Long-lasting Insecticidal Nets to Prevent Visceral Leishmaniasis in the Indian Subcontinent; Methodological Lessons Learned from a Cluster Randomised Controlled Trial

In a recent paper, Nagpal et al. voiced concerns about the limited or biased use of scientific evidence to support public health interventions to control neglected tropical diseases (NTDs). Visceral leishmaniasis (VL), also known as kala-azar, is one of the major NTDs and does not escape this problem. Transmission is vector-borne and the Indian subcontinent is the region reporting most of the VL cases worldwide. In this region, the main causative species is Leishmania donovani and Phlebotomus argentipes is the vector. Transmission is considered anthroponotic and peridomestic—occurring at night when female sand flies bite people sleeping inside their house. The World Health Organization and the governments of India, Nepal, and Bangladesh set out in 2005 to eliminate VL from the region by 2015 through a combination of early treatment of cases and vector control. However, while recent advances in diagnostic tools and drugs have significantly improved case management strategies, the available vector control tools against P. argentipes remain limited. The elimination initiative promotes the use of indoor residual spraying (IRS) of households and cattle sheds to reduce vector density, but the evidence underpinning the effectiveness of IRS in this region is scanty. Historical observations show that L. donovani transmission declined concomitantly with dichlorodiphenyltrichloroethane (DDT) spraying during the 1950s–60s to eradicate malaria. In the aftermath of this malaria eradication campaign, very few VL cases were observed in endemic regions until the mid-seventies, when there was resurgence of a VL epidemic in India. To date, there are no randomized trials showing the effect of IRS on the incidence of clinical VL, though some studies showed a reduction in vector density. When the VL elimination initiative was launched in 2005, there were no clear alternatives for IRS as a vector control strategy. Insecticide treated nets (ITNs) were proposed as an alternative or complement to IRS on the basis of analogy arguments regarding their given efficacy against malaria or on data from observational studies suggesting ITNs reduce the risk of VL; but as for IRS, there were no randomized trials evaluating the effect of ITNs on L. donovani transmission. In this context, a number of field studies were conducted in the Indian subcontinent in the past decade to evaluate the effectiveness and impact of ITNs and other vector control tools on VL. Most of these studies have been reviewed in detail in two recent papers. The only two studies evaluating the impact of vector control interventions on clinical outcomes found conflicting results. First, the KALANET project, a cluster randomised controlled trial (CRT) in India and Nepal, showed that mass-distribution of ITNs did not reduce the risk of L. donovani infection or clinical VL. Then, an intervention trial in Bangladesh suggested that widespread bed net impregnation with slow-release insecticide may reduce the frequency of VL. Technical (e.g., type of nets and insecticides, lack of replicas and randomisation in Bangladesh) and biological factors (e.g., insecticide susceptibility and sand fly behaviour) may explain the different results observed. This apparent contradiction raises the question about the role that ITN may play in controlling VL in the Indian subcontinent but has also triggered a lot of discussion on methodology and evidence levels required when evaluating vector control tools for VL. In this paper, we would like to summarise the lessons learned from the KALANET CRT in terms of methodology to inform the generation of future evidence and discuss interpretation of findings against this background

Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background

The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L.) donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread applicability

Post-Kala-azar Dermal Leishmaniasis in Nepal: A Retrospective Cohort Study (2000–2010)

Post-kala-azar dermal leishmaniasis (PKDL) is a skin disorder seen in patients treated for Leishmania donovani visceral leishmaniasis (VL), a neglected tropical disease that is fatal if left untreated. In the Indian subcontinent, PKDL is seen in 5–10% of all past VL cases and is also reported in some without history of VL. As persons with PKDL do not feel sick, the disease has only cosmetic significance for the individual and treatment is rarely sought. However, PKDL lesions harbour parasites and therefore could represent a source of transmission, through the bite of female sand flies. Our study shows that the occurrence of PKDL in patients with past treated VL is low in Nepal compared to neighboring countries. Treatment of the original VL episode with SSG (sodium stibogluconate), inadequate treatment and treatment on ambulatory basis were significantly associated with PKDL. Though SSG has since been replaced by other drugs, counseling and supervision of adherence to the prescribed VL treatment is of vital importance to reduce risk of treatment failure and relapse as well as later development of PKDL. Policy makers should include surveillance and case management of PKDL in the VL elimination program

