Posted on 14TH FEB 2017
tagged Ebola, Worldwide

A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

In this update:
- Rapid assay
- Referral pathway
- Breast milk
- Superspreaders
- West Africa tourist numbers

10 Feb 2017: Rapid Ebola test to detect early infection in the works
[Citation. DeMers H, Pandit S, Hannah EE, et al. (6 Feb 2017). A Library of Monoclonal Antibodies Developed for Rapid Diagnosis of Ebola Virus. 2017 ASM Biothreats: Research, Response and Policy, Washington, D.C., 6 Feb 2017.
Paired antibodies could target small bits of virus in blood sample.
Diagnosing Ebola earlier is becoming almost as easy as taking a home pregnancy test.
Scientists are developing antibodies for a test that can sniff out the deadly virus more quickly and efficiently than current tests, researchers reported 6 Feb [2017] at the American Society for Microbiology Biothreats meeting.
"Detecting Ebola's genetic material in patients' blood samples now takes a full day and requires access to a specialized laboratory. Simpler and speedier tests are available. They use antibodies -- specialized proteins that latch onto and flag virus particles -- and work somewhat like a pregnancy test. Within 10 or 15 minutes of dabbing a blood sample onto a piece of paper, a colored line confirms the presence of the virus. But currently these tests don't give accurate results until the patient has been sick for a while, said immunologist Haley DeMers of the University of Nevada, Reno School of Medicine.
"Antibodies more strongly attracted to the virus could track it down in a blood sample with just a few circulating particles, detecting disease before the virus takes over, DeMers and colleagues suspected. Their test uses 2 such antibodies. One, tagged with gold nanoparticles, drags the virus particles out of a sample. The tagged bits of virus wick up a piece of paper, where they're ensnared by a 2nd antibody that reveals their presence as a colored line. These antibody pairs need to work well together, grabbing different parts of the virus particle so they don't interfere with each other. After generating candidate antibodies in mice, DeMers and her colleagues tested over 1000 different pairings. They are now fine-tuning the 5 most effective combinations."
The 2014-2015 Ebola outbreak in West Africa demonstrated that there is a strong need for a rapid diagnostic test. Ebola virus (EBOV) has a high mortality rate and currently there is no FDA approved treatment or vaccine for this disease. A quick and accurate EBOV diagnostic is essential in order to isolate infected patients and reduce spread of the disease. A lateral flow immunoassay (LFI) is a membrane based rapid diagnostic test that relies on capture and detection of target molecules. The LFI platform is well suited to address the need for improved EBOV detection, as it can offer a sensitive, affordable diagnosis with a result in less than fifteen minutes that does not require sophisticated infrastructure or highly trained personnel. The goal of this study was to produce high affinity monoclonal antibodies (mAbs) specific to known EBOV biomarkers to be then used for the development of an EBOV LFI diagnostic. To create a diverse library of antibodies, mice were immunized with a variety of EBOV antigens, including EBOV recombinant VP40 (rVP40), EBOV virus like particles (eVLP) expressing EBOV VP40 and EBOV glycoprotein, and nano-eVLPs. Thirty-two EBOV reactive mAbs were produced and purified. MAbs were analyzed by enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), and Western blot to determine reactivity to eVLPs. Specificity to EBOV rVP40 or GP was also determined. LFI prototypes were then developed to assess all mAb combinations, with each tested in either the capture or detection role. Over 1000 different prototypes were tested, with the majority of LFIs showing reactivity to eVLPs. Top candidate prototypes were selected based on highest sensitivity after background subtraction and advanced for further optimization and testing that will include evaluation with purified inactivated EBOV.
Reported in Science News (https://www.sciencenews.org/article/rapid-ebola-test-detect-early-infect...).]

10 Feb 2017: Influence of referral pathway on Ebola virus disease case-fatality rate and effect of survival selection bias
[Citation. Rudolf F, Damkjær M, Lunding S, et al. Influence of referral pathway on Ebola virus disease case-fatality rate and effect of survival selection bias. Emerg Infect Dis. Apr 2017. 23(4). DOI:10.3201/eid2304.160485
Case-fatality rates in Ebola treatment centers (ETCs) varied widely during the Ebola virus disease (EVD) outbreak in West Africa. We assessed the influence of referral pathway on ETC case-fatality rates with a retrospective cohort of 126 patients treated at the Mathaska ETC in Port Loko, Sierra Leone. The patients consisted of persons who had confirmed EVD when transferred to the ETC or who had been diagnosed onsite. The case-fatality rate for transferred patients was 46% versus 67% for patients diagnosed onsite (p = 0.02). The difference was mediated by Ebola viral load at diagnosis, suggesting a survival selection bias. Comparisons of case-fatality rates across ETCs and clinical management strategies should account for potential survival selection bias.]

