2019年 · 第08卷第02期

Malaria-related mortality has a very high association with poverty rates, and the disease is most prevalent in low- and middle-income countries. To achieve the malaria-specific targets of the Sustainable Development Goals, malaria-endemic countries and development partners need to take concerted action to reduce malaria cases and deaths. Reaching all affected communities with malaria interventions requires strong political commitment and a significant expansion of international and domestic financial resources. World Malaria Day 2019 is an opportunity to review progress and challenges in this field.

Asia is a region that is rapidly urbanising. While overall urban health is above rural health standards, there are also pockets of deep health and social disadvantage within urban slum and peri-urban areas that represent increased public health risk. With a focus on vaccine preventable disease and immunisation coverage, this commentary describes and analyses strengths and weaknesses of existing urban health and immunisation strategy, with a view to recommending strategic directions for improving access to immunisation and related maternal and child health services in urban areas across the region. The themes discussed in this commentary are based on the findings of country case studies published by the United Nations Childrens Fund (UNICEF) on the topic of immunisation and related health services for the urban poor in Cambodia, Indonesia, Mongolia, Myanmar, the Philippines, and Vietnam.

Although overall urban coverage is higher than rural coverage in selected countries of Asia, there are also wide disparities in coverage between socio economic groups within urban areas. Consistent with these coverage gaps, there is emerging evidence of outbreaks of vaccine preventable diseases in urban areas. In response to this elevated public health risk, there have been some promising innovations in operational strategy in urban settings, although most of these initiatives are project related and externally funded. Critical issues for attention for urban health services access include reaching consensus on accountability for management and resourcing of the strategy, and inclusion of an urban poor approach within the planning and budgeting procedures of Ministries of Health and local governments. Advancement of local partnership and community engagement strategies to inform operational approaches for socially marginalised populations are also urgently required. Such developments will be reliant on development of municipal models of primary health care that have clear delegations of authority, adequate resources and institutional capabilities to implement.

The development of urban health systems and immunisation strategy is required regionally and nationally, to respond to rapid demographic change, social transition, and increased epidemiological risk.

At present, there is a continuous flow of immigrants from the south of the world to north-western countries. Often immigrants originate from areas of high-prevalence of viral hepatitis and pose a challenge to the healthcare systems of the host nations. Aims of this study is to evaluate the prevalence and virological and clinical characteristics of hepatitis C virus (HCV) infection in immigrants and the strategies to identify and take care of the immigrants infected with HCV.

We conducted an electronic literature search in several biomedical databases, including PubMed, Google Scholar, Scopus, Web of Science, using different combinations of key words: "HCV infection; chronic hepatitis C, immigrants; low-income countries". We included studies written in English indicating the epidemiological data of HCV infection in the immigrant population, studies that assessed the clinical presentation, clinical management and treatment with directly acting antiviral agent in immigrants, HCV infection is unevenly distributed in different countries, with worldwide prevalence in the general population ranging from 0.5 to 6.5%. In Western countries and Australia this rate ranges from 0.5 to 1.5%, and reaches 2.3% in countries of south-east Asia and eastern Mediterranean regions, 3.2% in China, 0.9% in India, 2.2% in Indonesia and 6.5% in Pakistan; in sub-Saharan Africa the prevalence of HCV infection varies from 4 to 9%. Immigrants and refugees from intermediate/high HCV endemic countries to less- or non-endemic areas are more likely to have an increased risk of HCV infection due to HCV exposure in their countries of origin. Because of the high HCV endemicity in immigrant populations and of the high efficacy of directly acting antiviral agent therapy, a campaign could be undertaken to eradicate the infection in this setting.

The healthcare authorities should support screening programs for immigrants, performed with the help of cultural mediators and including educational aspects to break down the barriers limiting access to treatments, which obtain the HCV clearance in 95% of cases and frequently prevent the development of liver cirrhosis and hepatocellular carcinoma.

The echinococcosis is prevalent in 10 provinces /autonomous region in western and northern China. Epidemiological survey of echinococcosis in China in 2012 showed the average prevalence of four counties in Tibet Autonomous Region (TAR) is 4.23%, much higher than the average prevalence in China (0.24%). It is important to understand the transmission risks and the prevalence of echinococcosis in human and animals in TAR.

