Risk factors for the development of severe typhoid fever in Vietnam

Background Typhoid fever is a systemic infection caused by the bacterium Salmonella enterica serovar Typhi. Age, sex, prolonged duration of illness, and infection with an antimicrobial resistant organism have been proposed risk factors for the development of severe disease or fatality in typhoid fever. Methods We analysed clinical data from 581 patients consecutively admitted with culture confirmed typhoid fever to two hospitals in Vietnam during two periods in 1993–1995 and 1997–1999. These periods spanned a change in the antimicrobial resistance phenotypes of the infecting organisms i.e. fully susceptible to standard antimicrobials, resistance to chloramphenicol, ampicillin and trimethoprim-sulphamethoxazole (multidrug resistant, MDR), and intermediate susceptibility to ciprofloxacin (nalidixic acid resistant). Age, sex, duration of illness prior to admission, hospital location and the presence of MDR or intermediate ciprofloxacin susceptibility in the infecting organism were examined by logistic regression analysis to identify factors independently associated with severe typhoid at the time of hospital admission. Results The prevalence of severe typhoid was 15.5% (90/581) and included: gastrointestinal bleeding (43; 7.4%); hepatitis (29; 5.0%); encephalopathy (16; 2.8%); myocarditis (12; 2.1%); intestinal perforation (6; 1.0%); haemodynamic shock (5; 0.9%), and death (3; 0.5%). Severe disease was more common with increasing age, in those with a longer duration of illness and in patients infected with an organism exhibiting intermediate susceptibility to ciprofloxacin. Notably an MDR phenotype was not associated with severe disease. Severe disease was independently associated with infection with an organism with an intermediate susceptibility to ciprofloxacin (AOR 1.90; 95% CI 1.18-3.07; p = 0.009) and male sex (AOR 1.61 (1.00-2.57; p = 0.035). Conclusions In this group of patients hospitalised with typhoid fever infection with an organism with intermediate susceptibility to ciprofloxacin was independently associated with disease severity. During this period many patients were being treated with fluoroquinolones prior to hospital admission. Ciprofloxacin and ofloxacin should be used with caution in patients infected with S. Typhi that have intermediate susceptibility to ciprofloxacin

Central nervous system infection diagnosis by next-generation sequencing: a glimpse into the future?

Japanese encephalitis virus was detected by deep sequencing for the first time in urine of a 16-year-old boy with encephalitis. Seroconversion and polymerase chain reaction analysis confirmed the metagenomics finding. Urine is useful for diagnosis of flaviviral encephalitis, whereas deep sequencing can be a panpathogen assay for the diagnosis of life-threatening infectious diseases

Central nervous system infection diagnosis by next-generation sequencing: a glimpse into the future?

Japanese encephalitis virus was detected by deep sequencing for the first time in urine of a 16-year-old boy with encephalitis. Seroconversion and polymerase chain reaction analysis confirmed the metagenomics finding. Urine is useful for diagnosis of flaviviral encephalitis, whereas deep sequencing can be a panpathogen assay for the diagnosis of life-threatening infectious diseases

Novel mutation of SARS-CoV-2, Vietnam, July 2020

A cluster of severe acute respiratory syndrome coronavirus 2 infections in Danang, Vietnam, began July 25, 2020, and resulted in 551 confirmed cases and 35 deaths as of February 2021. We analyzed 26 sequences from this cluster and identified a novel shared mutation in nonstructural protein 9, suggesting a single introduction into Vietnam

Economic burden attributed to children presenting to hospitals with hand, foot, and mouth disease in Vietnam

BACKGROUND: Hand, foot, and mouth disease (HFMD) has become a major public health concern in the Asia-Pacific region. Knowledge of its economic burden is essential for policy makers in prioritizing the development and implementation of interventions. METHODS: A multi-hospital-based study was prospectively conducted at 3 major hospitals in Ho Chi Minh City, Vietnam, during 2016-2017. Data on direct and productivity costs were collected alongside clinical information and samples and demographic information from study participants. RESULTS: A total of 466 patients were enrolled. Two hundred three of 466 (43.6%) patients lived in Ho Chi Minh City, and 72/466 (15.5%) had severe HFMD. An enterovirus was identified in 74% of 466 patients, with EV-A71, CV-A6, CV-A10, and CV-A16 being the most common viruses identified (236/466, 50.6%). The mean economic burden per case was estimated at US$400.80 (95$353.80-$448.90), of which the total direct (medical) costs accounted for 69.7$90 761 749 (95% CI, $79 033 973-$103 009 756). CONCLUSIONS: Our findings are of public health significance because for the first time we demonstrate that HFMD causes a substantial economic burden in Vietnam, and although multivalent vaccines are required to control HFMD, effective EV-A71 vaccine could substantially reduce the burden posed by severe HFMD. The results will be helpful for health policy makers in prioritizing resources for the development and implementation of intervention strategies to reduce the burden of HFMD

