ZIKA VIRUS (10): AMERICAS, ASIA, MIDDLE EAST, RESEARCH

Posted on 30TH MAY 2017
tagged Zika Virus, Americas; Asia; Middle East

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
---
Florida (Miami area)

Central America
---
Belize

Caribbean
---
Cuba
USA Virgin Islands

South America
---
Brazil

Asia
---
India (Ahmedabad, Gujarat state)

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

[2] Virus mutation
[3] Cryptic transmission
[4] Virus evolution and spread
[5] Adolescent cognitive impairment
[6] Maternal-fetal transmission in monkeys
[7] Intravaginal, intrarectal transmission, macaques
[8] Vaccine trial difficulty

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Cases in various countries
Americas
---
Americas cumulative case numbers
As of 25 May 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 / 499 / 0 / 1
USA / 0 / 225 / 5010 / 0 / 72

Latin America:
Mexico / 0 / 8762 / 15 / 0 / 5

Central American Isthmus:
Belize / 1294 / 206 / 0 / 0 / 0
Costa Rica / 6352 / 1806 / 32 / 0 / 5
El Salvador / 11 514 / 51 / 0 / 0 / 4
Guatemala / 3634 / 921 / 0 / 0 / 59
Honduras / 32 130 / 302 / 0 / 0 / 4
Nicaragua / 0 / 2060 / 3 / 0 / 2
Panamá / 4178 / 969 / 42 / 0 / 7

Latin Caribbean:
Cuba / 0 / 187 / 58 / 0 / 0
Dominican Republic / 4906 / 345 / 0 / 0 / 93
French Guiana / 10 385 / 483 / 10 / 0 / 17
Guadeloupe / 30 845 / 382 / 0 / 0 / 18
Haiti / 2955 / 5 / 0 / 0 / 1
Martinique / 36 680 / 21 / 0 / 0 /23
Puerto Rico / 0 / 40 274 / 137 / 5 / 35
Saint Barthelemy / 990 / 61 / 0 / 0 / 0
Saint Martin / 3280 / 200 / 0 / 0 / 1

Non-Latin Caribbean:
Anguilla / 29 / 23 / 1/ 0 / 0
Antigua and Barbuda / 465 / 14 / 2 / 0 / 0
Aruba / 1208 / 468 / 7 / 0 / 0
Bahamas / 0 / 25 / 3/ 0 / 0
Barbados / 705 / 150 / 0 / 0 / 1
Bonaire, St Eustatius and Saba / 235 / 381 / 0 / 0 / 0
Caymans / 232 / 31 / 10 / 0 / 0
Curacao / 2589 / 1259 / 0 / 0 / 0
Dominica / 1154 / 79 / 0 / 0 / 0
Grenada / 335 / 118 / 0 / 0 / 2
Guyana / 0 / 37 / 0 / 0 / 0
Jamaica / 7655 / 203 / 0 / 0 / 0
Montserrat / 18 / 5 / 0 / 0 / 0
Saint Kits and Nevis / 554 / 33 / 0 / 0 / 0
Saint Lucia / 822 / 50 / 0 / 0 / 0
Saint Vincent and the Grenadines / 508 / 83 / 0 / 0 / 0
Saint Maarten / 247 / 147 / 0 / 0 / 0
Suriname / 2768 / 723 / 0 / 4 / 4
Trinidad and Tobago / 0 / 718 / 1 / 0 / 3
Turks and Caicos / 201 / 25 / 3 / 0 / 0
Virgin Islands (UK) / 74 / 52 / 0 / 0 / 0
Virgin Islands (USA) / 1093 / 1026 / 2 / 0 / 0

Andean Area:
Bolivia / 1767 / 585 / 4 / 0 / 14
Colombia / 98 020 / 9802 / 0 / 0 / 155
Ecuador / 3972 / 1013 / 22 / 0 / 0
Peru / 5434 / 1006 / 22 / 0 / 0
Venezuela / 59 965 / 2413 / 0 / 0 / 0

