Correspondence

Thrombocytopenia and subcutaneous bleedings in a patient with Zika virus infection

In this article, we discuss pertinent cutaneous findings with which patients may present after travel to tropical destinations. We address arthropod-borne infectious diseases such as cutaneous leishmaniasis, Chagas disease, cutaneous larva migrans, and myiasis. We discuss other relevant diseases with cutaneous signs such as monkey pox and severe acute respiratory syndrome coronavirus 2. We provide clinicians with information regarding the background, diagnosis, treatment, and prevention of these tropical rashes. In addition, we address the impact that climate change will have on the temporal and geographic incidence of these rashes. Viral, fungal, and vector-borne diseases have seen a geographic expansion into more northern latitudes. Among these are tick-borne Lyme disease, aquatic snail-related seabather's eruption, and atopic dermatitis. As these diseases spread, we believe that the updated information within this article is significant to the practicing physician in today's warming world.

During the 2015 Zika virus infection (ZVI) epidemic swiping through the Americas, few cases of ZVI with severe, potentially life-threatening thrombocytopenia were reported. Platelet transfusion, corticosteroids and intravenous immunoglobulins (IVIG) were in most cases applied as therapeutic options, predominantly with success. We present a comprehensive overview concerning the pathophysiology, treatment strategies and outcomes of patients with ZVI and severe thrombocytopenia (platelet count <50 × 10⁹/L).

A literature search was performed.

Eleven case reports and case series with a total of 28 patients met the inclusion criteria; including five cases with lethal outcome. Therapeutic strategies, including platelet transfusion, administration of steroids and/or IVIG were described in 24 cases.

Severe thrombocytopenia is a rare, but potentially life-threatening complication of ZVI. The principal pathophysiological mechanism appears to immune-induced thrombocytopenia. Due to a paucity of cases, the optimal treatment strategy remains to be elucidated.

During pregnancy, a series of physiological changes are determined at the molecular, cellular and macroscopic level that make the mother and fetus more susceptible to certain viral and bacterial infections, especially the infections in this and the companion review. Particular situations increase susceptibility to infection in neonates. The enhanced susceptibility to certain infections increases the risk of developing particular diseases that can progress to become morbidly severe. For example, during the current pandemic caused by the SARS-CoV-2 virus, epidemiological studies have established that pregnant women with COVID-19 disease are more likely to be hospitalized. However, the risk for intensive care unit admission and mechanical ventilation is not increased compared with nonpregnant women. Although much remains unknown with this particular infection, the elevated risk of progression during pregnancy towards more severe manifestations of COVID-19 disease is not associated with an increased risk of death. In addition, the epidemiological data available in neonates suggest that their risk of acquiring COVID-19 is low compared with infants (<12 months of age). However, they might be at higher risk for progression to severe COVID-19 disease compared with older children. The data on clinical presentation and disease severity among neonates are limited and based on case reports and small case series. It is well documented the importance of the Zika virus infection as the main cause of several congenital anomalies and birth defects such as microcephaly, and also adverse pregnancy outcomes. Mycoplasma infections also increase adverse pregnancy outcomes. This review will focus on the molecular, pathophysiological and biophysical characteristics of the mother/placental-fetal/neonatal interactions and the possible mechanisms of these pathogens (SARS-CoV-2, ZIKV, and Mycoplasmas) for promoting disease at this level.

Zika virus (ZIKV) is a typical mosquito-borne flavivirus known to cause severe fetal microcephaly and adult Guillain-Barré syndrome. Currently, there are no specific drugs or licensed vaccines available for ZIKV infection, and further research is required to identify host cell proteins involved in the virus's life cycle. Viruses are known to use host cell membrane skeletal proteins, such as actin and spectrin, to complete cell entry, transportation, and release. Here, based on immunoprecipitation, the Axl and ZIKV envelope (E) protein were shown to interact with the cell membrane skeleton protein 4.1R. Furthermore, deletion of 4.1R significantly reduced virus titer and viral protein synthesis. Our study showed that 4.1R is an important host cell protein during ZIKV infection and may be involved in the process of viral entry into host cells.

The molecular evolution of life on earth along with changing environmental, conditions has rendered mankind susceptible to endemic and pandemic emerging infectious diseases. The effects of certain systemic viral and bacterial infections on morbidity and mortality are considered as examples of recent emerging infections. Here we will focus on three examples of infections that are important in pregnancy and early childhood: SARS-CoV-2 virus, Zika virus, and Mycoplasma species. The basic structural characteristics of these infectious agents will be examined, along with their general pathogenic mechanisms. Coronavirus infections, such as caused by the SARS-CoV-2 virus, likely evolved from zoonotic bat viruses to infect humans and cause a pandemic that has been the biggest challenge for humanity since the Spanish Flu pandemic of the early 20th century. In contrast, Zika Virus infections represent an expanding infectious threat in the context of global climate change. The relationship of these infections to pregnancy, the vertical transmission and neurological sequels make these viruses highly relevant to the topics of this special issue. Finally, mycoplasmal infections have been present before mankind evolved, but they were rarely identified as human pathogens until recently, and they are now recognized as important coinfections that are able to modify the course and prognosis of various infectious diseases and other chronic illnesses. The infectious processes caused by these intracellular microorganisms are examined as well as some general aspects of their pathogeneses, clinical presentations, and diagnoses. We will finally consider examples of treatments that have been used to reduce morbidity and mortality of these infections and discuss briefly the current status of vaccines, in particular, against the SARS-CoV-2 virus. It is important to understand some of the basic features of these emerging infectious diseases and the pathogens involved in order to better appreciate the contributions of this special issue on how infectious diseases can affect human pregnancy, fetuses and neonates.

Zika virus was first discovered in the Zika Forest of Uganda in 1947 and was until recently believed to be an infection of mild clinical significance. Infection with Zika virus presents with mild clinical symptoms including fever, headache, rash, conjunctivitis, arthralgia, and myalgia—only a small proportion of laboratory-confirmed infections manifested clinically detectable features. In 2016 the World Health Organization declared Zika virus infection and its associated congenital malformations and neurological disorders as a Public Health Emergency of International Concern, following a large-scale outbreak of microcephaly in Brazil. Molecularly confirmed or serologically confirmed acute Zika virus infection was associated with an increased incidence of a spectrum of significant neurological manifestations including Guillain-Barré syndrome, encephalitis, and transverse myelitis. Zika virus infection during the perinatal period results in congenital Zika syndrome, a condition characterized by microcephaly, reduced head circumference, and significant craniofacial disproportion. Although Zika virus is no longer a Public Health Emergency of International Concern, Zika virus screening during pregnancy in endemic regions remains relevant and necessary, due to the severe long-term sequelae and cost to the healthcare systems involved.