Dengue Infection in Pregnancy: Prevalence, Vertical Transmission, and Pregnancy Outcome

First clinical reports of acute hantavirus and dengue infections among pregnant women in the Caribbean

BACKGROUND

Hantavirus and dengue virus infections lead to diseases causing economic and public health concerns. Acute hantavirus infections can lead to similar clinical haemorrhagic signs as other endemic diseases including dengue and leptospirosis.

METHODS

Using a retrospective case analysis of pregnant dengue and hantavirus disease patients with clinical reports and compatible clinical laboratory information during pregnancy, we report the first evidence of dengue and hantavirus infections and a case of dual dengue and hantavirus infection among pregnant women in the Caribbean. Laboratory testing by enzyme-linked immunosorbent assay (ELISA) and non-structural protein 1 (NS1) for DENV and for hantavirus infection pseudotype focus reduction neutralisation tests (pFRNT), ELISA and immunochromatographic (ICG) strips.

RESULTS

Four pregnant cases with acute DENV infections were identified; however, only one out of the four cases (25%) had a detailed medical record to permit abstraction of clinical data. Six hantavirus infected pregnant cases were identified with gestation periods ranged from 36 to 39 weeks; none of the reported patients exhibited previous pregnancy complications prior to hospitalisation and infection. Acute liver damage was observed in three of the six cases (AST readings) who were subsequently diagnosed with hepatitis in pregnancy and variable clinical outcomes were observed with term and pre-term deliveries.

CONCLUSIONS

Whilst hantavirus infection in pregnancy is rare, consideration should be given to differential diagnosis with fever, kidney involvement, liver involvement, haemorrhagic symptoms and thrombocytopenia in endemic areas with clinically similar diseases such as dengue and leptospirosis.HighlightsFirst recorded case of hantavirus and dengue co-infection in a pregnant woman.First detailed report of clinical hantavirus infection in pregnant women in the Caribbean.First published report of clinical dengue infection in pregnant woman in the Caribbean.Possible complications of pregnancy following hantavirus infection.Pre-term birth and low birth weights.Clinical course of hantavirus infection in a Caribbean population.

Vertical dengue transmission complicated with neonatal encephalitis

Vertical transmission of the dengue virus is rare and infrequently reported in the literature. We report the case of a term newborn presented with high-grade fever, generalised petechial rash and hepatomegaly at the age of 5 days, with a history of dengue fever in the mother at 3 days before delivery. The diagnosis was nearly missed because the infant's dengue NS1 antigen test was initially negative and subsequently positive. After the convalescent phase, the infant developed a new-onset fever with lethargy and drowsiness. Dengue encephalitis was diagnosed with support from a positive dengue reverse-transcriptase PCR in the cerebrospinal fluid. This report has shown the importance of clinical awareness. Early recognition of congenital dengue and vigilant monitoring will contribute to appropriate early management and decrease neonatal morbidity and mortality.

Vector-borne disease, climate change and perinatal health

Vector-borne diseases (VBDs) are caused by infectious pathogens that spread from an infected human or animal reservoir to an uninfected human via a vector (mosquito, tick, rodent, others) and remain an important cause of morbidity and mortality worldwide. Pregnant individuals and their fetuses are especially at risk, as certain pathogens, such as Zika virus, have specific implications in pregnancy and for neonatal health. Global climate change is affecting the incidence and geographic spread of many VBDs. Thus, it is important for clinicians in the fields of obstetrics/gynecology and newborn medicine, regardless of geographic location, to familiarize themselves with a basic understanding of these conditions and how climate change is altering their distributions. In this chapter, we review the incidence, clinical presentation, implications during pregnancy and intersection with climate change for four of the most important VBDs in pregnancy: malaria, Zika, dengue and Chagas disease. Although not exhaustive of all VBDs, a more extensive table is included for reference, and our discussion provides a helpful framework for understanding other vector-borne pathogens and perinatal health.

The Innate Immune Response in DENV- and CHIKV-Infected Placentas and the Consequences for the Fetuses: A Minireview

Dengue virus (DENV) and chikungunya (CHIKV) are arthropod-borne viruses belonging to the Flaviviridae and Togaviridae families, respectively. Infection by both viruses can lead to a mild indistinct fever or even lead to more severe forms of the diseases, which are characterized by a generalized inflammatory state and multiorgan involvement. Infected mothers are considered a high-risk group due to their immunosuppressed state and the possibility of vertical transmission. Thereby, infection by arboviruses during pregnancy portrays a major public health concern, especially in countries where epidemics of both diseases are regular and public health policies are left aside. Placental involvement during both infections has been already described and the presence of either DENV or CHIKV has been observed in constituent cells of the placenta. In spite of that, there is little knowledge regarding the intrinsic earlier immunological mechanisms that are developed by placental cells in response to infection by both arboviruses. Here, we approach some of the current information available in the literature about the exacerbated presence of cells involved in the innate immune defense of the placenta during DENV and CHIKV infections.

Seroprevalence of Dengue, Chikungunya, and Zika viruses antibodies in a cohort of asymptomatic pregnant women in a low-income region of Minas Gerais, Brazil, 2018-2019

Dengue, Chikungunya, and Zika viruses are arthropod-borne viruses (arboviruses) that infect millions of individuals in tropical and subtropical regions. In the Americas, arboviruses represent a major public health problem, especially among vulnerable groups such as the elderly, children, and pregnant women. In this study, the seroprevalence of IgM or IgG against these arboviruses in pregnant, young women in the city of Diamantina, Minas Gerais, Brazil, and the influence of sociodemographic factors on the incidence/prevalence of infection in this group were investigated. A cross-sectional investigation was conducted on a total of 135 pregnant women for Dengue and Chikungunya IgM and 88 pregnant women for Zika IgG. Dengue IgM was found on the serum of twenty participants (14.8%) and only one woman (0.7%) tested positive for Chikungunya IgM. Zika IgG was found in three (3.4%) participants and 2 women who tested positive for Zika virus were also positive for Dengue virus IgM. Although the arboviruses seroprevalence was higher frequency among young (20-25 years old), brown and high school women, with a monthly income of 1-3 minimum wages, no association between these sociodemographic factors and arboviruses seroprevalence was found.