[Brazil and] Southern Cone:
Brazil / 223 230 / 133 527 / 0 / 11 / 2698
Argentina / 869 / 99 / 40 / 0 / 2
Chile / 0 / 0 / 34 / 0 / 0
Paraguay / 668 / 16 / 0 / 0 / 2
Uruguay / 0 / 0 / 1 / 0 / 0

Totals, Americas / 563 960 / 211 695 / 5957 / 20 / 3231

[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 at http://healthmap.org/promed/p/39455;
Caribbean at http://www.mapsofworld.com/caribbean-islands/ and
South America at http://healthmap.org/promed/p/6186. - Mod.TY]

North America
---
Florida (Miami area). 25 May 2017. (reported) Mosquitoes there started picking up the virus from infected travelers as early as March last year [2016], according to scientists who examined genetic information from samples from about 30 people with Zika as well as from mosquitoes. It wasn't until July [2016] that Florida health officials said they had detected a local infection - the 1st in the US mainland.
http://www.wptv.com/news/state/zika-hit-florida-months-before-infections...

[A recent study to gain insights into the timing, source, and likely route(s) of ZIKV introduction, the authors tracked the virus from its 1st detection in Florida by sequencing ZIKV genomes from infected patients and _Aedes aegypti_ mosquitoes. They showed that at least 4 introductions, but potentially as many as 40, contributed to the outbreak in Florida and that local transmission is likely to have started in the spring of 2016 -- several months before its initial detection (https://www.nature.com/nature/journal/vaop/ncurrent/full/nature22400.html). This report was provided by ProMED-mail rapporteur Mary Marshall. - Mod.TY]

Central America
---
Belize. 26 May 2017. November 2016 - April 2017 (conf) 124 cases.
https://www.sanpedrosun.com/health/2017/05/26/moh-continues-monitor-zika...

Caribbean
---
Cuba. 18 May 2017. (reported) [since 2017] 1847 cases [numbers of cases imported or locally acquired not indicated].
http://news.trust.org/item/20170518145438-wdbpf/

USA Virgin Islands. 23 May 2017. (conf) 1019 cases: case counts by island: Saint Thomas (reported) 1247 cases, (conf) 681 cases; Saint Croix (reported) 730 cases, (conf) 250 cases; Saint John (reported) 140 cases, (conf) 88 cases; ff the pregnant women tested for all islands, 238 were positive for Zika virus infection.
http://viconsortium.com/health/six-more-pregnant-women-test-positive-for...

South America
---
Brazil. 27 May 2017. Microcephaly since beginning of outbreak in November 2015 (suspected [susp]) 10 905 cases, (conf) 2698 cases; microcephaly and other developmental alterations up to 22 Apr 2017 (susp) 936 cases, (registered) 246 cases.
http://spanish.china.org.cn/international/txt/2017-05/27/content_4090497... [in Spanish]

Asia
---
India (Ahmedabad, Gujarat state). 26 May 2017 (conf) 1st locally acquired 3 cases in the Bapunagar area, Ahmedabad District, including 2 pregnant women who delivered normal babies. These cases indicate that there is low-level Zika virus circulation in this part of India.
http://www.who.int/csr/don/26-may-2017-zika-ind/en/
[This report was provided by ProMED-mail rapporteur Mary Marshall. - Mod.TY]

[Maps of India can be seen at http://www.mapsofindia.com/maps/india/india-political-map.htm and http://healthmap.org/promed/p/302. - Mod.TY]

Imported cases with no possibility of ongoing mosquito transmission
---
Israel. 21 May 2017. (reported) approximately 20 cases, all imported, however, the Health Ministry said that the Asian tiger mosquito [_Aedes albopictus_], which is known to transmit the virus, is common in Israel.
http://www.israelnationalnews.com/News/News.aspx/229952

