Barbara Knust

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.)

Rift Valley Fever Virus Vaccine Lacking the NSs and NSm Genes Is Safe, Nonteratogenic, and Confers Protection from Viremia, Pyrexia, and Abortion following Challenge in Adult and Pregnant Sheep

ABSTRACT Rift Valley fever virus (RVFV) is a mosquito-borne human and veterinary pathogen causing large outbreaks of severe disease throughout Africa and the Arabian Peninsula. Safe and effective vaccines are critically needed, especially those that can be used in a targeted one-health approach to prevent both livestock and human disease. We report here on the safety, immunogenicity, and efficacy of the ΔNSs-ΔNSm recombinant RVFV (rRVFV) vaccine (which lacks the NSs and NSm virulence factors) in a total of 41 sheep, including 29 timed-pregnant ewes. This vaccine was proven safe and immunogenic for adult animals at doses ranging from 1.0 × 103 to 1.0 × 105 PFU administered subcutaneously (s.c.). Pregnant animals were vaccinated with 1.0 × 104 PFU s.c. at day 42 of gestation, when fetal sensitivity to RVFV vaccine-induced teratogenesis is highest. No febrile reactions, clinical illness, or pregnancy loss was observed following vaccination. Vaccination resulted in a rapid increase in anti-RVFV IgM (day 4) and IgG (day 7) titers. No seroconversion occurred in cohoused control animals. A subset of 20 ewes progressed to full-term delivery after vaccination. All lambs were born without musculoskeletal, neurological, or histological birth defects. Vaccine efficacy was assessed in 9 pregnant animals challenged at day 122 of gestation with virulent RVFV (1.0 × 106 PFU intravenously). Following challenge, 100% (9/9) of the animals were protected, progressed to full term, and delivered healthy lambs. As expected, all 3 sham-vaccinated controls experienced viremia, fetal death, and abortion postchallenge. These results demonstrate that the ΔNSs-ΔNSm rRVFV vaccine is safe and nonteratogenic and confers high-level protection in sheep.

Genomic analysis of filoviruses associated with four viral hemorrhagic fever outbreaks in Uganda and the Democratic Republic of the Congo in 2012.

In 2012, an unprecedented number of four distinct, partially overlapping filovirus-associated viral hemorrhagic fever outbreaks were detected in equatorial Africa. Analysis of complete virus genome sequences confirmed the reemergence of Sudan virus and Marburg virus in Uganda, and the first emergence of Bundibugyo virus in the Democratic Republic of the Congo.

Solid Organ Transplant–associated Lymphocytic Choriomeningitis, United States, 2011

Lymphocytic choriomeningitis virus (LCMV) is carried by rodents. In very rare instances, it has been transmitted from person-to-person by organ transplantation. In 2011, a total of 14 organ recipients were infected with the virus, of which 11 died in the United States. The 4 most recent patients received organs from the same donor, which resulted in 2 deaths. Only after these 4 organ recipients became sick was it discovered that the donor had been exposed to rodents. Had this exposure been known before transplantation, the organ recipients may have been more closely monitored. Early diagnosis and treatment might have improved their chances of survival. Although organ donor screening reduces the risk for transmission of some viruses, it is not possible to screen for all possible viruses, including LCMV. For patients who get severely ill after receiving a transplant, clinicians should add LCMV infection to their list of possible causes.

Prognostic Indicators for Ebola Patient Survival

Odds of survival were greatest when first Ebola virus–positive blood sample collected had low viral load.

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.

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.

Evaluation of the effects of a killed whole-cell vaccine against Mycobacterium avium subsp paratuberculosis in 3 herds of dairy cattle with natural exposure to the organism

OBJECTIVE To evaluate effects of vaccination with a killed whole-cell vaccine against Mycobacterium avium subsp paratuberculosis (MAP) on fecal shedding of the organism, development of clinical paratuberculosis (Johnes disease [JD]), milk production, measures of reproduction, and within-herd longevity of dairy cattle naturally exposed to MAP. DESIGN Controlled clinical trial. ANIMALS 200 vaccinated and 195 unvaccinated (control) dairy cows from 3 herds in Wisconsin. PROCEDURES Every other heifer calf born in each herd received the MAP vaccine; 162 vaccinates and 145 controls that had ≥ 1 lactation were included in analyses. Bacteriologic culture of fecal samples for MAP was performed annually for 7 years; results were confirmed via histologic methods and PCR assay. Production records and culture results were evaluated to determine effects of vaccination on variables of interest in study cows. Annual whole-herd prevalence of MAP shedding in feces was also determined. RESULTS Vaccinates had a significantly lower hazard of testing positive for MAP via culture of fecal samples than did controls over time (hazard ratio, 0.57; 95% confidence interval, 0.34 to 0.97). Fewer vaccinates developed clinical JD than did controls (n = 6 and 12, respectively), but these differences were nonsignificant. Overall within-herd longevity, total milk production, and calving-to-conception intervals were similar between vaccinates and controls. In all herds, prevalence of MAP shedding in feces decreased over time. CONCLUSIONS AND CLINICAL RELEVANCE Vaccination with a killed whole-cell MAP vaccine appeared to be an effective tool as part of a program to control the spread of JD in dairy cattle.

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.

Characterization of the risk of deer-cattle interactions in Minnesota by use of an on-farm environmental assessment tool

OBJECTIVE To characterize the risk of interactions that may lead to the transmission of Mycobacterium bovis between cattle and white-tailed deer (Odocoileus virginianus) on farms in northern Minnesota. SAMPLE 53 cattle farms in northwestern Minnesota adjacent to an area where bovine tuberculosis-infected cattle and deer were detected. PROCEDURES A semiquantitative deer-cattle interaction assessment tool was used for the 53 cattle herds. Farm risk scores were analyzed on the basis of deer damage to stored feed. RESULTS 27 (51%) farms reported deer damage to stored cattle feeds within the year previous to the farm visit. A strong association was found between increases in the percentage of land that could serve as deer cover and deer damage to stored feeds on a farm. The total risk score was significantly associated with the probability of a farm having deer damage. By use of a logistic regression model, the total risk score and proportion of nonagricultural land around a farm could be used to predict the likelihood of deer damage to stored feeds. CONCLUSIONS AND CLINICAL RELEVANCE Management practices on many farms in northwestern Minnesota allowed potential deer-cattle interactions. The on-farm risk assessment tool served as a valuable tool for prioritizing the biosecurity risks for farms. Continued development of biosecurity is needed to prevent potential transmission of bovine tuberculosis between deer and cattle, especially on farms that have a higher risk of deer damage.