Abundance and infection of Biomphalaria glabrata with Schistosoma glabrata in the state of Rio de Janeiro, Brazil]

OBJECTIVES: To investigate the spatial distribution, abundance and natural schistosomiasis infection levels in the snail Biomphalaria glabrata, the intermediate host of Schistosoma mansoni in an area of the State of Rio de Janeiro, Brazil. METHODS: In the Pamparr?o area, Sumidouro county, RJ, Brazil, snail captures were carried out every other month from June 1991 to November 1995. There were 23 collecting sites along the Pamparr?o stream and its three tributaries (A, B and C). Captured snails were examined in the laboratory for infection. Data analyses were performed using Spearman coefficient (0.5% significance level) and Qui-square test. RESULTS: The abundance of B. glabrata was variable in both time and space. Most of the collection sites showed a negative correlation with rainfall. The tributary B had the highest and most steady infection rates (more than 25% in some sites). There were found significantly more infected snail in the dry season (chi2 = 20.08; p=0.001). CONCLUSIONS: B. glabrata population in the Pamparr?o valley was negatively influenced by rainfall, especially at the Pamparr?o stream. The dry season seems to promote the infection probably due to the lower water volume, increasing the chance of interaction between the intermediate host and the parasite.     

Geographic variability in geocoding success for West Nile virus cases in South Dakota

Geocoding, the process of assigning each case a set of coordinates that closely approximates its true location, is an important component of spatial epidemiological studies. The failure to accurately geocode cases adversely affects the validity and strength of conclusions drawn from the analysis. We investigated whether there were differences among geographic locations and demographic classes in the ability to successfully geocode West Nile virus (WNV) cases in South Dakota. We successfully geocoded 1354 cases (80.8%) to their street address locations and assigned all 1676 cases to ZIP code tabulation areas (ZCTAs). Using spatial scan statistics, significant clusters of non-geocoded cases were identified in central and western South Dakota. Geocoding success rates were lower in areas of low population density and on Indian reservations than in other portions of the state. Geocoding success rates were lower for Native Americans than for other races. Spatial epidemiological studies should consider the potential biases that may result from excluding non-geocoded cases, particularly in rural portions of the Great Plains that contain large Native American populations.     

脑外伤真菌感染的临床分析

目的探讨医院脑外科真菌感染的临床特点。方法分析笔者所在医院2006年5月～2010年5月手指的950例脑外伤患者真菌感染的临床资料。结果950例患者中感染真菌256例（26．9％）,感染病原菌280株,其中白色念珠菌113（40．3％）,热带念珠菌96例（34．3％）,近平滑念珠菌26例（9．3％）,光滑球拟酵母18例（6．4）％,新型隐球菌10例（3．6％）,副秃隐球菌6例（2．1％）,其他11例（3．9％）。其主要诱因为长期大剂量不合理使用抗菌素、长期使用激素或其他免疫抑制剂、气管插管及留置尿管等。结论近年来医院真菌感染的发病率明显增高,以呼吸道为主,白色念珠菌和热带念珠菌最常见,耐药菌有所提高。     

The rural–urban effect on spatial genetic structure of type II Toxoplasma gondii strains involved in human congenital toxoplasmosis,France, 2002–2009

Congenital toxoplasmosis involves Toxoplasma gondii type II strains in 95% of cases in France. We used spatial principal component analysis (sPCA) and 15 microsatellite markers to investigate the spatial genetic structure of type II strains involved in 240 cases of congenital toxoplasmosis in France from 2002 through 2009. Mailing addresses of patients were geo-referenced a posteriori in decimal degrees and categorized into urban or rural areas of residence. No spatial genetic structure was found for type II strains that infected mothers who were living in urban areas, but a global spatial genetic structure was found for those that infected mothers who were living in a rural environment. Our results suggest that sources of infection by T. gondii are different in rural and urban areas in France, and advocate for targeted messages in the prevention of toxoplasmosis according to the type of residence of susceptible people.     

