Abstract
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.
Keywords
Introduction
Dengue fever is caused by dengue virus and is transmitted by the bite of a female Aedes aegypti mosquito. This infection is endemic in India. During the perinatal period, dengue fever leads to increased morbidity and mortality. 1 Vertical transmission of dengue should be suspected when the mother has illness within 10 days before delivery. The newborn in such cases may become symptomatic within the first two weeks of delivery. We present a series of four cases of congenital dengue seen at our centre in the last two years.
Case 1
A 32-year old primigravida with severe dengue, diagnosed NS1 and IgM positive, presented with haemorrhagic shock and multi-organ dysfunction at 35 weeks’ gestation. She was delivered of a single, female of 2.3 kg at 37 weeks’ gestation by emergency Caesarean section. The baby did not cry immediately after birth, was resuscitated and then transferred to our neonatal intensive care unit. She was put on continuous positive airway pressure for 12 h and then weaned off to room air. Arterial blood gas analysis showed a metabolic acidosis together with raised ammonia. Dengue profile done on the first day of life was negative.
Serial blood counts revealed haemoconcentration and falling platelet counts. Repeat dengue profile on the second day was negative. The baby gradually developed erythematous rashes, mildly raised liver enzyme levels and a full blood count on the fourth day showed Hb 206 g/l, platelets 50 × 109/l and total leucocyte counts of 7.84 × 109/l . Blood culture was sterile. Dengue profile repeated on the fourth day showed dengue NS1 positive. The baby thus received intravenous immunoglobulin at 1 g/kg for 2 days. Gradually, she improved clinically and was withdrawn from hospital care against medical advice in view of monetary constraints on the sixth day.
Case 2
A 25-year old primigravida at 36 weeks and 5 days of gestation was admitted with complaints of fever for 5 days together with headache and mild erythematous rashes. Her dengue NS1 was positive with thrombocytopenia. At 37 weeks’ gestation, she delivered of a single, 2.98 kg male via Caesarean section. Laboratory tests on the second day showed Hb 188 g/l, platelets 167 × 109/l, and leucocytes 10.6 × 109/l, with dengue NS1 antigen test positive and IgG/IgM antibodies to dengue virus negative. This baby was managed conservatively and was discharged in a haemodynamically stable condition.
Case 3
A 27 year old, gravida 2 woman with dengue fever (dengue NS1 and IgM positive) was admitted on the second post-partum for further treatment. The baby delivered was a full-term single male weighing 2.9 kg with a normal birth history. On the third day, he developed a fever with erythematous rashes. Laboratory investigations showed haemoconcentration with mild thrombocytopenia (120 × 109/l) and positive dengue NS1. The baby was managed conservatively and was discharged on the seventh day in a haemodynamically stable condition with a platelet count of >150 × 109/l.
Case 4
A 3-kg male baby was delivered to a primigravida mother by emergency Caesarean section in view of foetal distress. Maternal dengue NS1 was positive with features of severe dengue infection. Dengue NS1 was positive for the neonate and serial blood counts showed decreasing platelets, which on the third day of illness had dropped to 6 × 109/l. The baby was administered intravenous immunoglobulin at a dose of 2 g/kg. Gradually platelet counts improved and the fever settled. Blood cultures remained sterile.
Discussion
When a pregnant woman suffers from dengue infection in late pregnancy, there is a risk of preterm delivery. If the mother delivers the baby at the height of viraemia, both the mother and the baby are at risk of developing life-threatening complications.
In the past 2 years, we have encountered 10 pregnant mothers who presented with fever and tested positive for dengue. Among newborns born to these mothers, four neonates tested positive for dengue infection. Laboratory diagnosis is vital for dengue virus infections. We did not collect any neonatal cord blood samples, but the clinical presentation in mother and neonate, along with laboratory test results (NS1 positive in all neonates) helped us to diagnose congenital dengue infection in all our cases.
Neonates with dengue infection have varied presentations. They may remain asymptomatic as seen in two of our cases. Others may develop febrile illness within the first 12 days of birth with symptoms lasting for 1–5 days. A strong suspicion is needed in neonates presenting with pallor, irritability, poor feeding, bleeding manifestations, rashes, fever, elevated liver enzymes and shock.2–6 It is of interest that three of our four cases (Table 1) had low platelet counts and this may be an important marker to diagnose congenital dengue infection in an appropriate clinical setting. 7
Clinical profile of mother and newborns with dengue infection.
It is important to rule out neonatal sepsis and other vertically transmitted infections as they may present with a similar clinical picture. Treatment of congenital dengue is supportive and symptomatic. Prevention of transmission of infection by vector control should be advised.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
