CRS INSIGHT
Zika Virus: Global Health Considerations
February 9, 2016 (IN10433)
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Related Author
Tiaji Salaam-Blyther
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Tiaji Salaam-Blyther, Specialist in Global Health (tsalaam@crs.loc.gov, 7-7677)
Background
Zika
Background
Zika is a virus that is primarily spread by Aedes mosquitoes—the same mosquitoes that transmit
dengue, chikungunya,
dengue, chikungunya, and yellow fever. Zika transmission has also been
documenteddocumented from mother to child during pregnancy, as well as
through sexual intercourse, blood transfusions, and laboratory exposure. Scientists first identified the virus in 1947
among monkeys living in the Ugandan Zika forest. Five years later, human cases were detected in Uganda and
Tanzania. The first human cases outside of Africa were diagnosed in the Pacific in 2007 and in Latin America in 2015.
The ongoing outbreak in Latin America began in Brazil in May 2015 and has since spread to 26 countries and
territories in the region. Health experts predict that the virus will likely spread to all countries in the Western
Hemisphere except Canada and Chile, the only countries in the region without Aedes mosquitoes. No instances of local
From January 1, 2007, to April 7, 2016, Zika has spread to 62 countries and territories (Figure 1), and the World Health Organization (WHO) expects the disease to spread to more countries where Aedes mosquitos reside. Scientists are also exploring whether other vectors can spread the disease.
Figure 1. Global Transmission of Zika
(as of April 7, 2016)
Source: Created by CRS from WHO, Zika Situation Report, April 7, 2016.
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An ongoing outbreak in Latin America began in Brazil in May 2015 and has since spread to 33 countries and territories in the region. No instances of local transmission have been reported in the continental United States, but cases have been reported
in the United States among travelers who
visited Central and South America, and transmission is ongoing in Puerto Rico. Outside of Latin America,
Cape Verde
—islands off the West African coast—has ongoing transmission and Samoa—islands in the Western Pacific—has
reported less than a dozen imported cases.
Figure 1. Countries and Territories with Zika Cases in the Americas
(January 31-February 6, 2016)
Source: Created by CRS from PAHO and CDC maps of Zika cases at http://www.paho.org and
http://www.cdc.gov/zika/geo/index.html, accessed on February 9, 2016.
Vietnam began to report new Zika cases in late March 2016 and Cape Verde—islands off the West African coast—has ongoing transmission, with nearly 7,500 suspected cases.
Scientists are unsure how many people have been
affected by the 2015 outbreak in Latin America. Experts at the World
Health Organization (WHO)infected by Zika in the Western Hemisphere. Experts at the WHO and its regional office for the Americas, the Pan American Health Organization (PAHO)
,
, cite several factors that complicate efforts to count Zika cases, including
the following:
Aa relatively small proportion (about 1 in 4) of infected people develop symptoms
.
The;
the virus is
only detectable for
only a few days in infected people's blood
.
Current; and
current tests cannot definitively distinguish Zika from similar viruses, such as dengue and chikungunya.
Zika typically causes mild symptoms, including fever, rash, and conjunctivitis, which usually last up to one week.
Hospitalization and death following infection are
rarerare. There are neither antiviral treatments for the disease nor
vaccines to prevent infection.
Health experts are uncertain whether Zika causes microcephaly, a potentially severe birth defect involving brain
damage. Since October 2015, Brazilian officials have reported more than 4,000 cases of microcephaly in areas with
ongoing Zika transmission, up from roughly 150 cases in previous years. Health officials are concerned that this may be
a result of infection in the fetus when a pregnant woman is infected.
U.S. and International Responses
Although a direct link between Zika infection and birth defects has not been definitively established, the suspected
causality has caused WHO to raise vaccines to prevent infection. The U.S. Centers for Disease Control and Prevention (CDC) has concluded that Zika causes microcephaly (a potentially severe birth defect involving brain damage), Guillain-Barré syndrome (GBS, a neurological condition that can lead to paralysis), and other neurological and autoimmune conditions. Scientists are also researching whether Zika can cause neurological problems in adults. A small study found that six adults had developed neurological complications after contracting Zika.