Neurological Manifestations of Perinatal Dengue

Dengue viruses (DENVs) are single-stranded RNA viruses belonging to the family Flaviviridae. There are four distinct antigenically related serotypes, DENVs types 1, 2, 3, and 4. These are all mosquito-borne human pathogens. Congenital dengue disease occurs when there is mother-to-fetus transmission of the virus and should be suspected in endemic regions in neonates presenting with fever, maculopapular rash, and thrombocytopenia. Although most of the infected infants remain asymptomatic, some can develop clinical manifestations such as sepsis-like illness, gastric bleeding, circulatory failure, and death. Neurological manifestations include intracerebral hemorrhages, neurological malformations, and acute focal/disseminated encephalitis/encephalomyelitis. Dengue NS1Ag, a highly conserved glycoprotein, can help the detection of cases in the viremic stage. We do not have proven specific therapies yet; management is largely supportive and is focused on close monitoring and maintaining adequate intravascular volume.

Arthropod-Borne Flaviviruses in Pregnancy

Flaviviruses are a diverse group of enveloped RNA viruses that cause significant clinical manifestations in the pregnancy and postpartum periods. This review highlights the epidemiology, pathophysiology, clinical features, diagnosis, and prevention of the key arthropod-borne flaviviruses of concern in pregnancy and the neonatal period-Zika, Dengue, Japanese encephalitis, West Nile, and Yellow fever viruses. Increased disease severity during pregnancy, risk of congenital malformations, and manifestations of postnatal infection vary widely amongst this virus family and may be quite marked. Laboratory confirmation of infection is complex, especially due to the reliance on serology for which flavivirus cross-reactivity challenges diagnostic specificity. As such, a thorough clinical history including relevant geographic exposures and prior vaccinations is paramount for accurate diagnosis. Novel vaccines are eagerly anticipated to ameliorate the impact of these flaviviruses, particularly neuroinvasive disease manifestations and congenital infection, with consideration of vaccine safety in pregnant women and children pivotal. Moving forward, the geographical spread of flaviviruses, as for other zoonoses, will be heavily influenced by climate change due to the potential expansion of vector and reservoir host habitats. Ongoing 'One Health' engagement across the human-animal-environment interface is critical to detect and responding to emergent flavivirus epidemics.

Clinical and experimental evidence for transplacental vertical transmission of flaviviruses

The Zika virus (ZIKV) epidemic outbreak in Americas in 2016 attracted global attention because of the association of the virus infection with severe birth defects such as microcephaly, mediated through transplacental virus transmission during pregnancy. Less well-known, but also reported is the increasing evidence that prenatal vertical transmission can be caused by other flaviviruses such as dengue virus (DENV). Currently, the mechanism(s) that cause the vertical transmission of flaviviruses is understudied. Here we review the published reports of clinical evidence of intrauterine transmission of ZIKV and other flaviviruses. We also discuss the animal models for flavivirus infection during pregnancy that have been developed to study the mechanisms underlying the transplacental transmission of flaviviruses in order to develop potential countermeasures for its prevention.

Varied presentations of congenital dengue infection in neonates

Dengue fever is a common viral infection in the tropics and is prevalent in Southeast Asia. Dengue infection is associated with increased morbidity and mortality in the perinatal period. Transplacental transfer of dengue infection is rare. Here we report of four such cases.

Maternal and foetal-neonatal outcomes of dengue virus infection during pregnancy

OBJECTIVE

Given that women of reproductive age in dengue-endemic areas are at risk of infection, it is necessary to determine whether dengue virus (DENV) infection during pregnancy is associated with adverse outcomes. The aim of this systematic review and meta-analysis is to investigate the consequences of DENV infection in pregnancy on various maternal and foetal-neonatal outcomes.

METHODS

A systematic literature search was undertaken using PubMed, Google Scholar, and Embase till December 2021. Mantel-Haenszel risk ratios were calculated to report overall effect size using random effect models. The pooled prevalence was computed using the random effect model. All statistical analyses were performed on MedCalc Software.

RESULT

We obtained data from 36 studies involving 39,632 DENV-infected pregnant women. DENV infection in pregnancy was associated with an increased risk of maternal mortality (OR = 4.14 [95% CI, 1.17-14.73]), stillbirth (OR = 2.71 [95% CI, 1.44-5.10]), and neonatal deaths (OR = 3.03 [95% CI, 1.17-7.83]) compared with pregnant women without DENV infection. There was no significant statistical association established between maternal DENV infection and the outcomes of preterm birth, maternal bleeding, low birth weight in neonates, and risk of miscarriage. Pooled prevalences were 14.9% for dengue shock syndrome, 14% for preterm birth, 13.8% for maternal bleeding, 10.1% for low birth weight, 6% for miscarriages, and 5.6% for stillbirth.

CONCLUSION

DENV infection in pregnant women may be associated with adverse outcomes such as maternal mortality, stillbirth, and neonatal mortality. Hence, pregnant women should be considered an at-risk population for dengue management programmes.

Knowledge, Attitude, and Practices towards Dengue Fever among University Students of Dhaka City, Bangladesh

Dhaka has become the worst affected city in Bangladesh regarding dengue fever (DF). A large number of university students are residing in this city with a high DF risk. This cross-sectional study was conducted to assess the DF status and responses among these students through their Knowledge, Attitude, and Practices (KAP) survey. A total of 625 students participated in an online self-reported survey. Statistical analyses were performed to assess the status and KAP regarding DF. University students from the city perceived their living places as moderately safe (45.28%) against DF, whereas about 20% reported their DF infection history. Some of these students had exemplary DF knowledge (66.72%), attitude (89.28%), and practices (68.32%). However, many of them were also observed with a lack of knowledge about this disease’s infectious behavior, recognizing Aedes mosquito breeding sites, multiple infection cases, and the risk of DF viral infection during pregnancy. Fair correlations (p < 0.001) were determined in the KAP domain. Gender, residential unit, major, and dengue-relevant subjects were found to be significant predictors (p < 0.05) of KAP level in the univariate analysis. Major subject and residential units remained significant predictors of overall KAP level in further multiple analysis. This study revealed the urgency of infectious disease-related subjects and the relevant demonstration into the university curriculum. The study’s findings can assist the university, government and non-governmental organizations, and the health and social workers to prepare a comprehensive dengue response and preparedness plan.

