Zika virus can lead to neurological complications: Doctors

As cases continue to climb in Karnataka and Maharashtra, Mumbai doctors caution about the neurological risks associated with the Zika virus. Last week, a 74-year-old man succumbed to this infection in the Shivamogga district of Karnataka. According to the Karnataka Health Ministry, he was discharged from the hospital on Thursday and was receiving treatment at home.

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While his diagnosis could only report fever, body aches and rashes, the Zika virus infection has been linked with Guillain-Barré Syndrome (GBS), a rare autoimmune disorder that takes a toll on the nervous system, informs Dr Manjusha Agarwal, a senior consultant working with Gleneagles Hospitals in Mumbai. Research is yet to confirm this, she adds.

With the virus turning fatal, Midday sought insights from Mumbai health experts who shed light on the virus's potential neurological impacts, the role of genome sequencing in understanding the virus and progress in vaccine development.

Link between Zika virus and neurological conditions
Tracing the connection between the Zika virus and neurology, Dr Divya Gopal, internal medicine at Sir HN Reliance Hospital tells Midday how the virus may give rise to microcephaly amongst infants. "When acquired, this condition leads to babies born with abnormally small heads due to incomplete brain development. Zika infection during pregnancy gives rise to serious neurological abnormalities in infants, collectively termed congenital Zika syndrome (CZS)."

This connection has led researchers to examine how the virus penetrates the placenta and infects the fetus, causing adverse impacts on brain development. In line with these observations, a study published in "The New England Journal of Medicine" links the virus with neurological complications. Conducted during the 2015-2016 outbreak in Brazil, the paper found an association between Zika virus infection during pregnancy and the occurrence of microcephaly in newborns.

Besides microcephaly, CZS may include seizures, developmental delays as well as vision and hearing impairments. Furthermore, Agarwal informs that Guillain-Barré Syndrome (GBS) caused by the virus, can result in muscle weakness and in severe cases, paralysis. The connection between the virus and GBS was observed during outbreaks, where an increase in GBS cases started coinciding with Zika virus infections.

Role of genome sequencing
The virus spreading in India has been found to belong to the family Flaviviridae and the genus Flavivirus, shares Gopal. Zika virus is primarily transmitted by the Aedes mosquito which is also responsible for the spread of dengue, Chikungunya and yellow fever viruses. In most areas, the primary vector of these viruses is Aedes aegypti, with Aedes albopictus a proven or potential vector in some settings.

In this scenario, genome sequencing becomes crucial as it helps in identifying and comparing the genetic variations within different strains of the virus. This also helps in understanding the evolution of the virus over time across different geographies, informs Dr P. Praneetha, consultant, department of general medicine, Meenakshi Mission Hospital, Mumbai.

Agarwal adds that genome sequencing helps virologists decode the virus's genetic makeup and detect specific mutations that may impact its transmission patterns. This information is essential for developing vaccines to tackle the spread of Zika. Also, it helps to predict future outbreaks and guides when it comes to public health strategies for effective prevention and control measures against Zika.

Is there a cure for the Zike virus?
Gopal hints at ongoing efforts towards developing vaccines and medicines for the Zika virus. "Vaccine development has made strides, with some candidates showing promising results in preclinical and early-stage clinical trials. Yet, despite progress, challenges remain in achieving a definitive cure."

Effective vaccines could provide a long-term solution to prevent Zika infections, however, they remain in the developing stage by scientists. Potential drugs are also been identified for treatment, informs Agarwal. Innovative approaches such as gene editing techniques, to create targeted therapies that can combat Zika more effectively are also taken into consideration.

How does the virus transmit between hosts?
Zika virus spreads primarily through mosquito bites and from pregnant women to their fetuses. Additionally, sexual transmission has been identified as another route of spread. The Aedes aegypti and Aedes albopictus mosquitoes are the main vectors responsible for transmitting the virus to humans when they feed on blood, shares Agarwal.

Moreover, the mosquito bites mostly during the daytime. This virus spreads via sexual contact and can be present in semen for several weeks after infection, posing a risk of spreading through unprotected intercourse. It is the need of the hour to understand the diverse transmission patterns and take necessary precautions.

Watch out for these symptoms

The initial symptoms of the Zika virus are generally mild and can include:

1. Fever
2. Rash
3. Joint Pain
4. Conjunctivitis (red eyes)
5. Headache

Praneetha outlines that symptoms typically appear 3 to 14 days after being bitten by an infected mosquito and usually last for several days to a week. Many people infected with Zika virus do not experience symptoms or have only mild symptoms. In some cases, fever with a rash can be the first symptom. Others may experience headache, joint pain and redness in the eyes.

Very rarely, the Zika virus can affect the brain and nerves in adults, potentially causing paralysis and difficulty in walking.

Diagnosing Zika virus
There are several steps to ascertain whether the virus is present or not. The patient's symptoms, travel history (if applicable), and potential exposure to mosquitoes or infected individuals are first evaluated. If the symptoms are present then a Lab test is advised which includes"

1. Polymerase Chain Reaction (PCR), is used to detect the RNA of the Zika virus in blood, urine or other body fluids.
2. Praneetha stresses that in detecting recent or past Zika virus infections. "Serological tests are also recommended which basically to detect Zika virus-specific antibodies produced by the immune system in response to infection."

Post diagnosis, the mainstays of Zika treatment are rest, fluid maintenance and symptom management, concludes Gopal.