If 2009 belonged to pandemic Influenza and 2014 to Ebola epidemic (in Northwest Africa) then 2016 belongs to Zika virus epidemics (in South America), and it’s spread to the Caribbean and the United States.
But if you think Zika virus is as lethal as Ebola virus or that of the 1918 pandemic Influenza then you will be flat out wrong.
Actually more than 80 percent of those infected with Zika virus will get well without having symptoms. Only 20 percent show symptoms such as rash, fever, joint pain or in some rare cases, neurological disease called Guillian Barr Syndrome. In other words 4 out of five or 8 out of 10 would show no symptoms.
The good news is, Zika is much less virulent than many other virus that has caused outbreaks or epidemics.
But the bad news is, Zika has arrived in the places where it was not seen before. That includes the United States, and in the South America and the Caribbean. And if it infects a pregnant woman then she may deliver baby with severe brain deformity, microcephaly that is.
In any outbreak, epidemic or pandemic ‘we need to fear the fear it produces that the actual agent that causes it’. For instance, Influenza (Flu) caused pandemic both in 1918 and in 2009. But the pandemic of 2009 was much milder than that of 1918.
The fear that influenza pandemic in 2009 caused went through the roof. But it turned out be no more virulent than the seasonal influenza though the strain of the virus caused it was new and spread among previously unimmunized population in different continents. The spread met the definition of ‘pandemic’ but the virus itself was far less potent than that of 1918.
Take another example where the amount of fear was more than the actual disease itself. The swine flu of epidemic in 1976. This was never an epidemic but the fear it produced was so high that the entire population of the United States was planned to be vaccinated. Actually, 40 million people in 1976 and 1977 were vaccinated against the strain of the virus. But the operation was stopped amid serious side effects and the doubts if it was ever an epidemic.
But there are several outbreaks and epidemics that were worth fearing and taking actions against. Ebola outbreak of 2014 and pandemic influenza of 1918 are examples.
The point here is, misleading information that cause unaccounted fear spread as fast as the disease itself, or even faster. Fear causes people to panic and take actions that may not be warranted for the disease.
Getting infected with Ebola virus was almost like getting a death sentence. It’s case fatality rate was as high as 90 percent. This means, as many as 90 out of 100 people who were infected with Ebola died. Such was the case too if infected with H5N1 Influenza virus. It too has high cases fatality ratio. H5N1 Influenza virus so far have been limited to fowl only and humans have been infected only with close contact with infected fouls. Sustained human to human transmission, if it happens with H5N1 Influenza, would have catastrophic impact.
Up to the time of this writing, there has been around 7500 cases of Zika virus infections in the United States, both in mainland and the US territories combined: 1831 cases in the Mainland US and 5548 in the US territories. Territories are Puerto Rico, Guam, America Samoa, US Virgin Islands and Northern Mariana Islands and that is where the majority of Zika cases are reported from: more than 75 percent of the total US cases.
As of writing of this article, except for 9 cases of Zika infection (out of 1831) in the mainland US were acquired from outside from the area where Zika were transmitted by mosquito.
Reverse is the scenario in the US territories. Almost all cases of Zika in the US territories, except for the few, are acquired from local mosquitoes. These few people are infected from outside the US territories. In the mainland or continental US, most the cases were acquired from travel to the Zika affected area and only a handful are locally transmitted via mosquito.
The organism that carries Zika virus is the mosquito called Aedes Aegypti that thrive in the elevation below 6500 feet. While most of the cases are transmitted from the bite of the mosquito, some cases have been known to have occured via sexual contact.
Neither Ebola viral disease nor influenza need mosquito to spread the viruses. In these two diseases, a person is either directly infected from another person or from infected object that has come in contact with the affected person, such as food, water and utensils.
Of the total Zika cases in the continental US, many are reported from Florida, but also from Texas, California, Virginia, New York. A surveillance system called ARBONET is used to track cases of Zika. Public health agencies have advised pregnant women to avoid travel to the areas where there is active transmission of zika virus. Northern part of Metro Miami is one.
Worldwide, World Health Organization reports Zika virus transmission has been reported in 62 countries since 2007. But microcephaly and Guillian Barr Syndrome has been reported to be linked with Zika in 14 different countries.
There are obvious reasons why Zika virus has caused fear and concern more than its worth. Zika might have gotten the same amount of fear its predecessor epidemic did: ebola virus disease. Though Zika is much milder than Ebola, public perception might have remained the same for both the disease. The venue of the 2016 Olympics being in Brazil, the country where the ground zero of the current epidemic has occurred, has given Zika the undue attention.
Then, there might be misinfomation that Zika deforms everyone’s brain just like it does to unborn babies inside a Zika infected mother.
Zika has taken a heavy toll in the socio economics of the United States and the world already. Florida is reporting severe loss of tourism dollars in billions. Due to the fears of Zika, leisure and business travel to Florida have been substantially cut down. It is reported that the travel to Olympics in Brazil has been significantly reduced due to fears from Zika.
