This is the first report for molecular epidemiology of DEN-4 viruses in Vietnam. At present, DEN-4 serotype can be classified into two genetically distinct types: genotypes I and II. In this study, phylogenetic analysis of DEN-4 viruses from Vietnam as well as previously published strains indicate that DEN-4 viruses could be genetically classified into more than 2 genotypes. Most recent Vietnamese DEN-4 strains (1998-2002) were clustered within a distinct genetic type, named genotype III, a newly recognized genetic type for DEN-4 viruses. In addition, two Vietnamese strains isolated in 1990 and 1997 also grouped separately forming another independent cluster in the tree, which we designated genotype IV. In this report present for the first time the existence of two new genotypes of DEN-4 in Vietnam. Evidence for local independent evolution and temporal correlation was observed.
Dengue ; Epidemiology, Genotype

Studying the susceptibility of Aedes aegypti to some insecticides in 22 places of 11 provinces and cities in 4 different regions of Vietnam. Results: Ae. aegypti mosquito was still susceptible to Malathion but resistant to DDT in most of studied places. Ae. aegypti was susceptible to insecticides of perythroid group (such as permethrine, lambda-cyhalothrine, deltamethrine, and alphamethrine) in many places in Northern and Central Vietnam, while it was resistant in Southern Vietnam and the Central Highlands. Ae. aegypti was also resistant highly and widely to etofenprox
Insecticides ; Mosquito Control ; chemistry

Haemophilus influenzae is one of the main pathogens of encephalitis in children less than 5 years old. The rate of ampicillin resistant strain is not high. No beta-lactamase-producing and ampicillin-resistant (BLNAR) isolates were found. The PFGE patterns of Hib isolates were highly divergent, but most could be classified into three groups (A, B and C). Hib isolates from the CSF of patients and from nasopharynges of household contacts showed the same PFGE patterns. This observation suggested that household contacts of patients are a possible reservoir of Hib.
Haemophilus influenzae type b ; Orf virus ; Diagnosis

In 2002, DHF viro-serological surveillance was started in 19 Southern provinces of Vietnam. 247 DEN virus strains (consist of 27 DEN-1, 99 DEN-2, 9 DEN-3 and 112 DEN-4) were isolated from 3318 blood samples. The predominant serotypes were DEN-4 (45.3%) and DEN-2 (40.1%). DEN-2 virus was more positively correlated with severe cases in comparison with other serotypes. However, high rates of virus isolation were obtained from DHF grade I-II patients (49%), and then from DF, viral infection and fever of unknown origin cases (40.1%). These should be main target subjects for the active surveillance of DHF. In addition, MAC-ELISA was done on 7498 DHF serum samples taken in Southern Vietnam with the average positive rate of 44.37%
Dengue ; epidemiology ; Laboratories

The decoloration of purified sera was achieved by using 0.1% caprylic acid solution with pH 4.2 at 56oC. The technique can shorten the duration of purification processes
tetanus antitoxin

A survey conducted on 15 consecutive lots of purified sera showed that SO2-4 content in hydrolyzed fluid as satisfying the requirement, then was quantified as small value in purified sera. However, among the lots of high SO2-4 content in purified sera (SAR 12,13, SAT 13,14), it was always lower than 0.15g/l. In comparing with the SO4 standard of China’s SAT;  1g/l, the SO4 content of our preparation was 7 times lower purified sera
BCG Vaccine ; Biology ; Vaccines

In the year 2001, the Arbo virus Laboratory had received Dengue hemorrhagic fever samples from 19 provincial center for Preventive Medicine to isolate virus. 83 dengue viruses of 4 type were detected. Among them, the two main germs were dengue 2 and dengue 4. Viruses were detected mainly in infected children with hemorrhagic fever of I-II degree. Dengue 2 was the causative agent of DHF of I-III degree with a higher number of cases than other serotypes. 4.046 sera samples was examined by Mac ELISA, among them 56.13% was (+). However in Ma-ELISA(+) regions, there is no effective methods for dengue control.
Dengue ; Dengue Hemorrhagic Fever ; Child ; epidemiology ; serum

Background: Streptococcus pneumonia (S.pneumoniae) is the main cause of acquired pneumonia in the community along with otitis media, sinusitis, septicemia and meningitis. Objectives: The study determined antimicrobial resistance and serotype distribution of Streptococcus pneumonia isolates from hospitalized children at Hai Phong Children's Hospital, Vietnam. Subjects and method: From June 2006 to September 2007, 80 pneumococccal isolates were tested for susceptibility to the 13 antibiotics and 84 pneumococcal isolates were serotyped. Results:Seventy-five percent of strains showed multi-drug resistance. Ninety percent of strains showed resistance to penicillin (48% intermediate and 42% fully resistant). In addition, 100% of isolates were resistant to cotrimoxazole, 74% of isolates were resistant to cephalexin; 71 % of isolates were resistant to erythroomycin and 58% were resistant to cefuroxxime. Almost all the isolates were susceptible to amoxicillin, cefotaxime, ceftriaxone, ceefepime, ofloxacin and 100% of isolates were susceptible to vancomycin. Among the 84 serotypes, 82% were included in the 23 valent pneumococcal polysaccharide vaccine including: 19F (30%), 23F (21 %), 14 (13%) and 6B (13%). Six other serotypes (13, 15C, 18, 11A, 15B and 6A) accounted for 12% of strains and 9 (11%) strains were untypeable. Conclusion: Pneumococcal antibiotics is spreading most rapidly among children in Vietnam, especially strains typs 19F and 23 F. Concerted efforts are necessary to prevent it spreading.\r\n", u'\r\n', u'
Antimicrobial resistance ; streptococcus pneumonia

Background: Not so many reports about the association between head and neck cancer (HNC) and oral health status related to periodontitis (OHS-P) has been published in different countries with different methods. So, there is a need for an extensive meta-analysis with the total articles published until 2020. Hence, this study aimed to estimate the association between HNC and OHS-P through a meta-analysis. Methods: Based on Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines, 22 studies were selected through PubMed and Cochrane Library databases. Metaanalysis using them was performed to evaluate the association. The risk of bias assessment using the Newcastle-Ottawa Scale (NOS) was applied to evaluate the quality of nonrandomized studies. Publication bias was evaluated by funnel plot and Egger's regression test. Results: Since heterogeneity was significant (I2 = 88%, P < 0.001), we adopted the random effect model for 22 studies. Those with bad OHS-P, compared to those with good OHS-P, were more likely to have the risk of HNC by 2.4 times (odds ratio [OR], 2.42; 95% confidence interval [CI], 1.88–3.13) for random effect model. The association included publication bias (Egger's regression, P value < 0.001). The association among five studies (I2 = 39%, P = 0.16) using alveolar bone loss (ABL) or clinical attachment level (CAL) for assessing periodontitis increased to OR of 3.85 (CI, 3.04–4.88) in the fixed effect model without publication bias (Egger's regression, P = 0.66). Moreover, the association was higher in 10 fair or good NOS studies (OR, 3.08) and in 7 Asian studies (OR, 2.68), which were from the fixed model without publication bias. Conclusion Our meta-analysis showed that bad OHS-P was associated with the risk of HNC.The association was stronger in studies using ABL or CAL for assessing periodontitis.