A social network analysis model approach to understand tuberculosis transmission in remote rural Madagascar.

BACKGROUND: Quality surveillance data used to build tuberculosis (TB) transmission models are frequently unavailable and may overlook community intrinsic dynamics that impact TB transmission. Social network analysis (SNA) generates data on hyperlocal social-demographic structures that contribute to disease transmission. METHODS: We collected social contact data in five villages and built SNA-informed village-specific stochastic TB transmission models in remote Madagascar. A name-generator approach was used to elicit individual contact networks. Recruitment included confirmed TB patients, followed by snowball sampling of named contacts. Egocentric network data were aggregated into village-level networks. Network- and individual-level characteristics determining contact formation and structure were identified by fitting an exponential random graph model (ERGM), which formed the basis of the contact structure and model dynamics. Models were calibrated and used to evaluate WHO-recommended interventions and community resiliency to foreign TB introduction. RESULTS: Inter- and intra-village SNA showed variable degrees of interconnectivity, with transitivity (individual clustering) values of 0.16, 0.29, and 0.43. Active case finding and treatment yielded 67%-79% reduction in active TB disease prevalence and a 75% reduction in TB mortality in all village networks. Following hypothetical TB elimination and without specific interventions, networks A and B showed resilience to both active and latent TB reintroduction, while Network C, the village network with the highest transitivity, lacked resiliency to reintroduction and generated a TB prevalence of 2% and a TB mortality rate of 7.3% after introduction of one new contagious infection post hypothetical elimination. CONCLUSION: In remote Madagascar, SNA-informed models suggest that WHO-recommended interventions reduce TB disease (active TB) prevalence and mortality while TB infection (latent TB) burden remains high. Communities' resiliency to TB introduction decreases as their interconnectivity increases. "Top down" population level TB models would most likely miss this difference between small communities. SNA bridges large-scale population-based and hyper focused community-level TB modeling.

Latent tuberculosis infection prevalence in rural Madagascar.

BACKGROUND: Understanding latent Mycobacterium tuberculosis infection (LTBI) prevalence is crucial for the design of TB control strategies. There are no data on LTBI in rural Madagascar. METHODS: Tuberculin skin tests were performed in 98 adults aged >15 y in five rural villages in the Ifanadiana district, Madagascar. RESULTS: Of adults, 78.6% were positive for LTBI, ranging between 28.6% and 95.0% among villages. The majority (65.3%) showed an induration reaction of >15 mm. CONCLUSIONS: LTBI prevalence is high in rural Madagascar. Long-term TB control strategies including LTBI testing and treatment must account for high and heterogeneous prevalence in remote, underdeveloped areas.

Assisted reproductive technologies (ART) and placental abnormalities.

Objectives Assisted reproductive technologies (ART) may be associated with placental abnormalities including placenta previa, umbilical cord abnormalities, and placental abruption. Our study evaluates the relationship between ART and placental abnormalities compared with spontaneously conceived controls. Methods An IRB-approved cohort study was conducted including women who delivered between January 2013 and December 2018. We excluded delivery prior to 23 weeks and known fetal anomalies. Patients were matched with controls (2:1) for parity, age, and mode of delivery. Controls were women who had spontaneously conceived and delivered immediately preceding and following the index delivery. The primary outcome was placental abnormalities found on both antenatal ultrasound and pathology in ART gestations compared with spontaneously conceived gestations. Results There were 120 ART pregnancies and 240 matched control pregnancies identified. The groups were similar for parity, BMI, comorbidities, number of multiples, mode of delivery, and female newborns. The ART group had a higher maternal age (37.1±5 y vs. 30.0±5 y; p<0.001), greater preterm birth (29 vs. 6%; p<0.001), and lower BW (2,928±803 g vs. 3,273±586 g; p<0.001). The ART group had a higher incidence of placenta previa on ultrasound (4.0 vs. 0.4%, p=0.01), adherent placentas at delivery (3 vs. 0% p=0.014), placental abruption (2 vs. 0%; p=0.04), as well as an increased rate of velamentous cord insertion (12 vs. 3%, p<0.001) and marginal cord insertion (28 vs. 15%, p=0.002). ART demonstrated a two-fold likelihood of abnormal placental pathology. Conclusions ART is associated with increased rate of placental abnormalities, including abnormal umbilical cord insertion and increased rates of adherent placentation. This information may be beneficial in planning and surveillance in patients with ART pregnancies.