Dengue virus infection during window period of consecutive outbreaks in Nepal and assessment of clinical parameters.

Nepal is an endemic country for dengue infection with rolling of every 3 year's clear cyclic outbreaks with exponential growth since 2019 outbreak and the virus gearing towards the non-foci temperate hill regions. However, the information regarding circulating serotype and genotype is not frequent. This research discusses on the clinical features, diagnosis, epidemiology, circulating serotype and genotype among 61 dengue suspected cases from different hospitals of Nepal during the window period 2017-2018 between the two outbreaks of 2016 and 2019. E-gene sequences from PCR positive samples were subjected to phylogenetic analysis under time to most recent common ancestor tree using Markov Chain Monte Carlo (MCMC) and BEAST v2.5.1. Both evolution and genotypes were determined based on the phylogenetic tree. Serotyping by Real-time PCR and Nested PCR showed the co-circulation of all the 3 serotypes of dengue in the year 2017 and only DENV-2 in 2018. Genotype V for DENV-1 and Cosmopolitan Genotype IVa for DENV-2 were detected. The detected Genotype V of DENV-1 in Terai was found close to Indian genotype while Cosmopolitan IVa of DENV-2 found spreading to geographically safe hilly region (now gripped to 9 districts) was close to South-East Asia. The genetic drift of DENV-2 is probably due to climate change and rapid viral evolution which could be a representative model for high altitude shift of the infection. Further, the increased primary infection indicates dengue venturing to new populations. Platelets count together with Aspartate transaminase and Aalanine transaminase could serve as important clinical markers to support clinical diagnosis. The study will support future dengue virology and epidemiology in Nepal.

Molecular phylogeny and distribution of dengue virus serotypes circulating in Nepal in 2017.

Dengue virus (DENV) infection is endemic in Nepal. Although infection rates are reported annually, little information is available about the circulating viral serotypes and genotypes. Here, we report the results of a multicentre cross-sectional study of DENV serotypes and genotypes sampled from individuals with suspected DENV infection in Nepal in 2017. Of the 50 patients sampled, 40 were serologically positive for DENV NS1, 29 for anti-DENV IgM, 21 for anti-DENV IgG and 14 were positive by qRT-PCR. The three serotypes DENV-1, 2 and 3 were detected and there was no DENV-4. Positive samples from serotyping were subjected to PCR amplification by envelope (E) gene specific primer and subsequent bidirectional sequencing of 5 samples. A time to most recent common ancestor phylogenetic tree was constructed from the new sequences obtained here together with historical DENV-1 and DENV-2 E gene sequences. The DENV-1 isolates (n = 2) from Nepalese individuals were closely related to Indian genotype V, whereas DENV-2 isolates (n = 3) belonged to Cosmopolitan genotype IVa, which is closely related to Indonesian isolates. Historical DENV isolates obtained between 2004 and 2013 clustered with Cosmopolitan IVb, Cosmopolitan IVa, and Asian II genotypes. All Nepalese isolates had different lineages with distinct ancestries. With the exception of isolates obtained in 2004, all other previously published isolates had ancestry to geographically distant part of the world. Molecular analysis revealed dengue epidemics to be comprised of different genotypes of serotype 1 and 2 raising concerns on potential role of different genotypes causing Dengue hemorrhagic fever. Also, our result indicated spread of DENV-2 in non-endemic area such as hilly region of Nepal which was considered to be free of dengue due to high altitude and cold weather.

Determination of CD4+ T- Lymphocytes in Healthy Children of Kathmandu.

