ZIKA VIRUS (03): AMERICAS, RESEARCH

Posted on 09TH MAR 2017
tagged Zika Virus, Americas

A ProMED-mail post
http://www.promedmail.org
ProMED-mail is a program of the
International Society for Infectious Diseases
http://www.isid.org

In this update:
[1] Cases in various countries:
Americas
Americas cumulative case numbers

North America
---
USA:
- Florida
- Texas

Central America
---
Panama (Herrera province)

Caribbean
---
Jamaica
Trinidad and Tobago

South America
---
Colombia

Imported cases with no possibility of ongoing mosquito transmission
---
Canada
USA:
- Case numbers mainland
- Donated blood
- Territories and Commonwealth

[2] Congenital Zika virus infection
[3] Diagnosis, nanotechnology
[4] mRNA vaccine
[5] Virus persistence
[6] Retinal pathology
[7] _Aedes aegypti_ vector competence
[8] Animals as Zika virus hosts

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[1] Cases in various countries
Americas
---
Americas cumulative case numbers
As of 2 Mar 2017
http://www.paho.org/hq/index.php?option=com_content&view=article&id=1239...
Country / Locally acquired: suspected / Confirmed [conf] / Imported / Deaths / Conf congenital syndrome
North America:
Bermuda / 0 / 0 / 6 / 0 / 0
Canada / 0 / 0 / 473 / 0 / 1
USA / 0 / 222 / 4747/ 0 / 48

Latin America:
Mexico / 0 / 8069 / 15 / 0 / 1

Central American Isthmus:
Belize / 816 / 73 / 0 / 0 / 0
Costa Rica / 6077 / 1725 / 32 / 0 / 2
El Salvador / 11 512 / 51 / 0 / 0 / 4
Guatemala / 3464 / 890 / 0 / 0 / 37
Honduras / 32 091 / 298 / 0 / 0 / 2
Nicaragua / 0 / 2060 / 3 / 0 / 2
Panama / 3762 / 897 / 42 / 0 / 5

Latin Caribbean:
Cuba / 0 / 187 / 58 / 0 / 0
Dominican Republic / 4896 / 345 / 0 / 0 / 59
French Guiana / 10 320 / 483 / 10 / 0 / 17
Guadeloupe / 30 845 / 382 / 0 / 0 / 14
Haiti / 2955 / 5 / 0 / 0 / 1
Martinique / 36 680 / 21 / 0 / 0 /22
Puerto Rico / 0 / 38 940 / 137 / 5 / 12
Saint Barthelemy / 990 / 61 / 0 / 0 / 0
Saint Martin / 3215 / 200 / 0 / 0 / 1

Non-Latin Caribbean:
Anguilla / 30 / 19 / 1/ 0 / 0
Antigua and Barbuda / 465 / 14 / 2 / 0 / 0
Aruba / 890 / 34 / 7 / 0 / 0
Bahamas / 0 / 25 / 3/ 0 / 0
Barbados / 699 / 46 / 0 / 0 / 0
Bonaire, St Eustatius and Saba / 0 / 343 / 0 / 0 / 0
Caymans / 217 / 31 / 10 / 0 / 0
Curacao / 0 / 2589 / 1259 / 0 / 0
Dominica / 1150 / 79 / 0 / 0 / 0
Grenada / 335 / 112 / 0 / 0 / 1
Guyana / 0 / 37 / 0 / 0 / 0
Jamaica / 7371 / 203 / 0 / 0 / 0
Montserrat / 18 / 5 / 0 / 0 / 0
Saint Kits and Nevis / 549 / 33 / 0 / 0 / 0
Saint Lucia / 822 / 50 / 0 / 0 / 0
Saint Vincent and the Grenadines / 508 / 83 / 0 / 0 / 0
Sint Maarten / 247 / 147 / 0 / 0 / 0
Suriname / 2767 / 723 / 0 / 4 / 4
Trinidad and Tobago / 0 / 718 / 1 / 0 / 3
Turks and Caicos / 175 / 25 / 3 / 0 / 0
Virgin Islands (UK) / 74 / 52 / 0 / 0 / 0
Virgin Islands (USA) / 1002 / 989 / 2 / 0 / 0

