The Double Burden of COVID-19 and Dengue in Nepal: The challenges ahead.

Coronavirus disease 2019 (COVID-19) pandemic has caused significant impact on the health care system. As a consequence, diagnosis and treatment of vector borne diseases including dengue has been equally affected. Nepal is no exception to this, where COVID-19 cases is exponentially increased and all resources are concentrated on its prevention, control and management. Dengue, one of the major vector-borne diseases in Nepal, is apparently overlooked despite approaching the peak season of the disease. The aim of this paper is to describe the double burden of COVID-19 and dengue in Nepal, particularly highlighting the co-circulation and possible coinfections. This has posed higher risk of increased severity, more severe cases and deaths in Nepal. Moreover, potential misdiagnosis of these viral diseases may lead to delayed or, inappropriate treatment and poor allocation of resources.

Microbial Variants from Iron Ore Slimes: Mineral Specificity and pH Tolerance.

This paper describes the isolation of the native bacterial strains from the iron ore mines slime pond and its extremophilic characteristics. The two microbial isolates designated as CNIOS-1 and CNIOS-2 were grown in selective silicate broth at pH 7.0 and the organisms were tested for their selective adhesion on silicate and alumina minerals. The silicate bacteria with their exopolymers are very potent to grow over aluminosilicates. It was established that CNIOS-1 grew preferentially in the presence of silicate mineral compared to CNIOS-2 which grew in the presence of alumina. The organisms were tested for growth at various pH and trials were carried to define their efficacy for eventual applications to remove gangue minerals of silica and alumina from the raw material.

Comparative study of microscopy and polymerase chain reaction for the diagnosis of suspected visceral leishmaniasis patients in Nepal.

BACKGROUND: Visceral leishmaniasis is potentially fatal protozoan diseases caused by Leishmania donovani. Nepal is an endemic region in which visceral leishmaniasis causes a major public health problem in the lowland areas that border the endemic areas of Bihar state in India. Accurate diagnosis to inform treatment is a first step in achieving the goal of visceral leishmaniasis elimination from South East Asian regions by 2020. OBJECTIVE: The objective of the present study was to compare between the Microcopy and polymerase chain reaction for diagnosis of visceral leishmaniasis. METHODS: In the present study, 236 bone marrow aspirations were collected from suspected visceral leishmaniasis patients in Janakpur Zonal Hospital, Dhanusa district, Terai region of Nepal in between 2003-2007. We evaluated bone marrow samples by microscopic examination with subsequent testing of the same sample by polymerase chain reaction and sequence analysis. RESULTS: Giemsa's solution stained bone marrow slides stored for over five years were used for polymerase chain reaction amplification. The result showed that 71% were polymerase chain reaction positive and 56% were microscopic positive. Out of 104 microscopic negative bone marrow samples, 15% of samples were positive by polymerase chain reaction. CONCLUSION: Polymerase chain reaction could make a very good option for diagnosis by using less or non-invasive material from visceral leishmaniasis patients in endemic areas of Nepal.

Prognostic value of rapid test for diagnosis of dengue in Nepalese patients during 2010 epidemic.

BACKGROUND: Dengue is an emerging vector borne disease in Nepal and rapid diagnostic test is important for early diagnosis of the disease. OBJECTIVES: The aim of the study was to evaluate the diagnostic accuracy of commonly used rapid immunochromatographic test kit in Nepal during 2010 dengue epidemic and to assess disease burden of dengue. METHODS: A total of 131 acute and nonacute serum samples were collected during recent epidemic of dengue in 2010 from clinically suspected Nepalese patients of different hospitals. Rapid immunochromatographic test kit was used for early diagnosis and enzyme immunosorbent was chosen as a reference assay. RESULTS: The sensitivity and specificity of rapid test was 70% and 76.54% respectively whereas the prevalence of the disease was 38.17%. The odds ratio for males was 1.8 however; the association with the disease was statistically not significant. CONCLUSION: The diagnostic accuracy of rapid immunochromatographic test for dengue diagnosis was low (k=0.46). So, it should be substituted by highly sensitive test device for prompt diagnosis and health personnel should consider appropriate timing of sample collection for better performance of rapid test.

The occurrence of amino acid substitutions D96N and S242N in VP7 of emergent G2P[4] rotaviruses in Nepal in 2004-2005: a global and evolutionary perspective.

