Risk factors of dengue fever in an urban area in Vietnam: a case-control study

Interactions between climate change, urban infrastructure and mobility are driving dengue emergence in Vietnam

Dengue is expanding globally, but how dengue emergence is shaped locally by interactions between climatic and socio-environmental factors is not well understood. Here, we investigate the drivers of dengue incidence and emergence in Vietnam, through analysing 23 years of district-level case data spanning a period of significant socioeconomic change (1998-2020). We show that urban infrastructure factors (sanitation, water supply, long-term urban growth) predict local spatial patterns of dengue incidence, while human mobility is a more influential driver in subtropical northern regions than the endemic south. Temperature is the dominant factor shaping dengue's distribution and dynamics, and using long-term reanalysis temperature data we show that warming since 1950 has expanded transmission risk throughout Vietnam, and most strongly in current dengue emergence hotspots (e.g., southern central regions, Ha Noi). In contrast, effects of hydrometeorology are complex, multi-scalar and dependent on local context: risk increases under either short-term precipitation excess or long-term drought, but improvements in water supply mitigate drought-associated risks except under extreme conditions. Our findings challenge the assumption that dengue is an urban disease, instead suggesting that incidence peaks in transitional landscapes with intermediate infrastructure provision, and provide evidence that interactions between recent climate change and mobility are contributing to dengue's expansion throughout Vietnam.

Global population surpasses eight billion: Are we ready for the next billion?

In November 2022, the global population had officially crossed eight billion. It has long been recognized that socioeconomic or health-related problems in the community always accompany an uncontrolled population expansion. International calls have been made regarding lack of universal health coverage, an insufficient supply of healthcare providers, the burden of noncommunicable disease, population aging and the difficulty in obtaining safe drinking water and food. The present health policy paper discusses how to conquer these crowded world issues, including (1) promoting government and international organization participation in providing appropriate infrastructure, funding and distribution to assist people's health and well-being; (2) shifting health program towards a more preventive approach and (3) reducing inequalities, particularly for the marginalized, isolated and underrepresented population. These fundamental principles of health policy delivery as a response to an increasingly crowded world and its challenges are crucial for reducing the burden associated with excessive healthcare costs, decreased productivity and deteriorating environmental quality.

Assessment of Symptoms and Risk Factors as a Screening Tool of Bacterial Vaginosis Among Reproductive Age-Group Females in West Bengal, India

Background Bacterial vaginosis (BV) is a ubiquitous vaginal discomfort and has overlapping symptoms with other reproductive tract infections. The World Health Organization suggested a symptomatic approach for diagnosing BV with insufficient laboratory setup. However, due to symptom overlap, BV is often misled and ends up with injudicious drug application. Objective The study aims to identify the most relevant symptoms and behavioral risk factors associated with BV in tertiary healthcare settings in West Bengal, India. It also seeks to develop a scoring system based on clinical symptoms to screen for BV, especially when laboratory facilities are limited. Methodology The study is a retrospective case-control study involving 95 women of reproductive age. It employs both univariate and multivariate binary logistic regression models to identify risk factors and symptoms associated with BV. The study also compares these clinical symptoms with laboratory tests (Amsel's test) and attempts to create a scoring system for BV diagnosis. Key Findings Good menstrual hygiene and condom use were identified as key behavioral practices reducing the risk of BV. Four clinical symptoms, like malodor (P = 0.007), lower abdominal pain (P = 0.015), abnormal vaginal discharge (P = 0.071), and painful intercourse (P = 0.08), were identified as notable predictors. Based on these four symptoms, the scoring system showed a sensitivity of 88.2%, a specificity of 67.25%, and an overall accuracy of 74.7%. An additional diagnosis of vulvovaginal candidiasis (VVC) revealed that the odds of malodor (P= 0.006) and burning sensation (P= 0.011) increased significantly during co-infection.

Perinatal Transmission of Dengue Infection among Dengue Hemorrhagic Fever Outbreaks in Southern Vietnam: The First Case Managed at Tu Du Hospital and Review of Literature

Dengue hemorrhagic fever is a high-risk pathology in pregnancy, leading to an increased mortality rate for both the mother and baby. Perinatal transmission of dengue infection may occur during the labor stage of the febrile phase, despite its extreme rarity. In the present case, a young female patient with pregnancy at 39 weeks 3 days of gestational age was hospitalized because of dengue hemorrhagic fever. Upon monitoring, her platelet count gradually decreased to a very low of 13,000 mm3 on the third day of fever. However, her platelet count increased soon afterwards. On the eighth day of admission, she was delivered by emergency cesarean section due to acute fetal distress. The female neonate was promptly assessed by the pediatric team upon cesarean surgery. The neonate was diagnosed with vertical transmission of dengue infection based on positive dengue virus nonstructural protein 1 antigen, and low platelet count was found on the first day postpartum. When there is a high suspicion of perinatal transmission, closely monitoring the newborn helps to avoid the adverse outcomes and mortality for the infant. Herein, we thoroughly report an unusual case of maternal-fetal transmission of dengue during pregnancy at our maternity hospital.

Survey of mosquito species and mosquito-borne viruses in residential areas along the Sino-Vietnam border in Yunnan Province in China

Mosquitoes are capable of carrying complex pathogens, and their feeding habits on the mammalian blood can easily mediate the spread of viruses. Surveillance of mosquito-based arbovirus enables the early prevention and control of mosquito-borne arboviral diseases. The climate and geography of Yunnan Province in China are ideal for mosquitoes. Yunnan shares borders with several other countries; therefore, there exists a high risk of international transmission of mosquito-mediated infectious diseases. Previous studies have focused more on the Sino-Laos and Sino-Myanmar borders. Therefore, we focused on the neighborhoods of Malipo and Funing counties in Wenshan Prefecture, Yunnan Province, China, which are located along the Sino-Vietnam border, to investigate the species of mosquitoes and mosquito-borne viruses in the residential areas of this region. This study collected 10,800 mosquitoes from 29 species of 8 genera and grouped to isolate mosquito-borne viruses. In total, 62 isolates were isolated and classified into 11 viral categories. We demonstrated a new distribution of mosquito-borne viruses among mosquitoes in border areas, including Tembusu and Getah viruses, which can cause animal outbreaks. In addition, Dak Nong and Sarawak viruses originating from Vietnam and Malaysia, respectively, were identified for the first time in China, highlighting the complexity of mosquito-borne viruses in the Sino-Vietnam border region. The awareness of the importance of viral surveillance and prevention measures in border areas should be further encouraged to prevent future outbreaks of potentially infectious diseases.

Whether Urbanization Has Intensified the Spread of Infectious Diseases-Renewed Question by the COVID-19 Pandemic

The outbreak of the COVID-19 epidemic has triggered adiscussion of the relationship between urbanization and the spread of infectious diseases. Namely, whether urbanization will exacerbate the spread of infectious diseases. Based on 31 provincial data from 2002 to 2018 in China, the impact of urbanization on the spread of infectious diseases from the dimensions of "population" and "land" is analyzed in this paper by using the GMM (generalized method of moments) model. The empirical study shows that the population increase brought by urbanization does not aggravate the spread of infectious diseases. On the contrary, urban education, employment and entrepreneurship, housing, medical and health care, and other basic public services brought by population urbanization can help reduce the risk of the spread of infectious diseases. The increasing density of buildings caused by land urbanization increases the risk of the spread of infectious diseases. Moreover, the impact of urbanization on the spread of infectious diseases has regional heterogeneity. Therefore, the prevention and control of disease play a crucial role.