Epidemiological Update - Zika Virus Infection - 30 June 2016
Zika virus – Incidence and trends
To date, 40 countries and territories have confirmed local, vectorial transmission of Zika virus disease in the Region of the Americas since 2015 (Figure 1). Since the last Pan American Health Organization/ World Health Organization (PAHO/WHO) Zika Epidemiological Update on 23 June 2016, no additional countries or territories confirmed vector-borne autochthonous transmission of Zika virus.
Congenital syndrome associated with Zika virus infection
Since the last PAHO/WHO Zika Epidemiological Update on 23 June 2016, French Guiana has reported a case of microcephaly associated with the Zika virus that was detected through an ultrasound performed on a pregnant woman who had been infected with Zika virus during her pregnancy. In addition, Brazil, Colombia, Martinique, and the United States of America updated the number of reported cases presented in Table 1.
According to the Brazil Ministry of Health, between 22 October 2015 and 25 June 2016 a total of 8,165 suspected cases of microcephaly and other congenital malformations of the central nervous system (CNS) have been reported in newborns. Of these, 1,638 cases were confirmed in accordance with Brazil’s Surveillance and Response Protocol2 (270 were confirmed by laboratory criteria). Out of the total cases reported, 3,466 cases were discarded as being due to noninfectious causes or not fitting the case definition, and 3,061 remain under investigation. Of the total reported cases, 4% (328 cases) correspond to stillbirths or neonatal deaths; 36 of them were confirmed by laboratory criteria.Regarding the geographical distribution, the total of confirmed cases occurred in 582 municipalities located in 27 Federal Units of Brazil.
Between epidemiological week (EW) 1 and EW 24 of 2016, 11 cases of microcephaly associated with Zika virus were reported in Colombia. In addition, 51 other cases of microcephaly suspected to be associated with Zika virus were discarded and 102 cases remain under investigation. See full report.
Up to EW 25 of 2016, there have been two cases of microcephaly and four other congenital malformations associated with Zika virus reported in Martinique. The anomalies were detected by ultrasound in pregnant women in whom Zika virus infection during pregnancy was confirmed.
United States of America
As of 23 June 2016, the United States Centers for Disease Control and Prevention (U.S. CDC) reported that there were a total of 7 liveborn infants with birth defects and 5 pregnancy losses with laboratory evidence of possible Zika virus infection.
The liveborn infants with birth defects include microcephaly, calcium deposits in the brain indicating possible brain damage, excess fluid in the brain cavities and surrounding the brain, absent or poorly formed brain structures, abnormal eye development, or other problems resulting from damage to the brain that affects nerves, muscles and bones, such as clubfoot or inflexible joints. The pregnancy losses include miscarriage, stillbirths, and terminations with evidence of the birth defects mentioned above