By Taiyee N. Quenneh, PhD
A mosquito-borne virus has re-emerged and is explosively spreading in the Americas (South America, North America, and the Caribbean). Brazil is the epicenter. There are few cases detected in the United States in people returning from the outbreak areas. Unlike the Ebola virus that has visible and noticeable symptoms, the Zika virus rarely exhibits symptoms. Only one in five persons who are infected will show symptoms, according to the US Centers for Disease Control and Prevention (CDC). The fact that the virus exhibits no symptoms in most infected people poses a greater public health danger. Like the onset of Ebola, where Liberia was caught unprepared, there are now sufficient global warnings from both the CDC and WHO for Liberia to initiate adequate public health preparation and response to the Zika pandemic.
What is known about Zika?
The Zika virus was first discovered in 1947 in the Zika forest in Uganda by scientists conducting research on Yellow fever. The Zika virus is transmitted to humans by an infected Aedes aegypti mosquito, a mosquito species that is very common in Liberia. This is the same mosquito species that transmits other viruses like yellow fever, dengue, and chikungunya. The Aedes aegypti mosquito only feeds in the daytime; therefore the reliance on mosquito nets for prevention may not be helpful. Zika may also be transmitted through sexual intercourse.
In the CDC bulletin on Zika, the virus has an incubation period of up to a week. That is the time it takes from exposure to the appearance of symptoms. The common symptoms (fever, joint pain, rash, muscle pain, headaches, and red eyes) are similar to those of malaria and Ebola. There are no known vaccines to prevent Zika, nor drug therapy to treat Zika infection. Getting enough rest, adequate hydration, and taking medication for fever and pain relief are helpful.
It has also been reported that a congenital disease known as microcephaly has been found in babies in Brazil, born to mothers who were infected with the Zika virus during pregnancy. Microcephaly is a health condition where a baby’s head is smaller than normal. This condition leads to seizures, developmental problems, hearing loss and other complications. I want to note that there is not enough scientific evidence to establish a causal link between Zika virus infection and microcephaly in children. However, it is important to consider the potential dangers of Zika as the link between microcephaly in children and Zika is scientifically established.
Zika outbreaks have been rare in Africa. The current epicenter of the Zika virus outbreak is Brazil. Outbreaks of Zika have also been reported in 22 countries in the Americas, the Pacific island of Samoa, and the Island country of Cape Verde in West Africa.
Short term prevention strategy
The rapid movement of populations and interconnectedness of countries make every country vulnerable to infectious pathogens like Zika, especially Liberia, which has an apparent weak disease surveillance system. To wall off any Zika outbreak in Liberia, public health authorities in Liberia must now take the following short term steps: (1) conduct a massive public awareness campaign on the prevention, transmission and health implications of the Zika virus; (2) emphasize safe sex and distribute condoms at places where they will be most accessible to the public; (3) recommend new disease assessment standards to be used by physicians and medical facilities that include Zika virus testing when a patient exhibits symptoms related to fever, joint pain, rash, muscle pain, headaches, and red eyes; (4) acquire laboratory equipment for rapid Zika virus testing; and (5) recruit community leaders who will serve as focus points in the event there is an outbreak. The last step is essential in that it allows community participation, a vital component to the success of any public health action.
Long term prevention strategy
Liberia’s long-term approach should be that of mosquito larvae elimination and poverty reduction. With mosquitoes serving as vectors to many common and emerging diseases, Liberia must put in place an aggressive effort to wipe out the insect. The Aedes aegypti mosquito is a carrier of Zika, yellow fever, dengue and the chikungunya viruses. The female anopheles mosquito is a carrier of the malaria parasite (plasmodium). Alarmingly, malaria kills an estimated eight children under the age of 5 years each day in Liberia. A strategy to eliminate mosquito, though daunting, provides a real chance of reducing the threat of outbreaks from Zika, dengue, yellow fever, chikungunya, and malaria. An aggressive and sustained indoor and outdoor spraying regime using insecticides such as DDT (with WHO approval) and other alternative chemicals is an effective evidence-based strategy. It has worked in eliminating malaria in the United States, Turkmenistan, and Morocco. The strategy can also work in Liberia.
A larger problem that looms over regions vulnerable to disease outbreaks is poverty. Take for instance, the current flashpoints of the Zika virus outbreak. These are largely densely populated urban slums in Brazil with less than ideal socio-environmental conditions – inadequate sanitation and waste management, lack of running water, and poor housing structures. Similar social conditions are a persistent and integral part of urban and rural life in Liberia. Couple these conditions with Liberia’s tropical climate, you have the ideal habitat for mosquito population development. Addressing these long-term disease prevention strategies may be challenging. Nonetheless, they are challenges Liberia must embrace now to protect the health of its people against emerging and re-emerging mosquito-borne viruses.
Taiyee Quenneh, a Liberian native, holds a Ph.D. in Public Health. He has authored several articles on public health concerns in Liberia. He lives in Atlanta, Georgia and can be reached at firstname.lastname@example.org