Characterizing the morbid genome of ciliopathies

Background Ciliopathies are clinically diverse disorders of the primary cilium. Remarkable progress has been made in understanding the molecular basis of these genetically heterogeneous conditions; however, our knowledge of their morbid genome, pleiotropy, and variable expressivity remains incomplete. Results We applied genomic approaches on a large patient cohort of 371 affected individuals from 265 families, with phenotypes that span the entire ciliopathy spectrum. Likely causal mutations in previously described ciliopathy genes were identified in 85% (225/265) of the families, adding 32 novel alleles. Consistent with a fully penetrant model for these genes, we found no significant difference in their “mutation load” beyond the causal variants between our ciliopathy cohort and a control non-ciliopathy cohort. Genomic analysis of our cohort further identified mutations in a novel morbid gene TXNDC15, encoding a thiol isomerase, based on independent loss of function mutations in individuals with a consistent ciliopathy phenotype (Meckel-Gruber syndrome) and a functional effect of its deficiency on ciliary signaling. Our study also highlighted seven novel candidate genes (TRAPPC3, EXOC3L2, FAM98C, C17orf61, LRRCC1, NEK4, and CELSR2) some of which have established links to ciliogenesis. Finally, we show that the morbid genome of ciliopathies encompasses many founder mutations, the combined carrier frequency of which accounts for a high disease burden in the study population. Conclusions Our study increases our understanding of the morbid genome of ciliopathies. We also provide the strongest evidence, to date, in support of the classical Mendelian inheritance of Bardet-Biedl syndrome and other ciliopathies

Visceral Leishmaniasis IgG1 Rapid Monitoring of Cure vs. Relapse, and Potential for Diagnosis of Post Kala-Azar Dermal Leishmaniasis.

Background: There is a recognized need for an improved diagnostic test to assess post-chemotherapeutic treatment outcome in visceral leishmaniasis (VL) and to diagnose post kala-azar dermal leishmaniasis (PKDL). We previously demonstrated by ELISA and a prototype novel rapid diagnostic test (RDT), that high anti-Leishmania IgG1 is associated with post-treatment relapse versus cure in VL. Methodology: Here, we further evaluate this novel, low-cost RDT, named VL Sero K-SeT, and ELISA for monitoring IgG1 levels in VL patients after treatment. IgG1 levels against L. donovani lysate were determined. We applied these assays to Indian sera from cured VL at 6 months post treatment as well as to relapse and PKDL patients. Sudanese sera from pre- and post-treatment and relapse were also tested. Results: Of 104 paired Indian sera taken before and after treatment for VL, when deemed clinically cured, 81 (77.9%) were positive by VL Sero K-SeT before treatment; by 6 months, 68 of these 81 (84.0%) had a negative or reduced RDT test line intensity. ELISAs differed in positivity rate between pre- and post-treatment (p = 0.0162). Twenty eight of 33 (84.8%) Indian samples taken at diagnosis of relapse were RDT positive. A comparison of Indian VL Sero K-SeT data from patients deemed cured and relapsed confirmed that there was a significant difference (p < 0.0001) in positivity rate for the two groups using this RDT. Ten of 17 (58.8%) Sudanese sera went from positive to negative or decreased VL Sero K-SeT at the end of 11-30 days of treatment. Forty nine of 63 (77.8%) PKDL samples from India were positive by VL Sero K-SeT. Conclusion: We have further shown the relevance of IgG1 in determining clinical status in VL patients. A positive VL Sero K-SeT may also be helpful in supporting diagnosis of PKDL. With further refinement, such as the use of specific antigens, the VL Sero K-SeT and/or IgG1 ELISA may be adjuncts to current VL control programmes

ACORN (A Clinically-Oriented Antimicrobial Resistance Surveillance Network) II: protocol for case based antimicrobial resistance surveillance

Background: Antimicrobial resistance surveillance is essential for empiric antibiotic prescribing, infection prevention and control policies and to drive novel antibiotic discovery. However, most existing surveillance systems are isolate-based without supporting patient-based clinical data, and not widely implemented especially in low- and middle-income countries (LMICs). Methods: A Clinically-Oriented Antimicrobial Resistance Surveillance Network (ACORN) II is a large-scale multicentre protocol which builds on the WHO Global Antimicrobial Resistance and Use Surveillance System to estimate syndromic and pathogen outcomes along with associated health economic costs. ACORN-healthcare associated infection (ACORN-HAI) is an extension study which focuses on healthcare-associated bloodstream infections and ventilator-associated pneumonia. Our main aim is to implement an efficient clinically-oriented antimicrobial resistance surveillance system, which can be incorporated as part of routine workflow in hospitals in LMICs. These surveillance systems include hospitalised patients of any age with clinically compatible acute community-acquired or healthcare-associated bacterial infection syndromes, and who were prescribed parenteral antibiotics. Diagnostic stewardship activities will be implemented to optimise microbiology culture specimen collection practices. Basic patient characteristics, clinician diagnosis, empiric treatment, infection severity and risk factors for HAI are recorded on enrolment and during 28-day follow-up. An R Shiny application can be used offline and online for merging clinical and microbiology data, and generating collated reports to inform local antibiotic stewardship and infection control policies. Discussion: ACORN II is a comprehensive antimicrobial resistance surveillance activity which advocates pragmatic implementation and prioritises improving local diagnostic and antibiotic prescribing practices through patient-centred data collection. These data can be rapidly communicated to local physicians and infection prevention and control teams. Relative ease of data collection promotes sustainability and maximises participation and scalability. With ACORN-HAI as an example, ACORN II has the capacity to accommodate extensions to investigate further specific questions of interest