Mosquito-borne disease and newborn health

While mosquito-borne diseases are currently most prevalent in mid-latitude countries, rising global temperatures could expand their range. This paper investigates whether one such disease, dengue, harms newborns. The empirical design exploits epidemiological patterns of the disease spreading. Dengue infection rates in the mother's municipality of residence which prevailed during the gestation period are instrumented with exogenous factors that determine dengue incidence in municipalities that have tight social connections to the maternal municipality. Using a large longitudinal dataset of Brazilian birth records, I find that a higher dengue rate during the third trimester of gestation has a detrimental effect on birth weight. In utero exposure to dengue also increases the probability of cesarean delivery and can lead to more serious consequences such as increased fetal and maternal mortality rates.

Route of Zika virus infection in Aedes aegypti by transmission electron microscopy

Background

Zika fever has been a global health security threat, especially in the tropical and subtropical regions where most of the cases occur. The disease is caused by Zika virus (ZIKV), which belongs to the family Flaviviridae, genus Flavivirus. The virus is transmitted by Aedes mosquitoes, mostly by Aedes aegypti, during its blood meal. In this study we present a descriptive analysis, by transmission electron microscopy (TEM), of ZIKV infection in A. aegypti elected tissues at the 3rd day of infection. ZIKV vertical transmission experiments by oral infection were conducted to explore an offspring of natural infection.

Results

Gut and ovary tissues harbored a higher number of viral particles. The ZIKV genome was also detected, by RT-qPCR technique, in the organism of orally infected female mosquitoes and in their eggs laid.

Conclusions

The data obtained suggest that the ovary is an organ susceptible to be infected with ZIKV and that virus can be transmitted from mother to a fraction of the progeny.

Neonatal dengue: an under-diagnosed entity

Neonatal dengue is an under-diagnosed disease likely due to low index of suspicion along with its resemblance to sepsis. We hereby report two cases of neonatal dengue, highlighting the need of high degree of suspicion in infants born to febrile mothers even with maternal serology being negative. Moreover, severity of neonatal illness positively correlates with the maternal disease.

Ebola, Dengue, Chikungunya, and Zika Infections in Neonates and Infants

Emerging infectious diseases, including Ebola, chikungunya, Zika, and dengue, may have significant impacts on maternal-fetal dyads and neonatal outcomes. Pregnant women infected with Ebola demonstrate high mortality and very low evidence of neonatal survival. Maternal chikungunya infection can result in high rates of perinatal transmission, and infected neonates demonstrate variable disease severity. Dengue can be transmitted to neonates via vertical transmission or perinatal transmission. Zika is characterized by mild disease in pregnant women, but congenital infection can be severe. Treatment largely is supportive for these diseases, and vaccine development remains under way, with promising recent advances, notably for Ebola.

Maternal and congenital infections arising from Zika, dengue and Chikungunya arboviruses in Salvador, Brazil

BACKGROUND

Salvador was one of the Brazilian cities most affected during the 2015 Zika virus (ZIKV) outbreak.

METHODS

A cross-sectional study was performed with enrolment of parturients and their newborns.

RESULTS

Positive IgM antibodies for ZIKV, dengue (DENV) and Chikungunya (CHIKV) were present in 6.9, 11.9 and 22.8% of the parturients, and IgG antibodies were detected in 72.3, 92.3 and 38.6%, respectively. No cases of DENV congenital infection were identified. ZIKV and CHIKV congenital infections were observed in 16.5 and 13% of newborns, respectively.

CONCLUSIONS

High exposure rates to the three arboviruses and the identification of newborns with ZIKV and CHIKV congenital infections reinforces the necessity of ZIKV and CHIKV prenatal and neonatal screening in endemic regions.

Congenital dengue in neonate

Congenital dengue should be considered as a cause of fever and rash in a neonate born to a mother especially in endemic areas.

Maternal and fetal outcomes of dengue fever in pregnancy: a large prospective and descriptive observational study

Purpose

The primary objective of the study was to assess maternal and fetal outcomes of pregnancies affected with dengue fever.

Methods

This was a prospective, observational and descriptive study carried out over a period of 1 year. 216 pregnant women with fever were screened. Of these, 44 women tested positive for dengue (non-structural protein antigen 1 or dengue IgM antibodies in the sera). The clinical and laboratory characteristics of women with dengue were recorded. Maternal outcomes, pregnancy outcomes and fetal outcomes were studied.

Results

Mean period of gestation was 31.89 ± 7.31 weeks. Thrombocytopenia was seen in 23 (52.3%) women. Of 40 women, 10 (25%) developed post-partum haemorrhage. The incidence of maternal systemic complications was high: eight (18.2%) women developed acute kidney injury and two (4.5%) required haemodialysis support; eight (18.2%) women developed ARDS and seven (15.9%) women required ventilatory support; four (9.1%) women developed acute liver failure. 18 (40.9%) women had evidence of shock. Seven (15.9%) women died and another seven (15.9%) were classified as WHO maternal near-miss cases. Two (4.5%) pregnancies suffered from miscarriages, four (9%) from still births and two (4.5%) from neonatal deaths. Preterm babies were delivered in 15 (34.1%) and low birth weight babies in 13 (29.5%).

Conclusions

Dengue in pregnancy adversely affects maternal and fetal outcomes with high maternal mortality of 15.9%. Prematurity and postpartum haemorrhage are significant risks to mother and baby. Vector control strategies should be implemented with vigour in affected areas.

