Diagnostic methods of malaria in Eastern Nepal: a comparative study of traditional and two rapid diagnostic tests

This study compared the diagnostic accuracy of Quantitative Buffy Coat (QBC) a fluorescent microscopy test and OptiMAL, an immunochromatographic dip stick test against conventional microscopy for the detection of malaria at a tertiary teaching hospital situated in Eastern Nepal. 100 clinically suspected malaria patients with positive and negative parasitemia were assessed under conventional microscopy. The blood samples withdrawn from these subjects were further evaluated by the QBC Method and OptiMAL dipstick test. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of QBC and OptiMAL tests as compared with microscopy were 100%, 100%, 100%, 100%, 1 and 96%, 100%, 100%, 96.15% and 0.98 respectively. In Nepal, thick and thin blood smears remain the gold standard for malaria species diagnosis in routine diagnostic laboratories. In this study the efficacy of newer malaria rapid diagnostic tests (RDT) surpassed the diagnostic efficacy of clinical microscopy and hence these RDT's will have a greater role in clinical practice. The cost of QBC technique may impose limitations on its use in Nepal but the OptiMAL test is likely to play an important part in urgent malaria diagnosis.

Malarial nephropathy in a tertiary care setup--an observational study

Malaria is endemic in Nepal. Its poor outcome is associated with acute renal failure (ARF), hepatopathy and cerebral malaria. The clinical profiles, biochemical parameters and outcome of 25 patients of falciparum malaria diagnosed either by optimal test, peripheral blood smear (PBS) or Quantitative buffy coat (QBC) admitted in BP Koirala Institute of Health Sciences were studied. Majority of patients (84%) was from the age group 15-45 years. Mean age was 33 +/- 16 years. There were 16 males and 9 females. All had history of fever. Twenty patients were optimal positive, 9 positive in PBS and 12 were QBC positive for Plasmodium falciparum. Mean duration of fever was 13 +/- 9 days. Patients with renal or hepatic involvement presented earlier. Renal dysfunction (S. creatinine > 1.5 mg/dl) was present in 60%. Ten patients had ARF (S. creatinine > 3 mg/dl); five out of them were oliguric/anuric. S. creatinine in patients without renal dysfunction, with renal dysfunction but without renal replacement therapy (RRT) and who underwent RRT were 1.1 +/- 0.24, 3.98 +/- 1.9 and 4.53 +/- 1.72 mg/dL respectively. Serum creatinine of patients with and without hepatic dysfunction respectively were 3.26 +/- 1.98 and 1.26 +/- 0.48 mg/dL (p = 0.001 (CI 0.9-3.10)). Total bilirubin of > 2.5 mg/dl was present in 77%. Total bilirubin of patients with renal dysfunction who underwent and who did not undergo RRT were 10.3 vs. 3.76 mg/dL (p = 0.024 (CI 1.07-12.0)). Fourteen patients had cerebral malaria. Eight patients underwent RRT (hemodialysis or peritoneal dialysis). Six patients died. Five died within 48 hrs of presentation. Patients who had renal and/or hepatic dysfunction had increased morbidity and mortality.

The Indian and Nepalese programmes of indoor residual spraying for the elimination of visceral leishmaniasis: performance and effectiveness

Although, when applied under controlled conditions in India and Nepal, indoor residual spraying (IRS) has been found to reduce sandfly densities significantly, it is not known if IRS will be as effective when applied generally in these countries, via the national programmes for the elimination of visceral leishmaniasis. The potential benefits and limitations of national IRS programmes for the control of sandflies were therefore evaluated in the districts of Vaishali (in the Indian state of Bihar), Sarlahi (in Nepal) and Sunsari (also in Nepal). The use of technical guidelines, levels of knowledge and skills related to spraying operations, insecticide bio-availability on the sprayed surfaces, concentrations of the insecticide on the walls of sprayed houses, insecticide resistance, and the effectiveness of spraying, in terms of reducing sandfly densities within sprayed houses (compared with those found in unsprayed sentinel houses or control villages) were all explored. It was observed that IRS programme managers, at district and subdistrict levels in India and Nepal, used the relevant technical guidelines and were familiar with the procedures for IRS operation. The performance of the spraying activities, however, showed important deficiencies. The results of bio-assays and the chemical analysis of samples from sprayed walls indicated substandard spraying and suboptimal concentrations of insecticide on sprayed surfaces. This was particularly obvious at one of the Nepali study sites (Sunsari district), where no significant vector reduction was achieved. Sandfly resistance to the insecticide used in India (DDT) was widespread but the potential vectors in Nepal remained very susceptible towards a pyrethroid similar to the one used there. The overall short-term effectiveness of IRS was found to be satisfactory in two of the three study sites (in terms of reduction in the densities of the sandfly vectors). Unfortunately, the medium-term evaluation, conducted 5 months after spraying, was probably made invalid by flooding or lime plastering in the study areas. Preparation for, and the monitoring of, the IRS operations against sandfly populations in India and Nepal need to be improved.

