Dengue Virus Serotypes 1 and 2 Responsible for Major Dengue Outbreaks in Nepal: Clinical, Laboratory, and Epidemiological Features

Abstract

Abstract.Dengue virus (DENV) is expanding toward previously nonendemic areas. DENV has recently been introduced in Nepal with limited information. We report the clinical features and serotype distribution of DENV in Nepal during the 2010 outbreaks. A total of 1,215 clinical dengue cases at two major hospitals of central and western Nepal were investigated. Demographic, clinical, and laboratory parameters were recorded. Serum specimens were tested for DENV by IgM/IgG enzyme-linked immunosorbent assays (ELISAs) and reverse transcription polymerase chain reaction (RT-PCR). We confirmed DENV infection in 403 (33%) patients from 12 districts with an estimated case fatality rate of 1.5%. DENV infection was more common in adults (87%) and urban settings (74%). We detected all four serotypes but DENV-1 and -2 were mainly responsible for major outbreaks (92%). Overall, 60% of all DENV infections were secondary and 17% were severe dengue; both being more frequent among the DENV-2 infections. Rash, bleeding, abdominal pain, hepatomegaly, elevated liver enzymes, and thrombocytopenia were significantly more common in severe dengue compared with nonsevere infections. We also confirmed the expansion of dengue to hill urban areas (DENV-1 and -2), including the capital Kathmandu (altitude, 1,300 m) though > 90% cases were from southern plains. Differential clinical and laboratory features probably help in clinical decisions. Multiple serotypes circulation and elevated secondary infections pose potential risk of severe outbreaks and deaths in the future. Therefore, a country with recent dengue introduction, like Nepal, urgently requires a systematic surveillance and appropriate control measures in place to respond to any disastrous outbreaks.

Study on clinical profile of dengue in a tertiary care hospital of Nepal

“…On analysis of seasonal variability, we found the number of dengue patients peaked in October and November. Similar variation was observed in other studies conducted in Nepal 11,16 , but studies conducted in China, India, Pakistan and Bangladesh found August and October to be peaked season for dengue. 5,6,11,[17][18][19]21 These observations might indicate that seasonal outbreaks in these countries are closely related and there might be consistent transmission of the disease among these countries.…”

“…These symptoms were also predominant in studies from Nepal 22 , India 17,18 Pakistan6, and Taiwan. 23 However another study conducted in Nepal 16 and in Pakistan, 19 fever with headache and nausea vomiting were the most predominant features. In addition to that, cough and anorexia were also the observed symptoms in our study which were also observed in other studies conducted in India and Pakistan.…”

“…Less than one-third of the patients had retro-orbital pain while abdominal pain and rash were less common presentation in our study in comparisons to other studies. 5,[16][17][18] Hemorrhagic manifestations or other complications were not observed in our patient. Thrombocytopenia, leucopenia and elevated liver enzymes (AST and ALT) were observed in our study, which were also mentioned in other studies.…”

“…Only a handful of studies have been conducted and most of them are limited to serological and demographical findings. [13][14][15][16] Limited data are available on clinical features, laboratory parameters and outcomes of patients with dengue from Nepal. Therefore, this retrospective study aimed to report the clinical features, laboratory parameters and management outcome in adult dengue patients admitted in medical ward and intensive care unit of Chitwan Medical College, Chitwan, Nepal.…”

Confirmation of local transmission of Orientia tsutsugamushi during scrub typhus outbreaks in Nepal

“…Nevertheless, we cannot overlook the serologically positive cases reported in 2004 and 2007 in Kathmandu valley [8,9] In Nepal, scrub typhus cases were reported nationwide (52 of 75 districts) in just three years since the disease may expand very rapidly as seen in other parts of the world [29,30]. In this study, the majority of cases were reported from lowland terai districts where other febrile illnesses including Japanese encephalitis (JE) [31,32], leptospirosis [33], and dengue [31,32] had been frequently reported. Even before the initiation of JE vaccination in Nepal, only onethird of the acute encephalitis syndrome (AES) cases were due to JE, which declined with immunization, however the AES still remains persistent clearly indicating other aetiologies of AES in the country.…”