Rotavirus is the leading cause of severe diarrhea among children worldwide. Strains with G2P[4] have captured recent attention because of its abrupt increase or re-emergence in many locations in the world. In Nepal, G2P[4] strains were detected at a rate of 1% in 2003-2004, but increased to 33% in 2004-2005. Thus, the VP7 genes of 45 emergent G2 strains from Nepal were sequenced and analyzed together with a total of 339 G2VP7 sequences detected over the last 34 years that were compiled from the DNA database. We found that all Nepalese VP7 sequences had a substitution from aspartic acid to asparagine at residue 96 (D96N) that was the hallmark of the lineage termed sublineage IVa, which replaced virtually all globally circulating G2 strains during the last decade. Within sublineage IVa, further sublineages emerged, of which a sublineage termed IVa-3 was identified to have another amino acid substitution from serine to asparagine at 242 (S242N). This sublineage, to which all Nepalese sequences belonged, now became the most frequent G2 sequence globally. In conclusion, the G2VP7 gene evolved in a dynamic fashion such that new lineages emerged within the previously dominant lineage, one of which became subsequently dominant.

Trends of rotavirus in Nepal.

BACKGROUND: Rotavirus gastroenteritis is the major cause of morbidity and mortality in infants and young children worldwide. Safe and effective rotavirus vaccine is needed to have significant impact on severe rotavirus gastroenteritis. Currently, two live oral rotavirus vaccines have been licensed in many countries. Knowledge on distribution of human rotavirus of G and P types are essential before rotavirus vaccines are introduced in the target populations. OBJECTIVE: To observe the trends of rotavirus strains in children below five years of age, during the years, 2003-2005 in Nepal. METHODS: Stool specimen collected from children with acute diarrhea who were referred to observation unit or hospitalized in Kanti Children Hospital between 2003 and 2005 were examined. Meteorological data was obtained from Ministry of Environment, Nepal to examine the possibility on the impact of weather on rotavirus infection. RESULTS: Of 1250 stool specimens, 271(22%) were positive for rotavirus by Rotaclone ELISA. G1 was the most common serotype in the first year of study, and G2 in the following year. G12 serotype emerged and remained predominant in two consecutive years. In addition, G9 and G3 emerged in the second year of the study. Children less than three years of age were commonly affected. The records reveal that rotavirus infection is related to the climate, and is commonly seen in the dry season, peaking in January. CONCLUSIONS: Continued surveillance of different regions is needed to monitor the trend of rotavirus strains and to establish rotavirus disease burden, which will help policy makers to make a decision in introducing rotavirus vaccine in Nepal.

Azathioprine induced pancytopenia: a serious complication.

Azathioprine is commonly used for treatment of lupus nephritis. Myelosuppression is known to occur with azathioprine, but severe pancytopenia is uncommon. A 23-year-old man with lupus nephritis was initially treated with intravenous cyclophosphamide pulses and oral prednisolone along with enalapril and frusemide. Following six months of cyclophosphamide, he was initiated on oral azathioprine as maintenance therapy. He subsequently returned with febrile neutropenia and severe bone marrow suppression. Fever responded to broad spectrum antibiotics and his counts gradually improved following granulocyte-macrophage colony stimulating factor. When last seen in October, he was symptom free and disease activity in control. We suggest that physicians remain sensitive to possibility of azathioprine induced severe bone marrow suppression. Frequent monitoring of blood counts is probably the best way to avoid this complication specially, where testing for thiopurine methyltransferase is not available.

Clinical profiling and use of loop-mediated isothermal amplification assay for rapid detection of Mycobacterium tuberculosis from sputum.

