The Zika Virus: An Introduction

1 What is the Zika Virus?

The Zika Virus is a mosquito-borne disease transmitted to people via a bite from an infected mosquito. The mosquito called the Aedes Aegypti, is the same species that carries dengue, yellow fever and the chikungunya virus. Zika virus infection in human beings has been reported as early as the 1950s.

1.1 Mode of Infection

A mosquito becomes infected when it consumes a blood meal from a Zika-infected person and later transmits the virus to others that it bites. This species of mosquito is known to bite largely during the daytime, although there have been cases where individuals are bitten at night.

Besides mosquitos, the Zika virus has also been reported to be able to be transmitted from one human being to another through sexual contact, blood transfusion and from a mother to her child during pregnancy.

1.2 Effects

After comprehensively reviewing evidence, there is a scientific consensus that the Zika virus is a cause of microcephaly and Guillain-Barré syndrome. The U.S. Centre for Disease Control and Prevention (CDC) has concluded the link of Zika to these disorders. Microcephaly is a condition where a baby’s head is smaller than those of other babies of the same age and sex as a result of the baby’s brain not growing properly. Guillain-Barré syndrome is a rare condition in which a person’s immune system attacks his or her nerves causing them to feel weak and could even lead to paralysis.

In August 2016, it is found that the Zika virus could affect adults and not just pregnant women or babies. Scientists and researchers discovered that Zika could have an impact on an adult’s brain and can potentially cause major and lasting damage. This information was obtained from experiments engineered to simulate human Zika Infection, conducted on adult mice. These experiments indicated that the virus attacks immature cells in the brain, which are vital for learning and memory. The gradual attack on these cells could, over time, lead to the shrinkage of the brain and cause a major impairment of cognitive processes.

2 Symptoms of Zika Infection

Zika is known to be a mild disease and those infected may have trivial symptoms alike those of dengue or chikungunya.

These symptoms include:

• Fever;
• Skin Rashes;
• Body/Muscle Aches;
• Headaches;
• Joint Pain; and
• Conjunctivitis (Red Eyes).

These symptoms often last for 5 to 7 days. However, most people infected with the virus do not develop symptoms with only one in five infected shows symptoms. In certain cases, it can be mistaken for dengue. As such, travel history is important. All travellers returning from regions with ongoing Zika virus transmission should consult a doctor and/or healthcare institutions regarding their travel history.

3 Outbreak of Zika

The Zika virus was first confirmed in Brazil in the early months of 2015. The number of cases in Brazil significantly increased over the following months, with a drastic rise in the total microcephaly cases. Towards the end of 2015, multiple regions in the Americas reported their first Zika cases along with multiple cases involving the Guillain-Barré syndrome (GBS). They consist of Columbia, El Salvador, Puerto Rico, Guatemala, Mexico, Paraguay and Venezuela.

The United States reported its first Zika case in early 2015 which was believed to have been transmitted through sexual contact rather than a mosquito bite. Between the months of February to July 2016, numerous countries reported their first Zika cases as well as microcephaly and GBS cases linked with the Zika virus. These countries include France, South Korea, Vietnam, Spain, Cuba, Bangladesh and Peru. During the month of August 2016, the United States reported a cluster of cases found in Florida with the total reaching over 45. In this period, Singapore also reported its first locally transmitted case. The total number of reported cases increased rapidly over the following days with the amount climbing higher than 150 within five days.

Ever since it was discovered, a total of over 70 countries worldwide have reported cases of Zika, both imported and locally transmitted. More than 50 of those regions are still reporting a widespread active transmission of the virus as of 1^st September 2016.

4 How is the World Reacting to Zika?

The recent 2015 to 2016 Zika outbreak in multiple regions in the Americas and Pacific has alarmed and raised concerns among people all around the globe. The growing number of confirmed Zika cases has led to the WHO declared it a Public Health Emergency of International Concern. This statement was also announced as a result of the clusters of microcephaly and Guillain-Barré syndrome cases in the Americas which were highly suspected to be associated with the Zika virus.

Following the news of the Zika outbreak in Singapore in late August 2016, multiple countries have reacted by issuing travel warnings to their citizens. These travel warnings include advice to travellers, especially pregnant women, to postpone or avoid travelling to Singapore if possible. It also informs the country’s citizens regarding the risks and effects of Zika and ways to prevent getting infected. The countries that have issued travel warnings include Australia, Taiwan, South Korea, the United States of America and Indonesia. Countries such as Great Britain gave out foreign travel advice to citizens travelling to Singapore, which advised women pregnant or planning to conceive, to discuss their travel plans with their doctors.

Singapore’s neighbouring countries, Malaysia and Indonesia, stepped up their prevention actions by implementing measures such as the introduction of thermal scanners at airports and border checkpoints. Singapore’s Ministry of Health (MOH) and National Environmental Agency (NEA) began vector control operations such as spraying of insecticides and larvicides at the reported areas immediately upon the reports. Inspections were done to locate and destroy any existing or potential breeding grounds in the affected areas. Tests were also conducted on individuals living or working near those areas, in particular on those that show or develop Zika-like symptoms.

5 How to Prevent Zika?