Use of network analysis multidrug-resistant tuberculosis contact investigation in Kanchanaburi, Thailand.

OBJECTIVE: To characterise MDR-TB outbreak and incorporate social network analysis with contact investigation to detect case-contact linkages and clusters. METHODS: MDR-TB cases registered in the district hospital between October 2012 and September 2015 were interviewed and their contacts were investigated. A relationship-based weighted network was constructed. RESULTS: Among 43 interviewed MDR-TB cases, 20 (47%) were male, five (12%) were asymptomatic (and discovered incidentally) and 22 (51%) had underlying diseases. From the documented 115 contacts, 61 (53%) were household contacts and 49 (43%) were close (non-household) contacts; 70 (61%) were screened for TB using various tests. In this network, we prioritised 37 contacts connected with more than one MDR-TB patient. The largest cluster was identified in the pharmacy unit of the hospital. CONCLUSION: This investigation yielded a significant number of MDR-TB contacts, and social network analysis facilitated the prioritisation for screening. Social network analysis is useful and feasible in this program setting and complements MDR-TB contact investigation.

OBJECTIF: Caractériser une épidémie de TB-MDR et incorporer une analyse du réseau social avec une investigation sur les contacts pour détecter les liens et les regroupements cas-contacts. MÉTHODES: Les cas de TB-MR enregistrés à l'hôpital de district entre octobre 2012 et septembre 2015 ont été interrogés et leurs contacts ont été investigués. Un réseau pondéré sur base de la relation a été construit. RÉSULTATS: Sur 43 cas de TB-MDR interviewés, 20 (47%) étaient des hommes, cinq (12%) étaient asymptomatiques (et ont été découverts fortuitement) et 22 (51%) avaient des maladies sous-jacentes. Parmi les 115 contacts recensés, 61 (53%) étaient des contacts dans le ménage et 49 (43%) étaient des contacts proches (hors ménage); 70 (61%) ont été dépistés pour la TB à l'aide de divers tests. Dans ce réseau, nous avons priorisé 37 contacts reliés à plus d'un patient atteint de TB-MR. Le regroupement le plus important a été identifié dans l'unité de pharmacie de l'hôpital. CONCLUSION: Cette investigation a abouti à un nombre important de contacts avec la TB-MDR et l'analyse du réseau social a facilité l'établissement des priorités pour le dépistage. L'analyse du réseau social est utile et réalisable dans le cadre de ce programme et complète l'investigation sur les contacts de TB-MDR.

Viral metacommunities associated to bats and rodents at different spatial scales.

One of the main goals of community ecology is to measure the relative importance of environmental filters to understand patterns of species distribution at different temporal and spatial scales. Likewise, the identification of factors that shape symbiont metacommunity structures is important in disease ecology because resulting structures drive disease transmission. We tested the hypothesis that distributions of virus species and viral families from rodents and bats are defined by shared responses to host phylogeny and host functional characteristics, shaping the viral metacommunity structures at four spatial scales (Continental, Biogeographical, Zoogeographical, and Regional). The contribution of host phylogeny and host traits to the metacommunity of viruses at each spatial scale was calculated using a redundant analysis of canonical ordering (RDA). For rodents, at American Continental scale the coherence of viral species metacommunity increased while the spatial scale decreased and Quasi-Clementsian structures were observed. This pattern suggests a restricted distribution of viruses through their hosts, while in the Big Mass (Europe, Africa, and Asia), the coherence decreased as spatial scale decreased. Viral species metacommunities associated with bats was dominated by random structures along all spatial scales. We suggest that this random pattern is a result of the presence of viruses with high occupancy range such as rabies (73%) and coronavirus (27%), that disrupt such structures. At viral family scale, viral metacommunities associated with bats showed coherent structures, with the emergence of Quasi- Clementsian and Checkerboard structures. RDA analysis indicates that the assemblage of viral diversity associated with rodents and bats responds to phylogenetic and functional characteristics, which alternate between spatial scales. Several of these variations could be subject to the spatial scale, in spite of this, we could identify patterns at macro ecological scale. The application of metacommunity theory at symbiont scales is particularly useful for large-scale ecological analysis. Understanding the rules of host-virus association can be useful to take better decisions in epidemiological surveillance, control and even predictions of viral distribution and dissemination. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available for this article at 10.1556/168.2018.19.2.9 and is accessible for authorized users.