Development of prevalence and incidence of non-tuberculous mycobacteria in German laboratories from 2016 to 2020

Numbers of non-tuberculous mycobacteria (NTM) pulmonary diseases (PD) have been repeatedly reported as increasing over the last decades, particularly in Europe. Sound epidemiological data are however missing for most European regions. This study calculated prevalence and incidence of NTM recovered from patients' lungs in Germany, the largest Central European country, over a five-year period. It furthermore determined regional particularities of NTM species and results from susceptibility testing. 22 German NTM laboratories provided their mycobacteriological diagnostic data of 11,430 NTM isolates recovered from 5998 pulmonary patients representing 30% of all notified NTM-PD cases of Germany from 2016 to 2020. NTM incidence and prevalence were calculated for every study year. The presented epidemiological indicators are particularly reliant as TB surveillance data were used as a reference and TB notification reaches almost 100% in Germany. Laboratory incidence and prevalence of NTM recovered from respiratory samples ranged from 4.5-4.9 and from 5.3-5.8/100,000 for the population of Germany, respectively, and did not change over the five-year study period. Prevalence and incidence were stable also when stratifying for facultative pathogenic NTM, M. avium/intracellulare complex (MAIC), and M. abscessus/chelonae complex (MABSC). The proportion of NTM with drug susceptibility testing (DST) increased from 27.3% (2016) to 43.8% (2020). The unchanging laboratory NTM prevalence/incidence in Germany represents a "ceiling" of possible NTM-PD notification when diagnostic strategies do not change in the coming years. A notable increase in NTM-DST may indicate better notification of NTM-PD and/or awareness of new clinical guidelines but still remains below clinical needs.

Comprehensive infectious disease screening in a cohort of unaccompanied refugee minors in Germany from 2016 to 2017: A cross-sectional study

BACKGROUND

Information regarding the prevalence of infectious diseases (IDs) in child and adolescent refugees in Europe is scarce. Here, we evaluate a standardized ID screening protocol in a cohort of unaccompanied refugee minors (URMs) in a municipal region of southwest Germany.

METHODS AND FINDINGS

From January 2016 to December 2017, we employed a structured questionnaire to screen a cohort of 890 URMs. Collecting sociodemographic information and medical history, we also performed a standardized diagnostics panel, including complete blood count, urine status, microbial stool testing, tuberculosis (TB) screening, and serologies for hepatitis B virus (HBV) and human immunodeficiency virus (HIV). The mean age was 16.2 years; 94.0% were male, and 93.6% originated from an African country. The most common health complaints were dental problems (66.0%). The single most frequent ID was scabies (14.2%). Of the 776 URMs originating from high-prevalence countries, 7.7% and 0.4% tested positive for HBV and HIV, respectively. Nineteen pathogens were detected in a total of 119 stool samples (16.0% positivity), with intestinal schistosomiasis being the most frequent pathogen (6.7%). Blood eosinophilia proved to be a nonspecific criterion for the detection of parasitic infections. Active pulmonary TB was identified in 1.7% of URMs screened. Of note, clinical warning symptoms (fever, cough >2 weeks, and weight loss) were insensitive parameters for the identification of patients with active TB. Study limitations include the possibility of an incomplete eosinophilia workup (as no parasite serologies or malaria diagnostics were performed), as well as the inherent selection bias in our cohort because refugee populations differ across Europe.

CONCLUSIONS

Our study found that standardized ID screening in a URM cohort was practicable and helped collection of relevant patient data in a thorough and time-effective manner. However, screening practices need to be ameliorated, especially in relation to testing for parasitic infections. Most importantly, we found that only a minority of infections were able to be detected clinically. This underscores the importance of active surveillance of IDs among refugees.

Decreased platelet reactivity identified by whole blood flow cytometry in Fanconi anaemia patients

disorder characterized by congenital anomalies and a high risk for bone marrow failure and cancer. Bleeding is a frequent complication in FA, leading to substantial morbidity and mortality. Thrombocytopenia is a major factor leading to this complication, but the bleeding tendency of FA patients often exceeds what one might expect based on their platelet counts. We therefore investigated if alterations of platelet function contribute to the bleeding tendency of FA patients. We assessed platelet function in 11 FA patients and 23 controls with whole blood flow cytometry. We analyzed the expression of platelet membrane glycoprotein receptors, reactivity of platelets to physiologic agonists and the proportion of young platelets. In FA patients platelet PAC-1 after stimulation with thrombin receptor activating peptide (TRAP) and adenosine diphosphate (ADP) were 15–70% lower than in controls. We found no or only minor differences of platelet glycoprotein receptor expression between groups. While the proportion of reticulated platelets was not different, the absolute number of reticulated platelets was markedly lower in FA patients. Our data show that FA is associated with reduced platelet reactivity, which may contribute to the high bleeding tendency in FA patients. Whole blood flow cytometry is a suitable method for analysis of platelet function in FA patients.

