BackgroundThere is little information about influenza disease among the Cambodian population. To better understand the dynamics of influenza in Cambodia, the Cambodian National Influenza Center (NIC) was established in August 2006. To continuously monitor influenza activity, a hospital based sentinel surveillance system for ILI (influenza like illness) with a weekly reporting and sampling scheme was established in five sites in 2006. In addition, hospital based surveillance of acute lower respiratory infection (ALRI) cases was established in 2 sites.MethodsThe sentinel sites collect weekly epidemiological data on ILI patients fulfilling the case definition, and take naso-pharyngeal specimens from a defined number of cases per week. The samples are tested in the Virology Unit at the Institut Pasteur in Phnom Penh. From each sample viral RNA was extracted and amplified by a multiplex RT-PCR detecting simultaneously influenza A and influenza B virus. Influenza A viruses were then subtyped and analyzed by hemagglutination inhibition assay. Samples collected by the ALRI system were tested with the same approach.ResultsFrom 2006 to 2008, influenza circulation was observed mainly from June to December, with a clear seasonal peak in October shown in the data from 2008.ConclusionInfluenza activity in Cambodia occurred during the rainy season, from June to December, and ended before the cool season (extending usually from December to February). Although Cambodia is a tropical country geographically located in the northern hemisphere, influenza activity has a southern hemisphere transmission pattern. Together with the antigenic analysis of the circulating strains, it is now possible to give better influenza vaccination recommendation for Cambodia.

Significance Metagenomic pathogen sequencing offers an unbiased approach to characterizing febrile illness. In resource-scarce settings with high biodiversity, it is critical to identify disease-causing pathogens in order to understand burden and to prioritize efforts for control. Here, metagenomic next-generation sequencing (mNGS) characterization of the pathogen landscape in Cambodia revealed diverse vector-borne and zoonotic pathogens irrespective of age and gender as risk factors. Identification of key pathogens led to changes in national program surveillance. This study is a “real world” example of the use of mNGS surveillance of febrile individuals, executed in-country, to identify outbreaks of vector-borne, zoonotic, and other emerging pathogens in a resource-scarce setting.

No abstract

A cohort of Japanese encephalitis (JE) survivors in Cambodia and Viet Nam were assessed at least 4 months after hospital discharge in order to understand the extent of disability after JE. We used a simple assessment tool which focuses on the impact on daily life. In total, 64 disability assessments were conducted: 38 in Cambodia and 26 in Viet Nam. In Cambodia, 4 (11%) children had severe sequelae, suggesting the children would likely be dependent, 15 (39%) had moderate sequelae and 17 (45%) had mild sequelae. In Viet Nam, two (8%) persons had severe sequelae, five (19%) had moderate sequelae and eight (31%) had mild sequelae. In many JE-endemic areas there are no multi-disciplinary teams with sophisticated equipment to assess patients after JE disease. This assessment tool can assist with patient management and generate data to support the need for programmes to prevent disease and improve outcomes for survivors.