BACKGROUND: Tuberculosis is a global health problem and the situation is worsening with newer incidences of drug resistance and HIV association. Diagnosis of tuberculosis can be done by many methods and test, culture of sputum being the ideal one. Nucleic acid amplification (NAA) assay are more time efficient one, that amplify and detect specific nucleic acid sequences allows rapid, sensitive and specific detection of M. tuberculosis in sputum samples. OBJECTIVES: The present study intends to compile the clinical presentations of the pulmonary tuberculosis (PTB) patients and to evaluate the efficacy of in-house loop-mediated isothermal amplification (LAMP) in detecting Mycobacterium tuberculosis in sputum samples by comparing with microscopy and culture. MATERIALS AND METHODS: Two hundred two sputum samples were collected from 202 patients at National Tuberculosis Center, Bhaktapur, Nepal. Complete clinical profiling, epidemiological data and record on BCG vaccination were noted and the samples were subjected for microscopy, culture and in-house LAMP with six primers specific for 16S RNA gene of Mycobacterium tuberculosis. RESULT: Of the 176 cases of clinical profiling, productive cough was most common symptom in 147 (83.52%), followed by chest pain 136 (77.27%), fever 133 (75.56%) and haemoptysis 61 (34.66%). There was a statistically significant association between BCG vaccination and development of TB (chi(2)=5.33, P=0.02). Of 202 cases, 115 (56.93%) were chest X-ray positive, 101(50%) were direct smear-positive and 100 (49.51%) were culture positive. LAMP had a sensitivity of 97% and specificity of 94.12% while comparing with culture. In addition, its sensitivity and specificity were 91.09% and 89.11% respectively with reference to microscopy. CONCLUSION: As in our previous study, overall, the result of present study further confirms that the in-house LAMP is a simple, rapid, sensitive and specific DNA amplification technique for PTB diagnosis. Because of rapidity of microscopy and specificity of culture, in-house LAMP assay can be used as a very powerful and useful supplementary tool with complete clinical profiling of the patients for rapid diagnosis of TB in both AFB-positive and negative cases who are suspected as PTB in disease endemic country like Nepal.

Process optimization and kinetics for leaching of rare earth metals from the spent Ni-metal hydride batteries.

Nickel-metal hydride batteries (Ni-MH) contain not only the base metals, but valuable rare earth metals (REMs) viz. La, Sm, Nd, Pr and Ce as well. In view of the importance of resource recycling and assured supply of the contained metals in such wastes, the present study has focussed on the leaching of the rare earth metals from the spent Ni-MH batteries. The conditions for the leaching of REMs from the spent batteries were optimized as: 2M H2SO4, 348K temperature and 120min of time at a pulp density (PD) of 100g/L. Under this condition, the leaching of 98.1% Nd, 98.4% Sm, 95.5% Pr and 89.4% Ce was achieved. Besides the rare earth metals, more than 90% of base metals (Ni, Co, Mn and Zn) were also leached out in this condition. Kinetic data for the dissolution of all the rare earth metals showed the best fit to the chemical control shrinking core model. The leaching of metals followed the mechanism involving the chemical reaction proceeding on the surface of particles by the lixiviant, which was corroborated by the XRD phase analysis and SEM-EDS studies. The activation energy of 7.6, 6.3, 11.3 and 13.5kJ/mol was acquired for the leaching of neodymium, samarium, praseodymium and cerium, respectively in the temperature range 305-348K. From the leach liquor, the mixed rare earth metals were precipitated at pH∼1.8 and the precipitated REMs was analyzed by XRD and SEM studies to determine the phases and the morphological features.

Systematic studies on adsorption of lead on sea nodule residues.

Lead adsorption from aqueous solutions was studied with the aim of detoxifying industrial effluents before their safe disposal onto land or into river waters. Sea nodule residue (SNR), a waste material containing oxides and oxyhydroxides of manganese, iron, silicon, etc., was used as an effective adsorbent for lead in this study. The effect of various parameters such as contact time, initial lead concentration, pulp density, particle size of the adsorbent, pH, and temperature was studied to optimize the conditions for maximum adsorption. Adsorption followed first-order kinetics and 99% of lead adsorption was achieved at a solid:liquid ratio of 1:330, in the pH range 5.5-6.0 at a particle size of -150 microm in 8 h for solution containing 200 ppm lead. The adsorption capacity was found to be 99.0 mg of lead per gram of SNR and the adsorption isotherms followed the Langmuir and Freundlich adsorption models. The mechanism of adsorption of lead onto the sea nodule residue was also investigated. It was possible to reduce the lead level from 25-200 ppm to acceptable levels (0.1 ppm) by adsorption over this solid waste.

Recovery of valuable metals from cathodic active material of spent lithium ion batteries: Leaching and kinetic aspects.