Andean Area:
Bolivia / 837 / 192 / 4 / 0 / 14
Colombia / 97 384 / 9799 / 0 / 0 / 127
Ecuador / 2785 / 929 / 15 / 0 / 0
Peru / 1919 / 864 / 22 / 0 / 0
Venezuela / 59 685 / 2413 / 0 / 0 / 0

[Brazil and] Southern Cone:
Brazil / 215 635 / 130 840 / 0 / 11 / 2386
Argentina / 2251 / 26 / 29 / 0 / 2
Chile / 0 / 0 / 33 / 0 / 0
Paraguay / 613 / 14 / 0 / 0 / 2
Uruguay / 0 / 0 / 1 / 0 / 0

Totals, Americas / 548 690 / 205 013 / 5656 / 20 / 2767

[Maps showing the location of the affected islands and countries in the Americas mentioned above and below can be accessed at
http://healthmap.org/promed/p/35574;
North America at http://healthmap.org/promed/p/106;
Central America http://healthmap.org/promed/p/39455;
Caribbean http://www.mapsofworld.com/caribbean-islands/ and
South America at http://healthmap.org/promed/p/6186. - Mod.TY]

North America
---
USA:
- Florida. 6 Mar 2017. (reported [rep]) Scripps Translational Science Institute researchers have found that there were likely dozens of separate introductions of the Zika virus into Florida. By sequencing viral samples from 17 people, the team found that those viruses could be traced to 4 different viral introductions. Then extrapolating that to the wider infected population, they estimated that "the number of introductions that caused the outbreak in Miami is quite substantial" and could be as many as 30
https://www.genomeweb.com/scan/zika-arrived-multiple-times.

- Texas. (McAllen city, Hidalgo county). 24 Feb 2017. (conf) 1st locally acquired case, sexual transmission ruled out.
http://www.mcallen.net/docs/default-source/emergency/zika-case-investiga...

Central America
---
Panama (Herrera province). 22 Feb 2017. (conf) 17 cases.
http://www.critica.com.pa/provincias/17-casos-de-zika-y-6-de-dengue-clas... [in Spanish]

Caribbean
---
Jamaica. 7 Mar 2017. (rep) 1 case with both mother and baby positive for Zika virus infection.
http://jamaica-gleaner.com/article/news/20170307/test-results-suspected-...

Trinidad and Tobago. 23 Feb 2017. (rep) since 11 Feb 2016, 718 cases of whom 463 pregnant, 4 cases of microcephaly in 2017 with 2 mothers positive for Zika virus infection during pregnancy.
http://www.trinidadexpress.com/20170223/news/tt-records-463-zika-pregnan...

South America
---
Colombia. 6 Mar 2017. (conf) 128 Zika virus associated cases of microcephaly from 1 Jan 2016 - 25 Feb 2017 with 11 cases on week 8 (week ending 25 Feb 2017); Neurological syndromes (including Guillain-Barré) 20 cases in the departments of Bolívar, Meta, Tolima, Santander, Antioquia, Atlántico, Valle del Cauca, Quindío, Casanare, Magdalena y Norte de Santander.
http://www.opinionysalud.com/microcefalia-zika-colombia-ins/ [in Spanish]

Imported cases with no possibility of ongoing mosquito transmission (except USA Florida and Texas)
---
Canada. 6 Mar 2017. (conf) The 1st study of Zika-infected patients in Canada has found a higher-than-expected rate of serious complications caused by the virus, including 2 cases of partial paralysis and 2 in which mothers transmitted Zika-related defects to their unborn babies.
http://www.theglobeandmail.com/news/national/first-study-of-zika-infecte...