Serosurvey for dengue virus infection among pregnant women in the West Nile virus enzootic community of El Paso Texas

All 4 dengue viruses (DENV) cause sporadic outbreaks of human disease in the Rio Grande Valley along the US-Mexico border. In addition, West Nile virus (WNV) is enzootic in most border communities, and is the only arbovirus known to cause human disease in the El Paso, Texas community. In an effort to determine if DENV were also endemic in the El Paso community, a serosurvey was conducted among mothers at the time of delivery of their babies in selected hospitals. Cord-blood plasma samples obtained from mothers were tested for DENV antibody by an enzyme-linked immuno-sorbent assay (ELISA), plaque reduction neutralization test (PRNT) and a multiplex microsphere immunoassay. All DENV antibody positive plasma samples were also tested for WNV antibody by the same assays to consider the possibility that DENV antibody positive samples reflected WNV cross reactive antibody. The results indicated that 0.74% (11/1,472) of the mothers had a previous DENV infection and that 3.3% (48/1,472) had a previous WNV infection. Of these mothers, 0.20% (3/1,472) had antibody to both DENV and WNV as evidence of infection by both viruses. The results indicated that 0.2% (3/1472) of the mothers were positive for antibody to only WNV envelope, thus suggesting an undetermined flavivirus infection. Although 6 of the 11 DENV antibody positive mothers did not have a history of travel to a DENV endemic country, the findings of this survey provided further evidence of local transmission of WNV and suggested the possibility of focal autochthonous transmission of DENV in the El Paso community.

Case Series of Dengue Fever in Peripartum Period: Maternal and Foetal Outcome

Introduction: Dengue fever is a major public health problem in tropical and subtropical areas. There are not many studies concerning the complications of dengue fever in pregnancy. We present four serial cases of dengue fever in pregnancy. Case illustration: Three of four cases were delivered by caesarean section; two of them died during post-caesarean care. All cases had the lowest platelet level below 50,000/µL and were given platelet transfusion during and after delivery; they also showed abnormal liver function tests. For foetal outcome, none tested positive for dengue. Discussion: Complication of dengue infection depends on a combination of host and viral virulence. Regardless of prophylactic platelet transfusion, some studies revealed clinical bleeding in patients with dengue infection due to an intricate effect on the haemostatic system. The adverse foetal outcome may contribute because of placental circulation caused by endothelial damage with increased vascular permeability leading to plasma leakage. There is no national guideline for dengue fever in pregnancy. Conclusions: The management of dengue fever in pregnancy at the tertiary hospital is still suboptimal. Dengue fever around peripartum presents a higher risk of morbidity and mortality for the mother and therefore needs a multidiscipline team approach.

Dengue virus infection and pregnancy outcomes during the 2017 outbreak in Ouagadougou, Burkina Faso: A retrospective cohort study

Introduction

Dengue fever is a re-emerging pathology in Burkina Faso. It affects everyone and pregnant women are not left out. The objective of this study was to estimate the burden of dengue fever and to assess its effects on pregnancy outcomes in hospitalized pregnant women during the 2017 outbreak in Ouagadougou, Burkina Faso.

Method

This was a retrospective cohort study including febrile pregnant women from five health facilities in Ouagadougou. The study was carried out from July 1st to December 31st, 2017. A logistic stepwise regression was performed to identify the pregnancy adverse outcomes risk factors.

Results

Our study included 424 pregnant women at a mean age of 27.1 years old (Standard deviation: 6.23 years). Overall 28.54% (121/424) were infected with dengue virus. During follow-up, 29.01% (123/424) presented an adverse pregnancy outcome. Adjusted for gestational age and clinical symptoms, the risk of adverse pregnancy outcome was twice as high among dengue infected women as compared to uninfected women with an adjusted Odds Ratio (aOR) = 2.09 (1.08–4.05). The risk of the adverse pregnancy outcome was higher in the third trimester of pregnancy with aOR = 1.66 (1.02–2.72) in dengue fever infected women.

Conclusion

Dengue fever is a risk factor for adverse pregnancy outcomes, especially in the third trimester in Burkina Faso. The implementation of effective anti-vectorial control interventions and better management of dengue fever during pregnancy are needed to improve pregnancy outcomes.

Vector-borne diseases in pregnancy

Vector-borne infections cause a significant proportion of world-wide morbidity and mortality and many are increasing in incidence. This is due to a combination of factors, primarily environmental change, encroachment of human habitats from urban to peri-urban areas and rural to previously uninhabited areas, persistence of poverty, malnutrition and resource limitation in geographical areas where these diseases are endemic. Pregnant women represent the single largest ‘at risk’ group, due to immune-modulation and a unique physiological state. Many of these diseases have not benefitted from the same level of drug development as other infectious and medical domains, a factor attributing to the ‘neglected tropical disease’ title many vector-borne diseases hold. Pregnancy compounds this issue as data for safety and efficacy for many drugs is practically non-existent, precluding exposure in pregnancy to many first-line therapeutic agents for ‘fear of the unknown’ or overstated adverse pregnancy-foetal outcomes. In this review, major vector-borne diseases, their impact on pregnancy outcomes, current treatment, vaccination and short-comings of current medical practice for pregnant women will be discussed.

Zika; a continuous global threat to public health

Zika virus is transmitted by Aedes mosquitoes, especially, Ae. aegypti and Ae. albopictus. About 80% of the cases do not manifest any symptoms, and it is a self-limiting, mild viral infection. In 20% of the cases and only in fraction of those who do show the symptoms, important complications including Guillaine Barre'syndrome and microcephaly may occur. The emergence of Zika in 2016 in Brazil spreading to about 70 other countries prompted the WHO officials to declare the disease a Public Health Emergency with International Concern (PHEIC). This has led to increased concerns in health authorities of almost all countries making them embark on the strengthened human and vector surveillance, vector control and clinical management of the disease. Although the main vectors of the disease have not yet been able to establish in Iran, because of their occurrence in neighboring countries as well as increased global travel and trade, the country established a national advisory committee for capacity building, vector and human surveillance and case management of Aedes-borne diseases. This study aims at performing a literature review about global situation of Zika and Aedes mosquitoes, their distribution, biology and ecology from the past to present and the threat posed to Iran. Aedes aegypti was historically present in the checklist of Iranian mosquitoes and Ae. albopictus has recently been collected from Southern Iran, however, the species has apparently failed to establish in the country as comprehensive follow up entomological surveillance could not reproduce the findings. Although Zika was not detected in Iran, considering the expansion in tourism, travel and trade to and from Zika infected and Aedes infested countries, suitable climate and favorable prediction for establishment of Aedes vectors, Iran may well be at risk of invasion of Aedes vector species and the diseases they carry. Therefore, this review is of value particularly to health authorities in Iran and other WHO Eastern Mediterranean countries for sustained vigilance and preparedness for early detection and response, including vector control.