Comparative study of kala-azar vector control measures in eastern Nepal

This study was conducted to explore the most effective vector control tool among indoor residual spraying (IRS), long lasting insecticidal nets (LLINs) and ecological vector management (EVM) as a part of the regional visceral leishmaniasis elimination initiative. Alpha-cypermethrin as IRS, PermaNet as LLINs and plastering the inner walls of houses with lime as EVM were the interventions. One baseline and three follow-up entomological surveys were carried out in all arms using CDC miniature light traps (LT) and mouth aspirators. Comparisons were made between intervention arms and control arms with pre-intervention and post-intervention vector densities. Light traps were found more efficient in the collection of Phlebotomus argentipes in comparison with aspiration. Vector densities were significantly low in both IRS arm (p=0.009 in LT and p<0.001 in aspirator collections) and LLIN arm (p=0.019 in LT and p=0.023 in aspirator collections) in comparison with control arm. However, in EVM arm, there was no significant difference in P. argentipes sand fly density in comparison with control arm (p=0.785) in LT collections in follow-up surveys. Hence, IRS was found most effective control measure to decrease vector density. LLINs were also found effective and can be considered as a promising alternative vector control tool in VL elimination initiative.

Population structure and geographical subdivision of the Leishmania major vector Phlebotomus papatasi as revealed by microsatellite variation

Multi-locus microsatellite typing (MLMT) has been employed to infer the population structure of Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) sandflies and assign individuals to populations. Phlebotomus papatasi sandflies were collected from 35 sites in 15 countries. A total of 188 P. papatasi individuals were typed using five microsatellite loci, resulting in 113 different genotypes. Unique microsatellite signatures were observed for some of the populations analysed. Comparable results were obtained when the data were analysed with Bayesian model and distance-based methods. Bayesian statistic-based analyses split the dataset into two distinct genetic clusters, A and B, with further substructuring within each. Population A consisted of five subpopulations representing large numbers of alleles that were correlated with the geographical origins of the sandflies. Cluster B comprised individuals collected in the Middle East and the northern Mediterranean area. The subpopulations B1 and B2 did not, however, show any further correlation to geographical origin. The genetic differentiation between subpopulations was supported by F statistics showing statistically significant (Bonferroni-corrected P < 0.005) values of 0.221 between B2 and B1 and 0.816 between A5 and A4. Identification of the genetic structure of P. papatasi populations is important for understanding the patterns of dispersal of this species and to developing strategies for sandfly control.

Use of rK39 for diagnosis of post kala-azar dermal leishmaniasis in Nepal

A recently developed nitrocellulose-based dipstick test, rK39, has been widely used for the diagnosis of kala-azar. In this study, we evaluated its use for the diagnosis of post kala-azar dermal leishmaniasis (PKDL). We also investigated the time taken by patients to develop PKDL after apparent cure of kala-azar (visceral leishmaniasis, VL) and the time taken by patients to come to the hospital after the appearance of symptoms of PKDL. A majority of patients developed the disease within three years after the apparent cure of kala-azar (KA). A majority of patients sought treatment within five years after the onset of PKDL. The amastigotes of Leishmania donovani bodies (LDBs) were demonstrated in 70, 20, and 20% of slit-skin smears (SSS) prepared, respectively, from nodular, papular, and macular forms. The presence of highest density (6+) LDBs in the SSS of 20% of nodular PKDL patients indicated that they may have acted as reservoir in the community. Other reservoirs are not known in Nepal. Only 8% cases were detected by aldehyde test. Although this test is obsolete it is still used in rural parts of Nepal. The dipstick (rK39) was 96% sensitive and 100% specific to diagnose PKDL. Its positive predictive value, negative predictive value, and diagnostic efficacy were 100, 91, and 97% respectively. Due to the advantage of cost compared with the direct agglutination test (DAT), and being easy to use and store in field conditions, rK39 is a good tool to diagnose PKDL in rural situations. All the PKDL patients were cured of the disease after treatment by SAG.