USA:
- Case numbers mainland. Zika virus disease in the United States, 2015-2017 as of 1 Mar 2017
http://www.cdc.gov/zika/geo/united-states.html
State / Symptomatic cases / Viremic blood donors
Alabama 38 / 0
Arizona 55 / 1
Arkansas 15 / 0
California 426 / 5
Colorado 55 / 0
Connecticut 58 / 0
Delaware 17 / 0
District of Columbia 31 / 0
Florida 1083 / 24
Georgia 109 / 0
Hawaii 16 / 0
Idaho 5 / 0
Illinois 94 / 0
Indiana 53 / 0
Iowa 26 / 1
Kansas 22 / 0
Kentucky 32 / 0
Louisiana 39 / 0
Maine 14 / 0
Maryland 131 / 0
Massachusetts 121 / 0
Michigan 68 / 0
Minnesota 64 / 0
Mississippi 25 / 0
Missouri 36 / 0
Montana 9 / 0
Nebraska 13 / 0
Nevada 22 / 1
New Hampshire 12 / 0
New Jersey 180 / 0
New Mexico 10 / 0
New York 1004 / 3
North Carolina 91 / 0
North Dakota 3 / 0
Ohio 85 / 0
Oklahoma 29 / 0
Oregon 47 / 0
Pennsylvania 174 / 0
Rhode Island 54 / 0
South Carolina 54 / 0
South Dakota 2 / 0
Tennessee 61 / 0
Texas 312 / 3
Utah 22 / 0
Vermont 11 / 0
Virginia 113 / 0
Washington 70 / 0
West Virginia 11 / 0
Wisconsin 50 / 0
Wyoming 2 / 0
Total 5074 / 38

- Territories and Commonwealth:
Symptomatic / Blood donors
American Samoa 120 / 0
Puerto Rico 37 197 / 318
US Virgin Islands 989 / 0
Total 38 306 / 318
[A map of the USA showing the states and territories mentioned above can be accessed at http://www.mapsofworld.com/usa/.]

--
communicated by:
ProMED-mail

and
Roland Hübner
Superior Health Council
Brussels
Belgium

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[2] Congenital Zika virus infection
Date: Fri 3 Mar 2017
Source: Centers for Disease Control and Prevention [CDC]. MMWR Morb Mortal Wkly Rep 2017;66:219-222 [edited]
http://dx.doi.org/10.15585/mmwr.mm6608a4

Cragan JD, Mai CT, Petersen EE, et al. Baseline prevalence of birth defects associated with congenital Zika virus infection -- Massachusetts, North Carolina, and Atlanta, Georgia, 2013-2014.

Summary
What is already known about this topic?
Zika virus infection causes serious brain abnormalities; however, the birth defects observed are not unique to congenital Zika virus infection, and the full range of effects of congenital Zika infection is not known.

What is added by this report?
CDC used data from population-based birth defects surveillance programs in Massachusetts, North Carolina, and Atlanta, Georgia, to retrospectively assess the prevalence of birth defects during 2013-2014 that met the surveillance case definition for birth defects potentially related to Zika virus infection, before introduction of Zika virus into the United States. After introduction of Zika virus, the proportion of infants and fetuses with birth defects born to mothers with laboratory evidence of possible Zika infection reported by the US Zika Pregnancy Registry during 15 Jan - 22 Sep 2016, was approximately 20 times higher than the prevalence of potentially Zika-related birth defects among pregnancies during the pre-Zika years.

What are the implications for public health practice?
Data on birth defects in the pre-Zika years serve as benchmarks to direct rapid ascertainment and reporting of birth defects potentially related to Zika virus infection. The higher proportion of these defects among pregnancies with laboratory evidence of possible Zika virus infection supports the relationship between congenital Zika virus infection and birth defects.

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[A 26 Feb 2017 report indicated that imaging and pathological findings in congenital Zika syndrome include moderate and severe microcephaly, in as many as 75 per cent of the cases, ophthalmological and auditory abnormalities, and arthrogryposis. However, these are not the only abnormalities that can be found, and the complete disease spectrum is still unknown. Some babies are born with head circumference at the lower limit of the normal range, but later progress to microcephaly. In the authors' experience, they correspond to about 10 per cent of microcephaly cases confirmed with positive IgM CSF (unpublished data). However, the clinical spectrum of the effects of Zika virus infection during pregnancy is not yet known. (http://link.springer.com/chapter/10.1007/978-3-319-53643-9_6).

