Infectious Diseases of Poverty最新文献

Background: China has successfully reduced tuberculosis (TB) incidence rate over the past three decades, however, challenges remain in improving the quality of TB diagnosis and treatment. In this paper, we assess the effects of the implementation of "China National Health Commission (NHC) and Gates Foundation TB Prevention and Control Project" on the quality of TB care in the three provinces.

Methods: We conducted the baseline study in 2016 and the final evaluations in 2019 in the 12 selected project counties. We obtained TB patients' information from the TB Information Management System and reviewed medical records of TB cases in the TB designated hospitals. We compared TB diagnosis and treatment services with the national practice guideline and used Student's t-test and Pearson χ² tests or Fisher's exact tests to compare the difference before and after the project implementation.

Results: The percentage of sputum smear-negative (SS-) patients taking culture or rapid molecular test (RMT) doubled between 2015 and 2018 (from 35% to 87%), and the percentage of bacteriologically confirmed pulmonary TB cases increased from 36% to 52%. RMT has been widely used and contributed an additional 20% of bacteriologically confirmed TB cases in 2018. The percentage of TB patients taking drug susceptibility tests (DST) also doubled (from 40% in 2015 to 82% in 2018), and the proportion of TB patients receiving adequate diagnosis services increased from 85% to 96%. Among all SS- TB patients, over 86% received the recommended diagnostic services at the end of the study period, an improvement from 75% prior to the project implementation. However, the proportion of TB patients treated irrationally using second-line anti-TB drugs (SLDs) increased from 12.6% in 2015 to 19.9% in 2018. The regional disparities remained within the project provinces, albeit the gaps between them narrowed down for almost all indicators.

Conclusions: The quality of TB diagnosis services has been improved substantially, which is attributable to the coverage of new diagnosis technology. However, irrational use of SLDs remains a concern after the project implementation.

Background: Severe fever with thrombocytopenia syndrome (SFTS), an emerging tickborne infectious disease caused by a novel banyangvirus (SFTS virus, SFTSV), was endemic in several Asian countries with a high mortality up to 30%. Until recently, SFTSV-associated re-infection have not been reported and investigated.

Case presentation: A 42-year-old female patient was identified as a case of SFTS with re-infection, with two episodes of SFTSV infection on June 2018 and May 2020. The diagnosis of SFTS was confirmed by detection of SFTSV RNA in the blood samples using real-time reverse-transcription polymerase chain reaction and antibodies specific for SFTSV using enzyme linked immunosorbent assay. The changes of viremia and antibody response differed between the two episodes. Phylogenetic analysis showed the two viral genome sequences were in the same clade, but showing 0.6% dissimilarity of the nearly whole nucleotide sequence. Analysis of clinical data revealed that the second episode showed milder illness than that of the first episode.

Conclusions: Epidemiological and clinical findings, viral whole genomic sequences, and serological evidence, provided evidence for the re-infection of SFTSV rather than prolonged viral shedding or relapse of the original infection. The patients with re-infection of SFTSV may be at high odds of clinically inapparent or mildly symptomatic. More attention should be directed towards the long-term follow up of the recovered patients in the future, to explicitly acquire the decay profile of their immunity response.

Background: Hepatitis E, an acute zoonotic disease caused by the hepatitis E virus (HEV), has a relatively high burden in developing countries. The current research model on hepatitis E mainly uses experimental animal models (such as pigs, chickens, and rabbits) to explain the transmission of HEV. Few studies have developed a multi-host and multi-route transmission dynamic model (MHMRTDM) to explore the transmission feature of HEV. Hence, this study aimed to explore its transmission and evaluate the effectiveness of intervention using the dataset of Jiangsu Province.

Methods: We developed a dataset comprising all reported HEV cases in Jiangsu Province from 2005 to 2018. The MHMRTDM was developed according to the natural history of HEV cases among humans and pigs and the multi-transmission routes such as person-to-person, pig-to-person, and environment-to-person. We estimated the key parameter of the transmission using the principle of least root mean square to fit the curve of the MHMRTDM to the reported data. We developed models with single or combined countermeasures to assess the effectiveness of interventions, which include vaccination, shortening the infectious period, and cutting transmission routes. The indicator, total attack rate (TAR), was adopted to assess the effectiveness.

