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Short and long term retention in antiretroviral care in health facilities in rural Malawi and Zimbabwe
No full textBACKGROUND: Despite the successful scale-up of ART services over the past years, long term retention in ART care remains a major challenge, especially in high HIV prevalence and resource-limited settings. This study analysed the short (12 months) term retention on ART in two ART programmes in Malawi (Thyolo district) and Zimbabwe (Buhera district). METHODS: Retention rates at six-month intervals are reported separately among (1) patients since ART initiation and (2) patients who had been on ART for at least 12 months, according to the site of ART initiation and follow-up, using the Kaplan Meier method. 'Retention' was defined as being alive on ART or transferred out, while 'attrition' was defined as dead, lost to follow-up or stopped ART. RESULTS: In Thyolo and Buhera, a total of 12,004 and 9,721 patients respectively were included in the analysis. The overall retention among the patients since ART initiation was 84%, 80% and 77% in Thyolo and 88%, 84% and 82% in Buhera at 6, 12 and 18 months, respectively. In both programmes the largest drop in ART retention was found during the initial 12 months on ART, mainly related to a high mortality rate in the health centres in Thyolo and a high loss to follow-up rate in the hospital in Buhera. Among the patients who had been on ART for at least 12 months, the retention rates leveled out, with 97%, 95% and 94% in both Thyolo and Buhera, at 18, 24 and 30 months respectively. Loss to follow-up was identified as the main contributor to attrition after 12 months on treatment in both programmes. CONCLUSIONS: To better understand the reasons of attrition and adapt the ART delivery care models accordingly, it is advisable to analyse short and long term retention separately, in order to adapt intervention strategies accordingly. During the initial months on ART more medical follow-up, especially for symptomatic patients, is required to reduce mortality. Once stable on ART, however, the ART care delivery should focus on regular drug refill and adherence support to reduce loss to follow up. Hence, innovative life-long retention strategies, including use of new communication technologies, community based interventions and drug refill outside the health facilities are required
Leishmaniasis direct agglutination test: using pictorials as training materials to reduce inter-reader variability and improve accuracy
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Electrospun cellulose acetate phthalate fibers for semen induced anti-HIV vaginal drug delivery
No full textDespite many advances in modern medicine, human immunodeficiency virus (HIV) still affects the health of millions of people world-wide and much effort is put in developing methods to either prevent infection or to eradicate the virus after infection has occurred. Here, we describe the potential use of electrospun cellulose acetate phthalate (CAP) fibers as a tool to prevent HIV transmission. During the electrospinning process, anti-viral drugs can easily be incorporated in CAP fibers. Interestingly, as a result of the pH-dependent solubility of CAP, the fibers are stable in vaginal fluid (the healthy vaginal flora has a pH of below 4.5), whereas the addition of small amounts of human semen (pH between 7.4 and 8.4) immediately dissolves the fibers which results in the release of the encapsulated drugs. The pH-dependent release properties have been carefully studied and we show that the released anti-viral drugs, together with the CAP which has been reported to have intrinsic antimicrobial activity, efficiently neutralize HIV in vitro
Cryopreserved Plasmodium vivax and cord blood reticulocytes can be used for invasion and short term culture
No full textThe establishment of a Plasmodium vivaxin vitro culture system is critical for the development of new vaccine, drugs and diagnostic tests. Although short-term cultures have been successfully set up, their reproducibility in laboratories without direct access to P. vivax-infected patients has been limited by the need for fresh parasite isolates. We explored the possibility of using parasite isolates and reticulocytes, both cryopreserved, to perform invasion and initiate short-term culture. Invasion results obtained with both cryopreserved isolates and reticulocytes were similar to those obtained with fresh samples. This method should be easily replicated in laboratories outside endemic areas and will substantially contribute to the development of a continuous P. vivax culture. In addition, this model could be used for testing vaccine candidates as well as for studying invasion-specific molecular mechanisms
hsp65 PCR-restriction analysis (PRA) with capillary electrophoresis for species identification and differentiation of Mycobacterium kansasii and Mycobacterium chelonae-Mycobacterium abscessus group
No full textOBJECTIVES: The aim of the present study was to identify and differentiate Mycobacterium kansasii and Mycobacterium chelonae-Mycobacterium abscessus group strains isolated from clinical and environmental sources in different countries. METHODS: PCR-restriction analysis of the hsp65 gene (PRA) with automated capillary electrophoresis was applied to the isolates previously identified by conventional biochemical testing and the molecular INNO-LiPA MYCOBACTERIA assay. RESULTS: PRA performed very well in comparison with the two other methods (96.4% concordance). Among 27M. kansasii isolates, this method detected five genetic types, of which type 1 represented the most common clinical isolate, as it is worldwide. PRA differentiated 29M. chelonae-M. abscessus group isolates into Mycobacterium immunogenum type 2 (n=13), M. chelonae (n=12), and M. abscessus types 1 (n=1) and 2 (n=1). M. immunogenum was the most frequent (69%) isolate from humans, but only one of 11 cases was clinically significant. M. chelonae was the most commonly (83%) recovered from water. PRA also identified two isolates with hsp65 alleles representing previously unreported patterns. CONCLUSIONS: PRA based on automated capillary electrophoresis is a rapid, simple, and reliable method for the identification and differentiation of both clinically relevant and environmental isolates of M. kansasii and M. chelonae-M. abscessus group
Genome-wide SNP and microsatellite variation illuminate population-level epidemiology in the Leishmania donovani species complex
No full textThe species of the Leishmania donovani species complex cause visceral leishmaniasis, a debilitating infectious disease transmitted by sandflies. Understanding molecular changes associated with population structure in these parasites can help unravel their epidemiology and spread in humans. In this study, we used a panel of standard microsatellite loci and genome-wide SNPs to investigate population-level diversity in L. donovani strains recently isolated from a small geographic area spanning India, Bihar and Nepal, and compared their variation to that found in diverse strains of the L. donovani complex isolates from Europe, Africa and Asia. Microsatellites and SNPs could clearly resolve the phylogenetic relationships of the strains between continents, and microsatellite phylogenies indicated that certain older Indian strains were closely related to African strains. In the context of the anti-malaria spraying campaigns in the 1960s, this was consistent with a pattern of episodic population size contractions and clonal expansions in these parasites that was supported by population history simulations. In sharp contrast to the low resolution provided by microsatellites, SNPs retained a much more fine-scale resolution of population-level variability to the extent that they identified four different lineages from the same region one of which was more closely related to African and European strains than to Indian or Nepalese ones. Joining results of in vitro testing the antimonial drug sensitivity with the phylogenetic signals from the SNP data highlighted protein-level mutations revealing a distinct drug-resistant group of Nepalese and Indian L. donovani. This study demonstrates the power of genomic data for exploring parasite population structure. Furthermore, markers defining different genetic groups have been discovered that could potentially be applied to investigate drug resistance in clinical Leishmania strains
Current developments and future perspectives for TB diagnostics
No full textTB persists as a global epidemic with high morbidity and mortality, especially in low-income countries. It is the only infectious disease ever declared as a global emergency by the WHO. The HIV pandemic and the emergence of drug resistance represent two additional obstacles to better control of the disease. Important progress has been made in the last decade in TB diagnostics. Major needs still exist, such as the availability of a real point-of-care test, a better diagnosis of TB in immune-compromised populations and in children, and the possibility to predict progression to disease in latently infected people. This review will summarize the current developments in TB diagnostics and the perspectives for future developments in the field