Treatment of visceral leishmaniasis in south-eastern Nepal: decreasing efficacy of sodium stibogluconate and need for a policy to limit further decline

Sodium stibogluconate (SSG) is the first-line therapy for visceral leishmaniasis (VL) in south-eastern Nepal. Recent studies from the neighbouring state of Bihar, India, have shown a dramatic fall in cure rates with treatment failure occurring in up to 65% of VL patients treated with SSG. A prospective study was conducted at a tertiary-level hospital located in south-eastern Nepal from July 1999 to January 2001. Parasitologically proven kala-azar patients with no previous history of treatment for VL were treated with SSG 20 mg/kg/d for 30 d which was extended to 40 d in those with persistent positive parasitology. Of the 110 patients who completed SSG therapy and were assessed at 1 and 6 months, definite cure was achieved in 99 patients (90%) and SSG failure occurred in 11 patients (10%). Except for the presence of hepatomegaly and a lower platelet count there was no clinical or laboratory baseline characteristic associated with treatment failure. A significantly lower cure rate (76%, P = 0.03) was observed in patients from the district of Saptari, which borders the antimony-resistant VL areas of Bihar. The efficacy of SSG as a first-line treatment for VL in south-eastern Nepal was still satisfactory, except for the patients living closer to the antimony-resistant VL areas of India. These findings indicate that the spread of resistance to antimonials is already taking place in Nepal and that a policy to control further spread should be urgently implemented.

Epidemiological study of kala-azar by direct agglutination test in two rural communities of eastern Nepal

We conducted a sero-epidemiological study of kala-azar in two endemic communities (Kasaini and Gidhaniya) situated in the Terai (plain) of eastern Nepal. Direct agglutination test (DAT) was used as a serological test for screening. Capillary blood samples were collected by filter paper method from 601 (96%) people of a total population of 628 in Kasaini and from 482 (94%) people of 515 in Gidhaniya. Positive DAT titres (1:2000) were found in 66 (6.09%) of 1083 sera tested. The male-female sero-prevalence ratio was 1.44:1 and the age group of 15 years and above was most affected. Among the bone marrow aspirates collected from 66 DAT seropositive cases, only 19 were positive for Leishmania donovani (LD bodies). Of the 47 DAT seropositive but LD bodies' negative cases, three were clinically active cases of kala-azar. Another nine developed clinical symptoms of kala-azar during 6 months follow-up and 23 were cases that had received prior treatment for kala-azar (within 1 year). The results of this study show the potential of the DAT on filter paper as a screening test for the surveillance of kala-azar at a community level.

Post kala-azar dermal leishmaniasis (PKDL): a first case report from Nepal

Post kala-azar dermal leishmaniasis (PKDL) is a non-ulcerative lesion of the skin caused by Leishmania donovani, which is usually seen after completion of treatment of the kala-azar. The condition is yet to be reported from Nepal. We document and report for the first time a case of PKDL in Nepal.

Post-kala-azar dermal leishmaniasis (PKDL): the first case report from Nepal

Post-kala-azar dermal leishmaniasis (PKDL) is condition characterized by non-ulcerative lesions of the skin caused by Leishmania donovani that is usually seen after the completion of treatment of kala-azar (visceral leishmaniasis). We document the first case report of PKDL in Nepal.

Prospective evaluation and comparison of the direct agglutination test and an rK39-antigen-based dipstick test for the diagnosis of suspected kala-azar in Nepal

The diagnosis of visceral leishmaniasis (kala-azar) remains difficult in rural endemic areas and practical and reliable tests are badly needed. Two serological tests, the Direct Agglutination Test (DAT) and an rK39-antigen-based dipstick test, were compared to parasitological diagnosis in a group of 184 patients presenting at a tertiary care centre in south-eastern Nepal with a history of fever > or = 14 days and splenomegaly; 139 patients had a parasitologically proven kala-azar and 45 patients had a negative parasitological work-up. The rK39 dipstick showed a sensitivity of 97% and a specificity of 71%. The DAT was up to 99% sensitive with a low cut-off titre (1:400) but its specificity did not exceed 82% even with a high cut-off titre (1:51 200). Both tests could be used for screening suspect patients in endemic areas. However, their use as confirmatory tests should be restricted to situations where the proportion of kala-azar among clinical suspect patients is high. The rK39 dipstick is cheaper and easier to use than the DAT and could be used widely provided that both its performance and production remain stable.