Brazil has reported the highest incidence of microcephaly, with over 4,000 suspected cases (944 of which have been confirmed), up from roughly 150 cases in previous years. Microcephaly has also been detected among women who contracted Zika in Cape Verde (2 cases), Colombia (32 cases), French Polynesia (8 cases), Martinique (1 case), and Panama (1 case). As of April 6, 2016, CDC reports 346 travel-associated Zika cases in the continental United States; 32 of these are pregnant, including 2 cases of microcephaly.
U.S. and International Responses
After the rise in Zika-related microcephaly and GBS cases, WHO raised the risk profile of Zika "from a mild threat to one of alarming proportions." The
WHO Director-General found four issues particularly troubling:
the possible the association of infection with birth malformations and neurological syndromes;
the potential for further international spread given the wide geographical distribution of the mosquito vector;
the lack of population immunity in newly affected areas; and
the absence of vaccines, specific treatments, and rapid diagnostic tests.
Citing these concerns and possible increases in mosquito populations due to El Niño, WHO Director-General Margaret
Chan convened an Emergency Committee meeting on February 1, 2016, under the International Health Regulations
and declared and
declared that the ongoing outbreak is a public health emergency of international concern (
PHEICPHEIC). A PHEIC
declaration
indicatessignals that the health event "may require immediate international action." Scientists are also considering
the risk of infection to and further global spread of the virus by visitors to Brazil for the 2016 Summer Olympics.
WHO and PAHO are supporting affected countries to detect, respond, and prevent Zika infections by
strengthening disease surveillance;
building laboratory capacity to detect the virus;
bolstering mosquito control;
preparing recommendations for the care of infected persons; and
defining and supporting priority research areas.
In February 2016, WHO released a global Strategic Response Framework and Joint Operations Plan to guide the international response to the spread of Zika virus infection and the neonatal malformations and neurological conditions associated with it. The $56 million plan provides a framework for helping affected countries to
- strengthen disease surveillance,
- build laboratory capacity to detect the virus,
- bolster mosquito control,
- provide care for infected persons, and
- define and support priority research areas.
Several U.S. agencies are collaborating with international agencies to research the modes of transmission and
complications that may arise following infection.
The U.S. Centers for Disease Control and Prevention (CDC) and
CDC and PAHO, for example, are partnering with Brazil's Ministry of Health to study the impacts of Zika during pregnancy
,
including a possible link to microcephaly. CDC and the National Institutes of Health (NIH) are working on an
improved diagnostic test. The Department of Defense (DOD) is providing information to NIH to facilitate the
development development of vaccines and effective treatments.
U.S. Funding for Global Disease Threats
International outbreaks of new and reemerging diseases have prompted calls for more funds to expand global capacity to
address diseases like Zika
The ongoing Zika outbreak emerged while the international community was still working to contain an Ebola outbreak in West Africa. In addition, Latin America and the Caribbean had just emerged from successive dengue and chikungunya outbreaks. The rapid pace at which global disease outbreaks have occurred in recent years has deepened support for accelerating implementation of the Global Health Security Agenda (GHSA). In February 2014, Kathleen Sebelius, the former Secretary of the U.S. Department of Health
and Human Services, and WHO Director-General Margaret Chan announced
the Global Health Security Agenda
(GHSA)GHSA, an international effort to accelerate IHR implementation and pandemic preparedness worldwide, particularly
in low-resource countries. U.S. resources that are available for addressing diseases with pandemic potential globally,
like the ongoing Zika outbreak, are outlined in
Table 1.
Table 1. President Barack Obama has requested $1.8 billion to address
the ongoing Zika outbreak, including over $375 million for international efforts. The Zika Emergency request is
outlined in Table 2.
Table 1. International Pandemic Preparedness Funds:
FY2014FY2016
FY2014-FY2016
(current $U.S. millions)
Agency/Program
USAID Global
Health Security
CDC Global Public
Health Protection
FY2014
Enacted
FY2015
Enacted
FY2016
Request
FY2016
Enacted
73
73
50
73
63
55
77
55
Source: State-Foreign Operations and CDC Congressional Budget
Justifications and the FY2016 Consolidated Appropriations.
