Clinical and Epidemiological Characterization of Laboratory-Confirmed Authoctonous Cases of Zika Virus Disease in Mexico

Abstract

Introduction: Since 2014, autochthonous circulation of Zika virus (ZIKV) in the Americas was detected (Easter Island, Chile). In May 2015, Brazil confirmed autochthonous ­­transmission and in October of that year Colombia reported their first cases. Now more than 52 countries have reported cases, including Mexico. To deal with this contingency in Mexico, several surveillance systems, in addition to systems for vector-borne diseases were strengthened with the participation of all health institutions. Also, the Ministry of Health defined an Action Plan against ZIKV for the whole country.Methods: We analyzed 93 autochthonous cases of ZIKV disease identified by Epidemiological Surveillance System for Zika Virus in Mexico. All autochthonous cases confirmed by laboratory since November 25, 2015 to February 19, 2016 were included. A description of clinical and epidemiological characteristics of 93 cases of ZIKV disease are presenting and, we describe the Action Plan against this public health emergency. Results: The distribution of cases by sex was 61 men and 32 women; mean age was 35 years old (S.D. 15, range 6-90). The main clinical features in the 93 cases were fever (96.6%), rash (93.3%), non-purulent conjunctivitis (88.8%), headache (85.4%), and myalgia (84.3%). No deaths were reported.Conclusion: The ZIKV epidemic poses new challenges to public health systems. The information provided for basic, clinical, and epidemiological research, in addition to the data derived from epidemiological surveillance is essential. However, there are still many unanswered questions regarding mechanisms of transmission, complications, and impact of this virus.

Mosquito-transmitted viruses – the great Brazilian challenge

“…In 2007, a major ZIKV epidemic was detected in the Yap island in Micronesia, caused by the Asian lineage,137, 138 and from 2013, this lineage caused epidemics in the Pacific Islands (French Polynesia, New Caledonia, Cook Islands, Tahiti, and Easter Island) 139, 140, 141, 142, 143. This same lineage is responsible for the epidemics in Brazil,144, 145, 146, 147 South and Central Americas, as well as the imported cases in North America and Europe 148, 149, 150, 151…”

Animal Models of Zika Virus Infection, Pathogenesis, and Immunity

“…ZIKV infection in adult humans results in conjunctivitis in ϳ50% of symptomatic infections (32)(33)(34), with uveitis having been diagnosed in multiple patients (35,36). ZIKV replication in eye-associated tissues has been reported in infected humans, with confirmation of viral RNA and infectious virus in conjunctival fluid (37).…”

Evidence of the presence of the Zika virus in Mexico since early 2015

“…By December 2015, 1 imported and 15 autochthonous cases of Zika virus disease were confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR) [3]. The Mexican Public Health Laboratory Network (RNLSP) has reported an accumulated number of 1285 cases of Zika Virus infections at the 29th EW 2016 in at least 15 states of Mexico [4]. To evaluate the possible circulation of Zika virus prior to the first documented case, we reanalyzed the stored samples from Veracruz and Yucatán, which were originally collected to test for dengue (DENV) and chikungunya (CHIKV) by RT-PCR; we tested specimens that were negative for these viruses despite the symptomatology (in this way, we excluded the coinfections of CHIKV with ZIKV or DENV with ZIKV) and samples that were negative for CHIKV or DENV.…”