A few years ago, the Nigerian Centre for Disease Control reported that the Zika virus (ZIKV) is widely circulating in Nigeria.
It would be recalled that a Zika virus outbreak began in Brazil in 2015. The virus was first recognized in early 2015 in the metropolitan area of Maranhao. At that time the threat it imposed was unknown. But in September 2015, there was an increase in the rate of microcephaly and it was subsequently linked to the virus.
By November, the country had declared a national emergency on Zika virus but in 2017, the rate of infection was said to have dropped by 95%.
Zika virus was discovered in Nigeria as far back as 1954. Although studies between 1975 and1979 revealed that 40% of Nigeria adults and 25% of Nigerian children have antibodies to Zika virus, meaning they are protected against this virus.
Let’s take a look at this virus.
The Zika virus is a member of the virus family Flaviviridae. It is spread by daytime-active Aedes mosquitoes, such as A. aegypti and A. albopictus. The name comes from the Ziika Forest of Uganda, where the virus was first isolated in 1947. The virus is related to the dengue, yellow fever, Japanese encephalitis, and West Nile viruses. Since the 1950s, it has been known to occur within a narrow equatorial belt from Africa to Asia. From 2007 to 2016, the virus spread eastward, across the Pacific Ocean to the Americas, leading to the 2015–16 Zika virus epidemic.
Zika virus is often symptomless although it sometimes portrays symptoms similar to a mild form of dengue fever. Some of the symptoms include minor headaches; general malaise; itching rash on the skin (first it appears on the face and then spreads all over the body); fever; pain in muscles and joints with possible edema of small joints; hyperemia and inflammation of the conjunctiva (conjunctivitis); pain in the eye area; intolerance to bright light.
Currently, there is no specific treatment of the virus although paracetamol can help relieve the symptoms.
When transmitted from mother to child, ZKV can result in microcephaly, severe brain malformations, and other birth defects. In adults, Zika infections may result rarely in Guillain–Barré syndrome.
The origin of ZKV can be traced to two lineages: the African lineage and the Asian lineage. Phylogenetic studies have revealed that the virus spreading in the Americas is 89% identical to African genotypes, but is most closely related to the Asian strain that circulated in French Polynesia during the 2013–2014 outbreak.
Zika can be transmitted from men and women to their sexual partners; most known cases involve transmission from symptomatic men to women. As of April 2016, sexual transmission of Zika has been documented in six countries – Argentina, Chile, France, Italy, New Zealand, and the United States – during the 2015 outbreak.
The ZKV epidemic in 2015 affected Latin America and the Caribbean. The affected countries include Barbados, Bolivia, Brazil, Colombia, the Dominican Republic, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname, and Venezuela. In 2016, it was revealed that over 50 countries had experienced active (local) transmission of Zika virus.
Other modes of transmission include pregnancy and blood transfusion.
You can prevent the transmission of Zika virus by reducing your exposure to mosquito bites in areas where the disease occurs, and proper use of condoms. The methods of preventing mosquito bites include the use of insect repellent, covering much of the body with clothing, mosquito nets, and getting rid of standing water where mosquitoes reproduce.
In January 2016, the United States Centers for Disease Control and Prevention (CDC) issued travel guidance on the countries that were affected by the Zika virus.
The US CDC published a list of precautions, and guidelines for pregnant women. As a matter of fact, one of the instructions was to postpone travelling to these affected countries if possible. Other Governments and Health Agencies followed suit and issued similar travel warnings. Also, the like of Colombia, the Dominican Republic, Puerto Rico, Ecuador, El Salvador, and Jamaica advised women to postpone getting pregnant until more is known about the risks.
Additionally, in October 2016, the CDC has advised men who have traveled to an area with Zika to use condoms or not have sex for at least six months after their return as the virus is still transmissible even if symptoms never develop.
Currently, there is no effective vaccine. Although as of March 2016, 18 companies and institutions were developing vaccines against Zika but they state a vaccine is unlikely to be widely available for about ten years.
In the last quarter of 2017, there was no reported case of a new ZKV infection but in January 2018, the virus was said to have resurface in Singapore.
The WHO is supporting countries to control Zika virus disease by taking actions outlined in the “Zika Strategic Response Framework”:
- Define and prioritize research into Zika virus disease by convening experts and partners.
- Enhance surveillance of Zika virus and potential complications.
- Strengthen capacity in risk communication to engage communities to better understand risks associated with Zika virus.
- Strengthen the capacity of laboratories to detect the virus.
- Support health authorities to implement vector control strategies aimed at reducing Aedes mosquito populations.
- Prepare recommendations for the clinical care and follow-up of people with complications related to Zika virus infection, in collaboration with experts and other health agencies.
The Nigerian Minister of Health, Prof. Adewole has urged Nigerians to be vigilant as it has been reported that the country is one of the most vulnerable countries.
The Minister also encouraged those working at various ports of entry into the country to interview anyone coming from any of the Latin American countries for evidence Zika virus symptoms. He also admonished that any case of unexplained fever that is more than 48 hours, especially in those with recent travels to Latin America, to health care professionals.
Overall, there has been no single case of Zika virus infection in the country and there is no need to panic. The Federal Ministry of Health will continue to monitor the situation and update Nigerians of any other developments.