1. Diagnosis: Treatment: Introduction: Prevention: Pathogenesis:
ZIKA VIRUS-NEW TERROR ON THE BLOCK
PREET SHAH, R. P. RAM
Jaslok Hospital and Research Centre, Mumbai
Diagnosis:
RT-PCR on serum.
Treatment:
Symptomatic
Prevention:
Using long-sleeved shirts and long pants, to stay in places with air conditioning or that use windows and door screens to keep mosquitoes outside, by sleeping under a mosquito bed net, using mosquito repellants, treating clothing with permethrin.
NO VACCINE CURRENTLY EXISTS FOR PROPHYLAXIS.
Introduction:
Zika virus(ZIKV) belonging to Flaviviridae family and flavivirus genus,causes "Zika disease" or Zika fever.It was first isolated in 1947 from Rhesus monkey in Zika Forest of Uganda and was first isolated from humans in 1968 in Nigeria.
Pathogenesis:
Virus first infects dendritic cells near site of inoculation,then spreads to lymph nodes and bloodstream. Flaviviruses replicate in the cytoplasm,but Zika virus antigens have been found in infected cell nuclei.
Transmission:
Transmitted by mosquitoes of genus Aedes- Aedes aegypti,Aedes africanus and others. The extrinsic incubation period in mosquitoes is 10 days. Hosts are monkeys and humans. Rarely, pregnant women infected with ZIKV near parturition can pass on the virus to the newborn around time of birth. As of 2nd February 2016, there have been only 3 reports suggesting sexual transmission (2008, 2013, Feb 2016).
GEOGRAPHIC DISTRIBUTION
The features are very similar to that of Dengue or Chikungunya, both common in India, which means that it can be easily mistaken for one of those illnesses.
In addition, the vector, Aedes aegypti ; and its breeding conditions (stagnant water sources) are both extremely common in India.
The Indian health fraternity thus needs to be aware of this new threat and its implications, as this is a time bomb, just waiting to explode !
The current Zika virus epidemic was declared as a global emergency by the WHO on 1st February 2016.
References:
Campos GS, Bandeira AC, Sardi SI. Zika Virus Outbreak, Bahia, Brazil. Emerging Infect Dis. 2015;21(10):
Schuler-faccini L, Ribeiro EM, Feitosa IM, et al. Possible Association Between Zika Virus Infection and Microcephaly - Brazil, MMWR Morb Mortal Wkly Rep. 2016;65(3):59-62.
MICROCEPHALY IN INFANT DUE TO ZIKV D
Clinical picture:
Infected patients may not develop symptoms. Among those who do, onset occurs 3-12 days after the mosquito bite. Mild fever, rashes that begin on face and spread to the rest of body; arthralgia(especially in hands and feet), myalgia, headache and conjunctivitis. Symptoms last between 2-7 days, and people rarely require hospitalization. No deaths reported so far.
The 2015 Brazil ZIKV outbreak was the first time that Zika virus was linked with newborn microcephaly, with over 4000 babies being born with it so far.
Recent reports suggest that ZIKV could lead to Guillain-Barre Syndrome (GBS) as well.