Journal of Tropical Diseases & Public Health

Zika Virus

Zika virus is an arthropod-borne virus (arbovirus) of the Flavivirus genus, primarily transmitted to humans through the bite of infected Aedes mosquitoes, particularly Aedes aegypti and Aedes albopictus. It was first identified in 1947 in Uganda and has since spread to various parts of the world.

Transmission

• Mosquito Bites: The primary mode of transmission is through the bite of infected mosquitoes.
• Sexual Transmission: Zika virus can also be transmitted through sexual contact from an infected person to their partner.
• Mother-to-Child Transmission: Infected pregnant women can transmit the virus to their fetus, leading to serious birth defects.
• Blood Transfusion: There is a potential risk of transmission through blood transfusions, though this is less common.

Symptoms

Symptoms typically appear 3 to 14 days after being bitten by an infected mosquito and may include:

• Mild Symptoms:
  • Fever
  • Rash
  • Joint pain
  • Muscle pain
  • Headache
  • Conjunctivitis (red eyes)

• Severe Symptoms:
  Most people infected with the Zika virus do not develop symptoms. However, some may experience severe symptoms or complications, especially in pregnant women, leading to:
  • Congenital Zika Syndrome: This can cause severe birth defects, including microcephaly (abnormally small head) and developmental delays in the fetus.

Diagnosis

Diagnosis of Zika virus infection is primarily based on:

• Clinical Assessment: Evaluating symptoms and recent travel history to areas with Zika outbreaks.
• Laboratory Tests:
  • Serology: Detection of IgM antibodies specific to Zika virus.
  • PCR Testing: Detection of viral RNA in blood or other bodily fluids, particularly during the first week of infection.

Treatment

Currently, there is no specific antiviral treatment for Zika virus. Management is symptomatic:

• Supportive Care: Rest, hydration, and pain relief with acetaminophen (avoid NSAIDs like ibuprofen during pregnancy).
• Monitoring: Pregnant women should be closely monitored for any complications or birth defects.

Prevention

Preventive measures focus on avoiding mosquito bites and reducing transmission risks:

• Avoid Mosquito Bites:
  • Use insect repellents containing DEET or picaridin.
  • Wear long-sleeved shirts and long pants.
  • Use mosquito nets and screens to keep mosquitoes out.

• Sexual Health Precautions:
  • Use condoms to reduce the risk of sexual transmission.
  • Men who have traveled to Zika-affected areas should consider using condoms for at least 3 months after returning.

• Pregnancy Precautions:
  • Women who are pregnant or planning to become pregnant should avoid travel to areas with active Zika virus transmission.

Public Health Implications

• Global Concern: Zika virus outbreaks have raised significant public health concerns, particularly in tropical and subtropical regions. The most notable outbreak occurred in Brazil from 2015 to 2016, leading to thousands of cases of congenital Zika syndrome.
• Monitoring and Surveillance: On-going surveillance of mosquito populations and human infections is crucial for controlling Zika transmission.
• Vaccine Research: Research is underway to develop effective vaccines against Zika virus, but no vaccines are currently available for widespread use.