and post-test counseling, enabled study staff to translate the study’s body fluid test results into individualized information and preventive action for study participants. Risk reduction behavioral counseling became an important EVD epidemic control measure.

Exposure Characteristics of Hantavirus Pulmonary Syndrome Patients, United States, 1993-2015

Those at highest risk are persons in occupations with potential for rodent exposure and American Indian women 40­–64 years of age.

High clinical suspicion of donor-derived disease leads to timely recognition and early intervention to treat solid organ transplant-transmitted lymphocytic choriomeningitis virus

Despite careful donor screening, unexpected donor-derived infections continue to occur in organ transplant recipients (OTRs). Lymphocytic choriomeningitis virus (LCMV) is one such transplant-transmitted infection that in previous reports has resulted in a high mortality among the affected OTRs. We report a LCMV case cluster that occurred 3 weeks post-transplant in three OTRs who received allografts from a common organ donor in March 2013. Following confirmation of LCMV infection at Centers for Disease Control and Prevention, immunosuppression was promptly reduced and ribavirin and/or intravenous immunoglobulin therapy were initiated in OTRs. The liver recipient died, but right kidney recipients survived without significant sequelae and left kidney recipient survived acute LCMV infection with residual mental status deficit. Our series highlights how early recognition led to prompt therapeutic intervention, which may have contributed to more favorable outcome in the kidney transplant recipients.

Ebola Virus RNA in Semen from an HIV-Positive Survivor of Ebola

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.

Notes from the Field: Rift Valley Fever Response - Kabale District, Uganda, March 2016

On March 9, 2016, a male butcher from Kabale District, Uganda, aged 45 years, reported to the Kabale Regional Referral Hospital with fever, fatigue, and headache associated with black tarry stools and bleeding from the nose. One day later, a student aged 16 years from a different sub-county in Kabale District developed similar symptoms and was admitted to the same hospital. The student also had a history of contact with livestock. Blood specimens collected from both patients were sent for testing for Marburg virus disease, Ebola virus disease, Rift Valley fever (RVF), and Crimean Congo Hemorrhagic fever at the Uganda Virus Research Institute, as part of the viral hemorrhagic fevers surveillance program. The Uganda Virus Research Institute serves as the national viral hemorrhagic fever reference laboratory and hosts the national surveillance program for viral hemorrhagic fevers, in collaboration with the CDC Viral Special Pathogens Branch and the Uganda Ministry of Health.

Prevention of sexual transmission of Ebola in Liberia through a national semen testing and counselling programme for survivors: an analysis of Ebola virus RNA results and behavioural data

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.

Ebola Surveillance - Guinea, Liberia, and Sierra Leone

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

Prognostic Indicators for Ebola Patient Survival

To determine whether 2 readily available indicators predicted survival among patients with Ebola virus disease in Sierra Leone, we evaluated information for 216 of the 227 patients in Bo District during a 4-month period. The indicators were time from symptom onset to healthcare facility admission and quantitative real-time reverse transcription PCR cycle threshold (Ct), a surrogate for viral load, in first Ebola virus-positive blood sample tested. Of these patients, 151 were alive when detected and had reported healthcare facility admission dates and Ct values available. Time from symptom onset to healthcare facility admission was not associated with survival, but viral load in the first Ebola virus-positive blood sample was inversely associated with survival: 52 (87%) of 60 patients with a Ct of >24 survived and 20 (22%) of 91 with a Ct of <24 survived. Ct values may be useful for clinicians making treatment decisions or managing patient or family expectations.

Management of a pet dog after exposure to a human patient with Ebola virus disease

In October 2014, a health-care worker who had been part of the treatment team for the first laboratory-confirmed case of Ebola virus disease imported to the United States developed symptoms of Ebola virus disease. A presumptive positive reverse transcription PCR assay result for Ebola virus RNA in a blood sample from the worker was confirmed by the CDC, making this the first documented occurrence of domestic transmission of Ebola virus in the United States. The Texas Department of State Health Services commissioner issued a control order requiring disinfection and decontamination of the health-care worker's residence. This process was delayed until the patient's pet dog (which, having been exposed to a human with Ebola virus disease, potentially posed a public health risk) was removed from the residence. This report describes the movement, quarantine, care, testing, and release of the pet dog, highlighting the interdisciplinary, one-health approach and extensive collaboration and communication across local, county, state, and federal agencies involved in the response.

