Case Report: Non-typhoidal Salmonella infections transmitted by reptiles and amphibians.

Non-typhoidal Salmonella infections (NTSI) can cause bacterial diarrhea, mostly leading to self-limiting gastroenteritis. However, in at-risk populations, NTSI can have severe complications. As transmission is most commonly foodborne, infection is rare in the breast- or bottle-fed very young. Another route is increasingly implicated, however, in newborns and infants especially: Contact with reptiles and amphibians. We describe infection with Salmonella enterica subsp. enterica ser. Monschaui (S. Monschaui), transmitted from bearded dragons, in a three-week-old boy. The boy initially appeared well, on the next morning deterioration was dramatic, with tachypnea, tachycardia, and mottled skin. Gram-negative sepsis was documented on day 2. His case prompted a review of published instances of reptile- and amphibian-associated salmonellosis (RAAS), summarized here. Association of S. Monschaui infection with exposure to reptiles and amphibians prompted inquiry into household pets. The parents had kept bearded dragons (Pogona sp.), the last of which died two weeks before the patient was born; confirmation of colonization with S. Monschaui was thus precluded. Among 63 reports (-5,000 cases) of RAAS or S. Monschaui, 62 appeared between 1995 and 2022, 10 were single case reports, and 53 were original articles with -5,000 cases; vectors included turtles, frogs, lizards, and snakes. RAAS is not a new phenomenon, but its incidence recently has risen due to the increased popularity of reptiles and amphibians as non-traditional pets. These animals can carry Salmonella sp. and transmit it to humans, posing a risk particularly to infants and other vulnerable persons. Risk mitigation requires that those bringing such pets into the home be informed of dangers associated with reptile and amphibian contact; that those selling reptiles and amphibians be mandated to inform customers comprehensively may be in order.

Severe Respiratory Distress in a Neonate due to Bilateral Dacryocystoceles.

Nasal passage contributes up to 50% of total resistance in normal breathing especially in neonates who are obligatory nose breathers. Any further increase in airway resistance may lead to severe respiratory distress. Dacryocystoceles are a rare cause of nasal obstruction in neonates. We present the case of a full-term 3-day-old female infant with progressive respiratory distress due to bilateral dacryocystoceles.

Influence of the delivery modus on subpopulations and replication of lymphocytes in mothers and newborns.

BACKGROUND: Several studies reported that the mode of delivery may induce changes to the immune system. Our hypothesis was that the delivery mode may influence mainly the naive T cell subpopulation. AIMS: Particular focus was set on the proportions and peripheral replicative history of naive T cells and cord blood serum concentrations of IL-7, a cytokine involved in peripheral naive T cell homeostasis. STUDY DESIGN, SUBJECTS AND OUTCOME MEASURES: In a prospective cohort study, proportions of lymphocyte populations were measured in mothers and newborns delivered by spontaneous vaginal delivery (SD), vacuum extraction (VE), primary (PCS) and secondary Cesarean sections (SCS) by flow cytometry. T-cell-receptor-excision-circles (TRECs) and relative telomere lengths (RTLs) were used to estimate the replicative history of peripheral naive T cells. The cytokine profile was assessed by ELISA. RESULTS: The study demonstrated that leukocytes, neutrophils and NK cells were increased in spontaneously delivered newborns compared to PCS, whereas circulating T cells were relatively lower. TRECs and RTLs were not significantly influenced by the delivery mode. IL-2, IL-8 and IFN-γ were increased in VD. IL-7 production tends to be increased in more stress-associated delivery modes, such as VE and SCS. CONCLUSIONS: Our results demonstrate proportional changes in newborns delivered by PCS and diminished cytokine production. It has to be proven whether these alterations may be of disadvantage regarding early defense of infectious diseases. Understanding the physiological role of these changes may help to find preventive strategies for neonatal infectious risks and the development of atopy or other immune diseases.

Lower CD28+ T cell proportions were associated with CMV-seropositivity in patients with Hashimoto's thyroiditis.