Lymphatic leishmaniasis--first case report from Nepal

We report a case of exclusive involvement of lymph node in leishmaniasis presenting as generalized lymphadenopathy. The diagnosis of lymphatic leishmaniasis was confirmed by the presence of Leishmania donovani body in fine needle aspiration cytology, positive direct agglutination test and anti-rK39 antibodies. The bone marrow aspiration was negative for Leishmania donovani body. This is the first case of lymphatic leishmaniasis reported from Nepal.

Post-kala-azar dermal leishmaniasis in Nepal

BACKGROUND

Post-kala-azar dermal leishmaniasis (PKDL) manifests as a skin eruption after healing of visceral leishmaniasis (VL), either spontaneously or as a result of treatment. This study was undertaken to describe the demographic, clinical, and histopathologic features of PKDL in Nepal.

METHODS

Demographic, clinical, microbiologic, and histopathologic features and response to treatment were studied in 22 patients with PKDL from April 1998 to March 2000.

RESULTS

PKDL accounted for 0.13% of all new dermatologic cases. There were 13 (59.1%) males and nine (40.9%) females. A past history of kala-azar was present in all but one patient. A family history of kala-azar was noted in eight (36.4%) patients. All patients presented with multiple types of lesion, except for two in whom only macular lesions were seen. Oral lesions in the form of nodules and plaques were seen in four patients. Generalized lymphadenopathy was present in five patients. Slit skin smears revealed Leishman-Donovan bodies (LDBs) in nine (40.9%) patients. In macular lesions, there was a sparse infiltrate of plasma cells, lymphocytes, or histiocytes in the upper dermis. There was a dense chronic inflammatory infiltrate comprising plasma cells, lymphocytes, histiocytes, and epithelioid cells in the entire dermis from papules, plaques, or nodules. Giemsa staining of biopsy specimens revealed LDBs in seven (38.9%) patients only. Fine needle aspiration from epitrochlear lymph nodes in two patients demonstrated LDBs. All patients responded well to treatment with minimal side-effects.

CONCLUSIONS

This study emphasizes the need to be aware of the possibility of cases of PKDL in endemic regions of leprosy, as the conditions may be difficult to distinguish clinically and histopathologically.

Factors associated with visceral leishmaniasis in Nepal: bed-net use is strongly protective

Since 1980, visceral leishmaniasis (VL) has reemerged as a public health problem in lowland Nepal. We conducted a case-control study to identify risk factors. In univariate analyses among 84 cases and 105 controls, protective factors included sleeping on a bed or cot (Odds ratio [OR] 0.44, P < 0.01) and sleeping under a bed-net regularly (OR 0.23, P < 0.001) or in the warm months (OR 0.20, P < 0.001). The bed-nets in use in this region were commercially available and untreated with insecticide. Ownership of a cow or buffalo was protective (OR 0.34, P < 0.001), whereas dampness observed in the mud floor of the house was a strong risk factor (OR 4.0, P < 0.001). In multivariable models, bed-net usage, cow or buffalo ownership, and damp floors were significantly associated with altered risk. A program to increase bed-net usage could therefore decrease the incidence of VL in Nepal.

A thirty day course of sodium stibogluconate for treatment of Kala-azar in Nepal

Twenty-seven cases of Kala-azar were treated with sodium stibogluconate at a dose of 20 mg/kg/day for 20 days (group A) and an equal number of cases were treated with the same dose but for a longer duration of 30 days (group B). Clinical and laboratory evaluation of these cases were carried out before and after therapy, during a follow up of cases every month, upto 6 months. Renal and liver function tests and electrocardiography were carried out of monitor any toxic effect of the drug during therapy. The cure rates of patients were 77.78% and 92.59% in group A and B cases respectively. Six and two patients in group A and B respectively were unresponsive to the treatment and showed relapse. Results of the study show that treatment of cases of Kala-azar with sodium stibogluconate in a dosage of 20 mg/kg/day for a longer period of 30 days is effective with a higher cure rate and minimum side effects, for treatment of cases of Kala-azar in this eastern part of Nepal, endemic for the disease.

