Mapping and modelling neglected tropical diseases and poverty in Latin America and the Caribbean

The prospects and opportunities for application of risk mapping and modelling of the neglected tropical diseases (NTDs) in Latin America are examined with the aim to broaden the interest in geospatial research there. Special reference is made to the potential use of geospatial tools in health planning and implementation of national disease control programmes

Frontiers of parasitology research in the People's Republic of China : infection, diagnosis, protection and surveillance

ABSTRACT: Control and eventual elimination of human parasitic diseases in the People's Republic of China (P.R. China) requires novel approaches, particularly in the areas of diagnostics, mathematical modelling, monitoring, evaluation, surveillance and public health response. A comprehensive effort, involving the collaboration of 188 scientists (<85% from P.R. China) from 48 different institutions and universities (80% from P.R. China), covers this collection of 29 articles published in Parasites & Vectors. The research mainly stems from a research project entitled 'Surveillance and diagnostic tools for major parasitic diseases in P.R. China' (grant no. 2008ZX10004-011) and highlights the frontiers of research in parasitology. The majority of articles in this thematic series deals with the most important parasitic diseases in P.R. China, emphasizing Schistosoma japonicum, Plasmodium vivax and Clonorchis sinensis plus some parasites of emerging importance such as Angiostrongylus cantonensis. Significant achievements have been made through the collaborative research programme in the following three fields: (i) development of control strategies for the national control programme; (ii) updating the surveillance data of parasitic infections both in human and animals; and (iii) improvement of existing, and development of novel, diagnostic tools to detect parasitic infections. The progress is considerable and warrants broad validation efforts. Combined with the development of improved tools for diagnosis and surveillance, integrated and multi-pronged control strategies now pave the way for elimination of parasitic diseases in P.R. China. Experiences and lessons learned can stimulate control and elimination efforts of parasitic diseases in other parts of the world

Present aspects of immunodiagnosis of schistosomiasis

Facilitated and improved by advances in molecular biology, techniques for the immunodiagnosis of schistosomiasis, including assays based on the detection of antigens circulating in the serum and/or excreted in the urine, have now reached the stage of multi-centre trials. There is a need to complement parasitological techniques as some national programmes are becoming increasingly succesful in establishng control of the disease and the classical approach frequently fails to reveal low-intensity infection. Epidemiological survey teams in some areas have tentatively started to use serology and their experience indicates that antibody detection suffies in eradicated or controlled areas with low expected prevalence but that detection of circulating antigens is needed for assessment of the incidence of infection or reinfection in areas recently brought under control. Before reagents and procedures can be recommended for routine use of national control programmes, the assays must be standardized with sera from clinically well-characterized patients in geographically defined regions, hence emphasizing the need for a reference serum bank. Implementation of serological testing, carried out by nationsl public health laboratories using standardized testing systems, would permit valid comparisons between different areas providing support for decisions regarding national health polices

Schistosomiasis research funding: the TDR contribution

In spite of the recent decline in financial support on the part of some major donors, the overall international support for schistosomiasis research in current US dollars has been holding steady. However, when adjusted for inflation, a clear decline during the last decade appears and only in a few countries has this decline been balanced by increased national or bilateral funding. The prevailing level of support for schistosomiasis research is barely sufficient to maintain estabilished laboratories and researchers, and highlights the need to attract young investigators. The important goal of brunging a new generation of scientists into the field of schistosomiaisis can only be achieved by a considerable long-term increase in funding, both at the national and the international levels. A break-through in current research emphasizing improved techniques for control is needed to encourage donors and governments to improve the situation

Prophylactic effect of artemether on human Schistosomiasis mansoni among Egyptian children : a randomized controlled trial

A double-blind, randomized controlled trial was conducted in an endemic focus for Schistosoma mansoni in Kafr El-Sheikh Governorate, Northern Nile Delta, Egypt, to evaluate the prophylactic effect of artemether (ART) given in conjunction with praziquantel (PZQ). The study encompassed 913 primary school children randomly assigned to two treatment groups PZQ/ART and PZQ/ART-placebo. At baseline, both groups received 40mg/kg body weight of PZQ twice four weeks apart, after which one group received 6mg/kg body weight of ART every 3 weeks in 5 cycles during the transmission season and the other group received ART-placebo. At the end of the study, prevalence of infection among the PZQ/ART was approximately half that of the PZQ/ART-placebo group, i.e. 6.7% versus 11.6%, and incidence of new infections for the PZQ/ART was 2.7% versus 6.5% for the PZQ/ART-placebo. In conclusion, PZQ/ART combined therapy might be considered as an adjunct measure against human schistosomiasis, by specifically reducing transmission and therefore contribute to disease elimination

Frequency evaluation of the doubly forbidden 1S0→3P0^1S_0\to ^3P_0 transition in bosonic 174^{174}Yb