7 Feb 2017 TX. Fort Worth: (PRWEB): Pasteurization Inactivates Ebola virus in breast milk
[Citation. Hamilton Spence E, Huff M, Shattuck K, et al. (30 Jan 2017). Ebola Virus and Marburg Virus in Human Milk Are Inactivated by Holder Pasteurization. Journal of Human Lactation. http://journals.sagepub.com/doi/full/10.1177/0890334416685564
According to this study, donor human milk processed at non-profit milk banks is safe from Ebola and Marburg viruses.
The article "Ebola Virus and Marburg Virus in Human Milk Are Inactivated by Holder Pasteurization" states that Holder pasteurization inactivates the viruses, and no further screening is needed to ensure the safety of donor human milk for high-risk infants.]
[Read C Peila et al. The Effect of Holder Pasteurization on Nutrients and Biologically-Active Components in Donor Human Milk: A Review. Nutrients. 2016 Aug 8(8):477 for a review of this method of pasteurization. - Mod.LK]

13 Feb 2017: Disease "superspreaders" were driving cause of 2014 Ebola epidemic
[Citation. SYLau M, BDDalziel, Funk S. (Jan 2017 EPub). Spatial and temporal dynamics of superspreading events in the 2014-2015 West Africa Ebola epidemic, PNAS, http://www.pnas.org/cgi/doi/10.1073
A new study about the overwhelming importance of "superspreaders" in some infectious disease epidemics has shown that in the catastrophic 2014-15 Ebola epidemic in West Africa, about 3 percent of the people infected were ultimately responsible for infecting 61 percent of all cases.
The unprecedented scale of the Ebola outbreak in Western Africa (2014-2015) has prompted an explosion of efforts to understand the transmission dynamics of the virus and to analyze the performance of possible containment strategies. Models have focused primarily on the reproductive numbers of the disease that represent the average number of secondary infections produced by a random infectious individual. However, these population-level estimates may conflate important systematic variation in the number of cases generated by infected individuals, particularly found in spatially localized transmission and superspreading events. Although superspreading features prominently in firsthand narratives of Ebola transmission, its dynamics have not been systematically characterized, hindering refinements of future epidemic predictions and explorations of targeted interventions. We used Bayesian model inference to integrate individual-level spatial information with other epidemiological data of community-based (undetected within clinical-care systems) cases and to explicitly infer distribution of the cases generated by each infected individual. Our results show that superspreaders play a key role in sustaining onward transmission of the epidemic, and they are responsible for a significant proportion (∼61 percent) of the infections. Our results also suggest age as a key demographic predictor for superspreading. We also show that community-based cases may have progressed more rapidly than those notified within clinical-care systems, and most transmission events occurred in a relatively short distance (with median value of 2.51 km). Our results stress the importance of characterizing superspreading of Ebola, enhance our current understanding of its spatiotemporal dynamics, and highlight the potential importance of targeted control measures.]
[Studies on pathogen transmission have demonstrated what is sometimes called the 20/80 rule, suggesting that a small proportion of the infected population contributes most to transmission of agents. These inter-individual variations in infectiousness have an impact on the dynamics of host-pathogen interactions and clearly affect design of control efforts. - Mod.LK]

8 Feb 2017 West Africa: Ebola outbreak and new visa regulations to blame for tourist number decline, committee hears
The Ebola outbreak in West Africa and the new visa regime had an impact on tourist numbers in 2015-16, the Select Committee on Trade and International Relations heard on Wednesday [8 Feb 2017].
South African Tourism (SAT) Chief Executive Officer Mr Sisa Ntshona told Members that 2015 had been a difficult year for tourism. SAT was in Parliament to brief the Committee on its annual report.
"The big story was around West Africa, as a result of the Ebola outbreak, and the new South African visa regulations. The world still thinks of Africa as a country," he said. He said this because the tendency among travel agents is to divert tourist traffic elsewhere that traditionally would have come to South Africa. He added that officials were not able to process the great number of applications outside the country.

[Compiled by: Celeste Whitlow ]

Communicated by:

[A map showing the distribution of EVD cases as of 27 Mar 2016 can be seen at http://apps.who.int/ebola/sites/default/files/thumbnails/image/sitrep_ca....