Plans for nationwide serosurveillance network in Vietnam

In recent years, serosurveillance has gained momentum as a way of determining disease transmission and immunity in populations, particularly with respect to vaccine-preventable diseases. At the end of 2017, the Oxford University Clinical Research Unit and the National Institute of Hygiene and Epidemiology held a meeting in Vietnam with national policy makers, researchers, and international experts to discuss current seroepidemiologic projects in Vietnam and future needs and plans for nationwide serosurveillance. This report summarizes the meeting and the plans that were discussed to set up nationwide serosurveillance in Vietnam

Evaluation of an algorithm for integrated management of childhood illness in an area of Vietnam with dengue transmission

OBJECTIVES: To determine whether nurses, using the WHO/UNICEF algorithm for integrated management of childhood illness (IMCI), modified to include dengue infection, satisfactorily classified children in an area endemic for dengue haemorrhagic fever (DHF). METHODS: Nurses assessed and classified, using the modified IMCI algorithm, a systematic sample of 1250 children aged 2 months to 10 years (n = 1250) presenting to a paediatric hospital in Dong Nai Province, Vietnam. Their classification was compared with that of a paediatrician, blind to the result of the nurses' assessment, which could be modified in the light of simple investigations, e.g. dengue serology. RESULTS: In children aged 2-59 months (n = 859), the nurses were able to classify, using the modified chart, the presenting illness in >99% of children and found more than one classification in 70%. For the children with pneumonia, diarrhoea, dengue shock syndrome, severe DHF and severe disease requiring urgent admission, the nurse's classification was >60% sensitive and >85% specific compared with that of the paediatrician. For the nurse's classification of DHF the specificity was 50-55% for the children <5 years and in children with definitive dengue serology. Alterations in the DHF algorithm improved specificity at the expense of sensitivity. CONCLUSION: Using the IMCI chart, nurses classified appropriately many of the major clinical problems in sick children <5 years in southern Vietnam. However, further modifications will be required in the fever section, particularly for dengue. The impact of using the IMCI chart in peripheral health stations remains to be evaluated

Emerging coxsackievirus A6 causing hand, foot and mouth disease, Vietnam

Hand, foot and mouth disease (HFMD) is a major public health issue in Asia and has global pandemic potential. Coxsackievirus A6 (CV-A6) was detected in 514/2,230 (23%) of HFMD patients admitted to 3 major hospitals in southern Vietnam during 2011–2015. Of these patients, 93 (18%) had severe HFMD. Phylogenetic analysis of 98 genome sequences revealed they belonged to cluster A and had been circulating in Vietnam for 2 years before emergence. CV-A6 movement among localities within Vietnam occurred frequently, whereas viral movement across international borders appeared rare. Skyline plots identified fluctuations in the relative genetic diversity of CV-A6 corresponding to large CV-A6–associated HFMD outbreaks worldwide. These data show that CV-A6 is an emerging pathogen and emphasize the necessity of active surveillance and understanding the mechanisms that shape the pathogen evolution and emergence, which is essential for development and implementation of intervention strategies

High cure rates for HCV genotype 6 in advanced liver fibrosis with 12 weeks sofosbuvir and daclatasvir: The Vietnam SEARCH Study

Background Genotype 6 is the most genetically diverse lineage of hepatitis C virus (HCV), and predominates in Vietnam. It can be treated with sofosbuvir with daclatasvir (SOF/DCV), the lowest costing treatment combination globally. In regional guidelines, longer treatment durations of SOF/DCV (24 weeks) are recommended for cirrhotic individuals, compared with other pangenotypic regimens (12 weeks), based on sparse data. Early on-treatment virological response may offer means of reducing length and cost of therapy in patients with liver fibrosis. Methods In this prospective trial in Vietnam, genotype 6-infected adults with advanced liver fibrosis or compensated cirrhosis were treated with SOF/DCV. Day 14 viral load was used to guide duration of therapy: participants with viral load <500 IU/ml at day 14 were treated with 12 weeks of SOF/DCV and those ≥500 IU/ml received 24 weeks. Primary endpoint was sustained virological response. Findings Of 41 individuals with advanced fibrosis or compensated cirrhosis who commenced treatment, 51% had genotype 6a, 34% 6e. The remainder had 6h, 6k, 6l or 6o. 100% had viral load <500 IU/ml by day 14, meaning all received 12 weeks of SOF/DCV. 100% achieved SVR12 despite a high frequency of putative NS5A inhibitor resistance-associated substitutions (RAS) at baseline. Interpretation 12 weeks of SOF/DCV achieves excellent cure rates in this population. This data supports the removal of costly genotyping in countries where genotype 3 prevalence in <5%, in keeping with WHO guidelines. NS5A-resistance associated mutations in isolation, do not affect efficacy of SOF/DCV therapy. Wider evaluation of response-guided therapy is warranted