Prevalence of arboviruses and other infectious causes of skin rash in patients treated at a tertiary health unit in the Brazilian Amazon

Abstract

Background In the clinical course of diseases such as arboviruses, skin rashes may appear, as is often seen in other infectious diseases. The aim of this study was to estimate the prevalence of arboviruses and other infectious causes of skin rash in a tertiary health unit in Manaus, Amazonas state, Western Brazilian Amazon Methodology/Principal findings This was a cross-sectional study of patients presenting with rash who sought care at Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD) from February 2018 to May 2019. Individuals of either gender, aged over 18 years, were invited to participate voluntarily. Infection by Zika virus (ZIKV), dengue virus (DENV), chikungunya virus (CHIKV), Mayaro virus (MAYV), Oropouche virus (OROV) and measles was evaluated using RT-qPCR (real-time polymerase chain reaction). Immunodiagnostic tests for EBV, CMV, HIV, syphilis, rubella and measles were also performed. A total of 340 participants were included, most were female (228, 67.1%) with an average age of 36.5 years (SD ± 12.2 years). The highest prevalence was of ZIKV monoinfections (65.3%, 222/340), followed by DENV (0.9%, 3/340) and CHIKV infection (0.3%, 1/340). No cases of MAYV, OROV or rubella were found. Other causes of skin rash were detected: measles (2.9%, 10/340), parvovirus B19 (0.9% 3/340), HIV (0.3%, 1/340) and syphilis 0.6% (2/340). The co-infections identified were ZIKV+HIV (0.3%, 1/340), ZIKV+measles (0.3%, 1/340), ZIKV+parvovirus B19 (0.3%, 1/340), ZIKV+EBV (0.3%, 1/340), EBV+parvovirus B19 (0.3%, 1/340), CMV+parvovirus B19 (0.6%, 2/340), CMV+syphilis (0.3%, 1/340), ZIKV+EBV+parvovirus B19 (0.3%, 1/340) and CMV+EBV+parvovirus B19 (0.9%, 3/340). Approximately one quarter of patients had no defined cause for their skin rash (25.3%, 86/340). Conclusions Despite the benign clinical evolution of most of the diseases diagnosed in this series of cases, syndromic surveillance of diseases such as syphilis and HIV are of utmost importance. Periodic serosurveillance might also aid in evaluating the trends of endemic diseases and eventual outbreaks. Author summary Arboviruses are transmitted to humans by infected arthropods mostly mosquitoes, many of which lay their eggs in containers with standing water in our homes. Dengue and Zika are some of the examples of these viruses that are responsible for affecting many people in big cities every year. The illnesses can cause fever, malaise, and red patches on the skin that may or may not itch. This study aimed to investigate whether people with red patches on their skin had these diseases transmitted by mosquitoes, in Manaus, Brazil. In addition, we investigated whether they were ill from other causes, as several other illnesses can also cause red patches on the skin. The exams were carried out on 340 people, men and women over 18 years of age. It was identified that 231 people were sick from arboviruses, 227 of which were sick from Zika, 3 from dengue and 1 from chikungunya. Other causes of red spots were also identified, as was the case of sexually transmitted infections syphilis and HIV, with two and three positive cases for each disease, respectively. In addition, some cases of diseases such and measles, which are transmitted by sneezing or coughing, have been identified.