Background: Dengue Fever/Dengue Hemorrhagic Fever (DF/DHF) has emerged as one of the most important public health concerns in Viet Nam in recent years. Key breeding containers plays an important role in driving dengue vector control in the public. Objectives: The research was conducted to discover the dengue situation, its vectors and key containers to make relevant recommendations in reducing effectively the vector population. Subjects and methods: Two hundred households in two communes of Nam Dinh province (100 in each studied commune) were selected randomly. Vectors collected from the field were identified using mosquito key. The number of dengue larvae and mosquitoes were directly counted or adjustment methods were used to estimate the true number in each type of water storage facility. Results: In Minh Thuan commune, Ae. albopictus larvae were mainly concentrated in jars (49%) and discards (59%), most of Ae. aegypti was found in cement tanks with a volume more than 500L (72%). In Trung Dong commune, larvae of Ae. albopictus concentrated in jars (40%) and discards (25%) and aquariums (15%), while most of the Ae. aegypti larvae was discovered in cement tanks with volumes more than 500L (86%). Mosquito density index of Ae. albopictus in Trung Dong and Minh Thuan communes was 0.56 and 0.38, respectively. The Aedes larvae, houses for larvae and Breteau index were nearly at the threshold of dengue epidemic occurrence for Ae. aegypti and over a certain threshold for Ae. albopictus. Some recommendations were provided to help reduce the dengue vectors. Conclusion: Investigation of key mosquito larvae in water containers was useful in driving the effective dengue vector control. Further studies are required to evaluate the impact and methods to manage water containers in the local area.
Dengue fever ; mosquito ; vector control

Background: We previously elucidated the protective mechanism of Korean red ginseng oil (RGO) against Brucella abortus infection, and our phytochemical analysis revealed that palmitic acid (PA) was an abundant component of RGO. Consequently, we investigated the contribution of PA against B. abortus. Objectives: We aimed to investigate the efficacy of PA against B. abortus. infection using a murine cell line and a murine model. Methods: Cell viability, bactericidal, internalization, and intracellular replication, western blot, nitric oxide (NO), and superoxide (O2 - ) analyses and flow cytometry were performed to determine the effects of PA on the progression of B. abortus. infection in macrophages. Flow cytometry for cytokine analysis of serum samples and bacterial counts from the spleens were performed to determine the effect of PA in a mouse model. Results: PA did not affect the growth of B. abortus.. PA treatment in macrophages did not change B. abortus. uptake but it did attenuate the intracellular survivability of B. abortus.. Incubation of cells with PA resulted in a modest increase in sirtuin 1 (SIRT1) expression.Compared to control cells, reduced nitrite accumulation, augmented O2 - , and enhanced pro-inflammatory cytokine production were observed in PA-treated B. abortus.-infected cells.Mice orally treated with PA displayed a decreased serum interleukin-10 level and enhanced bacterial resistance. Conclusions Our results suggest that PA participates in the control of B. abortus. within murine macrophages, and the in vivo study results confirm its efficacy against the infection. However, further investigations are encouraged to completely characterize the mechanisms involved in the inhibition of B. abortus. infection by fatty acids.

Background: We previously elucidated the protective mechanism of Korean red ginseng oil (RGO) against Brucella abortus infection, and our phytochemical analysis revealed that palmitic acid (PA) was an abundant component of RGO. Consequently, we investigated the contribution of PA against B. abortus. Objectives: We aimed to investigate the efficacy of PA against B. abortus. infection using a murine cell line and a murine model. Methods: Cell viability, bactericidal, internalization, and intracellular replication, western blot, nitric oxide (NO), and superoxide (O2 - ) analyses and flow cytometry were performed to determine the effects of PA on the progression of B. abortus. infection in macrophages. Flow cytometry for cytokine analysis of serum samples and bacterial counts from the spleens were performed to determine the effect of PA in a mouse model. Results: PA did not affect the growth of B. abortus.. PA treatment in macrophages did not change B. abortus. uptake but it did attenuate the intracellular survivability of B. abortus.. Incubation of cells with PA resulted in a modest increase in sirtuin 1 (SIRT1) expression.Compared to control cells, reduced nitrite accumulation, augmented O2 - , and enhanced pro-inflammatory cytokine production were observed in PA-treated B. abortus.-infected cells.Mice orally treated with PA displayed a decreased serum interleukin-10 level and enhanced bacterial resistance. Conclusions Our results suggest that PA participates in the control of B. abortus. within murine macrophages, and the in vivo study results confirm its efficacy against the infection. However, further investigations are encouraged to completely characterize the mechanisms involved in the inhibition of B. abortus. infection by fatty acids.

Background: Viet Nam confirmed its first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on 23 January 2020 among travellers from Wuhan, China, and experienced several clusters of community transmission until September. Viet Nam implemented an aggressive testing, isolation, contact tracing and quarantine strategy in response to all laboratory-confirmed cases. We report the results of SARS-CoV-2 testing during the first half of 2020 in northern Viet Nam. Methods: Between January and May 2020, 15 650 upper respiratory tract specimens were collected from 14 470 suspected cases and contacts in northern Viet Nam. All were tested for SARS-CoV-2 by real-time RT-PCR. Individuals with positive specimens were tested every three days until two tests were negative. Positive specimens from 81 individuals were cultured. Results: Among 14 470 tested individuals, 158 (1.1%) cases of SARS-CoV-2 infection were confirmed; 89 were imported and 69 were associated with community transmission. Most patients (122, 77%) had negative results after two tests, while 11 and 4 still tested positive when sampled a third and fourth time, respectively. SARS-CoV-2 was isolated from 29 of 81 specimens (36%) with a cycle threshold (Ct) value <30. Seven patients who tested positive again after testing negative had Ct values >30 and negative cultures. Conclusion Early, widespread testing for SARS-CoV-2 in northern Viet Nam identified very few cases, which, when combined with other aggressive strategies, may have dramatically contained the epidemic. We observed rapid viral clearance and very few positive results after clearance. Large-scale molecular diagnostic testing is a critical part of early detection and containment of COVID-19 in Viet Nam and will remain necessary until vaccination is widely implemented.