Visceral leishmaniasis in southeastern Nepal: a cross-sectional survey on Leishmania donovani infection and its risk factors.

OBJECTIVE: To document the frequency of Leishmania donovani infection at community level in a highly endemic region in southeastern Nepal, and to assess socioeconomic and environmental risk factors. METHODS: A random cross-sectional population survey was held in two visceral leishmaniasis (VL) foci in Morang District in April to May 2003, enrolling individuals 2 years or older and residing in the endemic area for at least 12 months. Leishmania infection was defined as a direct agglutination test (DAT) titre equal to or higher than 1:3200. Risk factors were identified by logistic regression. RESULTS: The direct agglutination test was positive in 7.5% (95% CI: 5.1-10.8) and the leishmanin skin test (LST) in 13.2% (95% CI: 9.9-17.2) of the 373 study participants. No case of current kala-azar was found, but 5.1 % (95% CI: 3.1-7.8) reported having suffered from VL. Independent risk factors for Leishmania infection were proximity of the house to ponds [odds ratio (OR) 3.7, 95% CI: 1.6-8.5], family size (OR 4.4, 95% CI: 1.6-12.6), age > or =15 years (OR 5.5, 95% CI: 1.2-25.0) and house constructed in mud (OR 3.0, 95% CI: 1.1-7.6). Bednets, not impregnated and in poor condition, were used by 95.2% (95% CI: 92.3-97.0) of the population, but did not show any protective effect. CONCLUSION: This study shows that there is a serious problem of transmission of VL in this area of Nepal. The risk factors identified are linked with the socioeconomic level and the environment. The population would benefit from a community intervention to improve the environmental and housing conditions in the villages.

Field validity, reproducibility and feasibility of diagnostic tests for visceral leishmaniasis in rural Nepal.

OBJECTIVES: To assess the field accuracy, reproducibility and feasibility of the formol gel test (FGT), the urine latex agglutination test (KAtex) and a rK39 antigen-based dipstick for the diagnosis of visceral leishmaniasis (VL) in rural Nepal. METHOD: Patients with clinical suspicion of VL were recruited at Rangeli District Hospital (DH), a 15-bed government hospital located in south-eastern Nepal. FGT, KAtex and rK39 dipstick tests were performed on site and later repeated at a reference kala-azar diagnostic laboratory to assess reproducibility. Diagnosis of VL was confirmed by either a positive bone marrow aspirate examination or a positive direct agglutination test (DAT titre > or = 1:3200) in patients who later responded to anti-leishmanial therapy. RESULTS: Of 155 patients initially recruited, 142 (85 with VL and 57 with another diagnosis) were included in the study. The sensitivity of the rK39 dipstick [89%; 95% confidence interval (CI): 81-94] was significantly higher than that of the KAtex (57%; 95% CI: 46-67) and the FGT (52%; 95% CI: 41-62). All three tests had a specificity of at least 90%. Agreement was higher for the rK39 dipstick (kappa = 0.87) than for the FGT (0.68) and the KAtex (0.43). All tests required < or = 20 min of actual work and < or = 40 min to obtain the results. CONCLUSION: The rK39 dipstick was easy to do, more accurate and reproducible than other rapid diagnostic tests for VL in a DH of rural Nepal. It should be integrated into the field diagnostic algorithm of VL in this region and mechanisms to secure its availability should be found.

A new PCR-ELISA for diagnosis of visceral leishmaniasis in blood of HIV-negative subjects.

The PCR-ELISA represents a promising advance for diagnosis of visceral leishmaniasis (VL) in blood samples. However, the method has been validated mostly with HIV-positive patients who are known to have high levels of parasitaemia. We developed a new PCR-ELISA assay for specific detection of Leishmania in patients' blood and validated it in Nepalese subjects with clinically suspected VL, almost all of whom were HIV-negative. For blood samples, PCR-ELISA was more sensitive (83.9%) than conventional PCR (73.2%), and demonstrated 100% and 87.2% specificity when using healthy controls who had never travelled to a VL-endemic area and controls from a VL-endemic area as references, respectively. We have demonstrated the ability of PCR-ELISA to detect parasites in blood of HIV-negative patients. The method could be used for epidemiological as well as clinical purposes, as it reduces the need for traumatic bone marrow sampling and risky spleen aspiration.

Impact of snake bites and determinants of fatal outcomes in southeastern Nepal.