USA:
- case numbers mainland. Zika virus disease in the United States, 1 Jan 2017 - 24 May 2017
http://www.cdc.gov/zika/geo/united-states.html
State / Symptomatic cases / Viremic blood donors
Alabama / 3 / 0
Arizona / 1 / 0
California / 13 / 1
Colorado / 3 / 0
Florida / 14 / 3
Georgia / 1 / 0
Illinois / 4 / 0
Indiana / 1 / 0
Iowa / 1 / 0
Kansas / 2 / 0
Kentucky / 1 / 0
Louisiana / 1 / 0
Maine / 1 / 0
Maryland / 3 / 0
Massachusetts / 5 / 0
Michigan / 6 / 0
Mississippi / 2 / 0
Missouri / 1 / 0
New Jersey / 2 / 0
New York / 24 / 1
North Carolina / 3 / 0
Ohio / 3 / 0
Oregon / 1 / 0
Pennsylvania / 3 / 0
Rhode Island / 2 / 0
Texas / 10 / 1
Vermont / 2 / 0
Virginia / 3 / 0
Washington / 2 / 0
West Virginia / 0 / 2
Wisconsin / 2 / 0
Total / 121 / 8

- Territories and Commonwealth:
Location / Symptomatic / Blood donors
American Samoa / 3 / 0
Puerto Rico / 459 / 3
US Virgin Islands / 36 / 0
Total / 498 / 3
[A map of the USA showing the states and territories mentioned above can be accessed at http://www.mapsofworld.com/usa/. - Mod.TY]

--
communicated by:
ProMED-mail

and
Roland Hübner
Superior Health Council
Brussels
Belgium

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[2] Virus mutation
Date: Thu 25 May 2017
Source: Nature doi:10.1038/nature22365 [edited]
https://www.nature.com/nature/journal/vaop/ncurrent/full/nature22365.html

ref: Liu Y, Liu J, Du S, et al. Evolutionary enhancement of Zika virus infectivity in _Aedes aegypti_ mosquitoes. Nature. 2017;545(7655):482-486. doi: 10.1038/nature22365
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Abstract
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Zika virus (ZIKV) remained obscure until the recent explosive outbreaks in French Polynesia (2013-2014) and South America (2015-2016). Phylogenetic studies have shown that ZIKV has evolved into African and Asian lineages. The Asian lineage of ZIKV was responsible for the recent epidemics in the Americas. However, the underlying mechanisms through which ZIKV rapidly and explosively spread from Asia to the Americas are unclear. Non-structural protein 1 (NS1) facilitates flavivirus acquisition by mosquitoes from an infected mammalian host and subsequently enhances viral prevalence in mosquitoes. Here we show that NS1 antigenaemia determines ZIKV infectivity in its mosquito vector _Aedes aegypti_, which acquires ZIKV via a blood meal. Clinical isolates from the most recent outbreak in the Americas were much more infectious in mosquitoes than the FSS13025 strain, which was isolated in Cambodia in 2010. Further analyses showed that these epidemic strains have higher NS1 antigenaemia than the FSS13025 strain because of an alanine-to-valine amino acid substitution at residue 188 in NS1. ZIKV infectivity was enhanced by this amino acid substitution in the ZIKV FSS13025 strain in mosquitoes that acquired ZIKV from a viraemic C57BL/6 mouse deficient in type I and II interferon (IFN) receptors (AG6 mouse). Our results reveal that ZIKV evolved to acquire a spontaneous mutation in its NS1 protein, resulting in increased NS1 antigenaemia. Enhancement of NS1 antigenaemia in infected hosts promotes ZIKV infectivity and prevalence in mosquitoes, which could have facilitated transmission during recent ZIKV epidemics.

--
communicated by:
ProMED-mail

[This interesting report indicates the occurrence of a mutation in the genome of the Zika virus strains from the Americas that promotes the infectivity of these viruses for _Aedes aegypti_ vector mosquitoes. The _Ae. aegypti_ mosquito used in these experiments was the Rockefeller strain, which has been maintained in laboratory colonies for many years. It would be interesting to repeat the susceptibility tests using wild-type _Ae. aegypti_ from the Americas, in parallel with the Rockefeller strain mosquitoes, as an indication of what may be occurring in nature. - Mod.TY]

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[3] Cryptic transmission
Date: Wed 24 May 2017
Source: Nature doi:10.1038/nature22401 [edited]
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature22495.html...

