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PAHO/WHO Epidemiological Alerts and Updates
Epidemiological Update
Neurological syndrome, congenital
anomalies, and Zika virus infection
17 January 2016
Given the increase of congenital anomalies, Guillain`Barr? syndrome, and other neurological
and autoimmune syndromes in areas where Zika virus is circulating, the Pan American Health
Organization / World Health Organization (PAHO/WHO) recommends its Member States
establish and maintain the capacity to detect and confirm Zika virus cases, prepare healthcare
facilities to respond to a possible increase demand of specialized care for neurological
syndromes, as well to strengthen antenatal care. In addition, Member States are urged to
continue with their efforts to reduce the presence of mosquito vectors through an effective
vector control strategy and communication to the public.
Situation summary
Autochthonous transmission of Zika virus
From February 20141 to 17 January 2016, there are 18 countries and territories in the Americas
that have confirmed autochthonous circulation of Zika virus (ZIKV) in 2015 and 2016: Brazil,
Barbados, Colombia, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Haiti, Honduras,
Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname, and Venezuela.
Between November 2015 and January 2016, local transmission of the virus was detected in 14 new
countries and territories.
Increase in neurological syndromes Guillain'Barr? Syndrome
During the Zika virus outbreak in French Polynesia (2013`2014),2 74 patients had presented
neurological syndromes or auto`immune syndromes after the manifestation of symptoms consistent
with Zika virus infection. Of these, 42 were classified as Guillain`Barr? syndrome (GBS). Of the 42
registered SGB, 24 (57%) were male, and 37 (88%) had signs and symptoms consistent with Zika virus
infection (3, 4, 5).
In July 2015, Brazil reported the detection of patients with neurological syndromes who had
recent history of Zika virus infection in the state of Bahia. There were 76 patients with neurological
syndromes identified, of which 42 (55%) were confirmed as GBS. Among the confirmed GBS, 26
(62%) had a history of symptoms consistent with Zika virus infection.
In addition, on 25 November 2015, the Aggeu Magalh?es Research Center of the Oswaldo
Cruz Foundation reported that ZIKV infection was found in 10 of the 224 suspected dengue patients
whose samples were analyzed for Zika virus infection. Seven of the 10 samples analyzed
corresponded to patients with neurological syndrome.
In January 2016, El Salvador reported the detection of an unusual increase of GBS since early
December 2015. On average, El Salvador records14 cases of GBS per month (169 cases per year),
however, between 1 December 2015 and 6 January 2016 there were 46 GBS recorded, of which 2
died. Twenty`five (54%) were male and 35 (76%) were over 30 years old. All were hospitalized and
treated with plasmapheresis or immunoglobulin. Of the deceased patients, one had a history of
multiple underlying chronic diseases. In 22 patients whose information was available 12 (54%) had
febrile rash illness between 7 and 15 days prior to the onset of GBS.
Currently, similar situations are being investigated in other countries of the Americas. These
findings are consistent with a temporal and spatial link between Zika virus circulation and the
increase of GBS. Although the etiopathogenesis and associated risk factors have not yet been well
established, Member States should implement surveillance systems to detect unusual increases in
cases and prepare health services for patients care with neurological conditions.
Other neurological syndromes
Zika virus can cause other neurological syndromes (meningitis, meningoencephalitis and
myelitis), as described in French Polynesia outbreak (2013`2014). While in the Region of the
Americas such syndromes have not been reported so far, health services and practitioners should
be alert about their possible occurrence to properly prepare health facilities for rapid detection
and appropriate treatment of cases.
Increase in microcephaly and other congenital anomalies
In October 2015, the Brazil International Health Regulations (IHR) National Focal Point (NFP)
notified the detection of an unusual increase in microcephaly3 cases in public and private
healthcare facilities in Pernambuco state, Northeast Brazil. 4 As of epidemiological week 1 of 2016,
there were 3,530 microcephaly cases recorded, including 46 deaths, in 20 states and the Federal
District. Between 2010 and 2014, an average of 163 (Standard deviation 16.9) microcephaly cases
was recorded nationwide per year.5 Figure 1 shows the comparative distribution of microcephaly
case (annual average between 2010 and 2014 compared with cases registered in 2015).
In January 2016, ophthalmological findings were reported in three children with microcephaly
and cerebral calcifications detected by CT scans and presumable intrauterine ZIKV infection. The
three infants had unilateral ocular findings involving the macular region and loss of foveal reflex. In
one child a well defined macular neuroretinal atrophy was detected (6).
...
Recommendations for public health authorities
While there is currently only ecological evidence of an association between increased
microcephaly, neurological and autoimmune syndromes, and prior infection with Zika virusI the
possible causative nature of the association cannot be ruled out with the evidence available.
Given this situation and considering the continued expansion of Zika virus in the Region of the
Americas, the Pan American Health Organization / World Health Organization (PAHO/WHO)
reinforces the recommendations relating to the Zika virus surveillance, including monitoring
neurological syndromes and congenital anomalies, which were published in the 1 December 2015
Epidemiological Alert. In addition to those recommendations, further guidelines on monitoring
neurological syndromes and the clinical management of Guillain`Barr? syndrome are provided
herein.
The recommendations will be reviewed and updated as new evidence becomes available.