BACKGROUND: The cluster differentiation (CD) of T-cell is the good marker for the immunological competence study. Nepal does not have a reference value for CD4+ T cell count and percentage for children, which severely limits the prospect of pediatric prognosis. METHODS: This cross-sectional study was conducted in Kathmandu valley where total 207 children of age 0-14 year age group were recruited in this study. We analyzed 50 cord blood and 157 peripheral blood samples in order to calculate the absolute count of CD4+ T lymphocyte using Fluorescence-activated cell sorting methodology. RESULTS: The reference range for absolute CD4+ T cell count was found to be 634-4040 cells/µL(mean1470; median: 1335 and 95% CI [1322-1617]) for male children and 491-2922 cells/µL (mean: 1443 median: 1326 and95% CI [1298-1588]) for the female children.We also observed elevated CD4 to the CD3 ratio in younger children (0.67 from cord blood Vs 0.53 from 10-14yr) compared to older ones. CONCLUSIONS: The observed CD4+ T cell counts among healthy children of Kathmandu highlights the gender differences skewed for male as well the need of defining specific reference values for other lymphocyte subsets as well in a country like Nepal which has a population with diverse genetic and socio-cultural parameters.

Microfilaria persistent foci during post MDA and the risk assessment of resurgence in India.

BACKGROUND: Pondicherry, a union territory in India, is an endemic district for bancroftian lymphatic filariasis transmitted by Culex quinquefasciatus where eight rounds of mass drug administration (MDA) were completed in 2011 (annually once from 2004 to 2011).The objectives of this study were to conduct a focal survey to assess microfilaria and antigen (Ag) prevalence among young adults and to assess vector infection and infectivity through a focal entomological survey. METHODS: Mosquitoes were collected using gravid traps in Sedurapet village of Pondicherry and dissected to enumerate W. bancrofti larvae stage first larval stage (L1), second larval stage (L2), and third larval stage (L3). Microfilarias (Mf) were detected using blood smears collected from inhabitants. RESULTS: A total of 360 individuals from 67 houses were enrolled in this study of which 290 (80.6%) were surveyed for the presence of Mf. Two Mf carriers were detected yielding an overall prevalence of 0.69% and two out of 85 (2.35%) were Mf antigen positive. Of the 2875 mosquitoes collected by gravid trap, Culex quinquefasciatus (93.9%) was the predominant species, followed by Anopheles subpictus (2.3%) and Culex vishnui (3.8%). The density of Cx. quinquefasciatus was 28.1 per trap-night. A total of 2429 Cx. quinquefasciatus were dissected and microscopically examined for abdominal conditions (gravid 85%, semi-gravid 9.4%, unfed 3.8%, and fully fed 1.9%) and filarial infection. One mosquito (infection rate equal to 0.04%) was found to harbor a second stage filarial larva, and none of the mosquitoes had infective stage larva. CONCLUSION: Our results show no reappearance of infection of lymphatic filariasis in Sedurapet village of Pondicherry after MDA, and thus, no further intervention is required in that area for possible resurgence of lymphatic filariasis. However, monitoring should be continued as part of post MDA activities until the endpoint of complete elimination is achieved. We demonstrated that xenomonitoring can be used to monitor the post MDA situation for possible risk of transmission to initiate control measures.

Profile of the 2016 dengue outbreak in Nepal.

OBJECTIVE: The objective of this study was to obtain clinical, virological and demographic data detailing the 2016 dengue outbreak in Nepal. RESULTS: Dengue disease was first reported in Nepal in 2004 and several major outbreaks have occurred since then, with a significant impact on public health. An outbreak of dengue fever occurred in Nepal during June to November 2016, with a peak number of cases reported in September. 1473 patients with laboratory confirmed DENV infections visited or were admitted to hospitals during this period. The most common clinical symptoms included fever, headache, joint pain and thrombocytopenia. Serotyping of 75 serum samples from patients having fever for less than 4 days was carried out with a dengue virus (DENV) serotype-specific RT-PCR strategy. Our results indicate that the dengue outbreak in Nepal during 2016 was caused predominantly, if not exclusively, by DENV-1, representing a shift in the prevailing serotype from DENV-2, the dominant serotype characterizing the 2013 dengue epidemic in Nepal. Hopefully, this report will assist Nepalese public health agencies in developing improved dengue-related programs including mosquito-vector control, DENV surveillance, and diagnosis and treatment of dengue fever patients, in order to reduce the impact of future dengue epidemics.

Emergence of dengue in Nepal.

