Therapeutic efficacy of antimalarial drugs along the eastern Indo-Nepal border: a cross-border collaborative study.

This collaborative cross-border study was performed to determine the therapeutic efficacy of antimalarial drugs used by the National Programmes for falciparum malaria along the eastern Indo-Nepal border where there is unregulated population movement across the border. The study was conducted at sites in Jhapa District, Nepal and Darjeeling District, India. The study was conducted from August 2003 to February 2004, following the WHO 28 day treatment protocol. The efficacy of chloroquine was tested in India among 91 subjects and of sulfadoxine-pyrimethamine in Nepal among 107 subjects with laboratory-confirmed Plasmodium falciparum malaria. Of the 102 subjects who completed the study in Nepal, there were 21 (20.6%) treatment failures comprising 7 (6.9%) early treatment failures (ETF) and 14 (14.7%) late treatment failures (LTF) (5 late clinical failures [LCF] and 9 late parasitological failures [LPF]). Of the 89 subjects who completed the study in India, there were 46 (51.7%) treatment failures comprising 7 (7.9%) ETFs and 39 (43.8%) LTFs (13 LCFs and 26 LPFs). Based on WHO guidelines both countries need to review their drug policy urgently and make appropriate changes, taking into account aspects of cross-border collaboration in the control of drug-resistant malaria.

Epidemiological situation of Japanese encephalitis in Nepal.

A human Japanese encephalitis (JE) case is considered to have elevated temperature (over 380 C) along with altered consciousness or unconsciousness and is generally confirmed serologically by finding of specific anti-JE IgM in the cerebro spinal fluid. No specific treatment for JE is available. Only supportive treatment like meticulous nursing care, introduction of Ryle's tube if the patient is unconscious, dextrose solution if dehydration is present, manitol injection in case of raised cranial temperature and diazepam in case of convulsion. Intra venous fluids, indwelling catheter in conscious patient and corticosteroids unless indicated should be avoided. Pigs, wading birds and ducks have been incriminated as important vertebrate amplifying hosts for JE virus due to viremia in them. Man along with bovines, ovines and caprines is involved in transmission cycle as accidental hosts and plays no role in perpetuating the virus due to the lack of viremia in them. The species Cx tritaeniorhyncus is suspected to be the principal vector of JE in Nepal as the species is abundantly found in the rice-field ecosystem of the endemic areas during the transmission season and JE virus isolates have been obtained from a pool of Cx tritaeniorhyncus females. Mosquito vector become infective 14 days after acquiring the JR virus from the viremic host. The disease was first recorded in Nepal in 1978 as an epidemic in Rupandehi district of the Western Development Region (WDR) and Morang of the Eastern Region (EDR). At present the disease is endemic in 24 districts. Although JE as found endemic mainly in tropical climate areas, existence and proliferation of encephalitis causing viruses in temperate and cold climates of hills and valleys are possible. Total of 26,667 cases and 5,381 deaths have been reported with average case fatality rate of 20.2% in an aggregate since 1978. More than 50% of morbidity and 60% mortality occur in the age group below 15 years. Upsurge of cases take place after the rainy season (monsoon). Cases start to appear in the month of April - May and reach its peak during late August to early September and start to decline from October. There are four designated referral laboratories, namely National Public Health Laboratory (Teku), Vector Borne Diseases Research and Training Center (Hetauda), B.P. Koirala Institute of Medical Sciences (Dharan) and JE Laboratory (Nepalgunj), for confirmatory diagnosis of JE. For prevention of JE infection; chemical and biological control of vectors including environmental management at breeding sites are necessary. Segregate pigs from humans habitation. Wear long sleeved clothes and trousers and use repellent and bed net to avoid exposure to mosquitos. For the prevention of the disease in humans, safe and efficacious vaccines are available. Therefore immunize population at risk against JE. Immunize pigs at the surroundings against JE. 225,000 doses of live attenuated SA-14-14.2 JE vaccine were received in donation from Boran Pharmaceuticals, South Korea for the first time in Nepal. Altogether 224,000 children aged between 1 to 15 years were vaccinated in Banke, Bardiya and Kailali districts during 1999. From China also, 2,000,000 doses of inactivated vaccine were received in 2000 and a total of 481,421 children aged between 6m to 10 yrs were protected from JE during 2001/2002. Ministry of Agriculture, Department of Livestock Services has vaccinated around 200,000 pigs against JE in terai zone during February 2001.

Efficacy of single-dose SA 14-14-2 vaccine against Japanese encephalitis: a case control study.

BACKGROUND: In China, since 1989, an estimated 120 million children have been immunised with the SA 14-14-2 live-attenuated Japanese encephalitis (JE) vaccine at ages 1, 2, and 6 years. A case-control study of licensed vaccine found two doses to be 98% effective. Subsequently, researchers found that single-dose vaccine efficacy was high; we aimed to confirm this result. METHODS: During July 11-24, 1999, 160000 doses of JE vaccine were given to children aged 1-15 years, resident in three districts of Nepal. Several cases of JE were admitted to hospital from early August. We obtained names and addresses of cases with serological evidence of a recent infection from Bheri Zonal Hospital, Nepalgunj. We did a matched case-control study and calculated the odds ratio of vaccination among JE cases and age-sex matched village controls. FINDINGS: 20 children, aged 1-15 years, were identified whose illness conformed with the JE case definition and were resident in villages receiving the vaccine. None of 20 JE cases had received JE vaccine compared with 326 of 557 age-sex matched village controls. The efficacy of a single dose of JE vaccine was 99.3% (CI 94.9-100%). INTERPRETATION: A single dose of JE vaccine is highly efficacious in preventing Japanese encephalitis when administered only days or weeks before exposure to infection.

Use of the recombinant K39 dipstick test and the direct agglutination test in a setting endemic for visceral leishmaniasis in Nepal.

We evaluated the field use of two serologic tests for visceral leishmaniasis (VL), the direct agglutination test (DAT) and rK39 dipstick test, in the context of a case-control study. Most VL cases in Nepal are currently diagnosed on clinical grounds and with relatively non-specific tests such as the formol-gel test. Among 14 newly diagnosed VL patients with bone-marrow slides confirmed positive in two independent laboratories, the sensitivity of both tests was 100%. Among 113 controls with no personal or household history of VL, the specificity of the rK39 was 100% while that of the DAT was 93%. The rK39 was less expensive than DAT, and has the advantages of ease of use and obtaining results within minutes. The wider use of the rK39 dipstick test could improve the specificity of VL diagnosis in Nepal.

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.