We report an uncertainty evaluation of an optical lattice clock based on the $^1S_0\leftrightarrow^3P_0$ transition in the bosonic isotope $^{174}$Yb by use of magnetically induced spectroscopy. The absolute frequency of the $^1S_0\leftrightarrow^3P_0$ transition has been determined through comparisons with optical and microwave standards at NIST. The weighted mean of the evaluations is $\nu$($^{174}$Yb)=518 294 025 309 217.8(0.9) Hz. The uncertainty due to systematic effects has been reduced to less than 0.8 Hz, which represents $1.5\times10^{-15}$ in fractional frequency.Comment: 4 pages, 3 figure -Submitted to PRA Rapid Communication

Complementation of Subquandles

Saki and Kiani proved that the subrack lattice of a rack $R$ is necessarily complemented if $R$ is finite but not necessarily complemented if $R$ is infinite. In this paper, we investigate further avenues related to the complementation of subquandles. Saki and Kiani's example of an infinite rack without complements is a quandle, which is neither ind-finite nor profinite. We provide an example of an ind-finite quandle whose subobject lattice is not complemented, and conjecture that profinite quandles have complemented subobject lattices. Additionally, we provide a complete classification of subquandles whose set-theoretic complement is also a subquandle, which we call \textit{strongly complemented}, and provide a partial transitivity criterion for the complementation in chains of strongly complemented subquandles. One technical lemma used in establishing this is of independent interest: the inner automorphism group of a subquandle is always a subquotient of the inner automorphism group of the ambient quandle

Sub-dekahertz ultraviolet spectroscopy of 199Hg+

Using a laser that is frequency-locked to a Fabry-Perot etalon of high finesse and stability, we probe the 5d10 6s 2S_1/2 (F=0) - 5d9 6s 2D_5/2 (F=2) Delta-m_F = 0 electric-quadrupole transition of a single laser-cooled 199Hg+ ion stored in a cryogenic radio-frequency ion trap. We observe Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 X 10^15 Hz), yielding a line Q = 1.6 X 10^14. We perform a preliminary measurement of the 5d9 6s2 2D_5/2 electric-quadrupole shift due to interaction with the static fields of the trap, and discuss the implications for future trapped-ion optical frequency standards.Comment: 4 pages, 4 figures, submitted for publicatio

Nucleic acid amplification techniques for the detection of Schistosoma mansoni infection in humans and the intermediate snail host: a structured review and meta-analysis of diagnostic accuracy

BACKGROUND: Schistosomiasis is a parasitic disease caused by hematodes of genus Schistosoma. This review evaluated the available nucleic acid amplification techniques for diagnosing S. mansoni infections in humans, intermediate host snails, and presumed rodent reservoirs. METHODS: Sensitivity, specificity, diagnostic odds ratio (DOR), and 95% CI were calculated based on available literature. The potential of PCR, nPCR, PCR-ELISA, qPCR, and LAMP was compared for diagnosing S. mansoni infections. RESULTS: A total of 546 published records were identified. Quality assessment by QUADAS-2 revealed an uncertain risk in most studies, and 21 references were included in the final. For human samples, the four nucleic acid amplification techniques showed an overall sensitivity of 89.79% (95% CI: 83.92%-93.67%), specificity of 87.70% (95% CI: 72.60%-95.05%), and DOR of 37.73 (95% CI: 21.79-65.33). LAMP showed the highest sensitivity, followed by PCR-ELISA, PCR, and qPCR, while this order was almost reversed for specificity; qPCR had the highest AUC. For rodent samples, qPCR showed modest sensitivity (68.75%, 95% CI: 43.32%-86.36%) and high specificity (92.45%, 95% CI: 19.94%-99.83%). For snail samples, PCR and nPCR assays showed high sensitivity of 90.06% (95% CI: 84.39%-93.82%) and specificity of 85.51% (95% CI: 54.39%-96.69%). CONCLUSION: Nucleic acid amplification techniques had high diagnostic potential for identifying S. mansoni infections in humans

Spatial epidemiology in zoonotic parasitic diseases: insights gained at the 1st International Symposium on Geospatial Health in Lijiang, China, 2007

The 1st International Symposium on Geospatial Health was convened in Lijiang, Yunnan province, People's Republic of China from 8 to 9 September, 2007. The objective was to review progress made with the application of spatial techniques on zoonotic parasitic diseases, particularly in Southeast Asia. The symposium featured 71 presentations covering soil-transmitted and water-borne helminth infections, as well as arthropod-borne diseases such as leishmaniasis, malaria and lymphatic filariasis. The work made public at this occasion is briefly summarized here to highlight the advances made and to put forth research priorities in this area. Approaches such as geographical information systems (GIS), global positioning systems (GPS) and remote sensing (RS), including spatial statistics, web-based GIS and map visualization of field investigations, figured prominently in the presentation