<i>Parambassis waikhomi</i>, a new species of glassfish (Teleostei: Ambassidae) from Loktak Lake, northeastern India

Parambassis waikhomi, a new species of glassfish from Loktak Lake, Chindwin basin in Manipur, northeastern India is distinguished from its congeners by the presence of 58-60 lateral line scales; two predorsal bones; a vertically elongated humeral spot; 24 vertebrae; maxilla reaching to ⅓ of the orbit; 8.2- 10.9 interorbital width; four preorbital ridge, 11 preorbital edge, six supraorbital ridge, 18 serrae at lower edge of preoperculum, 24 serrae at hind margin of preoperculum. The species differs from its nearest congener P. ranga by the presence of 9-10 (vs. 12-13) pectoral fin rays and 19-20 (vs. 22-28) gill rakers

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Not AvailableTwo grow-out studies one on the compatibility of Pengba, Osteobrama belangeri with catla and rohu; and the other on finding its ideal incorporation level in the three species major carp polyculture system (catla, rohu and mrigal) were conducted for 11 and six months, respectively. In Study-I, two treatments having pengba stocked either with catla or rohu at a combined stocking density of 6500 fingerlings ha−1 were evaluated against a control having rohu and catla stocked together. While incorporation of pengba did not affect survival of either catla or rohu (P > .05), growth of the latter two species improved in respective treatment (P .05) were similar and significantly higher than the rohu-pengba combination. Such results suggested feasibility of incorporating pengba in the major carp polyculture system. In Study-II, additional incorporation of pengba at 10 and 20% of the IMC density (6500 fingerlings ha−1) did not affect survival and growth of any of the major carps, reiterating its compatibility. With 10% addition, pengba yielded relatively higher survival (P > .05) as well as higher length and weight gains (P < .05) than the 20% incorporation level. But, its biomass yield was almost double in the 20% incorporation level. Thus, the two studies together while indicated compatibility of pengba with the two IMC species, it recommended incorporation of the new species upto an additional 20% level over and above the IMC stocking density to increase the biomass yield in the major carp polyculture system.Not Availabl

Urinary Calculi: A Microbiological and Biochemical Analysis at a Tertiary Care Hospital in Eastern Nepal

Background. The occurrence of urinary tract infection in presence of urolithiasis is frequently noted; however, microbial agents of urolithiasis and their antimicrobial susceptibility patterns remain underinvestigated. This study aimed to identify the microorganisms isolated from urine and stone matrices to determine their antimicrobial susceptibility, to find the association between the pathogens of urine and stone matrices, and to perform the biochemical analysis of stones. Methods. A total of 88 cases of urolithiasis admitted for elective stone removal at Department of surgery, B.P. Koirala Institute of Health Sciences (BPKIHS), were enrolled. Preoperative urine culture and postoperative stone culture were performed. Isolation, identification, and AST were done by the standard microbiological technique. Further qualitative biochemical analysis of stones was also attempted. Result. Among 88 stone formers recruited, culture of urine, whole stone, and nidus yielded the growth of bacteria 44, 32, and 30, respectively. Bacteria isolated from urine culture correlated with those from stone matrices with a sensitivity of 90%, specificity of 79.69%, PPV of 63.64%, and NPV of 95.45%. Escherichia coli (46.7%) was the most common bacteria followed by Klebsiella pneumoniae (16.7%) and Proteus mirabilis (13.3%) from urine and stone cultures. Almost all the uropathogens isolated were susceptible to commonly used antibiotics. Calcium oxalate (84.1%) was common biochemical constituent found in stone formers followed by calcium oxalate + phosphate (8%). Conclusions. The association of microorganism isolated from urine and nidus culture was significant that can predict the source of infective stone; however, in some cases, microorganisms and the antimicrobial susceptibility pattern from urine and nidus were different. This study emphasizes the use of appropriate antimicrobial agents to prevent the regrowth of residual stones and minimize the risk of infectious complications after surgical removal of stones