Maternal and neonatal sepsis caused by Haemophilus influenzae type d

The microbial pathology of maternal perinatal sepsis: A single-institution retrospective five-year review

INTRODUCTION

Greater than half of in-hospital maternal deaths are caused by sepsis, a condition that occurs when infection exceeds local tissue containment and results in organ dysfunction. Determining the source of infection can be challenging. Microbiological cultures of the uterine cavity are often difficult to obtain, so antimicrobial susceptibility results may not be available to guide treatment. The aim of this retrospective study was to assess the potential clinical value of microbiology samples used in the maternal "septic screen" of patients in an Irish maternity hospital.

METHODS

A review was completed of all maternal "septic screen" (i.e., high vaginal swabs, placenta swabs, blood cultures, throat swabs and urine samples) microbiology results from July 2016 to December 2021.

RESULTS

In the relevant period, 845 patients were subject to a "septic screen", of whom 430 also had a placental swab collected. These 430 patients comprise our study population. 2% of blood cultures yielded potential pathogens, compared with 37%, 33%, 9% and 7% respectively for placental swabs, high vaginal swabs, throat swabs and urine specimens. 95% of blood cultures were sterile, compared with 52%, 0%, 0% and 53% respectively for placental swabs, high vaginal swabs, throat swabs and urine specimens.

CONCLUSION

Of the five microbiological specimen types examined, placental swabs yielded the highest number of potential pathogens. Our results suggest that placental swabs are useful specimens for detecting potential pathogens from the uterine cavity, the most common source of perinatal infections.

Sepsis in Pregnancy: Recognition and Resuscitation

The normal physiologic changes of pregnancy complicate evaluation for sepsis and subsequent management. Previous sepsis studies have specifically excluded pregnant patients. This narrative review evaluates the presentation, scoring systems for risk stratification, diagnosis, and management of sepsis in pregnancy. Sepsis is potentially fatal, but literature for the evaluation and treatment of this condition in pregnancy is scarce. While the definition and considerations of sepsis have changed with large, randomized controlled trials, pregnancy has consistently been among the exclusion criteria. The two pregnancy-specific sepsis scoring systems, the modified obstetric early warning scoring system (MOEWS) and Sepsis in Obstetrics Score (SOS), present a number of limitations for application in the emergency department (ED) setting. Methods of generation and subsequently limited validation leave significant gaps in identification of septic pregnant patients. Management requires consideration of a variety of sources in the septic pregnant patient. The underlying physiologic nature of pregnancy also highlights the need to individualize resuscitation and critical care efforts in this unique patient population. Pregnant septic patients require specific considerations and treatment goals to provide optimal care for this particular population. Guidelines and scoring systems currently exist, but further studies are required.

Paediatric invasive Haemophilus influenzae in Queensland, Australia, 2002-2011: Young Indigenous children remain at highest risk

AIM

Haemophilus influenzae continues to cause invasive disease in children despite widespread Hib immunisation. The significance of non-B serotypes continues to be investigated, with evidence of increased invasive non-typeable H. influenzae (NTHi) world-wide. The aim of this study was to examine the current epidemiological and clinical features of invasive H. influenzae disease in children in Queensland, Australia.

METHODS

A retrospective review was performed of all cases of invasive H. influenzae disease in children <18 years of age in Queensland between January 2002 and December 2011. Cases were identified from pathology records and data requested from treating hospitals.

RESULTS

Laboratory data were obtained for 144 cases and clinical/demographic data for 123 cases. The majority (72%) of cases were children <5 years of age. Annual incidence rate for all children <5 years was 7.4/100 000, and for Aboriginal and Torres Strait Islander children <5 years was 10.2/100 000. Serotype was reported for 132 isolates, 69 NTHi and 63 encapsulated strains. The most common clinical diagnoses were pneumonia, meningitis and bacteraemia without clinical focus. Of the patients, 5 patients died, and 12 had significant morbidity at hospital discharge.

CONCLUSIONS

While rates of invasive H. influenzae disease have decreased dramatically following the introduction of Hib vaccination, H. influenzae remains a cause of significant morbidity and mortality, and Aboriginal and Torres Strait Islander children remain particularly vulnerable.

Haemophilus influenzae: a forgotten cause of neonatal sepsis?

Due to the introduction of the conjugate vaccine against serotype b, neonatal sepsis caused by Haemophilus influenzae became very rare. There is little data in Belgium concerning the prevalence of H. influenzae early onset neonatal sepsis and articles about neonatal sepsis and H. influenzae published in the last decade are scarce. We report two invasive infections with a non-typeable H. influenzae. These cases show that neonatal sepsis caused by non-typeable H. influenzae may be underestimated and we believe that there is need for a better registration of this kind of infection.

