ZIka virus (ZIKV) – Incidence and Trends
Since last update (February 18, 2016), three additional countries/territories have reported their first autochthonous (locally-acquired) confirmed cases of ZIKV: Saint Maarten (Kingdom of the Netherlands), Saint Vincent and the Grenadines, and Trinidad and Tobago. This brings to 31 the number of countries / territories in the Americas reporting autochthonous, confirmed ZIKV.
Caribbean countries/territories are reporting local transmission. This is in contrast to what was observed in the 2014-2015 Chikungunya outbreak.
Regionally, and in many countries, the epidemic appears to be increasing. As an example,
Colombia reported 3,765 new suspected and confirmed cases of ZIKV in the Epidemiological Week (EW) 6 and the trend up to EW 5 is increasing (see Figure 2).
Most cases were registered in the Departments of Norte de Santander, Huila, Cundinamarca,
Barranquilla and Tolima. Out of 37,011 reported cases (1,612 laboratory-confirmed), 6,356 (522 laboratory-confirmed) were in pregnant women.
On 23 February, the Ministry of Health of Brazil reported 360 additional cases of microcephaly (MC) in EW 7, bringing the total to 5,640 reported cases of MC. In terms of confirmed MC with clinical, imaging, and laboratory findings indicative of congenital infection, there were 75 new cases in EW 7, bringing the total to 583 confirmed cases. Among these, ZIKV was identified in 67 cases.
There were 12 additional deaths reported this week among MC cases (including miscarriages and stillbirths), bringing the total to 120 MC deaths. Among all reported cases of MC, 950 have been discarded, while another 3,935 remain under investigation.
The confirmed MC cases are distributed across 235 municipalities, and Brazil is still detecting cases of MC in new areas. However, in the Northeast region – where the first excess of MC cases was detected -- the trend of MC appears to be de deceasing, with two (2) consecutive weeks of decreasing cases detected.
Guillain-Barre syndrome (GBS) and other neurological disorders
Since last update (February 18, 2016), no additional countries have reported an excess of GBS in the context of ZIKV outbreaks. This leaves the total number of countries/territories detecting excess GBS to five: Brazil, Colombia, El Salvador, Suriname, and Venezuela.
A new update was provided by Colombia. Since EW 51 (2015) to EW 6 (2016), 201 GBS cases with history of suspected ZIKV infection were reported. Most of cases are from Norte de Santander and Barranquilla – area where much of the burden of ZIKV cases has been registered. There are more male than female cases, and most cases are in persons who are 30-49 years old.
In Martinique, authorities have confirmed that laboratory testing for ZIKV infection is only being carried out in cases of pregnant women and/or patients with severe cases or complications.
Since the last update, Martinique has detected two additional cases of GBS and laboratory analysis for ZIKV infection in these cases is underway. Since the beginning of the ZIKV outbreak in Martinique, ZIKV infection has been confirmed in two prior GBS patients.
A 54-year-old Dutch woman without medical problems fell ill while visiting Suriname, developed severe illness with thrombocytopenia and bleeding, and was found to be positive for ZIKV infection. The illness began 11 days after arrival, and involved fatigue, loss of appetite, generalized weakness, and swollen and painful wrists, hands, and ankles. Ten days later, she had vomiting and watery diarrhea, and developed subcutaneous hematomas on all extremities. PCR analysis of a blood sample, taken on day 2 of her illness and performed at the Academic Hospital of Paramaribo, was positive for ZIKV.