Factors Influencing Frequency of Pediatric Clinically Distinguishable Influenza: A 2 Season Case-Control Study

Background:

Little is known about the individual differences in susceptibility to, or lifetime frequency of clinically distinguishable influenza in children.

Methods:

Rapid enzyme linked immunoassay-confirmed influenza pediatric cases (n = 96) in season 1 (2017-2018) were compared to age-matched (mean 7.7 years) controls (n = 171) with no evidence of influenza in season 1. The 2 cohorts were again studied in season 2 (2018-2019) for influenza outcomes and influences. Medical records, questionnaires, and interviews were used to determine past influenza disease and vaccine histories.

Results:

After season 2, known lifetime influenza illnesses per year of age averaged 22.6% in cases and 5.6% in controls, with 62% of controls still having never experienced known influenza. Having had prior influenza was marginally significant as a risk for season 1 influenza in cases versus controls (P = .055), yet a significant risk factor in controls for season 2 (P = .018). Influenza vaccine rates were significantly higher in controls than in cases for season 1, with a greater female vaccine benefit. Lack of previous influenza had greater calculated effectiveness (52%) than vaccination (17%-26%) in escaping season 2 influenza. Lifetime rates of vaccination did not correlate with lifetime rates of known influenza in either cohort.

Conclusions:

Lifetime clinically distinguishable influenza rates varied among children, with many escaping it for years even without being immunized against it. Findings of less than expected clinical influenza, no correlation between vaccination frequency and disease frequency, sex differences, and an association between past clinical influenza and current risk, point to innate differences in individual influenza experiences.

Reasons for influenza vaccination underutilization: A case-control study

BACKGROUND

Influenza vaccines are underused.

METHODS

Most (131/140) patients from a pediatric practice who were tested for influenza in the 2012-2013 season were enrolled. Medical records plus questionnaires determined vaccine and past disease histories and influenza vaccine attitudes. Influenza-negative tested cases (n = 65) and negative controls (n = 110) closely age-matched to 55 test-positive cases were compared with influenza-positive cases (n = 66) regarding prior influenza, vaccine efficacy, and limited vaccine season conflicting with birth dates and preventative visit timing to determine possible validity of reasons given for underutilization.

RESULTS

The most common parental reason for not vaccinating was lack of perceived need. History of previous influenza was significantly (P < .0001) associated with disease. Live attenuated vaccine rates were greater in controls than in influenza patients for ages 2-18 years (P < .005) and for ages 6-18 years (P < .0001), whereas injectable vaccine rates were not (P = .30 and P = .60, respectively). Most positive cases (59%) and controls (89%) had no prior influenza.

CONCLUSIONS

Prior influenza disease may be a risk factor for infection that could influence vaccination benefit. Live attenuated influenza vaccine outperformed trivalent inactivated influenza vaccine. Limited disease experience in individuals with low influenza vaccination rates, along with vaccine efficacy limitations, lends validity to some underutilization.

Fatal Neonatal Herpes Simplex Infection Likely from Unrecognized Breast Lesions

Type 1 herpes simplex virus (HSV-1) is very prevalent yet in rare circumstances can lead to fatal neonatal disease. Genital acquisition of type 2 HSV is the usual mode for neonatal herpes, but HSV-1 transmission by genital or extragenital means may result in greater mortality rates. A very rare scenario is presented in which the mode of transmission was likely through breast lesions. The lesions were seen by nurses as well as the lactation consultant and obstetrician in the hospital after delivery of the affected baby but not recognized as possibly being caused by herpes. The baby died 9 days after birth with hepatic failure and disseminated intravascular coagulation. Peripartum health care workers need to be aware of potential nongenital (including from the breast[s]) neonatal herpes acquisition, which can be lethal.

Interaction of genes and nutritional factors in the etiology of autism and attention deficit/hyperactivity disorders: a case control study

OBJECTIVE

To compare risk factors of attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) to age/sex-matched controls with particular attention to family history, parental age and nutrition.

METHOD

31 ASD and 81 ADHD patients were compared to 612 age/sex-matched controls by reviewing charts for parental age, sibling order, gestational age, and early feeding, and by parental interview for early feeding and family history of psychopathology on affected patients and 139 of those controls.

FINDINGS

Parental age affected ASD and ADHD females but not males. First-born males were at increased risk for both disorders even though their siblings had older parents and their parents were not more likely to stop having children. Breastfeeding in the absence of parental psychopathology reduced ADHD risk, but breastfeeding of first-born males by older mothers with psychopathology was a risk for ASD. Breastfeeding was only a risk for ADHD if the mother had psychopathology. Parent emigration from a place of high fish consumption was a significant ASD risk factor.

RESULTING HYPOTHESES

ADHD and ASD share risk factors due to shared genetic and nutritional interactions, likely revolving around deficiencies of omega-3 fatty acids (n3FAs) during brain development. Fatty acid metabolism genes are important in that process. The 4:1 male to female ratio for both disorders results from hormonally driven fat metabolism differences. Risk factors for both disorders including maternal smoking, prematurity, and gestational diabetes may also be attributed to their effect on n3FA supplies. Breastfeeding can be a risk factor when the mother's genes and/or age affect her milk quality. Parental age and gene defects may affect female more than male offspring. Childbirth with adequate spacing and breastfeeding can override maternal age and protect subsequent offspring. Genetic variations in fat metabolism can be influenced by cultural/geographic diet, causing deficiencies in offspring with migration-influenced diet changes. Interaction of n3FA deficient diets, delayed child-bearing, and breastfeeding by mothers with psychopathology may be important factors in the rising incidence of ASD and ADHD in recent decades. Partial prevention through diet and supplements may be possible.