A 23 Feb 2017 report stated that early exposure of wild-type FVB/NJ and C57BL/6J strain mice to ZIKV at developmental day 5 (2nd week in humans) produced complex manifestations of anterior and posterior dysraphia and hydrocephalus, as well as severe malformations and delayed development in 10.5 days post-coitum (dpc) embryos. Exposure to the virus at 7.5-9.5 dpc induces intra-amniotic hemorrhage, widespread edema, and vascular rarefaction, often prominent in the cephalic region. At these stages, most affected embryos/fetuses displayed gross malformations and/or intrauterine growth restriction (IUGR), rather than isolated microcephaly. Disrupted conceptuses failed to achieve normal developmental landmarks and died in utero. Importantly, this is the only model so far to display dysraphia and hydrocephalus, the harbinger of microcephaly in humans, as well as arthrogryposis http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0005363. - Mod.TY]

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[3] Diagnosis, nanotechnology
Date: Mon 6 Mar 2017
Source: Nature Medicine doi:10.1038/nm.4302 [edited]
http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.4302.html

Bo Zhang, Benjamin A Pinsky, Jeyarama S Ananta, Su Zhao, et al. Diagnosis of Zika virus infection on a nanotechnology platform.

Abstract
We developed a multiplexed assay on a plasmonic-gold platform for measuring IgG and IgA antibodies and IgG avidity against both Zika virus (ZIKV) and dengue virus (DENV) infections. In contrast to IgM cross-reactivity, IgG and IgA antibodies against ZIKV nonstructural protein 1 (NS1) antigen were specific to ZIKV infection, and IgG avidity revealed recent ZIKV infection and past DENV-2 infection in patients in dengue-endemic regions. This assay could enable specific diagnosis of ZIKV infection over other flaviviral infections.

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[This represents another advance in technology for rapid, specific diagnosis of Zika virus infections distinguishing them from dengue virus infections. As the authors point out, specific diagnosis is important, especially for pregnant women, where there is risk of teratogenic effects on their developing fetuses. Of the recent diagnostic tests that have been reported this year (2017), it will be interesting to see which of them is technologically and economically most suitable for use in the developing countries, where rapid, accurate diagnosis of Zika virus infections is most needed and laboratory capability and financial support are most limited. - Mod.TY]

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[4] mRNA vaccine
Date: Thu 2 Mar 2017
Source: Nature doi:10.1038/nature21428 [edited]
http://www.nature.com/nature/journal/vaap/ncurrent/full/nature21428.html

Norbert Pardi, Michael J. Hogan, Rebecca S. Pelc, Hiromi Muramatsu, Hanne Andersen, et al. Zika virus protection by a single low-dose nucleoside-modified mRNA vaccination.

Abstract
Zika virus (ZIKV) has recently emerged as an explosive pandemic associated with severe neuropathology in newborns and adults. There are no ZIKV-specific treatments or preventatives; thus, development of a safe and effective vaccine is a high priority. Messenger RNA (mRNA) has emerged as a versatile and highly effective platform to deliver vaccine antigens and therapeutic proteins. Here, we demonstrate that a single low-dose intradermal immunization with lipid nanoparticle-encapsulated nucleoside-modified mRNA (mRNA-LNP) encoding the pre-membrane and envelope (prM-E) glycoproteins of a 2013 ZIKV outbreak strain elicited potent and durable neutralizing antibody responses in mice and non-human primates. Immunization with 30 μg of nucleoside-modified ZIKV mRNA-LNPs protected mice from ZIKV challenges at 2 weeks or 5 months post-vaccination, and a single dose of 50 μg was sufficient to protect non-human primates from a challenge at 5 weeks post-vaccination. These data demonstrate that nucleoside-modified mRNA-LNPs elicit rapid and durable protective immunity and thus represent a new and promising vaccine candidate for the global fight against ZIKV.

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[It will be interesting to see the results of phase I and II in humans. One hopes that it will be safe and efficacious. - Mod.TY]

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[5] Virus persistence
Date: Fri 24 Feb 2017
Source: NEJM Journal Watch [edited]
http://www.jwatch.org/na43512/2017/02/24/zika-persistence

Richard T Ellison III, MD reviewing Paz-Bailey G et al. N Engl J Med. 2017; 14 Feb.

The Zika virus is detectable in serum up to 80 days and in semen up to 125 days after symptom onset.
---------------------------------------
Clear evidence associates mosquitoborne Zika virus with birth defects and the Guillain-Barré syndrome. Because the virus is also transmitted through sexual contact and blood transfusion, more detailed data on its persistence in body fluids is urgently needed. To this end, researchers working with the Centers for Disease Control and Prevention report interim results in 150 of 350 participants with infection diagnosed by reverse transcriptase polymerase chain reaction (RT-PCR) from a prospective cohort study in Puerto Rico on the kinetics of Zika virus in serum, urine, saliva, semen, and vaginal secretions.