As a reminder, 80 percent of those infected with Zika will have no symptoms or very mild symptoms.
The question that may be on everyone’s mind is: why Zika virus is among us all suddently out of nowhere? Why viruses like Ebola, Influenza and Zika are infecting population where it was not been seen before? How they end up being in location where they were not before?
To get answers one need to understand the behavior of virus. Viruses are made of genetic materials called RNA or DNA surrounded by protein capsule. They replicate to produce many off springs just like other organisms do. While replicating into vast numbers, viruses tend to produce progenies with genetic materials that are little different than their predecessor.
These differences could be small or negligible or huge.
In the case of Influenza this change in the genetic material is responsible for the yearly seasonal influenza. The reason why different strain of influenza virus occurs is because of the small change in the genetic material that the replication produces. If the changes are substantial then the virus becomes completely new to the human immune system. This makes the virus infect large widespread unexposed population. This is when pandemic occurs.
Pandemic influenza of 1918, 1957, 1968 or, 2009 for that matter, are because of these substantial change in the generic materials of influenza virus.
Zika virus, a native of Africa and first identified in Uganda in 1947, was imported to Asia and then to Pacific Islands through human migration.
Then in 2014, no one really know exactly how, the virus traveled to Brazil. It could have traveled with soccer players from the Pacific islands during the FIFA 2014 held in Brazil. Some ardently believe this.
This is corroborated by the findings Zika virus found in Brazil resembles the Asian lineage rather than the African lineage. The islands are considered to be in Asia.
Brazilians were not exposed to Zika previously so they do not have immune power to counter the antigens of the new virus. This made Brazil a fertile ground for the Zika virus to spread indiscriminately. From Brazil, the virus traveled to other South American Countries as well as to the Caribbean. From their it sneak into the United States.
The first time the world knew about Zika’s spread in Brazil was when scores of babies were born with severe head deformity were linked to the virus.
Except for causing deformity in babies, Zika is otherwise mild infection that causes only 1 out of 5 infected person to demonstrate symptoms. These symptoms are general and mild, though rare neurological complications such as Guillen Bar Syndromes has been reported in some.
The ways one could prevent Zika is just like one does preventing other diseases that is spread via mosquito: malaria, yellow fever, dengue, chikungunya. Avoiding standing water around the house where mosquito larva can grow, using mosquito repellant and wearing long sleeved clothes when outside deter mosquito growth thus reduces their bites.
Zika infection can be diagnosed from urine or blood. Effective diagnosis could be made if the specimen are tested within days of the symptoms. But further away from the time period of the symptoms, lesser the chances are for diagnosing the disease.
Until now there is no vaccine against Zika virus nor there is any treatment. Anyone who show symptoms should take plenty of liquid, rest and if condition worsen should see her or his primary care doctor.
The politics of these three epidemics are worth noting. For Zika, the US congress has so far not approved to designate funding that Obama Administration has asked for to fight against Zika virus. The congress have hinted the Administration to ‘do with what it already has’. Giving up hope on Congress the administration, as of August 12, collected funds at the expense of various of its programs, agencies and projects and came out with 81 million dollars for fight against Zika. Half the funds will go towards developing vaccine spearheaded by national institute of health (NIH).
Politics of Ebola was intense. President Obama gave Ebola the same status as the foreign enemy of the United States and deployed thousands of military personnel in North Africa. Building make-shift hospitals and clinics, assisting in medical treatment, testing, training personnel and much more were the tasks of the military operation.
The congress, mostly republican but also democrats, heavily criticized Obama administration for not imposing travel ban from West Africa. The administration argued that such travel ban would not do any good or would worsen the fight against Ebola. Hundreds of US personnel were already in the Ebola affected area. Travel ban would hurt the control effort, argued the Administration.
For Influenza pandemic of 2009, politicians were divided if it was a real threat or a hoax. So was the media and the public. Experts believe that the disease did meet the definition of pandemic–the spread of novel strain of a virus in several continents, although its severity was no more than that of seasonal influenza. Questions were raised, and WHO struggled to answer.
WHO was criticized for its handling of all these three epidemic and pandemic of the 21st century. For Ebola WHO was questioned for its credibility for its delayed announcement of public health emergency. Only after 1000 people have died in Africa that WHO announced Ebola is a public health emergency. For Zika on the other hands, WHO was criticized for its hasty announcement.
Zika, Ebola and Influenza were the epidemic and pandemic of recent years in the 21st century. Science and politics of each of them have many similarities and differences.
{Dr. Sanjeeb Sapkota is a medical epidemiologist and lives in Lawrenceville, Georgia with his wife, two sons and parents. For question and comments please contact via email yesssapkota@gmail.com}
This post was originally posted on “Blogs of Sanjeeb Sapkota” Orignal Post: https://blogsofsanjeebsapkota.wordpress.com/2016/08/11/zika-how-it-compares-with-ebola-and-influenza/
