Novel influenza A(H1N1) virus among gravid admissions

Journal of SAFOG, 2014

Reports from the past pandemics (1918-1919) and the 2009 outbreak have shown that pregnant mothers are at risk of complications from the H1N1 influenza virus infection. This study was undertaken to analyze the clinical course of H1N1 infection in pregnancy, the maternal and perinatal outcome and the treatment efficacy of oseltamivir in H1N1 infected mothers. This is a descriptive study from the Institute of Obstetrics and Gynaecology and the case series were collected from September 2009 to December 2010. Influenza like illness (ILI) was suspected in 207 pregnant women, and the 32 cases who were positive for H1N1 influenza infection by RT PCR test were taken for this study. 90.6% were in the age group between 21 and 29 years of age and 34.4% were multigravid women. The most common presenting symptoms were fever and cough. Co-morbid conditions such as gestational hypertension, bronchial asthma and others were seen in 9 cases. In 53% of cases treatment was initiated with oseltamivir within 48 hours of onset of symptoms. All the patients recovered completely at the end of 5 days of treatment. There were no maternal or perinatal deaths.

Journal of Infectious Diseases, 2012

Background. Pregnant women were at increased risk for serious outcomes of 2009 pandemic influenza A virus subtype H1N1 (influenza A[H1N1]pdm09) infection, but little is known about the overall impact of the pandemic on neonatal and maternal outcomes. Methods. We identified live births that occurred from 1 July 2008 through 31 May 2010 in 5 Kaiser Permanente regions. Pregnant women were considered to have influenza if they had a positive result of a laboratory test for influenza virus or if they received a diagnosis of influenza during a period in which seasonal influenza virus or A(H1N1)pdm09 was the predominant circulating virus. Results. There were 111 158 births from 109 015 pregnancies involving 107 889 mothers; 368 pregnant women (0.3%) received a diagnosis of influenza due to seasonal virus, and 959 (0.9%) received a diagnosis of influenza due to A(H1N1)pdm09; 107 688 did not receive an influenza diagnosis. Pregnant women with influenza due to A(H1N1)pdm09 were more likely than women with seasonal influenza infection to be hospitalized within 30 days of the diagnosis (27% vs 12%; odds ratio [OR], 2.84 [95% confidence interval {CI}, 2.01-4.02]). Pregnant women with A(H1N1)pdm09 who started antiviral treatment ≥2 days after the diagnosis were significantly more likely to be hospitalized than those who started antiviral treatment <2 days after diagnosis (OR, 3.43 [95% CI, 1.55-7.56]). Mothers with seasonal influenza virus infection had an increased risk for having a small-forgestational-age infant (OR, 1.59 [95% CI, 1.15-2.20]). Conclusions. In this large, geographically diverse population, A(H1N1)pdm09 infection increased the risk for hospitalization during pregnancy. Late initiation of antiviral treatment was also associated with an increased risk for hospitalization.

American Journal of Obstetrics and Gynecology, 2011

T he emergence of 2009 pandemic influenza A (H1N1) virus (2009 H1N1) resulted in the first influenza pandemic in over 40 years. The Centers for Disease Control and Prevention (CDC) estimated that about 61 million people were infected, 274,000 were hospitalized, and about 12,740 died due to 2009 H1N1 in the United States. 1 About 90% of all hospitalizations and 87% of all deaths during the 2009 H1N1 pandemic were among people Ͻ65 years in contrast with experience from seasonal influenza when about 40% of all hospitalizations and 10% of deaths were found in this age group. 1 It is well recognized that pregnancy represents a risk factor for influenza complications and death during both pandemic and seasonal influenza. 2-6 Thus, with illness being widespread among the younger segments of the population We sought to describe characteristics of hospitalized reproductive-aged (15-44 years) women with seasonal (2005/2006 through 2008/2009) and 2009 pandemic influenza A (H1N1) virus infection. We used population-based data from the Emerging Infections Program in 10 US states, and compared characteristics of pregnant (n ϭ 150) and nonpregnant (n ϭ 489) seasonal, and pregnant (n ϭ 489) and nonpregnant (n ϭ 1088) pandemic influenza cases using 2 and Fisher's exact tests. Pregnant women represented 23.5% and 31.0% of all reproductive-aged women hospitalized for seasonal and pandemic influenza, respectively. Significantly more nonpregnant than pregnant women with seasonal (71.2% vs 36.0%) and pandemic (69.7% vs 31.9%) influenza had an underlying medical condition other than pregnancy. Antiviral treatment was significantly more common with pandemic than seasonal influenza for both pregnant (86.5% vs 24.0%) and nonpregnant (82.0% vs 55.2%) women. Pregnant women comprised a significant proportion of influenza-hospitalized reproductive-aged women, underscoring the importance of influenza vaccination during pregnancy.

Antiviral Therapy, 2011

was significantly more severe in pregnant than in nonpregnant women. In Spain, antiviral therapy was recommended for pregnant women from the beginning of the 2009 pandemic. Methods: The prospective cohort study included consecutive pregnant and non-pregnant women of reproductive age with a proven diagnosis of 2009 A(H1N1)v admitted to any of the 13 participating Spanish hospitals between 12 June and 10 November 2009. Results: In total, 98 pregnant and 112 non-pregnant women with proven 2009 A(H1N1)v hospitalized during the study period were included. Influenza was more severe among non-pregnant patients than pregnant patients with respect to outcomes of both intensive care unit admission (18% versus 2%; P<0.001) and death (5 versus 0; P=0.06). Pregnant women had fewer associated comorbid conditions other than pregnancy (18% versus 44%; P<0.001); they were also admitted earlier than non-pregnant women (median days since onset of symptoms: 2 versus 3; P<0.001) and a higher percentage received early antiviral therapy (41% versus 28%; P=0.03). Neither a multivariate nor a matched cohort analysis found pregnancy to be associated with greater severity than that associated with hospitalized, seriously ill non-pregnant women. Conclusions: 2009 A(H1N1)v influenza was not associated with worse outcomes in hospitalized pregnant women compared with non-pregnant ones of reproductive age in a context of early diagnosis and antiviral therapy.

American Journal of Obstetrics and Gynecology, 2011

We sought to describe the clinical characteristics of pregnant women with influenza-like illness during the 2009 H1N1 pandemic with the use of a standardized management algorithm. From June 2009 through March 2010, we assembled a prospective cohort of pregnant women with influenza-like illness at a single tertiary care center using a standardized algorithm. Clinical outcomes were compared between women with 2009 H1N1 virus and those without. In all, 45 women were included. Seventeen had 2009 H1N1 infection and 28 did not. Demographic characteristics were similar between groups. The median temperature upon presentation (99.7 vs 98.8°F, P ϭ .004) was slightly higher among those with 2009 H1N1. All those with 2009 H1N1 influenza and 89% of those without were treated with oseltamivir. A total of 12 women (27%) were hospitalized. There were no endotracheal intubations or deaths. Among this cohort of pregnant women, most were treated as outpatients and had favorable maternal outcomes.