Multidistrict Outbreak of Marburg Virus Disease-Uganda, 2012

In October 2012, a cluster of illnesses and deaths was reported in Uganda and was confirmed to be an outbreak of Marburg virus disease (MVD). Patients meeting the case criteria were interviewed using a standard investigation form, and blood specimens were tested for evidence of acute or recent Marburg virus infection by reverse transcription-polymerase chain reaction (RT-PCR) and antibody enzyme-linked immunosorbent assay. The total count of confirmed and probable MVD cases was 26, of which 15 (58%) were fatal. Four of 15 laboratory-confirmed cases (27%) were fatal. Case patients were located in 4 different districts in Uganda, although all chains of transmission originated in Ibanda District, and the earliest case detected had an onset in July 2012. No zoonotic exposures were identified. Symptoms significantly associated with being a MVD case included hiccups, anorexia, fatigue, vomiting, sore throat, and difficulty swallowing. Contact with a case patient and attending a funeral were also significantly associated with being a case. Average RT-PCR cycle threshold values for fatal cases during the acute phase of illness were significantly lower than those for nonfatal cases. Following the institution of contact tracing, active case surveillance, care of patients with isolation precautions, community mobilization, and rapid diagnostic testing, the outbreak was successfully contained 14 days after its initial detection.

Assessing prevention measures and Sin Nombre hantavirus seroprevalence among workers at Yosemite National Park

BACKGROUND

During 2012, a total of 10 overnight visitors to Yosemite National Park (Yosemite) became infected with a hantavirus (Sin Nombre virus [SNV]); three died. SNV infections have been identified among persons with occupational exposure to deer mice (Peromyscus maniculatus).

METHODS

We assessed SNV infection prevalence, work and living environments, mice exposures, and SNV prevention training, knowledge, and practices among workers of two major employers at Yosemite during September-October, 2012 by voluntary blood testing and a questionnaire.

RESULTS

One of 526 participants had evidence of previous SNV infection. Participants reported frequently observing rodent infestations at work and home and not always following prescribed safety practices for tasks, including infestation cleanup.

CONCLUSION

Although participants had multiple exposures to deer mice, we did not find evidence of widespread SNV infections. Nevertheless, employees working around deer mice should receive appropriate training and consistently follow prevention policies for high-risk activities.

Hantavirus infections among overnight visitors to Yosemite National Park, California, USA, 2012

TOC summary: A rare hantavirus outbreak reaffirms the need for control of deer mice and public awareness of the risks posed by contact with them.

In summer 2012, an outbreak of hantavirus infections occurred among overnight visitors to Yosemite National Park in California, USA. An investigation encompassing clinical, epidemiologic, laboratory, and environmental factors identified 10 cases among residents of 3 states. Eight case-patients experienced hantavirus pulmonary syndrome, of whom 5 required intensive care with ventilatory support and 3 died. Staying overnight in a signature tent cabin (9 case-patients) was significantly associated with becoming infected with hantavirus (p<0.001). Rodent nests and tunnels were observed in the foam insulation of the cabin walls. Rodent trapping in the implicated area resulted in high trap success rate (51%), and antibodies reactive to Sin Nombre virus were detected in 10 (14%) of 73 captured deer mice. All signature tent cabins were closed and subsequently dismantled. Continuous public awareness and rodent control and exclusion are key measures in minimizing the risk for hantavirus infection in areas inhabited by deer mice.

Clinical inquiries regarding Ebola virus disease received by CDC--United States, July 9-November 15, 2014

Since early 2014, there have been more than 6,000 reported deaths from Ebola virus disease (Ebola), mostly in Guinea, Liberia, and Sierra Leone. On July 9, 2014, CDC activated its Emergency Operations Center for the Ebola outbreak response and formalized the consultation service it had been providing to assist state and local public health officials and health care providers evaluate persons in the United States thought to be at risk for Ebola. During July 9-November 15, CDC responded to clinical inquiries from public health officials and health care providers from 49 states and the District of Columbia regarding 650 persons thought to be at risk. Among these, 118 (18%) had initial signs or symptoms consistent with Ebola and epidemiologic risk factors placing them at risk for infection, thereby meeting the definition of persons under investigation (PUIs). Testing was not always performed for PUIs because alternative diagnoses were made or symptoms resolved. In total, 61 (9%) persons were tested for Ebola virus, and four, all of whom met PUI criteria, had laboratory-confirmed Ebola. Overall, 490 (75%) inquiries concerned persons who had neither traveled to an Ebola-affected country nor had contact with an Ebola patient. Appropriate medical evaluation and treatment for other conditions were noted in some instances to have been delayed while a person was undergoing evaluation for Ebola. Evaluating and managing persons who might have Ebola is one component of the overall approach to domestic surveillance, the goal of which is to rapidly identify and isolate Ebola patients so that they receive appropriate medical care and secondary transmission is prevented. Health care providers should remain vigilant and consult their local and state health departments and CDC when assessing ill travelers from Ebola-affected countries. Most of these persons do not have Ebola; prompt diagnostic assessments, laboratory testing, and provision of appropriate care for other conditions are essential for appropriate patient care and reflect hospital preparedness.