This work is focussed on the processing of cathodic active material of spent lithium ion batteries (LIBs) to ensure resource recovery and minimize environmental degradation. The sulfuric acid leaching of metals was carried out for the recovery of all the valuable metals including nickel and manganese along with the frequently targeted metals like lithium and cobalt. The process parameters such as acid concentration, pulp density, time and temperature for the leaching of metals from the cathode powder containing 35.8% Co, 6.5% Li, 11.6% Mn and 10.06% Ni, were optimized. Results show the optimized leach recovery of 93.4% Li, 66.2% Co, 96.3% Ni and 50.2% Mn when the material was leached in 1M H2SO4 at 368 K and 50 g/L pulp density for 240 min. The need of a reductant for improved recovery of cobalt and manganese has been explained by the thermodynamic analysis (Eh-pH diagram) for these metals. Leaching of the valuable metals was found to follow the logarithmic rate law controlled by surface layer diffusion of the lixiviant reacting with the particles. The mode of leaching of the metals from the spent LIBs was further examined by chemical analysis of the samples at various stage of processing which was further corroborated by characterizing the untreated sample and the leach residues by XRD phase identification and the SEM-EDS studies.

Molecular evolution, distribution and genetic relationship among the dengue 2 viruses isolated from different clinical severity.

Twenty-two strains of dengue 2 virus, isolated in China, Latin America, New Guinea and Thailand were subjected to phylogenetic analysis. The UPGMA analysis was carried out on each gene region of dengue virus and demonstrated that outcome from most of the gene regions showed similar results except those from NS4B and YUTR with very short nucleotide length. Among ten regions examined, the results from E gene documented the geographical differences of the virus strains most clearly and all the American strains (Mara 4, IQT1797 and S1) were distantly related to the Asian isolates. As for the 16 Thai strains isolated in 1993, they were clustered into three groups and a strain from a DSS patient formed a distinct branch compared to the other two groups. This finding from phylogenetic analysis is consistent with earlier conclusion and support the severity related subtyping of dengue 2 virus based on amino acid changes.

Identification of a flavivirus isolated from mosquitos in Chiang Mai Thailand.

A virus isolate, ThCAr105/92, from a pool of mosquitos, Culex tritaeniorhynchus, collected in Chiang Mai, Thailand in 1992, appeared to be a member of the genus Flavivirus of the family Flaviviridae, based on the reverse transcription polymerase chain reaction (RT-PCR) using flavivirus cross-reacting primer pairs, electron microscopic examination, and serological tests. However, RT-PCR using Japanese encephalitis (JE) virus-specific primers showed that the isolate was different from JE virus. Sucrose density gradient sedimentation of the virus replicated in C6/36 cells indicated that the virus is relatively unstable in the infected culture fluids at 37 degrees C. Antibody prepared against this virus and a virus seed for the isolate were tested by cross neutralization against a panel of flaviviruses and the results showed that the new isolate was a distinct subtype of Tembusu virus.

Liquid-liquid extraction of Cd(II) from pure and Ni/Cd acidic chloride media using Cyanex 921: a selective treatment of hazardous leachate of spent Ni-Cd batteries.

The present paper is focused on solvent extraction of hazardous Cd(II) from acidic chloride media by Cyanex 921, a new extractant mixed with 10% (v/v) TBP in xylene. The optimum conditions for extraction and stripping of Cd(II) were investigated with an aqueous feed of 0.1 mol/L Cd(II) in 2.0 mol/L HCl. McCabe-Thiele diagram was in good agreement with the simulation studies, showing the quantitative extraction (99.9%) of Cd(II) within two counter-current stages utilizing 0.30 mol/L Cyanex 921 at O/A ratio of 3/2 in 10 min. Stoichiometry of the complexes extracted was determined and confirmed by numerical treatment and graphical method, revealing the formation of HCdCl3 · 2L and HCdCl3 · 4L for Cyanex 921(L) concentration in the range 0.03-0.1 mol/L and 0.1-1.0 mol/L, respectively. The thermodynamic parameters for the extraction of cadmium were also determined. The stripping efficiency of cadmium from the loaded organic with 0.10 mol/L HCl was 99.6% in a three-stage counter-current process at an O/A ratio of 2/3. Cyanex 921 was successfully applied for the separation of Cd(II) from Ni(II) in the simulated leach liquor of spent Ni-Cd batteries. The study demonstrates the applicability of the present hydrometallurgical approach for the treatment of hazardous waste, the spent Ni-Cd batteries.

Microbial processing of apatite rich low grade Indian uranium ore in bioreactor.