Dengue virus is a major health problem in Nepal. The endogenous dengue appeared in 2006 in the country with reported outbreaks in 2010, 2013 and 2016. Eleven years vertical data show there were sporadic cases in all the years and mostly adults between 25 and 40 years of age were infected with dengue virus. Compared with primary infections, secondary infections were observed in relatively larger numbers during the period of 2008-2016. Most of the cases had symptoms of dengue fever; while 7 and 19 cases demonstrated dengue hemorrhagic fever/dengue shock syndrome in 2010 and 2013 respectively. The proportion of dengue hemorrhagic fever amongst all cases of dengue fever was 2.5:4.7% in 2010 and 2013. We found there is shift of serotype from dengue virus serotype-1 (DENV-1) in 2010, DENV-2 in 2013 and DENV-1 in 2016. We feel there is urgent need for better community, hospital and laboratory based surveillance system capable of monitoring the circulating dengue virus (DENV) serotypes in different districts of Nepal. With improvement in surveillance system and efficient management of cases, the case fatality rate due to severe dengue can be reduced.

Epidemiological Profile and Risk Factors for Acquiring HBV and/or HCV in HIV-Infected Population Groups in Nepal.

HBV and HCV infections are widespread among the HIV-infected individuals in Nepal. The goals of this study were to investigate the epidemiological profile and risk factors for acquiring HBV and/or HCV coinfection in disadvantaged HIV-positive population groups in Nepal. We conducted a retrospective study on blood samples from HIV-positive patients from the National Public Health Laboratory at Kathmandu to assay for HBsAg, HBeAg, and anti-HCV antibodies, HIV viral load, and CD4+ T cell count. Among 579 subjects, the prevalence of HIV-HBV, HIV-HCV, and HIV-HBV-HCV coinfections was 3.62%, 2.93%, and 0.34%, respectively. Multivariate regression analysis indicated that spouses of HIV-positive migrant labourers were at significant risk for coinfection with HBV infection, and an age of >40 years in HIV-infected individuals was identified as a significant risk factor for HCV coinfection. Overall our study indicates that disadvantaged population groups such as intravenous drug users, migrant workers and their spouses, female sex workers, and men who have sex with HIV-infected men are at a high and persistent risk of acquiring viral hepatitis. We conclude that Nepalese HIV patients should receive HBV and HCV diagnostic screening on a regular basis.

Prevalence and risk of hepatitis E virus infection in the HIV population of Nepal.

BACKGROUND: Infection with the hepatitis E virus (HEV) can cause acute hepatitis in endemic areas in immune-competent hosts, as well as chronic infection in immune-compromised subjects in non-endemic areas. Most studies assessing HEV infection in HIV-infected populations have been performed in developed countries that are usually affected by HEV genotype 3. The objective of this study is to measure the prevalence and risk of acquiring HEV among HIV-infected individuals in Nepal. METHODS: We prospectively evaluated 459 Human Immunodeficiency Virus (HIV)-positive individuals from Nepal, an endemic country for HEV, for seroprevalence of HEV and assessed risk factors associated with HEV infection. All individuals were on antiretroviral therapy and healthy blood donors were used as controls. RESULTS: We found a high prevalence of HEV IgG (39.4%) and HEV IgM (15.3%) in HIV-positive subjects when compared to healthy HIV-negative controls: 9.5% and 4.4%, respectively (OR: 6.17, 95% CI 4.42-8.61, p < 0.001 and OR: 3.7, 95% CI 2.35-5.92, p < 0.001, respectively). Individuals residing in the Kathmandu area showed a significantly higher HEV IgG seroprevalance compared to individuals residing outside of Kathmandu (76.8% vs 11.1%, OR: 30.33, 95% CI 18.02-51.04, p = 0.001). Mean CD4 counts, HIV viral load and presence of hepatitis B surface antigen correlated with higher HEV IgM rate, while presence of hepatitis C antibody correlated with higher rate of HEV IgG in serum. Overall, individuals with HEV IgM positivity had higher levels of alanine aminotransferase (ALT) than IgM negative subjects, suggesting active acute infection. However, no specific symptoms for hepatitis were identified. CONCLUSIONS: HIV-positive subjects living in Kathmandu are at higher risk of acquiring HEV infection as compared to the general population and to HIV-positive subjects living outside Kathmandu.