Results: From 2005 to 2018, 44 923 hepatitis E cases were reported in Jiangsu Province. The model fits the data well (R² = 0.655, P < 0.001). The incidence of the disease in Jiangsu Province and its cities peaks are around March; however, transmissibility of the disease peaks in December and January. The model showed that the most effective intervention was interrupting the pig-to-person route during the incidence trough of September, thereby reducing the TAR by 98.11%, followed by vaccination (reducing the TAR by 76.25% when the vaccination coefficient is 100%) and shortening the infectious period (reducing the TAR by 50.05% when the infectious period is shortened to 15 days).

Conclusions: HEV could be controlled by interrupting the pig-to-person route, shortening the infectious period, and vaccination. Among these interventions, the most effective was interrupting the pig-to-person route.

Background: Schistosomiasis control is striving forward to transmission interruption and even elimination, evidence-lead control is of vital importance to eliminate the hidden dangers of schistosomiasis. This study attempts to identify high risk areas of schistosomiasis in China by using information value and machine learning.

Methods: The local case distribution from schistosomiasis surveillance data in China between 2005 and 2019 was assessed based on 19 variables including climate, geography, and social economy. Seven models were built in three categories including information value (IV), three machine learning models [logistic regression (LR), random forest (RF), generalized boosted model (GBM)], and three coupled models (IV + LR, IV + RF, IV + GBM). Accuracy, area under the curve (AUC), and F1-score were used to evaluate the prediction performance of the models. The optimal model was selected to predict the risk distribution for schistosomiasis.

Results: There is a more prone to schistosomiasis epidemic provided that paddy fields, grasslands, less than 2.5 km from the waterway, annual average temperature of 11.5-19.0 °C, annual average rainfall of 1000-1550 mm. IV + GBM had the highest prediction effect (accuracy = 0.878, AUC = 0.902, F1 = 0.920) compared with the other six models. The results of IV + GBM showed that the risk areas are mainly distributed in the coastal regions of the middle and lower reaches of the Yangtze River, the Poyang Lake region, and the Dongting Lake region. High-risk areas are primarily distributed in eastern Changde, western Yueyang, northeastern Yiyang, middle Changsha of Hunan province; southern Jiujiang, northern Nanchang, northeastern Shangrao, eastern Yichun in Jiangxi province; southern Jingzhou, southern Xiantao, middle Wuhan in Hubei province; southern Anqing, northwestern Guichi, eastern Wuhu in Anhui province; middle Meishan, northern Leshan, and the middle of Liangshan in Sichuan province.

Conclusions: The risk of schistosomiasis transmission in China still exists, with high-risk areas relatively concentrated in the coastal regions of the middle and lower reaches of the Yangtze River. Coupled models of IV and machine learning provide for effective analysis and prediction, forming a scientific basis for evidence-lead surveillance and control.

Background: To monitor the prevalence of schistosomiasis in school-aged children (SAC), the National Bilharzia Control Program (PNLB) was set up by the Senegalese authorities; however, geographically isolated Bedik ethnic groups that did not benefit from this program were found to be heavily infected with Schistosoma mansoni. This observation led us to implement a new schistosomiasis control program in 2008 under the aegis of the non-governmental organization "Le Kaïcedrat" and in partnership with the PNLB/WHO to monitor the prevalence of schistosomiasis in this area. In the village of Assoni, where 100% of SAC were infected, analysis of the stools of pre-school-aged children (PSAC) showed that they were massively infected, so we decided to focus our program on them.

Methods: From 2008 to 2020, we (i) monitored the prevalence of S. mansoni in PSAC in Assoni using double-stool smear preparation, (ii) treated the infected PSAC with a standard dose of praziquantel 40 mg/kg, (iii) ran educational campaigns each year in the village, and (iv) built latrines to improve sanitation and reduce schistosomiasis transmission. Linear regression was used to examine the trend in the annual schistosomiasis prevalence and a two-sided of Chi-squared test was used to compare prevalence between the different age groups of PSAC.

Results: We observed an extremely high prevalence of schistosomiasis (78%) in PSAC before implementation of the program in 2008. Contamination occurred in very young children, as 64.3% of children under 2 years old were infected. Moreover, prevalence increased with age and reached 96.8% in children 4 to < 6 years old. Our annual interventions in Assoni Village raised awareness among villagers that water bodies were areas of significant infestation, allowed the building of 88 latrines and led to a decrease in prevalence in PSAC as only 11% of these children were infected in 2020.