Knowledge, attitude and practice on dengue prevention and dengue seroprevalence in a dengue hotspot in Malaysia: A cross-sectional study

Dengue has become a global public health problem. Despite reactive efforts by the government in Malaysia, the dengue cases are on the increase. Adequate knowledge, positive attitude and correct practice for dengue control are essential to stamp out the disease. Hence, this study aims to assess the factors associated with dengue knowledge, attitude and practice (KAP), as well as the association with dengue IgM and IgG seropositivity. A community-based cross-sectional study was conducted in a closed, dengue endemic area with multi-storey dwellings . Five hundred individuals (aged 18 years and above) were approached for pre-tested KAP and seroprevalences assessment. The study showed only half of the total participants have good knowledge (50.7%) but they had insufficient knowledge about dengue during pregnancy. 53.2% of people had poor attitude and 50.2% reported poor practice for dengue control. Out of 85 respondents who agreed to participate in the dengue seroprevalence study, 74.1% (n = 63) were positive for dengue IgG and 7.1% (n = 6) were positive for dengue IgM. Among all sociodemographic variable, race is the only independent predicator for all KAP levels (P < 0.05). In conclusion, proactive and sustainable efforts are needed to bring a behavioural change among communities in order to fight dengue outbreaks in endemic areas.

Maternal and Neonatal Outcomes during Dengue Infection Outbreak at a Tertiary National Hospital in Endemic Area of Indonesia

Background

Dengue infection is the most common mosquito-borne disease in Indonesia. Dengue incidence during pregnancy increases with its prevalence among women of reproductive ages. It potentially causes serious maternal and neonatal morbidity and mortality; however, its impact during a period of disease outbreak has not been described. We aimed to assess the outcomes of pregnancies affected by dengue infection during an outbreak in an endemic area of Indonesia.

Methods

We conducted a prospective observational study at Sanglah General Hospital, Bali, Indonesia from April 2016 to April 2017. All pregnant women with clinical symptoms of dengue infection who tested positive for dengue nonstructural protein 1-antigen or anti-dengue immunoglobulin M were included in the study. Clinical features and hematological and biochemical parameters were documented to assess their relationship with maternal and neonatal outcomes.

Results

Our study population consisted of 41 pregnant women. Most were multigravida (58.5%). Dengue infection without warning signs was observed in 31.7% of the cases, while 53.7% had dengue infection with warning signs, and 14.6% had dengue shock syndrome/severe dengue infection. Most pregnancies were in the third trimester (78%); five cases (12.2%) suffered clinical complications. Preterm delivery was observed in seven cases (17.1%). Most patients (75.6%) decided to seek medical treatment at a critical phase of dengue infection (days 3–6).

Conclusion

The high incidence of associated morbidity and mortality should warrant clinicians in endemic regions to consider diagnoses of dengue infection when treating pregnant women with clinical signs and symptoms. Patients should be treated at centers with adequate resources for monitoring and emergency procedures. A more intensive study is needed in the future aiming to make a more comprehensive guideline.

Intensified Short Symptom Screening Program for Dengue Infection during Pregnancy, India

Mosquitoborne diseases (e.g., malaria, dengue, and chikungunya) are endemic to India and pose diagnostic challenges during pregnancy. We evaluated an intensified short symptom screening program in India to diagnose dengue during pregnancy. During October 2017–January 2018, we screened pregnant women during antenatal surveillance for symptoms of mosquitoborne diseases (fever only, fever with conjunctivitis, fever with rash, or all 3 symptoms) within the previous 15 days. Of 5,843 pregnant women screened, 52 were enrolled and tested for dengue, chikungunya, and Zika viruses by using a Trioplex real-time reverse transcription PCR. Of 49 who had complete results, 7 (14%) were dengue positive. Of these ocular pain was seen in 4 (57%) and conjunctivitis in 7 (100%). Intensified symptom screening using conjunctivitis, in addition to rash, in pregnant women with fever might improve dengue case detection and can be included in routine symptom screening during pregnancy.

Maternal-Fetal Interplay in Zika Virus Infection and Adverse Perinatal Outcomes

During pregnancy, the organization of complex tolerance mechanisms occurs to assure non-rejection of the semiallogeneic fetus. Pregnancy is a period of vulnerability to some viral infections, mainly during the first and second trimesters, that may cause congenital damage to the fetus. Recently, Zika virus (ZIKV) infection has gained great notoriety due to the occurrence of congenital ZIKV syndrome, characterized by fetal microcephaly, which results from the ability of ZIKV to infect placental cells and neural precursors in the fetus. Importantly, in addition to the congenital effects, studies have shown that perinatal ZIKV infection causes a number of disorders, including maculopapular rash, conjunctivitis, and arthralgia. In this paper, we contextualize the immunological aspects involved in the maternal-fetal interface and vulnerability to ZIKV infection, especially the alterations resulting in perinatal outcomes. This highlights the need to develop protective maternal vaccine strategies or interventions that are capable of preventing fetal or even neonatal infection.

Dengue and malaria infections in pregnancy : Maternal, fetal and neonatal outcomes at a tertiary care hospital

Background

Malaria and dengue cause major morbidity in developing nations and are more severe in pregnancy. Maternal, fetal, and neonatal outcomes in pregnant patients infected with dengue or malaria were studied.

Methods

The medical records of pregnant women admitted with either dengue or malaria infections from 2011–2015 to this hospital were reviewed. Clinical outcomes and laboratory tests were examined.