Among 127 symptomatic participants with acute febrile illness identified by screening in emergency departments or outpatient clinics and 23 household contacts of these index subjects (4 asymptomatic), the median time from symptom onset to loss of Zika virus (ZIKV) RNA detection was 14 days in serum, 8 days in urine, and 34 days in semen. The 95th percentile of time to RNA clearance was 54 days in serum, 39 days in urine, and 81 days in semen. The maximum observed durations were 80 days in serum in a pregnant woman, and 125 days in semen. ZIKV RNA was found in at least one saliva sample in 10 per cent of subjects and in vaginal secretions in only 1 of 50 women. Anti-ZIKV IgM antibodies were detected in 140 of 143 tested subjects.

Comment
The authors note that these estimates of viral persistence are subject to change, as a number of participants still had detectable RNA at the time that the last sample was collected. In addition, these results represent the presence of Zika virus RNA and not necessarily infectious virus. Still, these interim findings will help to better define optimal approaches to diagnosing Zika virus infection, protecting the blood supply, and counseling individuals on the risk for sexual transmission.

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communicated by:
ProMED-mail rapporteur Mary Marshall

[Reference
Paz-Bailey G, et al. Persistence of Zika virus in body fluids -- preliminary report. N Engl J Med. 2017; Feb 14; [e-pub] (http://dx.doi.org/10.1056/NEJMoa1613108).

The detection of Zika virus RNA in serum of a pregnant woman at 80 days is remarkable. Previous reports have suggested that infection of the placenta may contribute to long-term viremia of the mother. The detection of Zika virus RNA in semen up to 125 days is a long period of time, but does not reach the 188 days found in an infected man in France. As the above comment points out, the question with this persistence in semen is whether there is infectious virus present at titers sufficient to achieve sexual transmission.

A study in Puerto Rico found that approximately 50 per cent of serum samples in a small cohort of patients in still had detectable Zika virus RNA particles at 14 days after the onset of symptoms, whereas 90 per cent of dengue patients clear RNA within 10 days of the onset of symptoms, regardless of serotype, and the median RNA clearance for West Nile virus is 13 days
(http://www.healio.com/infectious-disease/emerging-diseases/news/online/%...).

In another study, mice were infected via subcutaneous injection of a pathogenic but nonlethal ZIKV strain. ZIKV replication persists within the testes even after clearance from the blood, with interstitial, testosterone-producing Leydig cells supporting virus replication. The authors found high levels of viral RNA and antigen within the epididymal lumen, where sperm is stored, and within surrounding epithelial cells. Unexpectedly, at 21 days post-infection, the testes of the ZIKV-infected mice were significantly smaller compared to those of mock-infected mice, indicating progressive testicular atrophy. (http://advances.sciencemag.org/content/3/2/e1602899.full). It will be interesting to know if there is any evidence of testicular atrophy in humans infected with Zika virus, especially those with persistent Zika virus RNA in semen. This report was provided by Roland Hübner. - Mod.TY]

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[6] Retinal pathology
Date: Thu 23 Feb 2017
Source: JCI Insight. 2017;2(4):e92340. doi:10.1172/jci.insight.92340 [edited]
https://insight.jci.org/articles/view/92340

Pawan Kumar Singh, John-Michael Guest, Mamta Kanwar, Joseph Boss, Nan Gao, et al. Zika virus infects cells lining the blood-retinal barrier and causes chorioretinal atrophy in mouse eyes.

