The transmission and spread of Zika Virus Disease (ZVD)
Dr.A.K.Wankar1, Dr.M.M.F.Siddiqui2, Dr.S.N.Rindhe3
1 Faculty, Department of Veterinary Physiology
2 Faculty, Department of Veterinary Medicine
3 Faculty, Livestock Product Technology
College of Veterinary & Animal Sciences, Parbhani, MAFSU
Our association with the animals is an old one. In recent times modernization, urbanization, globalization, international travelling and trading, global warming and loss of ecological habitat, has increased the human-animal contact several folds. This also led do transmission of the infectious diseases amongst them (the zoonotic diseases). Till date, a total of 1407 human diseases pathogens are identified out of which, 816 are zoonotic in nature, while, 177 are emerging or re-emerging ones [1].
Viruses, bacteria, fungi, parasites all are responsible for zoonotic diseases in humans. Following are some of the important and common zoonotic diseases globally, monkey pox disease, lassa fever, anthrax, plague, brucellosis, spotted fever caused by Rickettsiae, Marburg disease and Ebola, Japanese Encephalitis (JE), and the most recent ones; Nipah, Kyasanur forest disease (KFD), and Crimean-Congo hemorrhagic fever (CCHF), respectively. In India, the recent emergence of Kyasanur forest disease (KFD), Crimean-Congo hemorrhagic fever (CCHF) and Zika Virus Disease (ZVD) has shown how vulnerable we are against the emerging and re-emerging type of organisms, about which we know very little [6].
The Zika Virus Disease (ZVD)
This disease is caused by a RNA virus, belonging to the family Flaviviridae. Other members of the same family are responsible for diseases like chickungunya, dengue, yellow fever. This is mosquito borne, viral disease, caused by the mosquitoes of Aedes aegypti and A. albopictus. Humans get infected by bite of an infected mosquito, i.e., in an anthroponotic manner and also, transmission through blood transfusion, sexual intercourse and perinatal way have been identified [3].
Only female mosquitoes are responsible for blood sucking and disease transmission. They are indiscriminate feeders and active from dawn to dusk (only during light hours). Eggs are laid in objects like tanks, water storage containers, discarded buckets, discarded buckets, coolers, bottles, coconuts shells and other man-made objects etc and the lifecycle is completed within 8-10 days.
First reported case came from Uganda, in 1947 in a rhesus monkey and first human case was confirmed in Nigeria (Africa) in the year 1954. India reported its first ZVD case from the states of Tamilnadu and Gujrat in the year 2017. Since, 2018, the zoonoses is on the rise and now after 2018, outbreaks have been endemic to state of Rajasthan, Madhya Pradesh and Gujrat, respectively. In entire India till date there are more than 284 cases of ZVD. [4]
The disease symptoms are usually mild to weak, like fever, body ache, headaches, anxiety, fever, joint pain, rash, headaches etc., and the mortality rate is also low. Other symptoms include, oedema of extremities, dizziness, asthenia, and non-purulent conjunctivitis, aphthous ulcers, asthenia, and non-purulent conjunctivitis, asthenia etc. Recently, Guillain-Barré syndrome (GBS) in adults and congenital Zika syndrome (CZS) in foetuses was observed.
The Guillain-Barré syndrome (GBS) is characterised by weakening of respiratory muscles, impaired respiratory functions and death. While, the congenital Zika syndrome (CZS) is manifested in foetuses as premature birth, spontaneous abortion, stillbirth, placental insufficiency, microcephaly, opthalmic abnormalities, calcification of brain, neurological malformations, hydranencephaly, limb contractures etc. [5].
Some preventive measures
The susceptibility of young children, elderly, pregnant women and people with chronic debilitating diseases is always high, hence special care should be taken for them. Following are some of the essential measures for prevention of ZVD,
- Avoiding mosquitoes at their active hours by use of full clothes, application of insect repellents, sprays, coils etc
- Removal and drainage of water from all the possible breeding sites for the vector, especially before the monsoon season
- Modification of the natural breeding environments of the mosquitoes ex. use of larvivorous fishesh, application of larvicides or adultisides
- Establishment of special task forces, awareness campaigns and diagnostic centres at endemic regions for ZVD
- Screening and isolation of all national or international travellers coming from Zika Endemic regions, followed by quarantine and treatment of the infected ones
- Use of condoms and other protections by males and pregnant women should abstain from sex with male partners if travelled from Zika endemic regions.
References
1.Woolhouse ME, Gowtage-Sequeria S. 2005. Host range and emerging and reemerging pathogens. Emerg Infect Dis, 11:1842-7.
2.Kumar R, Singh SP, Savalia CV. 2015. Overview of emerging zoonosis in India: Areas of concern. J Trop Dis, 3:165-8.
3.Kuldeep Dhama, Kumaragurubaran Karthik, Ruchi Tiwari, Rekha Khandia, Ashok Munjal, Sandip Chakraborty, Jay Prakash Yadav, Deepak Kumar, Shyma K Latheef, Mani Saminathan,Yashpal Singh Malik, Hafiz M.N. Iqbal, Raj Kumar Singh. 2018. Zika virus / zika fever: a comprehensive update. Journal of Experimental Biology and Agricultural Sciences, 6(1):1 – 31.
- Saxena SK, Kumar S, Sharma R, Maurya VK, Dandu HR, Bhatt MLB. Zika virus disease in India-Update October 2018. 2019. Travel Med Infect Dis, 27:121-122. doi: 0.1016/j.tmaid.2018.10.022.Epub 2018 Nov 3.
5.Musso D, Gubler DJ. 2016. Zika Virus. Clinical Microbiology Reviews,
29: 487-524.