Decreased platelet reactivity identified by whole blood flow cytometry in Fanconi anaemia patients

Fanconi anaemia (FA) is a rare inherited chromosome instability disorder characterized by congenital anomalies and a high risk for bone marrow failure and cancer. Bleeding is a frequent complication in FA, leading to substantial morbidity and mortality. Thrombocytopenia is a major factor leading to this complication, but the bleeding tendency of FA patients often exceeds what one might expect based on their platelet counts. We therefore investigated if alterations of platelet function contribute to the bleeding tendency of FA patients. We assessed platelet function in 11 FA patients and 23 controls with whole blood flow cytometry. We analyzed the expression of platelet membrane glycoprotein receptors, reactivity of platelets to physiologic agonists and the proportion of young platelets. In FA patients platelet reactivity was decreased: Expression of P-selectin and binding of PAC-1 after stimulation with thrombin receptor activating peptide (TRAP) and adenosine diphosphate (ADP) were 15-70% lower than in controls. We found no or only minor differences of platelet glycoprotein receptor expression between groups. While the proportion of reticulated platelets was not different, the absolute number of reticulated platelets was markedly lower in FA patients. Our data show that FA is associated with reduced platelet reactivity, which may contribute to the high bleeding tendency in FA patients. Whole blood flow cytometry is a suitable method for analysis of platelet function in FA patients.

Chorioamnionitis is associated with increased CD40L expression on cord blood platelets

Chorioamnionitis (CA) is a severe infection responsible not only for premature birth but also for many severe neonatal diseases. The aim of the present study was to investigate the expression of CD40L and P-selectin on platelets and the plasma levels of their soluble forms in the umbilical cord blood in infants with documented chorioamnionitis. Umbilical cord blood samples were obtained from 10 healthy term newborns, 10 non-infected preterm infants, 10 preterm infants with premature rupture of membranes and 9 preterm infants with clinical and histological CA. The expression of CD40L and P-selectin on platelets was analyzed by flow cytometry. Soluble P-selectin (sCD62P), soluble CD40L (sCD40L) and interleukine-6 (IL-6) were measured in plasma by ELISA assays. Neonates with CA had significantly higher percentages of platelets expressing CD40L in basal conditions (5.3 +/- 2.9% vs. 1.6 +/- 0.7% and in non-infected preterm infants p < 0.05), while the percentages of P-selectin positive platelets were similar among all groups. In contrast, the level of sP-selectin was higher in infants with CA (222 +/- 128 ng/ml vs. 104 +/- 71 ng/ml in non-infected preterm infants, p < 0.05) but no differences were found in the levels of sCD40L. As expected, the levels of IL-6, a pro-inflammatory cytokine were significantly higher in samples obtained from preterm neonates whose mothers had also elevated inflammatory parameters. Our observations suggest that platelets are involved in the complex inflammatory pathogenesis of CA. Neither P-selectin expression on cord blood platelets nor plasma sP-selectin or sCD40L were suitable platelet markers in CA, whereas CD40L was significantly elevated in histologically proven CA.

Neonatal platelets from cord blood and peripheral blood

The haemostatic system in neonates is different from that of adults, possibly contributing to an increased incidence of bleeding disorders, such as intracranial hemorrhage. In this study, we analyzed platelets from cord blood and peripheral blood, collected at three time points after delivery from 20 term and 37 preterm neonates as well as blood from 20 healthy adults. Platelet membrane glycoproteins (GP) were quantified and P-selectin expression and PAC-1 binding ability before and after stimulation with TRAP were analyzed by whole blood flow cytometry. We found no significant differences in neonatal platelets from cord blood and peripheral blood within the first 24h of life. Platelets from infants less than 30 weeks of gestation expressed lower levels of GP (33271+/-9381 vs. 44085+/-17287 for GPIIIa, P<0.05) and were less reactive than platelets from term newborns (4.3+/-3.3 vs. 20.1+/-11.8% PAC-1 positive platelets after stimulation with TRAP, P<0.05). A significantly lower level of GPIIb/IIIa expression on platelets from peripheral blood was seen in term newborns as well as preterm infants, compared to adults. There was only a partial enhancement in the degranulation ability (alpha-granules) (13.4+/-12.3 vs. 50.3+/-16.1% P-selectin positive platelets, P<0.05) and no significant increase for PAC-1 binding (13.6+/-10.9 vs. 15.3+/-5.9% PAC-1 positive platelets, P=0.8) during the first 12 days of life. In conclusion, we could demonstrate that neonatal platelet reactivity increases with gestational age.