Abstract
Zika virus (ZIKV) is an important pathogen that causes not only neurologic, but also ocular, abnormalities. Thus, it is imperative that models to study ZIKV pathogenesis in the eye are developed to identify potential targets for interventions. Here, we studied ZIKV interactions with human retinal cells and evaluated ZIKV's pathobiology in mouse eyes. We showed that cells lining the blood-retinal barrier (BRB), the retinal endothelium, and retinal pigment epithelium (RPE) were highly permissive and susceptible to ZIKV-induced cell death. Direct inoculation of ZIKV in eyes of adult C57BL/6 and IFN-stimulated gene 15 (ISG15) KO mice caused chorioretinal atrophy with RPE mottling, a common ocular manifestation of congenital ZIKV infection in humans. This response was associated with induced expression of multiple inflammatory and antiviral (IFNs) response genes in the infected mouse retina. Interestingly, ISG15 KO eyes exhibited severe chorioretinitis, which coincided with increased retinal cell death and higher ZIKV replication. Collectively, our study provides the first evidence to our knowledge that ZIKV causes retinal lesions and infects the cells lining the BRB and that ISG15 plays a role in retinal innate defense against ZIKV infection. Our mouse model can be used to study mechanisms underlying ZIKV-induced chorioretinitis and to gauge ocular antiviral therapies.

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[It will be interesting to see whether the findings in the mouse model are validated in monkeys or in humans. - Mod.TY]

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[7] _Aedes aegypti_ vector competence
Date: April 2017 [ahead of print]
Source: Emerg Infect Dis. http://dx.doi.org/10.3201/eid2304.161484 [edited]
https://wwwnc.cdc.gov/eid/article/23/4/16-1484_article#suggestedcitation

Roundy CM, Azar SR, Rossi SL, Huang JH, Leal G, Yun R, et al. Variation in _Aedes aegypti_ mosquito competence for Zika virus transmission.

Abstract
To test whether Zika virus has adapted for more efficient transmission by _Aedes aegypti_ mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexico strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexican strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61 per cent transmission occurred after a murine blood meal (saliva titers up to 4 log10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, _Ae. aegypti_ mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas.

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[The increased susceptibility of mosquitoes exposed to infected mice over those fed artificially is interesting and will be a useful observation for the design of future experiments to determine vector competence and efficiency. - Mod.TY]

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[8] Animals as Zika virus hosts
Date: Wed 1 Mar 2017
Source: Vector-Borne and Zoonotic Diseases 17(3): 161-164. doi:10.1089/vbz.2016.2099 [edited]
http://online.liebertpub.com/doi/abs/10.1089/vbz.2016.2099#utm_source=ET...

Ragan Izabela K, Blizzard Emily L, Gordy Paul, and Bowen Richard A. Investigating the potential role of North American animals as hosts for Zika virus.

Abstract
The recent emergence of the mosquitoborne Zika virus (ZIKV) in the Americas has become a global public health concern. We describe a series of experimental infections designed to investigate whether animals within certain taxonomic groups in North America have the potential to serve as ZIKV amplifying or maintenance hosts. Species investigated included armadillos, cottontail rabbits, goats, mink, chickens, pigeons, ground hogs, deer mice, cattle, raccoons, ducks, Syrian golden hamsters, garter snakes, leopard frogs, house sparrows, and pigs. Infectious virus was isolated from blood only in frogs and armadillos; however, the magnitude of viremia was low. In addition, neutralizing antibodies were detected after infection in goats, rabbits, ducks, frogs, and pigs. This study indicates that the animals tested to date are unlikely to act as animal reservoirs for ZIKV, but that rabbits and pigs could potentially serve as sentinel species. Understanding the transmission cycle and maintenance of ZIKV in animals will help in developing effective surveillance programs and preventative measures for future outbreaks.

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[Finding vertebrate hosts that maintain or amplify a virus, such as Zika, when it occurs in a new ecosystem and a new locality is usually time consuming. The number of candidate species to be tested experimentally is huge. The above studies eliminate a wide range of vertebrate animals that includes wild and domestic mammals, birds, reptiles and amphibians. In a search for vertebrate hosts, one can sample a variety of animals at a locality of natural transmission and test them for antibodies. However, finding serologically positive species does not indicate that they have viremias and can serve as sources of infectious blood meals for vector mosquitoes. That step requires the kind of studies reported above. It would be interesting to look at non-human primates in the areas of the American tropics where there have been Zika virus outbreaks in humans. If serological positive individuals are found, then one could test those primates in the laboratory to determine the amplitude and duration of viremia and ability to infect mosquitoes. - Mod.TY]