BACKGROUND: Alterations in the naive T cell subpopulations have been demonstrated in patients with T cell mediated autoimmune disorders, reminiscent of immunological changes found in the elderly during immunosenescence, including the switch from CD45RA + to CD45RO + T cells and decreased thymic function with increased compensatory proliferative mechanisms, partly associated with latent Cytomegalovirus (CMV) infection. The present study was aimed to investigate proportions of lymphocytes, their relation to CMV-seropositivity and the replicative history of CD45RA + expressing T cells in Hashimoto's thyroiditis (HT, n = 18) and healthy controls (HC, n = 70). METHODS: Proportions of peripheral T cells were investigated by flow cytometry. The replicative history was assessed by T cell receptor excision circles (TRECs) and relative telomere length (RTL). Expression of CD62L was analyzed by immunohistochemistry in thyroid sections. The role of CMV was assessed by serology, ELISPOT assay and in situ hybridization. RESULTS: Our results demonstrated a significant increase of CD28-negative T cells, associated with CMV-seropositivity in HT patients. HT showed abundant CD45RO + T cells with peripheral loss of CD62L-expressing CD8 + CD45RA + T cells, the latter mainly depending on disease duration. CD62L was expressed in thyroid lymphocyte infiltrations. The diagnosis of HT and within the HT group CMV-seropositivity were the main determinants for the loss of CD28 expression. RTL was not different between HC and HT. HT showed significantly lower TRECs in CD4 + CD45RA + T cells compared to HC. CONCLUSIONS: Patients with HT display a peripheral T cell phenotype reminiscent of findings in elderly persons or other autoimmune disorders. Whether these mechanisms are primary or secondary to the immunological alterations of autoimmune conditions should be investigated in longitudinal studies which may open research on new therapeutic regimes for treatment of HT and associated autoimmune diseases.

Reduced varicella-zoster-virus (VZV)-specific lymphocytes and IgG antibody avidity in solid organ transplant recipients.

BACKGROUND: Varicella-zoster-virus (VZV) infection may cause significant morbidity and mortality in immunocompromised patients. So far, only IgG-anti-VZV antibody concentrations were used to estimate immunity against VZV, but the antibody binding strength (avidity) together with VZV-specific cellular responses have not been evaluated in solid organ transplant (SOT) recipients. METHODS: Thus, we assessed the humoral and cellular immune responses to two doses of the VZV vaccine (vacc) and wild-type VZV infection (wt) in 23 kidney (KTx) and 19 liver transplant (LTx) recipients including children and adults compared to 48 healthy controls (HC) for measurement of IgG-anti-VZV relative avidity index (RAI) and frequency of VZV-specific peripheral blood mononuclear cells (PBMCs) in vaccinated individuals using an adapted ELISA and IFN-gamma ELISPOT, respectively. RESULTS: KTx(wt) (median RAI 72.3%) or LTx(wt) (79.2%) and KTx(vacc) (91.0%) or LTx(vacc) (72.5%) showed lower avidities compared to HC(wt) (84.5%) and HC(vacc) (94.0%), respectively, despite equally distributed IgG-anti-VZV concentrations. RAI>60% (high avidity) was detected in all HC, but only in 69.0% of SOT patients. KTx(vacc) (median 64 spot forming units SFU/500,000 PBMCs) and LTx(vacc) (67 SFU) had significantly lower VZV-specific cellular responses compared to HC(vacc) (268 SFU). CONCLUSIONS: The diminished cellular reactivity to VZV has to be considered in SOT patients receiving immunosuppressive treatments when evaluating immunity against VZV. IgG antibody avidity and VZV-specific cellular responses may serve as additional markers to evaluate immunity against VZV in SOT recipients. The role of wild-type exposures and endogenous VZV re-activation on long-term immunity in SOT patients has to be awaited to establish recommendations for vaccine spacing in these patients, considering immunogenicity and safety aspects.

Aciclovir and varicella-zoster-immunoglobulin in solid-organ transplant recipients.

Clear recommendations for the management of acute varicella-zoster virus (VZV) infections for cases of significant exposure and the use of prophylactic drugs after solid-organ transplantation are missing due to the lack of evidence by prospective studies. Heterogeneity in patient groups, patient numbers, age groups, immunosuppressive regimens, timing, and dosage of aciclovir and/or varicella-zoster immunoglobulin (VZIG), pre-transplant vaccination or VZV wild-type infection and inconsistency of data make comparability of different studies impossible. Although the benefit of aciclovir and/or VZIG is uncertain in immunosuppressed children, prospective controlled double-blind studies are not feasible for ethical considerations as fatal cases with disseminating varicella disease are well known in these patient groups despite the use of aciclovir and/or VZIG, whereas severe side-effects of these drugs are rare. However, a reporting bias is likely as mainly severe or fatal cases might have been predominantly published or cases of successfully used aciclovir and/or VZIG in mild cases or in cases of breakthrough infections after vaccination. As neither VZIG prophylaxis nor treatment with intravenous aciclovir offers complete protection against severe VZV infection to immunosuppressed pediatric solid-organ transplant recipients, high priority should be given to vaccination against VZV prior to transplantation, and, most importantly, in their close contact persons. Clinical observations suggest that only assessment of humoral immunity together with cellular immunity may allow predication about protection in exposed patients.