ref: Faria NR, Quick J, Claro IM, et al. Establishment and cryptic transmission of Zika virus in Brazil and the Americas. Nature. 2017. doi: 10.1038/nature22401
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Abstract
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Transmission of Zika virus (ZIKV) in the Americas was 1st confirmed in May 2015 in north east Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200 000 by 24 Dec 2016) and the most cases associated with microcephaly and other birth defects (2366 confirmed by 31 Dec 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the 1st detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of north east Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

--
communicated by:
ProMED-mail

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[4] Virus evolution and spread
Date: Wed 24 May 2017
Source: Nature doi:10.1038/nature22402 [edited]
https://www.nature.com/nature/journal/vaop/ncurrent/full/nature22402.html

ref: Metsky HC, Matranga CB, Wohl S, et al. Zika virus evolution and spread in the Americas. Nature. 2017. doi: 10.1038/nature22402
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Abstract
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Although the recent Zika virus (ZIKV) epidemic in the Americas and its link to birth defects have attracted a great deal of attention, much remains unknown about ZIKV disease epidemiology and ZIKV evolution, in part owing to a lack of genomic data. Here we address this gap in knowledge by using multiple sequencing approaches to generate 110 ZIKV genomes from clinical and mosquito samples from 10 countries and territories, greatly expanding the observed viral genetic diversity from this outbreak. We analysed the timing and patterns of introductions into distinct geographic regions; our phylogenetic evidence suggests rapid expansion of the outbreak in Brazil and multiple introductions of outbreak strains into Puerto Rico, Honduras, Colombia, other Caribbean islands, and the continental United States. We find that ZIKV circulated undetected in multiple regions for many months before the 1st locally transmitted cases were confirmed, highlighting the importance of surveillance of viral infections. We identify mutations with possible functional implications for ZIKV biology and pathogenesis, as well as those that might be relevant to the effectiveness of diagnostic tests.

--
communicated by:
ProMED-mail rapporteur Mary Marshall

[One hopes that a repository of low-passage Zika virus from a wide variety of locations and over time has been established for additional studies of pathogenesis and virus-vector relationships. - Mod.TY]

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[5] Adolescent cognitive impairment
Date: Tue 6 Jun 2017
Source: Emerg Infect Dis. 2017;23(6):1047-1048 [edited]
https://wwwnc.cdc.gov/eid/article/23/6/16-2029_article

ref: Zucker J, Neu N, Chiriboga CA, et al. Zika virus-associated cognitive impairment in adolescent, 2016. Emerg Infect Dis. 2017;23(6):1047-1048. doi: 10.3201/eid2306.162029.
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Abstract
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Incidence of neurologic manifestations associated with Zika virus infection has been increasing. In 2016, neuropsychological and cognitive changes developed in an adolescent after travel to a Zika virus-endemic area. Single-photon emission computed tomography and neuropsychological testing raised the possibility that Zika virus infection may lead to neuropsychiatric and cognitive symptoms.

Conclusion
----------
Although we cannot entirely rule out Epstein-Barr virus as a possible trigger, the length of time between previous infection and onset of neuropsychological symptoms would be unusual. In addition, although it is impossible to exclude contributions of coinfection from other mosquitoborne viruses (for example, dengue and chikungunya), given the Zika virus positivity on RT-PCR, the patient's condition met criteria for definitive Zika virus infection and the CSF IgM titer was consistent with CNS involvement of Zika virus. The changes on single-photon emission computed tomographs and neuropsychological test scores raise the possibility that Zika virus infection may trigger neuropsychiatric and cognitive symptoms. Although we cannot prove that the patient's symptoms were related to Zika virus, clinicians should be aware of this potential association and the value of closely monitoring patients with Zika virus infection.

--
communicated by:
ProMED-mail

[Although this report is of a single patient, it does bring up the possibility that Zika virus infection of adolescents may cause neuropsychological and cognitive changes. Clinicians attending these patients should be aware of these possibilities. - Mod.TY]

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[6] Maternal-fetal transmission in monkeys
Date: Thu 25 May 2017 [ahead of print]
Source: PLoS Pathogens https://doi.org/10.1371/journal.ppat.1006378 [edited]
http://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1...