Current available data on snake bites in Nepal are based solely on hospital statistics. This community-based study aimed at evaluating the impact of snake bites and determining the risk factors associated with a fatal outcome in southeastern Nepal. A total of 1,817 households, selected by a random proportionate sampling method, were visited by trained field workers in five villages. Extensive data from snake bite victims during the 14 previous months were recorded and analyzed. One hundred forty-three snake bites including 75 bites with signs of envenoming were reported (annual incidence = 1,162/100,000 and 604/100,000, respectively), resulting in 20 deaths (annual mortality rate = 162/100,000). Characteristics of krait bites such as bites occurring inside the house, while resting, and between midnight and 6:00 am were all factors associated with an increased risk of death, as were an initial consultation with a traditional healer, a long delay before transport, and a lack of available transport. An initial transfer to a specialized treatment center and transport by motorcycle were strong protective factors. Among the 123 survivors, wounds required dressing and surgery in 30 (24%) and 10 (8%) victims, respectively, the mean working incapacity period was 15 days, and the mean out-of-pocket expense was 69 U.S. dollars. Snake bite is a major but neglected public health problem in southeastern Nepal. Public health interventions should focus on improving victims' rapid access to anti-snake venom serum by promoting immediate and fast transport to adequate treatment centers, particularly for bites occurring at night.

A comparative study of the effectiveness of diagnostic tests for visceral leishmaniasis.

We compared the validity of pancytopenia, the formol-gel test (FGT), the indirect fluorescence antibody test (IFAT), the direct agglutination test (DAT), and the rK39 dipstick test as diagnostic criteria for visceral leishmaniasis (VL) in Nepal. Between September 2000 and January 2002, 310 clinical suspects had a bone marrow aspirate, and if negative, a spleen aspirate smear examined for Leishmania donovani. Sensitivity and specificity of all tests were determined compared with parasitology and by latent class analysis (LCA). Compared with parasitology, the sensitivities of the other tests were as follows: pancytopenia = 16.3% (95% confidence interval [CI] = 11.3-22.5%), FGT = 39.9% (95% CI = 32.7-47.4%), IFAT = 28.4% (95% CI = 22.0-35.5%), DAT = 95.1% (95% CI = 90.8-97.7%), and the rK39 dipstick test = 87.4% (95% CI = 81.7-91.9%). Sensitivity estimates obtained by LCA were similar, but specificity estimates were substantially higher (DAT = 93.7% versus 77.8%; rK39 dipstick test = 93.1% versus 77.0%). The DAT or the rK39 dipstick test can replace parasitology as the basis of a decision to treat VL in Nepalese peripheral health services.

Snakebite-reappraisal of the situation in Eastern Nepal.

Four thousand and seventy eight cases of snakebite, occurring between January and December 2000, were analysed for clinical and epidemiological features. Cases of about 379 had features of envenoming and 81 died. All the victims with systemic envenoming had neurotoxicity. No case with coagulopathy was recorded. Snakebite was more frequent between the ages of 10 and 40 years (76%) and in males (73%). The majority (80%) of the snakebites were observed during the monsoon. Seventy percent of the bites with clinical features of envenoming occurred between 1400 and 2200 h. Five thousand eight hundred and fifty nine vials of polyvalent antisnake venom were used. Case fatality rate varied in the ten centres surveyed. It was as low as 3% in some to as high as 58% in others. Overall death rate among all snakebite cases was 2%.

Measuring the burden of ocular morbidity.

This hospital-based study highlights the spectrum of eye ailments in 35,273 patients who attended the Department of Ophthalmology at the B P Koirala Institute of Health Sciences, Eastern Nepal, during a 5-year period with varied clinical diagnosis. The attendance each year showed a progressive increase with a male preponderance. More than 13% of the patients were children. Cataract was the most common problem for which patients needed ophthalmic advice; diabetic and hypertensive retinopathy were frequent occurrences and infection was a common problem. Over 21% of the eyes examined had a refractive error: as high as 2.54% were amyblyopic caused by non-correction of refractive errors. Allergic conjunctivitis was frequently encountered. As shown by the magnitude of the problem, the existing eye care facilities must be enhanced and new strategies developed.

Krait bite requiring high dose antivenom: a case report.

Anti snake venom (ASV) is the most specific therapy available for treatment of snakebite envenomation. The ASV available in Nepal are polyvalent ASV produced in India and are effective against envenomation by cobra and krait, the two most common species found in Eastern Nepal. Neurotoxic signs respond slowly and unconvincingly and continuous absorption of venom may cause recurrent neurotoxicity. Therefore, close observation and continuous administration of ASV is essential to save the victim. We report a case of neurotoxic envenomation due to bite by common krait (Bangarus caeruleus). The victim required very high dose of polyvalent ASV for reversal of neurological manifestations.

Visceral leishmaniasis in two cases of leukemia.

Two cases of visceral leishmaniasis (VL), one in a 51-year-old man with accelerated-phase chronic myeloid leukemia and another in a 35-year-old woman with acute myeloblastic leukemia, are reported. Incidental finding of Leishman-Donovan (LD) bodies in patients with leukemia highlights VL as a potent opportunistic infection in immunosuppressed patients.