Influenza-like illness in pregnant women during summertime: clinical, epidemiological and microbiological features

Causes and consequences of fever during pregnancy: A retrospective study in a gynaecological emergency department

OBJECTIVE

Fever is a very common reason for emergency consultation during pregnancy, and may be associated with maternal, obstetrical and/or fetal adverse outcomes. The aim of this study was to determine the etiologies and to analyze the maternal or fetal complications of fever in pregnancy.

STUDY DESIGN

A retrospective single center study including all patients who consulted for fever above 38 °C during pregnancy in the gynecological emergency ward from August 2016 to July 2017.

RESULTS

A total of 100 pregnant women who consulted for fever were included. The etiologies were common viral infections (37 %), influenza (21 %), pyelonephritis (11 %), viral gastroenteritis (6%), chorioamnionitis (5%), other (5%). The etiology was unknown for 15 %. Fever was confirmed during consultation in 45/100 patients (45 %). Among patients with confirmed fever, 21/45 (47 %) were hospitalized with a median stay of 3 days [IQR 2-4] and 10/45(22 %) developed fetal or maternal complications. Probabilistic antibiotics were delivered for 34/45, 76 % patients. Only 14/45, 31 % had confirmed bacterial infections. Of the 32 patients with confirmed fever who had no etiologic diagnosis at the initial work-up in the emergency room, 19/32, 59 % received presumptive treatment with amoxicillin against Listeria monocytogenes. None had confirmed listeriosis, and all were probably common viral infections. Among all patients, the complications rate was 13 % and 22 % in the subgroup with fever confirmed at presentation.

CONCLUSIONS

This study quantifies the main etiologies and complications of fever during pregnancy. A challenge is to reduce excessive antibiotic use by improving rapid diagnosis of bacterial and viral infections. Prospective studies are needed to target patients at risk of complications in an optimal way and to study new management strategies.

Efficacy and effectiveness of maternal influenza vaccination during pregnancy: a review of the evidence

Influenza vaccine is universally recommended for pregnant women during any trimester of pregnancy. In light of this recommendation, a comprehensive literature review was conducted to examine the available evidence regarding influenza vaccine efficacy and effectiveness during pregnancy. A comprehensive Medline search identified potentially relevant articles published between January 1, 1964 and February 1, 2013. Articles were selected that specifically evaluated the efficacy and effectiveness of maternal influenza vaccine in protecting women and infants from influenza infection. These were reviewed with a particular focus on the methods used to confirm influenza infection. Ten of 476 articles met the inclusion criteria. None of the six studies evaluating maternal outcomes were randomized controlled studies using a laboratory-confirmed influenza diagnosis to measure vaccine efficacy. Two studies included reverse-transcriptase polymerase chain reaction confirmation; four relied solely on clinical outcomes. The reported vaccine effectiveness (VE) ranged from -15 to 70 %. Seven studies examined the potential for maternal vaccination to protect infants. Four of these applied some form of laboratory confirmation, with VE ranging from 41 to 91 %. Vaccination against infectious disease is an unparalleled public health success. However, studies to date demonstrate that influenza vaccine provides only moderate protection from influenza infection in pregnant women. This review found broad heterogeneity among studies, with no uniform outcome measured and little data based on laboratory-confirmed influenza, leading to wide-ranging estimates of effectiveness. Rigorously designed studies assessing clearly defined outcomes are needed to support the development of reasoned public health policy about influenza prevention in this population.

Rhinoviruses as an underestimated cause of influenza-like illness in pregnancy during the 2009-2010 influenza pandemic

During the 2009-2010 influenza pandemic, pregnant women were identified at high risk for severe infection. In case of influenza-like illness they were systematically treated with oseltamivir. When performed, virological diagnosis showed that some of these women were not influenza-infected. The objectives of the study were to identify viruses which could induce an influenza-like illness in pregnant women during the 2009-2010 pandemic, then to establish possible links between detected viruses and symptoms, and then characterize human rhinoviruses (HRV) strains detected in some samples. Nasal swabs from 78 pregnant women presenting with influenza-like illness and previously tested for influenza virus by RT-PCR in 2009-2010 were further assayed by multiplex RespiFinder assay and bocavirus PCR to search for 13 other viruses. Genotyping of HRV strains was carried out using partial genomic sequencing in the VP4/VP2 region. Influenza A virus infection was confirmed in 33 women (42%). Non-influenza viruses were detected in 18 additional cases (23%). Rhinoviruses were the most numerous (13%) and belonged to 9 different genotypes distributed between the 3 genogroups. When comparing symptoms observed in influenza-infected women and women infected by other viruses, shivers were more frequent in the former group (P=0.02), and expectorations in the latter (P=0.03). During the influenza pandemic 2009-2010, non-influenza viruses and mostly rhinoviruses were an underestimated cause of influenza-like illness in pregnant women. Viral diagnosis should help to stop empiric oseltamivir therapy in influenza-negative patients and antibiotic treatment in patients infected with a non-influenza virus.