Cholera continues to be an important cause of human infections, and outbreaks are often observed after natural disasters, such as the one following the 2010 earthquake in Haiti. Once the cholera outbreak was confirmed, rumors spread that the disease was brought to Haiti by a battalion of Nepalese soldiers serving as United Nations peacekeepers. This possible connection has never been confirmed. We used whole-genome sequence typing (WGST), pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility testing to characterize 24 recent Vibrio cholerae isolates from Nepal and evaluate the suggested epidemiological link with the Haitian outbreak. The isolates were obtained from 30 July to 1 November 2010 from five different districts in Nepal. We compared the 24 genomes to 10 previously sequenced V. cholerae isolates, including 3 from the Haitian outbreak (began July 2010). Antimicrobial susceptibility and PFGE patterns were consistent with an epidemiological link between the isolates from Nepal and Haiti. WGST showed that all 24 V. cholerae isolates from Nepal belonged to a single monophyletic group that also contained isolates from Bangladesh and Haiti. The Nepalese isolates were divided into four closely related clusters. One cluster contained three Nepalese isolates and three Haitian isolates that were almost identical, with only 1- or 2-bp differences. Results in this study are consistent with Nepal as the origin of the Haitian outbreak. This highlights how rapidly infectious diseases might be transmitted globally through international travel and how public health officials need advanced molecular tools along with standard epidemiological analyses to quickly determine the sources of outbreaks.

Background Shigella is a major cause of gastroenteritis especially in children. In developing countries, the incidence is frequent and results are often life threatening. Changing epidemiology and emerging antibiotic resistance warrants continuous monitoring of susceptibility. The present study highlights the changing epidemiology and drug resistance patterns of Shigella isolated at different hospitals of Nepal over a period of 13 years (Jan. 2003–Dec. 2015).MethodsThis study was carried out in 12 participating laboratories. Stool specimens received at respective laboratories were processed for isolation and identification of Shigella species and confirmed by serotyping at National Public Health Laboratory. Antimicrobial resistance patterns were determined by Kirby Baeur disc diffusion test.ResultsA total of 332 isolates were identified as Shigella species of which Shigella flexneri (50 %) was the predominant serotype. Shigella dysenteriae, Shigella sonnei, Shigella boydii, and untypable Shigella spp. respectively, accounted for 28.6, 27.54, 10.2, 4.5, and 6.6 % of the total number. Change in prevalent serotype is noted over the years. S. dysenteriae was the prevalent species in Nepal in 2003 and 2004, but since 2005, S. flexneri remained prevalent. Majority of the isolates were recovered from children aged 1–10 years and was statistically significant (p = 0.023) compared to the other age groups. High resistance among all Shigella species to the first-line drugs like ampicillin (88 %), cotrimoxazole (76 %), ciprofloxacin (39 %,) and nalidixic acid (80 %) was observed; 46.1 % of total isolates were multidrug resistant (MDR), and the most common MDR profile was ampicillin, nalidixic acid, and co-trimoxazole. Prevalence of MDR increased significantly in 2010 as compared to 2003. Only few Shigella isolates were resistant to ceftriaxone.ConclusionsThe study revealed S. flexneri as the predominant serogroup in Nepal. Children below 10 years were more prone to the disease. Nalidixic acid, ampicillin, co-trimoxazole, and ciprofloxacin should not be used empirically as the first-line drugs in treatment of shigellosis. Since the distribution of different species of Shigella and their antibiotic susceptibility profile may vary from one geographical location to another and may also change with time, continuous local monitoring of resistance patterns is necessary for appropriate antimicrobial therapy.

Background In Nepal, cases of Cholera occur annually either as sporadic or as outbreaks claiming the lives of many in rural areas. The present study is a laboratory based surveillance which aims to analyze the changing epidemiology and antimicrobial susceptibility trend of V. cholerae strains isolated or referred to National Public Health Laboratory (NPHL) over a period of 11 years (2006–2016). Methods Specimens of fresh stool /rectal swab either received at sentinel sites or NPHL were processed following standard microbiological techniques. Suspected colonies on selective medium were identified using routine biochemical tests and confirmed by serotyping. Antimicrobial susceptibility testing was performed following Kirby Baeur disc diffusion method. Results Of the 836 confirmed isolates, 87% (728/836) were V.cholerae O1 Ogawa,12% (103/836) were V.cholerae O1 Inaba and only 6 isolates were V.cholerae O1 Hikojima. In 2006 all the Vibrio isolates were of Inaba serotype, followed by all 3 serotypes during 2007.During 2008–2014 only Ogawa serotype was isolated while few cases of Inaba again surfaced in 2015. Resistance to ampicillin decreased from 93% in 2006 to 18% by 2010 and again raised to 100% by 2016.Cotrimoxazole resistance remained at constant range (77–100%).Nalidixic acid resistance was 100% since 2006.Ciprofloxacin and tetracycline resistance emerged in 2007, reached a peak during 2010–2012 and declined to 0 by 2016.Susceptibility to Furazolidone has re-emerged.63.6% of the isolates were Multi drug resistant. Conclusion With changing epidemiology and antibiogram of V.cholerae in Nepal, the present study reflects the importance of continuous monitoring, which could be used by policy makers and health professionals for better management of outbreaks. Decline in tetracycline and ciprofloxacin resistance along with emerging sensitivity to furazolidone shows that these drugs could make an effective comeback in future.

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The live attenuated Japanese encephalitis (JE) vaccine SA14-14-2 has been used in Nepal for catch-up campaigns and is now included in the routine immunisation schedule. Previous studies have shown good vaccine efficacy after one dose in districts with a high incidence of JE. The first well-documented dengue outbreak occurred in Nepal in 2006 with ongoing cases now thought to be secondary to migration from India. Previous infection with dengue virus (DENV) partially protects against JE and might also influence serum neutralising antibody titres against JEV. This study aimed to determine whether serum anti-JEV neutralisation titres are: 1. maintained over time since vaccination, 2. vary with historic local JE incidence, and 3. are associated with DENV neutralising antibody levels. We conducted a cross-sectional study in three districts of Nepal: Banke, Rupandehi and Udayapur. Udayapur district had been vaccinated against JE most recently (2009), but had been the focus of only one campaign, compared with two in Banke and three in Rupandehi. Participants answered a short questionnaire and serum was assayed for anti-JEV and anti-DENV IgM and IgG (by ELISA) and 50% plaque reduction neutralisation titres (PRNT 50 ) against JEV and DENV serotypes 1–4. A titre of ≥1:10 was considered seropositive to the respective virus. JEV neutralising antibody seroprevalence (PRNT 50 ≥ 1:10) was 81% in Banke and Rupandehi, but only 41% in Udayapur, despite this district being vaccinated more recently. Sensitivity of ELISA for both anti-JEV and anti-DENV antibodies was low compared with PRNT 50. DENV neutralising antibody correlated with the JEV PRNT 50 ≥1:10, though the effect was modest. IgM (indicating recent infection) against both viruses was detected in a small number of participants. We also show that DENV IgM is present in Nepali subjects who have not travelled to India, suggesting that DENV may have become established in Nepal. We therefore propose that further JE vaccine campaigns should be considered in Udayapur district, and similar areas that have had fewer vaccination campaigns.