Conclusion: Our study allowed Assoni to be the first village in Senegal to treat PSAC since 2014, but only on an individual basis. It also shows that schistosomiasis is difficult to eradicate and that multi-sectorial actions are required to keep its prevalence at a low level.

School-aged children (SAC) have a considerable burden of intestinal schistosomiasis in Madagascar yet its burden in pre-school aged children (PSAC) is currently overlooked. To assess the at-risk status of PSAC, we undertook a pilot epidemiological survey in June 2019 examining children (n = 89), aged 2-4-years of balanced gender, in six remote villages in Marolambo District, Madagascar. Diagnosis included use of urine-circulating cathodic antigen (CCA) dipsticks and coproscopy of stool with duplicate Kato-Katz (K-K) thick smears. Prevalence of intestinal schistosomiasis by urine-CCA was 67.4% (95% confidence interval [CI]: 56.5-77.2%) and 35.0% (95% CI: 24.7-46.5%) by K-K. The relationship between faecal eggs per gram (epg) and urine-CCA G-scores (G1 to G10) was assessed by linear regression modelling, finding for every increment in G-score, epg increased by 20.4 (6.50-34.4, P = 0.006). Observed proportions of faecal epg intensities were light (78.6%), moderate (17.9%) and heavy (3.6%). Soil-transmitted helminthiasis was noted, prevalence of ascariasis was 18.8% and trichuriasis was 33.8% (hookworm was not reported). Co-infection of intestinal schistosomiasis and soil-transmitted helminthiasis occurred in 36.3% of PSAC. These results provide solid evidence highlighting the overlooked burden of intestinal schistosomiasis in PSAC, and they also offer technical  guidance for better surveillance data for the Madagascan national control programme.

Background: Soil-transmitted helminth (STH) infections have long been an important public health concern in the Philippines. In this review, we describe the current status of STH infections there and highlight the control efforts undertaken to reduce STH burden.

Main text: A nationwide STH mass drug administration (MDA) programme was started in 2006 but the overall STH prevalence remains stubbornly high across the Philippines, ranging from 24.9% to 97.4%. The continued increase in the prevalence may have been due to the challenges related to MDA implementation which include the lack of people's awareness about the importance of regular treatment, misconceptions about the MDA strategy, lack of confidence on the drugs used, fear of adverse events and general distrust of government programs. There are existing water, sanitation and hygiene (WASH) programmes implemented in communities [e.g., Community-Led Total Sanitation (CLTS) program and providing toilet bowls and provision of subsidy for latrine construction] and schools [e.g., WASH in School (WINS) program], but sustained implementation is required to achieve expected outcomes. Although WASH in general is being taught in schools, integration of STH as a disease and community problem in the current public elementary school curriculum is still inadequate. The Integrated Helminth Control Program (IHCP) currently implemented in the country, which is focused on improved sanitation and personal hygiene, health education and preventive chemotherapy, will require continuous appraisal. The sustainability of this programme still continues to be a challenge.

Conclusions: Despite the major efforts to control STH infections for almost two decades in the Philippines, persistently high STH prevalence has been reported across the country, which is likely due to suboptimal MDA coverage and limitations in WASH and health education programs. Sustainable delivery of integrated control approaches will continue to play a pivotal role in the control and elimination of STH in the Philippines.

Background: Many valuable and productive patented technologies have been developed to control schistosomiasis in China in the past 70 years. We conducted a research to analyse patented technologies for schistosomiasis control and prevention filed by Chinese applicants for determining the future patent layout.

Methods: The patent databases of China National Intellectual Property Administration and Baiten were comprehensively searched, and patented technologies for schistosomiasis control and prevention, published between January 1950 and December 2020 filed by Chinese applicants were sorted on 30 December 2020. The patent types, technical fields, and patent development trends were analysed using patent indexing.

Results: There are 184 valid schistosomiasis control technology patents, among them 128 invention patents. The patents related to schistosomiasis control and prevention technology have gone through the germination, growth, and maturity stages. These phases correspond with three phases in schistosomiasis control in China. The main technical aspects were fundamental research (n = 37), detection (n = 13), chemotherapy (n = 61), and armamentarium/devices (n = 73), of which the number of patents for detection for diagnosis was smaller. The top three specialised technical fields for patents subgroups, focusing on antiparasitic agents, DNA or RNA, vectors and medicines, of which schistosomicides are the major dominant subgroup.