See Also
Zika virus (02): Americas, Asia, Africa, Pacific, research, observations 20170217.4846633
Zika virus (01): Americas, Asia, Africa, research 20170117.4772206
2016
---
Zika virus (63): Americas, Asia, research, observations 20161212.4693852
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Zika virus (61): Americas, Asia, Pacific, research 20161124.4650886
Zika virus (60) - Americas, Asia, research, observations 20161121.4644809
Zika virus (59) - Americas, Asia, research, comment 20161113.4625265
Zika virus (58): Americas, Asia, Pacific, Africa, research 20161110.4618543
Zika virus (57): Americas, Asia, Pacific, Europe, research, observations 20161104.4606432
Zika virus (56): Americas, Asia, Pacific, Europe, research, observations 20161023.4578711
Zika virus (55) - Americas, Asia, Europe, research, observations 20161019.4571149
Zika virus (54): Americas, PAHO/WHO 20161007.4542586
Zika virus (53): Americas, Asia, Pacific, research, observations 20161006.4541952
Zika & chikungunya viruses: comparative transmission 20161005.4539231
Zika virus (52)f: Americas, Asia, Europe, research, observations 20161001.4529740
Zika virus (51): Americas, PAHO/WHO 20160923.4511356
Zika virus (50): Americas, Asia, Europe, Pacific, research, observations 20160922.4506931
Zika virus (49): Americas, Asia, Europe, Middle East, research, notes 20160915.4491053
Zika virus (48): Americas, PAHO/WHO 20160909.4477370
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Zika virus (45): worldwide, WHO, research, comment 20160904.4464015
Zika virus (43): Americas, Europe: Tampa Florida area, research 20160823.4436991.
Zika virus (45): worldwide, WHO, research, comment 20160904.4464015
Zika virus (42): Americas, Europe 20160821.4430310
Zika virus (41): Americas, Asia, Europe 20160812.4412646
Zika virus (40) - Americas 20160810.4407318
Zika virus (39): Americas, Europe 20160729.4378060
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Zika virus (36) - Americas: USA (FL, UT) RFI 20160720.4356276
Zika virus (34): Americas, Asia, Africa, Europe 20160707.4331999
Zika virus (33): Americas, Asia, Europe 20160701.4321150
Zika virus (32): Americas, Asia, Pacific, Europe 20160622.4303191
Zika virus (31): worldwide, WHO 20160617.4290853
Zika virus (30): Americas, Asia, Atlantic, Europe 20160616.4292221
Zika virus (29): Americas, Asia, Europe 20160529.4253278
Zika virus (28): Americas, Asia, Pacific, Atlantic, Europe 20160524.4240474
Zika virus (27): Americas, Asia, Europe 20160511.4214303
Zika virus (26): Americas, Asia, Europe, Indian Ocean 20160504.4202525
Zika virus (25): Americas 20160501.4195452
Zika virus (24): Americas 20160422.4177323
Zika virus (23): Americas 20160419.4168370
Zika virus (22): sexual transmission 20160416.4162854
Zika virus (21): Americas (Brazil) diagnostic imaging 20160415.4160993
Zika virus (20): Americas, Pacific, Asia, Europe 20160414.4160595
Zika virus (19): Americas 20160411.4152933
Zika virus (18): Americas 20160402.4134955
Zika virus (17): Americas, Pacific 20160401.4129524
Zika virus (16): Americas, Asia, Pacific, Atlantic 20160325.4118019
Zika virus (15): Americas 20160321.4109160
Zika virus (14): Americas, Europe, Atlantic Ocean 20160317.4102468
Zika virus (13): Americas, Asia, Europe, Pacific 20160311.4086075
Zika virus (12): Brazil, microcephaly 20160305.4070601
Zika virus (11): Americas, Europe, Asia 20160301.4059896
Zika virus (10): Americas, Asia, Europe, Pacific 20160229.4058161
Zika virus (09): Americas, Africa, Europe, Pacific 20160223.4042828
Zika virus (08): Americas, Asia, Europe, Pacific 20160217.4026836
Zika virus (07): update 20160216.4023810
ProMED-mail endorses sharing of Zika virus data 20160211.4012212
Zika virus (06): overview 20160209.4007411
Zika virus (05): Americas, Asia, Pacific 20160203.3990632
Zika virus (04): WHO declares worldwide PHEIC 20160201.3985366
Zika virus (03): Americas, Asia 20160128.3974426
Zika virus - Americas (02) 20160111.3925377
Zika virus - Americas (01) 20160108.3921447
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