Zika virus: Epidemiological surveillance of the Mexican Institute of Social Security

Abstract

IntroductionAt the end of 2015, the first cases of Zika were identified in southern Mexico. During 2016, Zika spread as an outbreak to a large part of the country's coastal zones.MethodologyThe Zika epidemiological surveillance system records cases with clinical symptoms of Zika virus disease (ZVD) and those confirmed by means of a reverse polymerase chain reaction (RT-PCR) assay. This report includes the suspected and confirmed cases from 2016. Incidence rates were estimated by region and in pregnant women based on the proportion of confirmed cases.ResultsIn total, 43,725 suspected cases of ZVD were reported. The overall incidence of suspected cases of ZVD was 82.0 per 100,000 individuals and 25.3 per 100,000 Zika cases. There were 4,168 pregnant women with suspected symptoms of ZVD, of which infection was confirmed in 1,082 (26%). The estimated incidence rate of ZVD for pregnant women nationwide was 186.1 positive Zika cases per 100,000 pregnant women.ConclusionsThe incidence of Zika in Mexico is higher than that reported previously in the National System of Epidemiological Surveillance. Positive cases of Zika must be estimated and reported.

Clinical Symptoms of Arboviruses in Mexico

“…As for ZIKV, most symptoms were found in region 2 and region 4 ( Figure 2 ). Limited studies have shown region 5 to have many cases, but these studies have not examined the cases’ clinical symptoms as our research did [ 23 , 46 ]. The outcomes from the regional variation of symptoms may be used to look at the severity of symptoms comparing endemic vs. non-endemic municipalities to narrow down other regional differences, healthcare worker practices, and the possible role of access to publicly funded healthcare services.…”

Pregnant Women Infected with Zika Virus Show Higher Viral Load and Immunoregulatory Cytokines Profile with CXCL10 Increase

“…ZIKV infection in humans remained a sporadic zoonotic disease in Africa and Southeast Asia until the first large urban outbreak that struck Micronesia in 2007 [ 1 ]. Over the next five years, the disease spread to Polynesia, Easter Island, the Cook Islands, and New Caledonia and was introduced and disseminated rapidly in South America in 2015 and to Central America and the Caribbean, including Mexico, the following year [ 2 , 3 , 4 ]. After these large epidemics, ZIKV infection has remained endemic with a low transmission rate in South and Central America, including Mexico, Peru, and Colombia.…”

“…Recent studies suggest that asymptomatic cases account for less than 30% [ 6 ] and not 80%, as previously estimated [ 7 ]. The characteristic clinical features include a fine maculopapular skin rash that is diffusely distributed and is associated with two or more of the following symptoms: fever, headache, nonpurulent conjunctivitis, arthralgia, pruritus, and retro-ocular pain [ 4 ]. However, the nonspecific clinical symptoms of ZIKV infection are often misdiagnosed as other arboviral infections, especially dengue virus (DENV) infection.…”

“…The two main public health concerns relating to ZIKV infection are its association with neurological manifestations, mainly Guillain–Barré syndrome, meningitis, and meningoencephalitis in the adult population [ 9 ] and the vertical transmission during pregnancy that is linked to the development of brain abnormalities in the fetus and other anomalies related to the congenital Zika syndrome [ 4 , 10 ]. The risk factors associated with ZIKV infection in pregnancy and congenital Zika syndrome remain unclear and vary widely by country; however, its incidence was reported to be particularly high in Brazil [ 2 ].…”

Predict the incidence of Guillain Barré Syndrome and arbovirus infection in Mexico, 2014–2019

“…Estimation of arbovirus cases: laboratory samples were not taken to confirm all DENV, ZIKV or CHIKV suspected cases; therefore, positive cases were estimated according to previous studies [36].…”