Dengue Zika and Chikungunya: Similarities and Differences

 

Although transmitted by the same species of mosquito named Aedes aegypti, Dengue, Zika and Chuikungunya widely vary from one another in terms of their symptoms. While most of the time, the early symptoms of these diseases include high fever and body aches, a simple bite by a contaminated Aedes aegypti mosquito can also lead to the serious complication called Microcephaly- a neurological condition in which babies are born with an awfully small head.

A recent study in the epidemiological bulletin published by the Ministry of Health (India), it highlights that the incidence of Dengue and  Chikungunya is  significantly higher in India , compared to the rest of the world, whereas Zika virus  thrive  well in  the African environment. Last year, about 3000 suspected cases of Microcephaly (a complication caused by Zika Virus) have been recorded in Africa and certain South American states. In fact, the recent outbreak of Zika across South American nations has put 2016 Olympics under massive threat.

On the other hand, an epidemiological bulletin (released by WHO) has also claimed that in 2015, more than 10 million of people across the world was affected by Dengue virus.

Breeding of Aedes aegypti

While  talking about the  contamination  statistics  of these three diseases, the  bulletin published by WHO has  also pointed out that Aedes aegypti is  basically a  domestic  mosquito,  which  breeds in clear water sources accumulating inside our homes.  During the summer months, the proliferation of Aedes aegypti tends to increase due to rise in the ambient temperature. This is why, government in several countries enact alerts against Aedes aegypti mostly during the summer months.

Transmission Cycle of Aedes aegypti

Essentially female mosquitoes are responsible for spreading these three deadly viral diseases. Aedes aegypti lays her eggs in the accumulated clear waters. After fertilization, the mosquito larvae is released in the water where it lives for about a week. After which, they become adult mosquitoes. The Aedes aegypti breeds in a phenomenal speed, but its average life cycle is not more than 45 days.

However, an Aedes aegypti is simply a carrier of these viruses as it becomes a contamination vector only after biting a person infected with the Dengue virus (DEN-1, DEN-2, DEN-3 or DEN-4), Zika (ZIKV) or Chikungunya (CHIKV). So it is extremely important to safeguard the infected person (during his treatment period) from mosquito bites.

Dengue, Zika and Chikungunya: Symptoms

Besides being transmitted by the same species of mosquito, there’s nothing much in common about these diseases.  Though in many cases, these diseases cause malaise, headaches, body aches and fever, the earlier symptoms are mostly latent. “Among the differences, the headache is usually more intense in dengue, while the joint pain is more intense in Chikungunya and Zika rarely has a fever or other characteristic symptoms,” says Esper Kallas, Coordinator of the Infectious Diseases Core Hospital Syrian-Lebanon.

The following chart gives you a detailed information about the basic symptoms of Dengue, Zika and Chikungunya, as illustrated below:

blog chart

Diagnosis and Treatment

A proper and early diagnosis is important to analyse the symptoms, so that you get the right kind of treatment from the very beginning.  For general lab tests (like blood, sputum and urine test) are unable to differentiate between these three ailments and normal fever, so it’s important to carry out several invasive lab tests to confirm the diagnosis.

For example, an early symptom of Dengue is the rapid drop in the platelet count (which is detected through blood test). But a serology test is also done in most cases, because it detects whether the diseased person’s blood is infected with Dengue causing antibodies.  The same is  done  for the  diagnosis  of Chikungunya,  but, there’s  no such  specific  serological test  available for Zika. So, quite obviously, the diagnosis of Zika becomes more difficult at times. However,  several  private laboratories in  the  African  countries  are emphasizing  on  genetic material testing ( PCR ) for detecting the presence of  Zika virus in the  human  body. But, genetic material test for Zika can only be applied after five days have passed from the onset of the symptoms.

In addition to PCR, the clinicians of Oswaldo Cruz Foundation have also introduced 500,000 other tests, called NAT Kit, for the diagnosis of Dengue, Chikungunya and Zika. Studies reveal that NAT Kit was already used since January 2014 for the detection of HIV and Hepatitis C in Brazilian blood banks. According to the official statement from the Oswaldo Cruz Foundation, “The NAT Kit discriminate against dengue, Chikungunya and Zika, allows for the simultaneous identification of the genetic material for the three viruses, avoiding the need for three separate tests”, thus giving a higher flexibility and improved accuracy in the differential diagnosis of Dengue, Zika and Chikungunya diseases.

Treatment

While none of these diseases have a specific medication to deal with, it’s important to combat the virus by controlling the symptoms of these disease.  However, for Dengue, the blood count of the patients are also monitored from time to time, because significant drop in the platelet count can also lead to serious complications- at times even death. Hence, people with major complications suffering from these ailments are kept on intravenous hydration for speedy recovery from these diseases.

Complication

The possible complications of Dengue, Zika and Chikungunya varies widely from one another. Despite the mildest of all (at least in terms of early symptoms)  Zika  virus  has  the  potential  of causing a lifetime deformity in the  human  brain,  which  is way more awful than  the  complications  triggered by  Dengue and Chikungunya viruses. Unfortunately, there’s no specific action to deal with the effects of  Zika  virus and  hence protecting the  foetus is  not always  possible, if the  mother is  infected with this  virus during gravidity.

On the  other hand,  Chikungunya  shows  several striking symptoms  and  in most cases the  consistent  usage of pain-medications and  anti-inflammatory corticosteroids, various  serious side effects tend  to crop  up in the recovery phase.  This is however, not the case with Zika and Dengue.

Here’s a look into the possible complications of Dengue, Zika and Chikungunya, as illustrated below:
blog chart 2

So, whether you are suffering from Dengue, Zika or Chikungunya, the situation might turn worse anytime, if the symptoms are not treated in time. As, in most cases, the patient affected with these ailments suffer due to the delay in detection of the symptoms. So act fast and get yourself diagnosed if you are suffering from longstanding fever, before it gets too late.