Notes: Includes only funds appropriated for international pandemic
preparedness. U.S. agencies may use additional resources from
other accounts to address global disease outbreaks worldwide.
Through FY2015 Ebola Emergency appropriations, Congress
provided $597 million to CDC to establish and strengthen National
Public Health Institutes and for other international preparedness
activities. It is unclear whether these resources are being used for
ongoing Zika responses.
Table 2. Zika Emergency Request
Agency/Activity
U.S. Centers for Disease Control and Prevention
(CDC) – domestic response
Puerto Rico's Medicaid Federal Medical
Assistance Percentage (FMAP) – health services
for pregnant women
National Institutes of Health (NIH) and Food and
Drug Administration (FDA) – Vaccine Research
and Diagnostic Development
Establishment of an Urgent and Emerging Threat
Fund at HHS to support State responses and
other emerging needs related to Zika
U.S. Agency for International Development
(USAID) – support affected countries to respond
to Zika outbreak
U.S. Department of State – support for U.S.
citizens in affected countries, as well as Zika
responses by the World Health Organization
(WHO) and the Pan American Health
Organization (PAHO)
Amount
$828 million
$250 million
$200 million
$210 million
$335 million
$41 million
Source: White House, Preparing for and Responding to the Zika Virus
Agency/Program
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FY2014 Enacted
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FY2015 Enacted
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FY2016 Request
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FY2016 Enacted
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FY2017 Request
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USAID Global Health Security
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73
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73
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50
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73
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73
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CDC Global Public Health Protection
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63
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55
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77
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55
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65
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Source: State-Foreign Operations and CDC Congressional Budget Justifications and the FY2016 Consolidated Appropriations.
Notes: Includes only funds appropriated for international pandemic preparedness. U.S. agencies may use additional resources from other accounts to address global disease outbreaks worldwide. Through FY2015 Ebola Emergency appropriations, Congress provided $597 million to CDC to establish and strengthen National Public Health Institutes and for other international preparedness activities. It is unclear whether these resources are being used for ongoing Zika responses.
On February 8, 2016, President Barack Obama requested $1.9 billion in FY2016 emergency funds to address the ongoing Zika outbreak, including over $375 million for international efforts. The Zika emergency request is outlined in Table 2 and is detailed in CRS Report R44460, Zika Response Funding: In Brief. The press has reported that some Members of the House Appropriations Committee expect the Administration to expend unobligated Ebola funds before considering the Zika request. Other Members oppose this idea and maintain that remaining Ebola funds should be preserved and used to strengthen the weak health systems in West Africa that initially failed to detect and contain the outbreak. Citing concerns about an impending spread of Zika to the United States and a pressing need to address Zika immediately, President Obama announced on April 6, 2016, that his Administration would redirect $510 million of emergency Ebola funds to reimburse agencies already responding to the Zika outbreak and to ensure continuity of these efforts. Congress is considering whether the Administration has sufficient authority to the $510 million.
Table 2. Zika Emergency Request
Agency/Activity
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Amount
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U.S. Centers for Disease Control and Prevention (CDC) – domestic response
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$828 million
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Puerto Rico's Medicaid Federal Medical Assistance Percentage (FMAP) – health services for pregnant women
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$250 million
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National Institutes of Health (NIH) and Food and Drug Administration (FDA) – Vaccine Research and Diagnostic Development
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$200 million
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Establishment of an Urgent and Emerging Threat Fund at HHS to support State responses and other emerging needs related to Zika
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$210 million
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U.S. Agency for International Development (USAID) – support affected countries to respond to Zika outbreak
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$335 million
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U.S. Department of State – support for U.S. citizens in affected countries, as well as Zika responses by the World Health Organization (WHO) and the Pan American Health Organization (PAHO)
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$41 million
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Source: White House, Preparing for and Responding to the Zika Virus at Home and Abroad, Fact Sheet, February 8, 2016.