Response to importation of a case of Ebola virus disease--Ohio, October 2014

On September 30, 2014, the Texas Department of State Health Services reported a case of Ebola virus disease (Ebola) diagnosed in Dallas, Texas, and confirmed by CDC, the first case of Ebola diagnosed in the United States. The patient (patient 1) had traveled from Liberia, a country which, along with Sierra Leone and Guinea, is currently experiencing the largest recorded Ebola outbreak. A nurse (patient 2) who provided hospital bedside care to patient 1 in Texas visited an emergency department (ED) with fever and was diagnosed with laboratory-confirmed Ebola on October 11, and a second nurse (patient 3) who also provided hospital bedside care visited an ED with fever and rash on October 14 and was diagnosed with laboratory-confirmed Ebola on October 15. Patient 3 visited Ohio during October 10-13, traveling by commercial airline between Dallas, Texas, and Cleveland, Ohio. Based on the medical history and clinical and laboratory findings on October 14, the date of illness onset was uncertain; therefore, CDC, in collaboration with state and local partners, included the period October 10-13 as being part of the potentially infectious period, out of an abundance of caution to ensure all potential contacts were monitored. On October 15, the Ohio Department of Health requested CDC assistance to identify and monitor contacts of patient 3, assess the risk for disease transmission, provide infection control recommendations, and assess and guide regional health care system preparedness. The description of this contact investigation and hospital assessment is provided to help other states in planning for similar events.

Estimating the future number of cases in the Ebola epidemic--Liberia and Sierra Leone, 2014-2015

The first cases of the current West African epidemic of Ebola virus disease (hereafter referred to as Ebola) were reported on March 22, 2014, with a report of 49 cases in Guinea. By August 31, 2014, a total of 3,685 probable, confirmed, and suspected cases in West Africa had been reported. To aid in planning for additional disease-control efforts, CDC constructed a modeling tool called EbolaResponse to provide estimates of the potential number of future cases. If trends continue without scale-up of effective interventions, by September 30, 2014, Sierra Leone and Liberia will have a total of approximately 8,000 Ebola cases. A potential underreporting correction factor of 2.5 also was calculated. Using this correction factor, the model estimates that approximately 21,000 total cases will have occurred in Liberia and Sierra Leone by September 30, 2014. Reported cases in Liberia are doubling every 15-20 days, and those in Sierra Leone are doubling every 30-40 days. The EbolaResponse modeling tool also was used to estimate how control and prevention interventions can slow and eventually stop the epidemic. In a hypothetical scenario, the epidemic begins to decrease and eventually end if approximately 70% of persons with Ebola are in medical care facilities or Ebola treatment units (ETUs) or, when these settings are at capacity, in a non-ETU setting such that there is a reduced risk for disease transmission (including safe burial when needed). In another hypothetical scenario, every 30-day delay in increasing the percentage of patients in ETUs to 70% was associated with an approximate tripling in the number of daily cases that occur at the peak of the epidemic (however, the epidemic still eventually ends). Officials have developed a plan to rapidly increase ETU capacities and also are developing innovative methods that can be quickly scaled up to isolate patients in non-ETU settings in a way that can help disrupt Ebola transmission in communities. The U.S. government and international organizations recently announced commitments to support these measures. As these measures are rapidly implemented and sustained, the higher projections presented in this report become very unlikely.

Lymphocytic choriomeningitis virus in employees and mice at multipremises feeder-rodent operation, United States, 2012

Outbreaks can be prevented with strict biosecurity and microbiological monitoring.

We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention.

Trace-forward investigation of mice in response to lymphocytic choriomeningitis virus outbreak

During follow-up of a 2012 US outbreak of lymphocytic choriomeningitis virus (LCMV), we conducted a trace-forward investigation. LCMV-infected feeder mice originating from a US rodent breeding facility had been distributed to >500 locations in 21 states. All mice from the facility were euthanized, and no additional persons tested positive for LCMV infection.

Novel paramyxovirus associated with severe acute febrile disease, South Sudan and Uganda, 2012

In 2012, a female wildlife biologist experienced fever, malaise, headache, generalized myalgia and arthralgia, neck stiffness, and a sore throat shortly after returning to the United States from a 6-week field expedition to South Sudan and Uganda. She was hospitalized, after which a maculopapular rash developed and became confluent. When the patient was discharged from the hospital on day 14, arthralgia and myalgia had improved, oropharynx ulcerations had healed, the rash had resolved without desquamation, and blood counts and hepatic enzyme levels were returning to reference levels. After several known suspect pathogens were ruled out as the cause of her illness, deep sequencing and metagenomics analysis revealed a novel paramyxovirus related to rubula-like viruses isolated from fruit bats.

Twenty-year summary of surveillance for human hantavirus infections, United States

In the past 20 years of surveillance for hantavirus in humans in the United States, 624 cases of hantavirus pulmonary syndrome (HPS) have been reported, 96% of which occurred in states west of the Mississippi River. Most hantavirus infections are caused by Sin Nombre virus, but cases of HPS caused by Bayou, Black Creek Canal, Monongahela, and New York viruses have been reported, and cases of domestically acquired hemorrhagic fever and renal syndrome caused by Seoul virus have also occurred. Rarely, hantavirus infections result in mild illness that does not progress to HPS. Continued testing and surveillance of clinical cases in humans will improve our understanding of the etiologic agents involved and the spectrum of diseases.