A stratified and proportionate sampling method was used to select samples in TAR. The selected residents were examined by B-ultrasonography diagnostic, and the faeces of dogs were tested for the canine coproantigen against Echinococcus spp. using enzyme-linked immunosorbent assay. The internal organs of slaughtered domestic animals were examined by visual examination and palpation. The awareness of the prevention and control of echinococcosis among of residents and students was investigated using questionnaire. All data were inputted using double entry in the Epi Info database, with error correction by double-entry comparison, the statistical analysis of all data was processed using SPSS 21.0, and the map was mapped using ArcGIS 10.1, the data was tested by Chi-square test and Cochran-Armitage trend test.

A total of 80 384 people, 7564 faeces of dogs, and 2103 internal organs of slaughtered domestic animals were examined. The prevalence of echinococcosis in humans in TAR was 1.66%, the positive rate in females (1.92%) was significantly higher than that in males (1.41%), (χ²=30.31, P<0.01), the positive rate of echinococcosis was positively associated with age (χ²_trend = 423.95, P<0.01), and the occupational populations with high positive rates of echinococcosis were herdsmen (3.66%) and monks (3.48%). The average positive rate of Echinococcus coproantigen in TAR was 7.30%. The positive rate of echinococcosis in livestock for the whole region was 11.84%. The average awareness rate of echinococcosis across the region was 33.39%.

A high prevalence of echinococcosis is found across the TAR, representing a very serious concern to human health. Efforts should be made to develop an action plan for echinococcosis prevention and control as soon as possible, so as to control the endemic of echinococcosis and reduce the medical burden on the population.

Opisthorchis viverrini infection is highly prevalent in northeast Thailand. This liver fluke is classified as a carcinogen due to its causal links with cholangiocarcinoma (CCA) development. Although treatment with praziquantel (PZQ) effectively cures O. viverrini infection, the prevalence remains high due to the traditional consumption of raw fish. Therefore, re-infection is common in the endemic community, leading to severe hepatobiliary morbidities including the fatal CCA. In this study, we evaluate the association between the frequency of previous PZQ treatment and current O. viverrini infections among Thai adults living in the endemic area of northeast Thailand.

This study includes all participants who were screened for O. viverrini infection in the Cholangiocarcinoma Screening and Care Program (CASCAP), northeast Thailand. History of PZQ treatment was recorded using a health questionnaire. O. viverrini infections were diagnosed using urine antigen detection. Associations between PZQ and O. viverrini were determined by adjusted odds ratio (aOR) and 95% confidence interval (CI) using multiple logistic regression.

Among participants, 27.7% had previously been treated once with PZQ, 8.2% twice, 2.8% three times, and 3.5% more than three times. Current O. viverrini prevalence was 17% (n = 524). Compared with participants who never used PZQ, the aOR for infection among those who used the drug once was 1.09 (95% CI: 0.88-1.37), twice was 1.19 (95% CI: 0.85-1.68), three times was 1.28 (95% CI: 0.74-2.21), and more than three times was 1.86 (95% CI: 1.18-2.93; P = 0.007).

The population with a frequent history of PZQ use and still continued raw fish consumption showed high levels of repeated reinfection with O. viverrini. They were infected, treated and re-infected repeatedly. These findings suggest that certain participants continue raw fish consumption even after previous infection. This is a particular problem in highly endemic areas for O. viverrini and increases the risk of CCA.

In response to the high financial burden of health services facing tuberculosis (TB) patients in China, the China-Gates TB project, Phase II, has implemented a new financing and payment model as an important component of the overall project in three cities in eastern, central and western China. The model focuses on increasing the reimbursement rate for TB patients and reforming provider payment methods by replacing fee-for-service with a case-based payment approach. This study investigated changes in out-of-pocket (OOP) health expenditure and the financial burden on TB patients before and after the interventions, with a focus on potential differential impacts on patients from different income groups.

Three sample counties in each of the three prefectures: Zhenjiang, Yichang and Hanzhong were chosen as study sites. TB patients who started and completed treatment before, and during the intervention period, were randomly sampled and surveyed at the baseline in 2013 and final evaluation in 2015 respectively. OOP health expenditure and percentage of patients incurring catastrophic health expenditure (CHE) were calculated for different income groups. OLS regression and logit regression were conducted to explore the intervention's impacts on patient OOP health expenditure and financial burden after adjusting for other covariates. Key-informant interviews and focus group discussions were conducted to understand the reasons for any observed changes.

Data from 738 (baseline) and 735 (evaluation) patients were available for analysis. Patient mean OOP health expenditure increased from RMB 3576 to RMB 5791, and the percentage of patients incurring CHE also increased after intervention. The percentage increase in OOP health expenditure and the likelihood of incurring CHE were significantly lower for patients from the highest income group as compared to the lowest. Qualitative findings indicated that increased use of health services not covered by the standard package of the model was likely to have caused the increase in financial burden.

