Zika virus disease, a vector-borne disease, is stealthily spreading across the country, cautions a retrospective study reported in the journal Frontiers in Microbiology.¹

The study retrospectively analyzed 1520 serum, urine, plasma and whole blood samples from 1475 patients from 14 states/UTs (Delhi, Kerala, Punjab, Rajasthan, Uttar Pradesh, Uttarakhand, Madhya Pradesh, West Bengal, Bihar, Odisha, Telangana, Assam, Jharkhand and Bihar) from May to October 2021. These samples had been stored with virus research and diagnostic laboratories (VRDLs) and had earlier tested negative for dengue and Chikungunya with NS1 and IgM ELISA. These samples were tested again for Dengue, Chikungunya and Zika with Real time RT-PCR test.

Out of the 1520 samples examined, 75 samples from 67 patients tested positive for Zika, while samples from 121 patients were positive for dengue and 10 patients for Chikungunya on RT PCR, which also revealed coinfections of zika, dengue and Chikungunya (dengue/Zika, dengue/Chikungunya and dengue/Chikungunya/Zika). All four serotypes of dengue were found with DEN-II being the most common followed by DEN-IV.

Further analysis of data of the 67 Zika positive cases showed that the majority (86.56%) had been treated as outpatients, while 13% were managed as inpatients. Fever was the main presenting symptom in nearly 84% patients, while 78% had skin rash as the main presenting feature. Other clinical presentations were arthralgia (~45%) and conjunctivitis (34%), while one patient reported microcephaly.

Circulation of Zika virus in 2021 had earlier been reported from Kerala, UP and Maharashtra. This retrospective study shows that the “silent” spread of Zika virus had increased in extent as it was also detected in Delhi, Jharkhand, Rajasthan, Punjab and Telangana indicating local transmission of the virus in the country even as the country was grappling with the Covid-19 pandemic because of which the major share of resources was directed toward curbing the spread of SARS-CoV-2. The virus has been detected in 16 states/UTs from 2017 to 2021, according to the study.  Coinfections of Zika and dengue and chikungunya were also detected, which are an area of concern.

These findings highlight the necessity of continuous active surveillance for Zika virus disease to prevent future outbreaks. In an earlier editorial in 2019, Dr KK Aggarwal was being prescient, when he had said, “Zika is now here to stay and we must anticipate and be prepared to prevent any more outbreaks, which may occur anytime in the near future and anywhere in the country. Otherwise, a contained outbreak such as the Rajasthan Zika outbreak may well turn into an epidemic”.

Given the spread of the infection, screening of antenatal women for Zika is also warranted. It further advocates the need for the adoption of RT PCR testing to enhance detection of Zika as some cases were missed by the ELISA test. Needless to say, effective vector control measures are required.

Reference

1. Yadav PD, et al. Zika a vector borne disease detected in newer states of India amidst the COVID-19 pandemic. Front Microbiol. 2022 Jun 10;13:888195. doi: 10.3389/fmicb.2022.888195.

Track our earlier editorials on Zika virus disease at:

• https://www.emedinexus.com/post/5514/who-priority-diseases-zika-virus-infections
• https://www.emedinexus.com/post/9661/
• https://www.emedinexus.com/post/10091
• https://www.emedinexus.com/post_detail.php?wid=7681&c=1
• https://kkaggarwal.com/Editorial/diagnostic-testing-of-concurrent-suspected-dengue-or-zika-in-symptomatic-patients/