Disease Outbreak News
1 March 2016
On 25 February 2016, the National IHR Focal Point of Saint Vincent and the Grenadines notified PAHO/WHO of the country’s first case of Zika virus infection.
The patient is a 34-year-old female who visited on 16 February a health centre in Union Island after experiencing fever, headache, chills, cough and weakness of the lower extremities. She was kept for observation at the hospital overnight. The patient has no history of travel in the 30 days prior to being admitted to hospital. No clusters of febrile-like illness were noted on the island.
A venous blood sample was collected on 17 February and sent to the Caribbean Public Health Agency (CARPHA) for testing. On 23 February, the sample tested positive for Zika virus infection by polymerase chain reaction (PCR).
Public health response
Health authorities in Saint Vincent and the Grenadines are taking the following measures:
- increasing environmental and laboratory surveillance,
- conducting public education programs,
- carrying out national clean-up campaigns,
- communicating with health practitioners,
- mobilizing national and regional resources.
WHO risk assessment
The detection of autochthonous cases of Zika virus infection indicates that the virus is spreading geographically to previously unaffected areas (Saint Vincent and the Grenadines). The notification of autochthonous transmission in a new country does not change the overall risk assessment. The risk of a global spread of Zika virus to areas where the competent vectors, the Aedes mosquitoes, are present is significant given the wide geographical distribution of these mosquitoes in various regions of the world. WHO continues to monitor the epidemiological situation and conducts risk assessment based on the latest available information.
Despite some reports of a potential association between Zika virus, microcephaly and other neurological disorders, at this stage, it is not possible to establish a causal relationship between these events. Until more is understood, Members States are advised to standardize and enhance surveillance for microcephaly and other neurological disorders, particularly in areas of known Zika virus transmission and areas at risk of such transmission.
The proximity of mosquito vector breeding sites to human habitation is a significant risk factor for Zika virus infection. Prevention and control relies on reducing the breeding of mosquitoes through source reduction (removal and modification of breeding sites) and reducing contact between mosquitoes and people. This can be achieved by reducing the number of natural and artificial water-filled habitats that support mosquito larvae, reducing the adult mosquito populations around at-risk communities and by using barriers such as insect screens, closed doors and windows, long clothing and repellents. Since the Aedes mosquitoes (the primary vector for transmission) are day-biting mosquitoes, it is recommended that those who sleep during the daytime, particularly young children, the sick or elderly, should rest under mosquito nets (bed nets), treated with or without insecticide to provide protection. Mosquito coils or other insecticide vaporizers may also reduce the likelihood of being bitten.
During outbreaks, space spraying of insecticides may be carried out following the technical orientation provided by WHO to kill flying mosquitoes. Suitable insecticides (recommended by the WHO Pesticide Evaluation Scheme) may also be used as larvicides to treat relatively large water containers, when this is technically indicated.
Basic precautions for protection from mosquito bites should be taken by people traveling to countries with transmission of Zika virus, especially by pregnant women. These include use of repellents, wearing light colored, long sleeved shirts and pants and ensuring rooms are fitted with screens to prevent mosquitoes from entering.
WHO does not recommend any travel or trade restriction to Saint Vincent and the Grenadines based on the current information available.