The implementation of the new financing and payment model did not protect patients, especially those from the lowest income group, from financial difficulty, due partly to their increased use of health service. More financial resources should be mobilized to increase financial protection, particularly for poor patients, while cost containment strategies need to be developed and effectively implemented to improve the effective coverage of essential healthcare in China.

Helminthiases have placed a huge burden of disease on the population in China. However, widespread control activities have led to significant achievements. As health education has been widely disseminated and plays an important role in the control and elimination of these diseases, we collected health education products aimed at controlling and preventing helminthiases in China. We analyzed their characteristics and assessed their quality.

Firstly, health education products aimed at controlling and preventing helminthiases were collected from a diverse range of organizations. Secondly, the expert brainstorming and Delphi methods were applied to establish an evaluation system, which was then used to assess the collected products systematically. Those deemed excellent were awarded. Characteristics - including type, source, targeted disease(s), targeted population, and languages - of the collected products and the awarded products were presented here.

In total, 96 health education products on helminthiases were collected from 53 organizations. Most products belonged to either the graphic design (47) or daily-use (24) category. Seventy were collected from Centers for Disease Control and Prevention and 20 from institutes or control stations of parasitic diseases, primarily at the provincial and county levels. Regarding disease targets of the products, 67 focused on a single helminthiasis, 25 on multiple helminthiases, and the remaining four on non-specific diseases. Of the 67 single helminthiasis-focused products, most targeted schistosomiasis (37), followed by echinococcosis (16). The majority of products (79) targeted the general population, while 11 targeted students specifically. Regarding languages, 86 products were only in Chinese, while the other ten were in both Chinese and the minority languages of China. Out of these ten products, one targeted schistosomiasis and the other nine targeted echinococcosis. Thirty-four products were awarded. The characteristics of the awarded products were similar to those of the collected products.

A diverse range of health education products have been designed and applied for the prevention and control of helminthiases in China. Many products have good features such as specifying the targeted diseases and populations. However, there are significant gaps in terms of both the quantity and quality of products pertaining to some of the diseases. Experiences from the awarded products could be drawn upon to design more products aimed at a range of different helminthiases.

With the closure of the Three Gorges Dam in 2003 the hydrology of Poyang Lake was altered dramatically leading to significant changes in the environment. In order to assess the impact on schistosomiasis this study assessed the spatial and temporal patterns of the snail intermediate host, Oncomelania hupensis in the Poyang Lake tributaries. The results of the study have important implications for future snail control strategies leading to disease elimination.

The marshland area surrounding Poyang Lake was divided randomly into 200 × 200 m vector grids using ArcGIS software, and the surveyed grids were randomly selected by the software. The snail survey was conducted in each selected grid using a survey frame of 50 × 50 m with one sideline of each grid serving as the starting line. No less than ten frames were used in each surveyed grid with Global Positioning System (GPS) recordings for each. All snails in each frame were collected to determine infection status by microscopy. Altitude data for all frames were extracted from a lake bottom topographic map in order to analyze the average altitude. All snail survey data were collected and statistically analyzed with SPSS 20.0 software in order to determine the difference of the percentage of frames with living snails and mean density of living snails in different regions of Poyang Lake. The altitude of the snail-infested marshlands and snail dens were subsequently identified.

A total of 1159 potential snail sampling grids were surveyed, of which 15 231 frames (0.1 m²/frame) were investigated. 1241 frames had live Oncomelania snails corresponding to 8.15% of the total number of frames. The mean density of living snails was 0.463/0.1 m² with a maximum of 57 snails per frame. The percent of frames with snails in the southern sector (8.13%) of Poyang Lake did not differ statistically from the north (8.21%). However, the mean density of live snails in the northern sector (0.164/0.1 m²) of the lake was statistically higher (F= 6.727; P = 0.010) than the south (0.141/0.1 m²). In the south of the lake, the elevation of snail-inhabited marshland ranged between 11-16 m, and could be further subdivided into two snail-concentrated belts at 12-13 m of elevation and 15-16 m of elevation respectively. In the north of the lake, the elevation of snail-inhabited marshland ranged between 9-16 m with the elevation of 12-14 m being the snail-concentrated zone.

The elevation of snail-infested marshlands in the Poyang Lake region ranged from 9 to 16 m. The snail distribution and habitat has moved north of the lake and to a lower altitude due to changes in the water level post dam closure. Based on the current geological features of the snail habitant focused mollusciciding should occur in snail dense northern regions with frequent bovine and human traffic. Targeting these identified 'hotspots’ of transmission will assist in elimination efforts.

Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis. Some plant extracts have shown obvious molluscicidal activity, and a new compound Luo-Wei, also named tea-seed distilled saponin (TDS), was developed based on the saponins extracted from Camellia oleifera seeds. We aimed to test the molluscicidal activity of 4% TDS against the intermediate host snails in China and Egypt, and evaluate its environmental safety to non-target organisms.

In the laboratory, Oncomelania hupensis, Biomphalaria alexandrina and Bulinus truncatus were exposed to 4% TDS, and the median lethal concentration (LC₅₀) was estimated at 24, 48 and 72 h. In the field, snail mortalities were assessed 1, 2, 3 and 7 d post-immersion with 2.5 g/m³ 4% TDS and 1, 3, 7 and 15 d post-spraying with 5 g/m² 4% TDS. In addition, the acute toxicity of 4% TDS to Japanese quail (Coturnix japonica), zebrafish (Brachydanio rerio) and freshwater shrimp (Macrobrachium nipponense) was assessed by estimations of LC₅₀ or median lethal dose (LD₅₀).

In the laboratory, the LC₅₀ values of 4% TDS for O. hupensis were 0.701, 0.371 and 0.33 mg/L at 24, 48 and 72 h, respectively, and 4% TDS showed a 0.33 mg/L 24 h LC₅₀ against B. alexandrina, and a 1.396 mg/L 24 h LC₅₀ against B. truncatus. Across all study regions, the pooled mortalities of O. hupensis were 72, 86, 94 and 98% at 1, 2, 3 and 7 d, following field immersion of 4% TDS at a dose of 2.5 g/m³, and were 69, 77, 85 and 88% at 1, 3, 7 and 15 d, following field spraying at 5 g/m², respectively. 4% TDS had moderate toxicity to Japanese quail (7 d LD₅₀ > 60 mg/kg) and to shrimp (96 h LC₅₀ = 6.28 mg/L; 95% CI: 3.53-11.2 mg/L), whereas its toxicity to zebrafish was high (96 h LC₅₀ = 0.15 mg/L; 95% CI: 0.14-0.17 mg/L).

4% TDS is active against O. hupensis, B. alexandrina and B. truncatus under laboratory and field conditions, and it may be a candidate molluscicide of plant origin.

Tuberculosis (TB) and HIV remain a major causes of morbidity and mortality globally. We conducted an analysis of TB/HIV surveillance data to describe the trends in HIV testing coverage and HIV positivity rate among TB patients in Viet Nam, 2011-2017.

This was a descriptive study based on review and analysis of surveillance data from the National Tuberculosis Control Programme from 2011 to 2017. During this period, 721 342 TB cases were diagnosed. Of these, 520 490 (72.2%) had a previously documented HIV status or were tested for HIV during TB care and treatment. The proportion of TB patients whose HIV status was reported increased, from 58.5% in 2011 to 82.9% in 2017 (P value for trend = 0.014). The proportion of TB patients infected with HIV decreased, from 8.0% in 2011 to 3.7% in 2017 (P value for trend = 0.018).

The proportion of TB patients with a reported HIV status was increased from 2011 to 2017, however HIV testing coverage remained below the National Tuberculosis Control Programme targets (≥ 90%). National Tuberculosis Control Programme needs to focus on ensuring every registered TB patients has a documented HIV status, ensuring full coverage of HIV testing as part of routine TB care.

The 2014-2016 Ebola virus epidemic in West Africa was the largest outbreak of Ebola virus disease (EVD) in history. Clarifying the influence of other prevalent diseases such as human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) will help improve treatment and supportive care of patients with EVD.

We examined HIV and hepatitis C virus (HCV) antibody prevalence among suspected EVD cases from the Sierra Leone-China Friendship Biological Safety Laboratory during the epidemic in Sierra Leone. HIV and HCV antibodies were tested in 678 EVD-negative samples by enzyme-linked immunosorbent assay. A high HIV prevalence (17.6%) and low HCV prevalence (0.22%) were observed among the suspected cases. Notably, we found decreased HIV positive rates among the suspected cases over the course of the epidemic. This suggests a potentially beneficial effect of an improved public health system after assistance from the World Health Organization and other international aid organizations.

This EVD epidemic had a considerable impact on the public health system and influenced the prevalence of HIV found among suspected cases in Sierra Leone, but also provided an opportunity to establish a better surveillance network for infectious diseases.