ProMED HealthMaps:
Liberia http://healthmap.org/promed/p/54
Guinea http://healthmap.org/promed/p/45
Sierra Leone http://healthmap.org/promed/p/46]

See Also
Ebola update (06): research, treatment, funding 20170206.4819835
Ebola update (05): news, vaccine, funding, documentary films 20170129.4801064
Ebola update (04): research 20170123.4786222
Ebola update (03): news, research 20170115.4767977
Ebola update (02): news, research, vaccine, comment 20170108.4750411
Ebola update (01): News, research, vaccine 20170103.4738060
Ebola update (72): vaccine, research, NGO, media 20161226.4724859
Ebola update (71): research, economy 20161218.4706276
Ebola update (70): news, research, economy, funding 20161211.4690740
Ebola update (69): news, NGO, research, economy, funding, vaccine 20161204.4675615
Ebola update (68): news, economy 20161127.4657148
Ebola update (67): news, research, funding 20161120.4642402
Ebola update (66): news, research, funding, economy 20161115.4629793
Ebola update (65): news, research, commentary, economy, funding, vaccine 20161106.4609611
Ebola update (64): news, research 20161030.4595759
Ebola update (63): news, research 20161023.4579436
Ebola update (62): news, research, treatment, funding 20161017.4564066
Ebola update (61): news, funding, economy 20161009.4547627
Ebola update (60): news, research, economy 20161002.4531285
Ebola update (59): news, research, funding 20160925.4514591
Ebola update (58): news, research, funding, vaccine 20160918.4497393
Ebola update (57): news, research, funding 20160911.4481043
Ebola update (56): news, vaccine, research 20160904.4465145
Ebola update (55): research, funding 20160828.4446844
Ebola update (54): rapid test recall, nurse, research 20160821.4431433
Ebola update (53): Guinea, research 20160814.4415032
Ebola update (52): funding, research 20160808.4400521
Ebola update (51): funding, research, miscellaneous 20160731.4383179
Ebola update (50): Liberia, Sierra Leone, research 20160724.4366266
Ebola update (49): Sierra Leone, research, history 20160717.4350351
Ebola update (48): CDC, research, funding, economy 20160710.4336146
Ebola update (47): Liberia, US preparedness, funding, research 20160703.4323924
Ebola update (46): Liberia, Sierra Leone, treatment comment, research, funding 20160626.4310569
Ebola update (45): Liberia, vaccine, treatment, funding, research 20160619.4296380
Ebola update (44): Liberia, WHO, funding, research 20160612.4283379
Ebola update (43): digital wallet response, Guinea, diagnostic assay 20160605.4266788
Ebola update (42): Guinea, vaccine, research 20160529.4253046
Ebola update (41): update, funding 20160522.4238249
Ebola update (40): Liberia, Sierra Leone, research, vaccines 20160514.4222416
Ebola update (39): Guinea persistence in semen, Liberia, research, vaccine 20160508.4209313
Ebola update (38): WHO sitrep. evolution rate, Liberia, Sierra Leone, research 20160501.4195742
Ebola update (37): Guinea, Liberia, diagnostics, vaccine, funding, research 20160427.4187854
Ebola update (36): Guinea, Liberia, vaccine, research 20160421.4172812
Ebola update (35): vaccine, comment 20160418.4167038
Ebola update (34): Guinea, Liberia, comment, vaccine funding 20160417.4165862
Ebola update (33): Guinea, Liberia, Sierra Leone, research, funding, vaccine 20160413.4158203
Ebola update (32): Liberia, Guinea, support 20160410.4150454
Ebola update (31): Liberia, Guinea re-emergence, research, funding 20160406.4142990
Ebola update (30): Liberia re-emergence, Uganda NOT, RFI 20160404.4136987
Ebola update (29): Liberia re-emergence, Guinea contacts, news, RFI 20160402.4134878
Ebola update (28): news, research, vaccine 20160330.4128527
Ebola update (27): Ebola Reston virulence, Africa suspicious deaths RFI, news 20160327.4121931
Ebola update (26): Guinea flare-up, Liberia 20160324.4114807
Ebola update (25): Guinea flare-up, Liberia, Sierra Leone, research 20160320.4107350
Ebola update (24): Guinea, confirmed 20160317.4101955
Ebola update (23): comment, pregnant women, news, research 20160316.4098040
Ebola update (22): long-term sequelae, news, research 20160313.4090091
Ebola update (21): Sierra Leone, herd immunity, possible new drug 20160310.4081498
Ebola update (20): new antiviral, prevention 20160306.4073116
See archives for more reports.