Knowledge, attitudes, and practices about kala-azar and its sandfly vector in rural communities of Nepal

Reported are the results of a study of the knowledge, attitudes and practices (KAP) about kala-azar of the inhabitants of two villages (Titaria and Haraincha) situated in terai (plain) areas of Nepal. The villagers had poor knowledge about the transmission of kala-azar, with most villagers perceiving that mosquitos, instead of sandflies, were responsible for transmission of the infection. Most also failed to recognize the common symptoms of kala-azar. The majority of the respondents, 78.9% in Titaria and 48.4% in Haraincha, were aware that the condition can be treated, while fewer than 2% believed that it cannot be treated at all. More than 58% of villagers in Titaria and 36.8% in Haraincha used bednets. The residents of both villages were highly responsive to a programme to spray houses with insecticides. Fewer than 5% of respondents slept outdoors in farm outhouses and these individuals did not take any personal vector control measures. The results of this study show the importance of understanding the beliefs and practices of communities in the successful planning and implementation of kala-azar control activities in Nepal.

Model biological microemulsions: Part I--Phase behaviour and physicochemical properties of cholesteryl benzoate and sodium deoxycholate contained microemulsions

Phase behaviour and some physicochemical properties of cholesteryl benzoate-contained microemulsions of xylene and heptane with water using sodium deoxycholate and butan-1-ol as surfactant and co-surfactant respectively have been studied. While the microemulsion area of xylene depends insignificantly on the surfactant/co-surfactant ratio, that of heptane shows appreciable dependence. At surfactant + co-surfactant percentage of 50 or above, both the systems become oil continuous. With respect to time and temperature, the microemulsion systems have been found to be very stable. At low percentage of water, the xylene system is considerably viscous; that of heptane is less viscous but shows viscosity maximum at 45% water. Cholesterol in xylene has given greater viscosity than cholesteryl benzoate. The equivalent conductance of both the systems increase with increasing water content and the values are comparable. Unlike normal electrolyte solutions, the products of equivalent conductance and viscosity (the Walden product) sharply rise with increased water content, which suggests a special mechanism of conduction via 'channel' formation. The overall rigidity of the microemulsions is suggested by their lower specific volumes and compressibilities at all compositions. The excess specific volumes and excess compressibilities at different percentages of water are presented.

Urinary excretion of foreign antigens and RNA following primary and secondary injections of antigens

Two soluble antigens, BSA and KLH labeled with sulfanilate-(35)S, when injected intravenously into normal animals, were excreted in the urine to over 70% in 24 hr. Over the next 6 days, 25% more was excreted after which time only a trace could be detected. Much of the antigen remaining from the primary injection appeared in the urine following a secondary injection of the unlabeled protein carrier at 7 days after primary injection. The antigen material found in the urine was quite heterogeneous with respect to physical properties and much of it was associated with RNA material as shown by chromatographic analyses. The main difference between the labeled material released following the primary and secondary injection was the higher degree of association of antigen material with nucleotide material after secondary injection as compared with primary injection. Further study is needed to distinguish qualitative from quantitative changes of the components, antigen and nucleic acid, and also the nature of their association. Possible similarities were found for the RNA-antigen material released from tissue after secondary injection of unlabeled antigen, and the material that was isolated previously from liver.

Lipid composition of beef heart ventricle

The lipid class composition of beef heart ventricle was determined by a combination of diethylaminoethyl cellulose column chromatography and quantitative thin-layer chromatography. Percentages of the total lipid were: triglyceride, 43.6; cholesterol, 7.4; phosphatidyl choline, 22.8; phingomyelin, 4.0; phosphatidyl ethanolamine, 11.2; diphosphatidyl glycerol, 5.8; phosphatidyl serine, 1.2; phosphatidyl inositol, 3.0; phosphatidyl glycerol, 0.9; unsaturated hydrocarbon, 0.02; saturated hydrocarbon, 0.20. Nonlipid components represented 33.6% of the crude chloroform/methanol extracts.