Nasopharyngeal and Adenoid Colonization by Haemophilus influenzae and Haemophilus parainfluenzae in Children Undergoing Adenoidectomy and the Ability of Bacterial Isolates to Biofilm Production

Haemophili are pathogenic or opportunistic bacteria often colonizing the upper respiratory tract mucosa. The prevalence of Haemophilus influenzae (with serotypes distribution), and H. parainfluenzae in the nasopharynx and/or the adenoid core in children with recurrent pharyngotonsillitis undergoing adenoidectomy was assessed. Haemophili isolates were investigated for their ability to biofilm production.Nasopharyngeal swabs and the adenoid core were collected from 164 children who underwent adenoidectomy (2-5 years old). Bacteria were identified by the standard methods. Serotyping of H. influenzae was performed using polyclonal and monoclonal antisera. Biofilm formation was detected spectrophotometrically using 96-well microplates and 0.1% crystal violet.Ninety seven percent (159/164) children who underwent adenoidectomy were colonized by Haemophilus spp. The adenoid core was colonized in 99.4% (158/159) children, whereas the nasopharynx in 47.2% (75/159) children (P < 0.0001). In 32% (51/159) children only encapsulated (typeable) isolates of H. influenzae were identified, in 22.6% (36/159) children only (nonencapsulated) H. influenzae NTHi (nonencapsulated) isolates were present, whereas 7.5% (12/159) children were colonized by both types. 14.5% (23/159) children were colonized by untypeable (rough) H. influenzae. In 22% (35/159) children H. influenzae serotype d was isolated. Totally, 192 isolates of H. influenzae, 96 isolates of H. parainfluenzae and 14 isolates of other Haemophilus spp. were selected. In 20.1% (32/159) children 2 or 3 phenotypically different isolates of the same species (H. influenzae or H. parainfluenzae) or serotypes (H. influenzae) were identified in 1 child. 67.2% (129/192) isolates of H. influenzae, 56.3% (54/96) isolates of H. parainfluenzae and 85.7% (12/14) isolates of other Haemophilus spp. were positive for biofilm production. Statistically significant differences (P = 0.0029) among H. parainfluenzae biofilm producers and nonproducers in the adenoid core and the nasopharynx were detected.H. influenzae and H. parainfluenzae carriage rate was comparatively higher in the adenoid core than that in the nasopharynx in children undergoing adenoidectomy, suggesting that their involvement in chronic adenoiditis. The growth in the biofilm seems to be an important feature of haemophili colonizing the upper respiratory tract responsible for their persistence.

Advances in medical diagnosis of intra-amniotic infection

INTRODUCTION

Intrauterine infection is a global problem and a significant contributor to morbidity and perinatal death. The host response to infection causes an inflammatory state that acts synergistically with microbial insult to induce preterm birth and fetal damage. Prompt and accurate diagnosis of intra-amniotic infection in the asymptomatic stage of the disease is critical for improved maternal and neonatal outcomes.

AREAS COVERED

This article provides an overview of the most recent progress, challenges, and opportunities for discovery and clinical implementation of various maternal serum, cervicovaginal, and amniotic fluid biomarkers in pregnancies complicated by intra-amniotic infection.

EXPERT OPINION

Clinically relevant biomarkers are critical to the accurate diagnostic of intrauterine infection. Front-end implementation of such biomarkers will also translate in lower incidence of early-onset neonatal sepsis (EONS) which is an important determinant of neonatal morbidity and mortality associated with prematurity. However, of the hundreds of differentially expressed proteins, only few may have clinical utility and thus function as biomarkers. The small number of validation studies along with barriers to implementation of technological innovations in the clinical setting are current limitations.

The burden of nonencapsulated Haemophilus influenzae in children and potential for prevention

PURPOSE OF REVIEW

In countries with established Haemophilus influenzae serotype b (Hib) immunization programmes, nonencapsulated H. influenzae (ncHi) is responsible for most invasive H. influenzae infections across all age groups and is associated with higher case fatality. A pneumococcal conjugate vaccine has recently been licensed, which may potentially also protect against invasive H. influenzae infections.

RECENT FINDINGS

Invasive ncHi disease is uncommon in childhood but has a much higher incidence in the first month of life. Most neonates with invasive ncHi infections are born prematurely and develop septicaemia in the first 48 h of life which can be fatal. After this period, invasive ncHi incidence falls rapidly and remains low throughout childhood. Most infants and children who develop invasive ncHi disease have significant underlying comorbidities, particularly neurological disease, malignancy and other conditions requiring immunosuppressive therapy. Although characteristically associated with respiratory tract infections, at least a quarter of invasive ncHi infections present with meningitis.

SUMMARY

A vaccine against ncHi could have an important preventive role in children with comorbidities. Future studies should focus on assessing specific risk factors for neonatal and childhood ncHi disease and long-term outcomes of children with invasive ncHi meningitis.