Viral etiologies of acute respiratory infections among hospitalized Vietnamese children in Ho Chi Minh City, 2004-2008.

Background: The dominant viral etiologies responsible for acute respiratory infections (ARIs) are poorly understood, particularly among hospitalized children in resource-limited tropical countries where morbidity and mortality caused by ARIs are highest. Improved etiological insight is needed to improve clinical management and prevention.

Objectives: We conducted a three-year prospective descriptive study of severe respiratory illness among children from 2 months to 13 years of age within the largest referral hospital for infectious diseases in southern Vietnam.

Random PCR and ultracentrifugation increases sensitivity and throughput of VIDISCA for screening of pathogens in clinical specimens.

Introduction: Virus discovery based on cDNA-AFLP (VIDISCA) is a sequence-independent virus discovery method that was recently developed and successfully used to characterize unknown viruses in cell cultures. Its applicability, however, is limited by its low sensitivity.

Methodology: We evaluated whether the introduction of prior amplification of target sequences by random PCR (rPCR) increases the sensitivity of this method to improve its use on clinical specimens.

Viral etiology of encephalitis in children in southern Vietnam: results of a one-year prospective descriptive study.

Background: Acute encephalitis is an important and severe disease in children in Vietnam. However, little is known about the etiology while such knowledge is essential for optimal prevention and treatment. To identify viral causes of encephalitis, in 2004 we conducted a one-year descriptive study at Children's Hospital Number One, a referral hospital for children in southern Vietnam including Ho Chi Minh City.

A real-time RT-PCR for detection of clade 1 and 2 H5N1 influenza A virus using locked nucleic acid (LNA) TaqMan probes.

Background: The emergence and co-circulation of two different clades (clade 1 and 2) of H5N1 influenza viruses in Vietnam necessitates the availability of a diagnostic assay that can detect both variants.

Results: We developed a single real-time RT-PCR assay for detection of both clades of H5N1 viruses, directly from clinical specimens, using locked nucleic acid TaqMan probes. Primers and probe used in this assay were designed based on a highly conserved region in the HA gene of H5N1 viruses.

Prevalence of antibodies against avian influenza A (H5N1) virus among Cullers and poultry workers in Ho Chi Minh City, 2005.

Background: Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh City in 2004 and 2005.

Methodology/principal Findings: Single sera from 500 poultry workers and poultry cullers exposed to infected birds were tested for antibodies to avian influenza H5N1, using microneutralization assays and hemagglutination inhibition assay with horse blood.

Protective and enhancing HLA alleles, HLA-DRB1*0901 and HLA-A*24, for severe forms of dengue virus infection, dengue hemorrhagic fever and dengue shock syndrome.

Background: Dengue virus (DV) infection is one of the most important mosquito-borne diseases in the tropics. Recently, the severe forms, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), have become the leading cause of death among children in Southern Vietnam. Protective and/or pathogenic T cell immunity is supposed to be important in the pathogenesis of DHF and DSS.

Volume replacement in infants with dengue hemorrhagic fever/dengue shock syndrome.

Volume replacement was studied prospectively in 208 infants with dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). The mean volume of intravenous fluid used was 110.4 mL/kg administered over a mean period of 25.

Oseltamivir resistance during treatment of influenza A (H5N1) infection.

Influenza A (H5N1) virus with an amino acid substitution in neuraminidase conferring high-level resistance to oseltamivir was isolated from two of eight Vietnamese patients during oseltamivir treatment. Both patients died of influenza A (H5N1) virus infection, despite early initiation of treatment in one patient. Surviving patients had rapid declines in the viral load to undetectable levels during treatment.

Association between sex, nutritional status, severity of dengue hemorrhagic fever, and immune status in infants with dengue hemorrhagic fever.

The association between sex, nutritional status, and the severity of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), and immune status was investigated in 245 Vietnamese infants with predominantly primary infections with dengue virus. Male and female infants were at equal risk of developing DHF/DSS. However, infants of low height and weight for age were under-represented among DHF/DSS cases compared with 533 healthy baby clinic infant controls.

Fatal avian influenza A (H5N1) in a child presenting with diarrhea followed by coma.

In southern Vietnam, a four-year-old boy presented with severe diarrhea, followed by seizures, coma, and death. The cerebrospinal fluid contained 1 white cell per cubic millimeter, normal glucose levels, and increased levels of protein (0.81 g per liter).

Dengue hemorrhagic fever in infants: a study of clinical and cytokine profiles.

A prospective study of clinical and cytokine profiles of 107 infants with dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS) was conducted. Fever, petechiae on the skin, and hepatomegaly were the most common clinical findings associated with DHF/DSS in infants. DSS occurred in 20.