ref: Nguyen SM, Antony KM, Dudley DM, et al. Highly efficient maternal-fetal Zika virus transmission in pregnant rhesus macaques. PLoS Pathog. 2017;13(5):e1006378. doi: 10.1371/journal.ppat.1006378
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Abstract
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Infection with Zika virus (ZIKV) is associated with human congenital fetal anomalies. To model fetal outcomes in nonhuman primates, we administered Asian-lineage ZIKV subcutaneously to 4 pregnant rhesus macaques. While non-pregnant animals in a previous study contemporary with the current report clear viremia within 10-12 days, maternal viremia was prolonged in 3 of 4 pregnancies. Fetal head growth velocity in the last month of gestation determined by ultrasound assessment of head circumference was decreased in comparison with biparietal diameter and femur length within each fetus, both within normal range. ZIKV RNA was detected in tissues from all 4 fetuses at term cesarean section. In all pregnancies, neutrophilic infiltration was present at the maternal-fetal interface (decidua, placenta, fetal membranes), in various fetal tissues, and in fetal retina, choroid, and optic nerve (1st trimester infection only). Consistent vertical transmission in this primate model may provide a platform to assess risk factors and test therapeutic interventions for interruption of fetal infection. The results may also suggest that maternal-fetal ZIKV transmission in human pregnancy may be more frequent than currently appreciated.

Author summary
--------------
Maternal ZIKV infection in pregnancy is associated with severe fetal anomalies, including microcephaly. It has been shown that infection manifests differently in pregnancy than in the non-pregnant state, with prolonged maternal viremia. ZIKV is spread by mosquitoes and through sexual contact and since its 1st detection in early 2015, has become endemic to the Americas. While much has been learned from studying infected human pregnancies, there are still many questions concerning transmission of ZIKV from mother to fetus. Investigating ZIKV infection in non-human primates could help answer these questions due to similarities in the immune system and the tissues separating the fetus from the mother during pregnancy. Our study serves to model ZIKV transmission in early and late pregnancy, as well as study the effects of this infection on the fetus and mother at these different times in pregnancy. The data collected provides an important insight on ZIKV in pregnancy where the pregnancies have been monitored throughout the entire infection period until term, and suggests that vertical transmission may be very efficient, although severe fetal outcomes are uncommon.

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communicated by:
ProMED-mail

[Although an expensive model system, this study indicates that pregnant rhesus monkeys may be a reliable system biologically close to humans. Several drugs have been reported to interfere with Zika virus replication cycles. It will be interesting to see results if these drugs are tested in this pregnant rhesus monkey model system. - Mod.TY]

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[7] Intravaginal, intrarectal transmission, macaques
Date: 26 May 2017 [expedited ahead of print]
Source: Emerg Infect Dis. https://doi.org/10.3201/eid2308170036 [edited]
https://wwwnc.cdc.gov/eid/article/23/8/17-0036_article

ref: Haddow AD, Nalca A, Rossi FD, et al. High infection rates for adult macaques after intravaginal or intrarectal inoculation with Zika virus. Emerg Infect Dis. 2017;23(8). doi: 10.3201/eid2308.170036
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Abstract
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Unprotected sexual intercourse between persons residing in or traveling from regions with Zika virus transmission is a risk factor for infection. To model risk for infection after sexual intercourse, we inoculated rhesus and cynomolgus macaques with Zika virus by intravaginal or intrarectal routes. In macaques inoculated intravaginally, we detected viremia in 75 per cent of macaques and virus RNA in 100 per cent, followed by seroconversion. In macaques inoculated intrarectally, we detected viremia, virus RNA, or both, in 100 per cent of both species, followed by seroconversion. The magnitude and duration of infectious virus in blood of macaques suggest humans infected with Zika virus through sexual transmission will likely generate viremias sufficient to infect competent mosquito vectors. Our results indicate that transmission of Zika virus by sexual intercourse might serve as a virus maintenance mechanism in the absence of mosquito-to-human transmission and could increase the probability of establishment and spread of Zika virus in regions where this virus is not present.