Conclusions: We recommend that technologies to be patented for schistosomiasis control and prevention be focused on detection, preliminary studies for molecular detection methods should be significantly enhanced, and patent layout must be performed, which will, in turn, promote accuracy of early diagnosis, not only in humans but also in livestock. It is necessary to develop more anti-schistosomal drugs safely and effectively, exceptionally eco-friendly molluscicides and herbal extracts anti-schistosomes, improve treatment, develop vaccines for use in humans.

Background: In Ethiopia, schistosomiasis is caused by Schistosoma mansoni and S. haematobium with the former being widespread and more than 4 million people are estimated to be infected by S. mansoni annually with 35 million at risk of infection. Although many school- and community-based epidemiological surveys were conducted over the past decades, the national distribution of schistosomiasis endemic areas and associated socio-environmental determinants remain less well understood. In this paper, we review S. mansoni prevalence of infections and describe key biogeographical characteristics in the endemic areas in Ethiopia.

Methods: We developed a database of S. mansoni infection surveys in Ethiopia through a systematic review by searching articles published between 1975 and 2019 on electronic online databases including PubMed, ScienceDirect, and Web of Science. A total of 62 studies involving 95 survey locations were included in the analysis. We estimated adjusted prevalence of infection from each survey by considering sensitivity and specificity of diagnostic tests using Bayesian approach. All survey locations were georeferenced and associated environmental and geographical characteristics (e.g. elevation, normalized difference vegetation index, soil properties, wealth index, and climatic data) were described using descriptive statistics and meta-analysis.

Results: The results showed that the surveys exhibited a wide range of adjusted prevalence of infections from 0.5% to 99.5%, and 36.8% of the survey sites had adjusted prevalence of infection higher than 50%. S. mansoni endemic areas were distributed in six regional states with the majority of surveys being in Amhara and Oromia. Endemic sites were found at altitudes from 847.6 to 3141.8 m above sea level, annual mean temperatures between 17.9 and 29.8 ℃, annual cumulative precipitation between 1400 and 1898 mm, normalized difference vegetation index between 0.03 and 0.8, wealth index score between -68 857 and 179 756; and sand, silt, and clay fraction in soil between 19.1-47.2, 23.0-36.7, and 20.0-52.8 g/100 g, respectively.

Conclusions: The distribution of S. mansoni endemic areas and prevalence of infections exhibit remarked environmental and ecological heterogeneities. Future research is needed to understand how much these heterogeneities drive the parasite distribution and transmission in the region.

Background: Echinococcosis is a global zoonotic parasitic disease caused by Echinococcus larvae. This disease is highly endemic in Sichuan Province, China. This study investigates the prevalence and spatial distribution characteristics of human echinococcosis at the township level in Sichuan Province, geared towards providing a future reference for the development of precise prevention and control strategies.

Methods: Human prevalence of echinococcosis was evaluated using the B-ultrasonography diagnostic method in Sichuan Province between 2016 and 2019. All data were collected, collated, and analyzed. A spatial distribution map was drawn to intuitively analyze the spatial distribution features. Eventually, the spatial autocorrelation was specified and local indicators of spatial association (LISA) clustering map was drawn to investigate the spatial aggregation of echinococcosis at the township level in Sichuan Province.

Results: The prevalence of echinococcosis in humans of Sichuan Province was 0.462%, among which the occurrence of cystic echinococcosis (CE) was 0.221%, while that of alveolar echinococcosis (AE) was 0.244%. Based on the results of the spatial distribution map, a predominance of echinococcosis in humans decreased gradually from west to east and from north to south. The Global Moran's I index was 0.77 (Z = 32.07, P < 0.05), indicating that the prevalence of echinococcosis in humans was spatially clustered, exhibiting a significant spatial positive correlation. Further, the findings of local spatial autocorrelation analysis revealed that the "high-high" concentration areas were primarily located in some townships in the northwest of Sichuan Province. However, the "low-low" concentration areas were predominantly located in some townships in the southeast of Sichuan Province.

Conclusions: Our findings demonstrated that the prevalence of echinococcosis in humans of Sichuan Province follows a downward trend, suggesting that the current prevention and control work has achieved substantial outcomes. Nevertheless, the prevalence in humans at the township level is widely distributed and differs significantly, with a clear clustering in space. Therefore, precise prevention and control strategies should be formulated for clusters, specifically strengthening the "high-high" clusters at the township level.