...
Epidemiological Update
Neurological syndrome, congenital
anomalies, and Zika virus infection
17 January 2016
Given the increase of congenital anomalies, Guillain`Barr? syndrome, and other neurological
and autoimmune syndromes in areas where Zika virus is circulating, the Pan American Health
Organization / World Health Organization (PAHO/WHO) recommends its Member States
establish and maintain the capacity to detect and confirm Zika virus cases, prepare healthcare
facilities to respond to a possible increase demand of specialized care for neurological
syndromes, as well to strengthen antenatal care. In addition, Member States are urged to
continue with their efforts to reduce the presence of mosquito vectors through an effective
vector control strategy and communication to the public.
Situation summary
Autochthonous transmission of Zika virus
From February 20141 to 17 January 2016, there are 18 countries and territories in the Americas
that have confirmed autochthonous circulation of Zika virus (ZIKV) in 2015 and 2016: Brazil,
Barbados, Colombia, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Haiti, Honduras,
Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname, and Venezuela.
Between November 2015 and January 2016, local transmission of the virus was detected in 14 new
countries and territories.
Increase in neurological syndromes Guillain'Barr? Syndrome
During the Zika virus outbreak in French Polynesia (2013`2014),2 74 patients had presented
neurological syndromes or auto`immune syndromes after the manifestation of symptoms consistent
with Zika virus infection. Of these, 42 were classified as Guillain`Barr? syndrome (GBS). Of the 42
registered SGB, 24 (57%) were male, and 37 (88%) had signs and symptoms consistent with Zika virus
infection (3, 4, 5).
In July 2015, Brazil reported the detection of patients with neurological syndromes who had
recent history of Zika virus infection in the state of Bahia. There were 76 patients with neurological
syndromes identified, of which 42 (55%) were confirmed as GBS. Among the confirmed GBS, 26
(62%) had a history of symptoms consistent with Zika virus infection.
In addition, on 25 November 2015, the Aggeu Magalh?es Research Center of the Oswaldo
Cruz Foundation reported that ZIKV infection was found in 10 of the 224 suspected dengue patients
whose samples were analyzed for Zika virus infection. Seven of the 10 samples analyzed
corresponded to patients with neurological syndrome.
In January 2016, El Salvador reported the detection of an unusual increase of GBS since early
December 2015. On average, El Salvador records14 cases of GBS per month (169 cases per year),
however, between 1 December 2015 and 6 January 2016 there were 46 GBS recorded, of which 2
died. Twenty`five (54%) were male and 35 (76%) were over 30 years old. All were hospitalized and
treated with plasmapheresis or immunoglobulin. Of the deceased patients, one had a history of
multiple underlying chronic diseases. In 22 patients whose information was available 12 (54%) had
febrile rash illness between 7 and 15 days prior to the onset of GBS.
Currently, similar situations are being investigated in other countries of the Americas. These
findings are consistent with a temporal and spatial link between Zika virus circulation and the
increase of GBS. Although the etiopathogenesis and associated risk factors have not yet been well
established, Member States should implement surveillance systems to detect unusual increases in
cases and prepare health services for patients care with neurological conditions.
Other neurological syndromes
Zika virus can cause other neurological syndromes (meningitis, meningoencephalitis and
myelitis), as described in French Polynesia outbreak (2013`2014). While in the Region of the
Americas such syndromes have not been reported so far, health services and practitioners should
be alert about their possible occurrence to properly prepare health facilities for rapid detection
and appropriate treatment of cases.
Increase in microcephaly and other congenital anomalies
In October 2015, the Brazil International Health Regulations (IHR) National Focal Point (NFP)
notified the detection of an unusual increase in microcephaly3 cases in public and private
healthcare facilities in Pernambuco state, Northeast Brazil. 4 As of epidemiological week 1 of 2016,
there were 3,530 microcephaly cases recorded, including 46 deaths, in 20 states and the Federal
District. Between 2010 and 2014, an average of 163 (Standard deviation 16.9) microcephaly cases
was recorded nationwide per year.5 Figure 1 shows the comparative distribution of microcephaly
case (annual average between 2010 and 2014 compared with cases registered in 2015).
In January 2016, ophthalmological findings were reported in three children with microcephaly
and cerebral calcifications detected by CT scans and presumable intrauterine ZIKV infection. The
three infants had unilateral ocular findings involving the macular region and loss of foveal reflex. In
one child a well defined macular neuroretinal atrophy was detected (6).
...
Recommendations for public health authorities
While there is currently only ecological evidence of an association between increased
microcephaly, neurological and autoimmune syndromes, and prior infection with Zika virusI the
possible causative nature of the association cannot be ruled out with the evidence available.
Given this situation and considering the continued expansion of Zika virus in the Region of the
Americas, the Pan American Health Organization / World Health Organization (PAHO/WHO)
reinforces the recommendations relating to the Zika virus surveillance, including monitoring
neurological syndromes and congenital anomalies, which were published in the 1 December 2015
Epidemiological Alert. In addition to those recommendations, further guidelines on monitoring
neurological syndromes and the clinical management of Guillain`Barr? syndrome are provided
herein.
The recommendations will be reviewed and updated as new evidence becomes available.
...