Results

Of 85 women, 56%, 21%, and 22% had contracted dengue, malaria, and multiple infections, respectively. Pregnant women who had contracted dengue fever alone were more likely to present to the hospital at an earlier gestational age (24 weeks, p = 0.03). Women with multiple infections, were more likely to deliver earlier (30 weeks, p < 0.01). Women with malaria were more likely to have low birth weight deliveries (mean birth weight 2394 g, p = 0.03). The incidence of in-hospital deaths among the cohort was 7%.

Conclusion

It is imperative to develop guidelines to screen for and diagnose dengue and malaria in pregnancy.

Electronic supplementary material

The online version of this article (10.1007/s00508-019-01606-8) contains supplementary material, which is available to authorized users.

Dengue during pregnancy and live birth outcomes: a cohort of linked data from Brazil

OBJECTIVES

Dengue is the most common viral mosquito-borne disease, and women of reproductive age who live in or travel to endemic areas are at risk. Little is known about the effects of dengue during pregnancy on birth outcomes. The objective of this study is to examine the effect of maternal dengue severity on live birth outcomes.

DESIGN AND SETTING

We conducted a population-based cohort study using routinely collected Brazilian data from 2006 to 2012.

PARTICIPATING

We linked birth registration records and dengue registration records to identify women with and without dengue during pregnancy. Using multinomial logistic regression and Firth method, we estimated risk and ORs for preterm birth (<37 weeks' gestation), low birth weight (<2500 g) and small for gestational age (<10thcentile). We also investigated the effect of time between the onset of the disease and each outcome.

RESULTS

We included 16 738 000 live births. Dengue haemorrhagic fever was associated with preterm birth (OR=2.4; 95% CI 1.3 to 4.4) and low birth weight (OR=2.1; 95% CI 1.1 to 4.0), but there was no evidence of effect for small for gestational age (OR=2.1; 95% CI 0.4 to 12.2). The magnitude of the effects was higher in the acute disease period.

CONCLUSION

This study showed an increased risk of adverse birth outcomes in women with severe dengue during pregnancy. Medical intervention to mitigate maternal risk during severe acute dengue episodes may improve outcomes for infants born to exposed mothers.

Molecular epidemiology of dengue, yellow fever, Zika and Chikungunya arboviruses: An update

Arboviruses are a group of viruses transmitted by arthropods. They are characterized by a wide geographic distribution, which is associated with the presence of the vector, and cause asymptomatic infections or febrile diseases in humans in both enzootic and urban cycles. Recent reports of human infections caused by viruses such as dengue, Zika, and chikungunya have raised concern regarding public health, and have led to the re-evaluation of surveillance mechanisms and measures to control the transmission of these arboviruses. Viruses such as Mayaro and Usutu are not currently responsible for a high number of symptomatic infections in humans, but should remain under epidemiological surveillance to avoid the emergence of new epidemics, as happened with Zika virus, that are associated with new or more severe symptoms. Additionally, significant variation has been observed in these viruses, giving rise to different lineages. Until recently, the emergence of new lineages has primarily been related to geographical distribution and dispersion, allowing us to ascertain the possible origins and direction of expansion of each virus type, and to make predictions regarding regions where active infections in humans are likely to occur. Therefore, this review is focused on untangling the molecular epidemiology of Dengue, Yellow fever, Zika and Chikungunya due to their recent epidemics in Latinamerica but provides an update on the geographical distribution globally of these viral variants, and outlines the need for further understanding of the genotypes/lineages assignment.

Estimating the Risk of Vertical Transmission of Dengue: A Prospective Study

The incidence of dengue worldwide is increasing rapidly. A better understanding of dengue transmission may help improve interventions against this major public health problem. The virus is mostly transmitted by vectors. There are, however, other modes of transmission, notably mother-to-child transmission or vertical transmission. We studied a prospective cohort of 54 women who had dengue while pregnant during the 2012-2013 epidemic in French Guiana to estimate the mother-to-child transmission rate and assess the clinical and biological presentation of neonatal dengue. The rate of vertical transmission was between 18.5% (95% confidence interval [CI]: 9.25-31.4) and 22.7% (95% CI: 11.5-37.8), depending on the calculation method used. Mother-to-child transmission occurred both in early and late pregnancy. There were 52 births, including three newborns who presented neonatal dengue with warning signs requiring platelet transfusion. This quantification of the mother-to-child transmission of dengue highlights three points: first, vertical transmission of dengue is not negligible; second, it is more frequent when maternal dengue occurs late during pregnancy near delivery; and third, reliable diagnostic tests must be used to allow the diagnosis of vertical transmission. Our findings indicate that if there is a known history of maternal dengue during pregnancy, or if there is fever during the 15 days before term, cord blood and placenta should be sampled after delivery and tested for the virus, and the newborn should be closely monitored during the postpartum period.

Maternal, Fetal, and Neonatal Outcomes in Pregnant Dengue Patients in Mexico

To increase our understanding of the consequences of dengue virus infection during pregnancy, a retrospective analysis was performed on the medical records of all completed pregnancies (live births and pregnancy losses) at nine public hospitals in the Gulf of Mexico from January to October 2013. Eighty-two patients developed clinical, laboratory-confirmed dengue virus infections while pregnant. Of these, 54 (65.9%) patients were diagnosed with dengue without warning signs, 15 (18.3%) patients were diagnosed with dengue with warning signs, and 13 (15.9%) patients had severe dengue. Five (38.5%) patients with severe dengue experienced fetal distress and underwent emergency cesarean sections. Four patients delivered apparently healthy infants of normal birthweight while the remaining patient delivered a premature infant of low birthweight. Patients died of multiple organ failure during or within 10 days of the procedure. Severe dengue was also associated with obstetric hemorrhage (30.8%, four cases), preeclampsia (15.4%, two cases), and eclampsia (7.7%, one case). These complications were less common or absent in patients in the other two disease categories. Additionally, nonsevere dengue was not associated with maternal mortality, fetal distress, or adverse neonatal outcomes. In summary, the study provides evidence that severe dengue during pregnancy is associated with a high rate of fetal distress, cesarean delivery, and maternal mortality.