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communicated by:
ProMED-mail rapporteur Mary Marshall

[These experiments provide additional support to the observations in humans that vaginal and rectal sexual intercourse engaged in by men who are infected with Zika virus can lead to transmission to susceptible partners. Moreover, the infected macaques develop viremias of sufficient magnitude to infect _Aedes aegypti_ vector mosquitoes. - Mod.TY]

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[8] Vaccine trial difficulty
Date: Fri 26 May 2017
Source: Nature News [edited]
http://www.nature.com/news/drop-in-cases-of-zika-threatens-large-scale-t...

Studies of thousands of pregnant women that were set up to probe the link between Zika and birth defects may not provide definitive answers because of a sharp drop in the number of new cases, researchers have warned. The unexpected development is making the disease harder to study, and threatens to hamper trials of experimental vaccines that might protect pregnant women in future outbreaks.

"We're seeing few, if any, cases, particularly in southern Brazil, which we thought might be the next big area to be hit this year," says Oliver Brady, an epidemiologist at the London School of Hygiene and Tropical Medicine.

The 2 largest studies each intend to recruit 10 000 or more pregnant women. The Zika in Infants and Pregnancy (ZIP) study was launched last June [2016] by the US National Institutes of Health (NIH) and the Fundação Oswaldo Cruz-Fiocruz (Fiocruz), a national scientific agency in Brazil, and has so far recruited almost 3000 women. The other study is just beginning to recruit. It is being carried out by the ZIKAlliance, a multidisciplinary consortium of 53 research centres that launched in December [2016] with EUR 12 million (USD 13.5 million) from the European Union. Both trials are taking place across multiple sites in South America and the Caribbean.

But with the drop in new cases the ZIKAlliance is now reconsidering its plan. "We are going to be pragmatic, we are going to try, but if there are not enough infected cases, then there is little point," says the consortium's scientific coordinator Xavier de Lamballerie, a virologist at Aix-Marseille University and French national biomedical agency INSERM.

The ZIKAlliance intends to capture what cases it can at its sites, and is considering focusing resources in sites where Zika has been rarer, such as Bolivia, where future flare-ups might be more likely. "We will track cases there where they are," he says, "It's a race against the clock."

The ZIP study is similarly faced with low numbers of Zika cases, says Anthony Fauci, director of the NIH's National Institute of Allergy and Infectious Diseases (NIAID). "That's good for the population -- if making it more difficult to get reasonable data for the study," he says. The low level of cases will also affect field trials of experimental vaccines, he adds. One such trial, the NIH VRC 705 phase II trial, began in March [2017] and aims to enrol at least 2490 volunteers in 7 countries in the Americas.

Epidemiologists say that they are unsure why the number of cases of the mosquitoborne disease has declined so steeply, and whether it will spike again in some region in South America or elsewhere. Often, the disease causes no symptoms, so most cases go undetected; it's possible that the rapid spread of the disease in the Americas has meant it has burnt itself out because enough people have become immune to the virus.

Large-scale trials inevitably take time to organize. But delays incurred in obtaining ethical and other approvals in the trials' host countries have slowed the process further, as have a lack of clear rules for matters such as the shipping and ownership of samples.

[byline: Declan Butler]

--
communicated by:
ProMED-mail rapporteur Mary Marshall

[This is a good news / bad news situation. The good news is that fewer individuals, and especially pregnant women, are becoming infected. The bad news is that after considerable effort and cost, there are now vaccines ready for clinical trials in the field, but with fewer cases, these trials will either take much longer to complete, or may even be abandoned. - Mod.TY]

[

A HealthMap/ProMED-mail map can be accessed at: http://healthmap.org/promed/p/12214.]

See Also

Zika virus (09): Americas, Asia, Europe, research, observations 20170517.5043638
Zika virus (08): Americas, Asia, research, observations 20170501.5005629
Zika virus (07): Americas, PAHO/WHO 20170429.5003908
Zika virus (06): Americas, Pacific, Asia, Africa, research 20170416.4974439
Zika virus (05): Americas, Pacific, Asia, research, observations 20170326.4927523
Zika virus (04): Americas, Asia Europe, research, observations 20170320.4912123
Zika virus (03): Americas, research 20170309.4888510
Zika virus (02): Americas, Asia, Africa, Pacific, research, observations 20170217.4846633
Zika virus (01): Americas, Asia, Africa, research 20170117.4772206
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