Bioreactor leaching using enriched culture of Acidithiobacillus ferrooxidans and Leptosprillium ferrooxidans was investigated for the apatite rich Indian (Narwapahar) uranium ore. Bioreactor leaching of Narwapahar ore of <45 µm size at pH 2.0 and 10% (w/v) PD using 10% (v/v) inoculum of the bacterium at 35 °C (A. ferrooxidans) and 40 °C (L. ferrooxidans), solubilised 57% and 63% uranium in 5 days, respectively; the E(SCE) values being 561 and 588 mV. Leaching kinetics improved so much so that ~83% uranium was recovered in just 10h with 10% inoculum of A. ferrooxidans containing biogenic Fe(3+); at 20% PD uranium recovery rose to 87%. Role of temperature (25-40 °C) was noticed with 90.3% uranium bioleaching in 10h at 40 °C with L. ferrooxidans as against 77% leaching with A. ferrooxidans at pH 2.0, 40 °C and 20% (w/v) PD.

Chemical and microbial remediation of hexavalent chromium from contaminated soil and mining/metallurgical solid waste: a review.

Chromium is a highly toxic non-essential metal for microorganisms and plants, and its occurrence is rare in nature. Lower to higher chromium containing effluents and solid wastes released by activities such as mining, metal plating, wood preservation, ink manufacture, dyes, pigments, glass and ceramics, tanning and textile industries, and corrosion inhibitors in cooling water, induce pollution and may cause major health hazards. Besides, natural processes (weathering and biochemical) also contribute to the mobility of chromium which enters in to the soil affecting the plant growth and metabolic functions of the living species. Generally, chemical processes are used for Cr- remediation. However, with the inference derived from the diverse Cr-resistance mechanism displayed by microorganisms and the plants including biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux, bioremediation is emerging as a potential tool to address the problem of Cr(VI) pollution. This review focuses on the chemistry of chromium, its use, and toxicity and mobility in soil, while assessing its concentration in effluents/wastes which becomes the source of pollution. In order to conserve the environment and resources, the chemical/biological remediation processes for Cr(VI) and their efficiency have been summarised in some detail. The interaction of chromium with various microbial/bacterial strains isolated and their reduction capacity towards Cr(VI) are also discussed.

Characterizing toxic Cr(VI) contamination in chromite mine overburden dump and its bacterial remediation.

Cr(VI) generated due to natural oxidation of chromite mineral present in chromite mine overburden (COB) dumps of Sukinda, India, has been characterized by different physico-chemical methods. The Cr(VI) was found to be associated with goethite matrix at a contamination level of 500 mg Cr(VI)kg(-1) of COB. Bacillus sp. isolated from the overburden sample exhibiting high tolerance to the hexavalent chromium, was used for the remediation of Cr(VI) in the overburden. The process was optimized while varying the parameters such as pH (2-9), pulp density (10-60%) and temperature (25-40 °C). Optimal reduction of more than 98% of Cr(VI) in the COB sample was achieved in 16 h at pH∼7.0 and 60% pulp density with the Bacillus sp. (4.05 × 10(7)cells mL(-1)) in absence of media. The exponential rate equation yielded rate constant value of 2.14 × 10(-1)h(-1) at 60% pulp density. The mode of bio-reduction of Cr(VI) in the overburden sample was established by FT-IR, XRD, EPMA and SEM-EDS studies.

Understanding the burden of disease in Nepal: a call for local evidence.

The burden of disease, most commonly expressed in terms of Disability-Adjusted Life Years, has become a crucial component in decision making processes within the health sector. In Nepal, however, burden of disease estimates are scarce and lack representativeness. To improve our understanding of the burden of disease in Nepal and thereby increase the efficiency of health policies, there is an urgent need to strengthen the local evidence base. All relevant stakeholders should therefore collaborate to generate new data, improve existing data generation mechanisms, make generated data available, and optimize the use of available data.

Synthesis of zinc-based nanomaterials: a biological perspective.

Nanoparticles are the materials characterised by dimensions of the order of 100 nm or less. They exhibit a high surface/volume ratio leading to different properties very different from those of the bulk materials. The development of uniform nanoparticles has been intensively pursued because of their technological and fundamental scientific importance. A number of chemical methods are available and are extensively used, but these are often energy intensive and use toxic chemicals. An alternative approach for the synthesis of uniform nanoparticles is the biological route that occurs at ambient temperature, pressure and at neutral pH. The main aim of this review is to enlist and compare various methods of synthesis of zinc-based nanoparticles with emphasis on the biological method.