Zika, chikungunya and dengue: the causes and threats of new and re-emerging arboviral diseases

The recent emergence and re-emergence of viral infections transmitted by vectors—Zika, chikungunya, dengue, Japanese encephalitis, West Nile, yellow fever and others—is a cause for international concern. Using as examples Zika, chikungunya and dengue, we summarise current knowledge on characteristics of the viruses and their transmission, clinical features, laboratory diagnosis, burden, history, possible causes of the spread and the expectation for future epidemics. Arboviruses are transmitted by mosquitoes, are of difficult diagnosis, can have surprising clinical complications and cause severe burden. The current situation is complex, because there is no vaccine for Zika and chikungunya and no specific treatment for the three arboviruses. Vector control is the only comprehensive solution available now and this remains a challenge because up to now this has not been very effective. Until we develop new technologies of control mosquito populations, the globalised and urbanised world we live in will remain vulnerable to the threat of successive arbovirus epidemics.

History and Emergence of Zika Virus

Zika virus was discovered in East Africa in 1947 by the Rockefeller Foundation during investigations on the ecology of yellow fever. Although it was subsequently shown to have widespread distribution in Africa and Asia, it was not known to cause epidemics until 2007. This paper describes the history of the virus discovery, emergence and evolution as an epidemic virus, and the its evolving clinical spectrum.

Dengue Maculopathy with Foveolitis in a Postpartum Female

Dengue fever is common in the tropics and its clinical manifestations and complications are well-known. However, dengue-related ocular complications are rare. Here we present a postpartum female who complained of bilateral central scotoma, at five days after the clinical diagnosis of dengue fever. The ocular examination was suggestive of dengue maculopathy and foveolitis. She was treated with a combination of intravenous methylprednisolone and immunoglobulin. The final visual recovery was good.

Vertical Transmission of Dengue Virus in the Peripartum Period and Viral Kinetics in Newborns and Breast Milk: New Data

SUMMARY

We investigated 10 mother-newborn pairs and found a 90% rate of dengue virus (DENV) transmission during the perinatal period. Here, we describe DENV kinetics in the sera of newborns before the onset of disease. Of the breast-milk samples analyzed, 75% tested positive for DENV.

BACKGROUND

Dengue is the most common mosquito-borne viral disease in humans. With this study, we aimed to investigate the risk of vertical (DENV) transmission during the peripartum period and to describe its viral kinetics in serum and breast milk.

METHODS

We carried out a prospective study during the 2012-2013 dengue epidemic in New Caledonia, its most severe on record. All mothers hospitalized at the Centre Hospitalier Territorial in Nouméa, New Caledonia, with symptoms of dengue infection between 7 days before and 2 days after delivery and/or whose infant was infected during breastfeeding were investigated. DENV was detected and quantified by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) in sera and breast milk (mothers), sera and gastric fluid (newborns), cord blood, and placentas. DENV kinetics and sequences in sera and breast milk were studied. Clinical presentation and biological evolution in mother-newborn pairs were analyzed.

RESULTS

Ten mother-newborn pairs were investigated over an 11-month period. One premature birth, 3 hemorrhagic complications, and 1 maternal death occurred. Nine newborns were infected and symptomatic. One case of deep thrombocytopenia and 1 case of anoxic encephalopathy occurred. DENV was detected in breast milk samples from 9 (75%) of 12 infected breastfeeding mothers. Original DENV kinetics in sera and breast milk were described.

CONCLUSIONS

The occurrence of vertical DENV transmission was high (90%) in viremic mothers at delivery, and these mothers and their infants were at major risk for obstetric and neonatal complications. The modes of viral transmission are difficult to clarify. The risk of DENV transmission through breast milk seems plausible. Close follow-up of mothers and prolonged surveillance of their newborns are required for minimizing complications. Complementary studies are needed to elaborate preventive recommendations.

Timing of the human prenatal antibody response to Plasmodium falciparum antigens

Plasmodium falciparum (Pf)-specific T- and B-cell responses may be present at birth; however, when during fetal development antibodies are produced is unknown. Accordingly, cord blood samples from 232 preterm (20–37 weeks of gestation) and 450 term (≥37 weeks) babies were screened for IgM to Pf blood-stage antigens MSP1, MSP2, AMA1, EBA175 and RESA. Overall, 25% [95% CI = 22–28%] of the 682 newborns were positive for IgM to ≥1 Pf antigens with the earliest response occurring at 22 weeks. Interestingly, the odds of being positive for cord blood Pf IgM decreased with gestational age (adjusted OR [95% CI] at 20–31 weeks = 2.55 [1.14–5.85] and at 32–36 weeks = 1.97 [0.92–4.29], with ≥37 weeks as reference); however, preterm and term newborns had similar levels of Pf IgM and recognized a comparable breadth of antigens. Having cord blood Pf IgM was associated with placental malaria (adjusted OR [95% CI] = 2.37 [1.25–4.54]). To determine if in utero exposure occurred via transplacental transfer of Pf-IgG immune complexes (IC), IC containing MSP1 and MSP2 were measured in plasma of 242 mother-newborn pairs. Among newborns of IC-positive mothers (77/242), the proportion of cord samples with Pf IC increased with gestational age but was not associated with Pf IgM, suggesting that fetal B cells early in gestation had not been primed by IC. Finally, when cord mononuclear cells from 64 term newborns were cultured in vitro, only 11% (7/64) of supernatants had Pf IgM; whereas, 95% (61/64) contained secreted Pf IgG. These data suggest fetal B cells are capable of making Pf-specific IgM from early in the second trimester and undergo isotype switching to IgG towards term.

Clinical Impact of Non-Congenital Zika Virus Infection in Infants and Children

PURPOSE OF REVIEW

While the Zika virus (ZIKV) has been noted for its distinct neurotropism and identified as a significant cause for a congenital infection syndrome, there has been increased recognition of the importance to better understand the clinical impact of non-congenital ZIKV infection in infants and children. This article reviews reports of perinatal and breast milk transmission of ZIKV and summarizes current clinical outcome data of pediatric non-congenital ZIKV infection.