Dengue virus infection in a French traveller to the hilly region of Nepal in 2015: a case report.

BACKGROUND: Dengue viral infections are known to pose a significant risk during travel to tropical regions, but it is surprising to find dengue transmission in the hilly region of Nepal, which is over 1800mtr above sea level. CASE PRESENTATION: A 43-year-old Caucasian female traveler from France presented with fever and abdominal pain following a diarrheal illness while visiting the central hilly region of Nepal. Over the course of 9 days, she developed fever, body aches, and joint pain, with hemorrhagic manifestation. She was hospitalized in India and treated with supportive care, with daily monitoring of her platelets. An assessment by enzyme-linked immunosorbent assay showed that she was positive for dengue non-structural protein 1. Upon her return to France, dengue virus was confirmed by reverse transcriptase-polymerase chain reaction. CONCLUSION: The district where this dengue case was reported is in the hilly region of Nepal, neighboring the capital city Kathmandu. To the best of our knowledge, there has previously been no dengue cases reported from the district. This study is important because it aims to establish a potential region of dengue virus circulation not only in the tropics, but also in the subtropics as well, which in Nepal may exceed elevations of 1800mtr. This recent case report has raised alarm among concerned health personnel, researchers, and organizations that this infectious disease is now on the way to becoming established in a temperate climate.

First report of hepatitis E virus viremia in healthy blood donors from Nepal.

The aim of this study was to detect the prevalence of hepatitis E virus (HEV) in healthy blood donors so as to decipher the maintenance of (HEV) reservoir if any. Five hundred and eighty-one blood samples along with clinical information were collected from central blood bank, Kathmandu between February and March 2014. Samples were tested for hepatitis B virus surface antigen, anti-hepatitis C virus antibodies, anti-hepatitis A virus IgM, HEV antigen, HEV viral load and anti-HEV antibodies (IgM and IgG) by ELISA. Only those samples positive with anti-HEV IgM were tested for HEV RNA by reverse transcriptase nested PCR. Age adjusted prevalence of IgM anti HEV and IgG anti HEV were 3.6 and 8.3 % respectively. No significant difference in Median ALT levels was noted between HEV RNA positive and negative subjects. Sequence analysis of HEV shows all genotype belongs to genotype 1a. Phylogenetic analysis shows the virus has homology of 95 % with strain from India and Nepal outbreak of April 2014. This study sheds light on how inter epidemic reservoirs can be maintained in healthy population with asymptomatic cases. This raises an important question regarding nature of HEV as well as its tendency to circulate in blind sight and also cause periodic outbreaks in endemic setting like Kathmandu.

Evaluation of sensitivity and specificity of ELISA against Widal test for typhoid diagnosis in endemic population of Kathmandu.

BACKGROUND: Widal test, which has poor predictive outcomes in predominant typhoid population, is not standard enough to predict accurate diagnosis. This study aims to compare the diagnostic accuracy of Widal test to ELISA using blood culture as gold standard. METHODS: The blood samples were collected in Capital Hospital, Kathmandu, Nepal from febrile patients having ≥48 h fever in 3 years study period for blood culture, Widal test and IgG-IgM ELISA. RESULTS: Amongst 1371 febrile cases, 237 were Salmonella typhi positive to blood culture and 71.4 % typhoid fever patient were of 46-60 years old with male to female ratio of 2:1. Blood culture confirmed patients had ≥1:40 anti-TH and anti-TO titre in 45.56 % (n = 108) and 43.88 % (n = 104) patients respectively. The sensitivity and specificity of IgG (0.96 and 0.95) and IgM (0.95 and 0.94) at 95 % confidence level were significant compared to Widal anti-TH (0.72 and 0.58) and TO (0.80 and 0.51) test (p value, 0.038) at titre level ≥1:200. Further the PPV of Widal TH and TO (0.38 and 0.23) was low compared to IgG and IgM ELISA (0.78 and 0.77) (p value, 0.045). CONCLUSION: Widal test is not sensitive enough for an endemic setting like Nepal and thus should be either replaced with more accurate test like ELISA or follow an alternative diagnostic methodology.