RECENT FINDINGS

Perinatal transmission and presence of infective ZIKV particles in breast milk have been reported. Most symptomatic non-congenital ZIKV infection in infants and children is mild and self-limited, but long-term follow-up studies are lacking. The mechanism and impact of perinatal and breast milk transmission is unclear. The current WHO infant feeding guidelines in areas of ZIKV transmission support breastfeeding. Unless any scientific data raise concern regarding transmission via breastfeeding, the current guidelines should continue to be followed. Prospective population-based cohort studies to investigate maternal, perinatal, infant, and child outcomes are needed.

Miscarriage following dengue virus 3 infection in the first six weeks of pregnancy of a dengue virus-naive traveller returning from Bali to Italy, April 2016

We report miscarriage following dengue virus (DENV)-3 infection in a pregnant woman returning from Bali to Italy in April 2016. On her arrival, the woman had fever, rash, asthenia and headache. DENV RNA was detected in plasma and urine samples collected the following day. Six days after symptom onset, she had a miscarriage. DENV RNA was detected in fetal material, but in utero fetal infection cannot be demonstrated due to possible contamination by maternal blood.

A rare case of dengue encephalopathy complicating a term pregnancy

BACKGROUND

Dengue fever has an expanded clinical spectrum ranging from an asymptomatic infection to life threatening dengue hemorrhagic fever and refractory shock. Dengue infection in pregnancy can be a diagnostic dilemma, particularly considering the physiological changes in pregnancy and the obstetric complications encountered in clinical practice. Hence the knowledge of its diagnosis and management in its atypical presentations is of paramount importance. Here we report an unusual case of uncomplicated dengue encephalopathy in a term mother, probably the first to be reported from the Indian subcontinent.

CASE PRESENTATION

A 28 year old woman, 37 weeks of pregnancy presented with fever of four days duration. She eventually developed irritability, altered sensorium, somnolence, and unresponsiveness to commands by the 5th day of febrile illness without any circulatory compromise. Physical examination and investigations including serology confirmed dengue fever. After excluding all other possible causes, the transient neurological deterioration was finally attributed to dengue encephalopathy which is an uncommon manifestation of the disease, particularly in pregnancy. Her deteriorated neurological status which had lasted for 6 days improved spontaneously with the convalescence of dengue infection. Cautious fluid management was carried out in correlation to clinical and hematological parameters. The pregnancy was continued uncomplicated till the platelet count had risen to more than 50,000 cells/cumm. She delivered vaginally a healthy male baby.

CONCLUSIONS

Dengue fever in pregnancy is increasingly being encountered due to its rising disease burden. Dengue encephalitis/encephalopathy must be suspected in the differential diagnosis of fever and altered sensorium, even in pregnancy, in the tropical countries where the infection is rampant. Management of dengue infection in term pregnancy is a challenge for both the clinician and obstetrician. Further discussion and research are mandatory to decide on optimal management of these patients, with regard to monitoring, fluid management, and the precise timing and mode of delivery in order to prevent fatal morbidity and mortality to both mother and fetus.

Altered intrauterine ultrasound, fetal head circumference growth and neonatal outcomes among suspected cases of congenital Zika syndrome in Brazil

Abstract Objectives: to describe altered intrauterine ultrasound, analyze fetal head circumference (HC) growth and neonates' outcomes among presumed cases of congenital Zika syndrome in Brazil. Methods: 30 women were included in the study with suspected history of Zika virus (ZIKV) infection during pregnancy and fetal's brain altered on ultrasound diagnosis. Sociodemographic and obstetric characteristics, prenatal altered ultrasounds, HC and other perinatal outcomes have been described. The relation between HC and gestational age was analyzed by using random regression effects based on polynomials fractions. The Z test was calculated to determine an instant variant mean rate of the HC for each gestational age. Results: the mean gestational age of the ultrasound diagnosis was 33.3 + 4.7 weeks and HC at birth was 28.9 + 1.6 cm. The main altered brain ultrasound was microcephaly (96.7%). The analysis of the fetal head circumference showed an estimated increase of the average HC, as to gestational age, it did not occur in a linear form. The instant HC variation rate increased according to gestational age (p<0,001). Conclusions: Fetal's main morphological alteration was microcephaly, observing an increase in the head circumference according to gestational age in a non-linear form and the variation decreased with gestational age.

Congenital and perinatally-acquired infections in resource-constrained settings

INTRODUCTION

Congenital and perinatal infections are a leading cause of neonatal and infant morbidity and mortality. Maternal screening, vaccines or treatment where available, constitute effective prevention strategies to reduce the burden of these diseases. Data on the burden of congenital and perinatal infections are very limited for low and middle-income regions.

AREAS COVERED

This review aims to summarize the burden of congenital and perinatal infections and the main challenges for their control in resource-limited settings. Articles were identified through the main electronic databases and cover the period 1971-2016. Expert commentary: Estimates from low and middle-income countries indicate that the burden of congenital infections may be higher in these regions than in industrialized countries. As preventive and curative strategies are available to tackle some of these infections, efforts at the international and national levels must be made to implement those and thus reduce their burden in resource-limited countries.

Non-vector-borne transmission of Zika virus: A systematic review

BACKGROUND

Increasing numbers of confirmed cases of Zika virus (ZIKV) infection resulting from non-mosquito-borne transmission have been reported.

METHODS

We performed a systematic literature review (PRISMA guidelines) on intrauterine, intrapartum, sexual and animal bite ZIKV transmission. The presence of the virus in breast milk, urine, saliva and blood transfusions was also reviewed.

RESULTS

The search resulted in 285 papers of possible relevance, of which we included 53 in the systematic review. Mother-to-child transmission was most frequently described with adverse infant outcomes including microcephaly, intracranial calcification and fetal death. Zika virus RNA has been detected in amniotic fluid, breast milk, seminal fluid, saliva, urine and blood. Semen and blood products have proved to be infectious. Male-to-female and male-to-male ZIKV transmission is documented. There are contradictory results concerning the infectiousness of breast milk and urine and data on saliva, animal bites, transplantation, needlestick injury and laboratory work are inconclusive.

CONCLUSIONS

Our systematic analysis shows that non-vector-borne ZIKV transmission plays a role in the spread of ZIKV and has great societal impact. It has important public health implications for the prevention and control of ZIKV globally and will be a basis for policy and further research.