Schistosomiasis: new occurrence of Biomphalaria straminea in Belo Horizonte, Minas Gerais

In Belo Horizonte, Minas Gerais, Brazil, the snail Biomphalaria straminea was found in the Pampulha region. Recently the snail was found in ditches in the old Santa Lúcia Reservoir, a now-extinct focus of schistosomiasis transmission by B. glabrata. The snails were collected and examined to verify whether they were naturally infected with Schistosoma mansoni. Negative specimens were used for breeding or infection with the LE strain of S. mansoni from the laboratory and another strain obtained from eggs found in the feces of a schoolchild (VGS) from Belo Horizonte. Among the 1890 snails collected from 1994 to 1995, none were infected with S. mansoni. Among 87 snails collected and exposed to the LE strain, 9 (10.3%) shed cercariae; among 83 snails from F1, and exposed to LE, 10 (12.0%) shed cercariae. Among 88 snails exposed to VGS, 10 (11.3%) shed cercariae. In Belo Horizonte, schistosomiasis is transmitted by B. glabrata and B. tenagophila. However, currently there exists the risk of appearance of a focus in which B. straminea could be the host if prophylactic measures are not taken by the authorities responsible for the construction of a park and lake at that site.     

内蒙古蚤类的鼠疫流行病学意义

目的 研究内蒙古4型疫源地蚤类中自然染疫蚤的种类,分析该地区蚤类的鼠疫流行病学意义.方法 收集整理历年鼠疫自然疫源地流行病学调查和检测中检出鼠疫菌的蚤种种名和检出地点.结果 内蒙古发现的122种(亚种)蚤类中,从30种(亚种)蚤体中检出鼠疫菌.结论 4型疫源地中3个疫源地的主要媒介蚤种都可自然感染鼠疫菌,几乎所有次要媒介蚤中都检出鼠疫菌.     

Spatial distribution patterns of Echinococcus multilocularis (Leuckart 1863) (Cestoda: Cyclophyllidea: Taeniidae) among red foxes in an endemic focus in Brandenburg,Germany.

Over a period of 40 months, 4374 foxes were randomly sampled from an area located in northwestern Brandenburg, Germany, and examined parasitologically for infections with Echinococcus multilocularis. Spatial analysis of the origin of infected animals identified two (one central and one southeastern) high-endemic foci with an estimated prevalence of 23.8%. By contrast, a prevalence of 4.9% was found in the remaining (low-endemic) area. The prevalences among juvenile and adult foxes were compared in the high-endemic and the low-endemic areas. To analyse the central high-endemic focus further, the random sample was stratified by zones representing concentric circles with a radius of 13 km (zone 1) or x(n-1) + 7 km for the remaining three zones from the apparent centre of this focus (anchor point). Prevalences calculated for each zone showed a decrease from zone 1 (18.8%) to zone 4 (2.4%) with significant differences for all zones but zones 3 and 4. The relative risk of an infection decreased rapidly in a distance range of 26 km around the high-endemic focus, whereas the relative risk remained unchanged within a distance of 5 km around the anchor point. The importance of heterogeneous spatial distribution patterns for the diagnosis and epidemiology of the infection is discussed.     

Present status of bancroftian filariasis in Maceió, State of Alagoas, Brazil

Epidemiological and entomological surveys were carried out in the human and mosquito populations in Maceió, Alagoas, in order to assess the present status of bancroftian lymphatic filariasis. Examination of thick blood smears of 10,450 students from different areas of the city revealed 0.66% Wuchereria bancrofti microfilaria carriers. The distribution of filariasis is focal in the city, 80% of the individuals with patent infection living in two neighboring areas with 1.24% and 5.25% prevalence. Parallel studies performed with samples of all age groups in the human population showed similar microfilaria prevalence rates observed previously in the student survey. However, thick blood smears taken from members of families with at least one subject with patent infection gave a prevalence six times greater suggesting, increased transmission in households. The percentage of carriers was higher in the youngest age group (< 20 years). Culex quinquefasciatus mosquitos caught at the locations where the autochthonous cases were found presented natural infection rates ranging from 0.28% to 4.62%. The combination of all these findings indicates occurrence of active transmission of W. bancrofti in the urban area of Maceió, Alagoas State. Based on these data, measures for the potential control of filariasis were planned.     

Environmental and social determinants in schistosomiasis mansoni in Ravena, Minas Gerais, Brazil

This study identified the role of biological and social determinants in the transmission of schistosomiasis mansoni in Ravena, Minas Gerais, Brazil, in 1980. This data was used to characterize the clinical and epidemiological profiles of the endemic desease in the population, allowing for the determination of the efficacy of the potable water supply and the specific treatment of those infected with S. mansoni. The district contains three locations, Ravenopolis, Ravena and Lavapes, where the prevalence of the endemic disease was, 20.1%, 42.6% and 63.9%, respectively. The prevalence in the district was statistically higher in men. The age brackets that displayed differences by gender were 10-14 and 15-19 years. Severity of infection was statistically different among individuals within the 10-14 year bracket in ali three locations, and in the 15-19 year bracket among individuals from Ravenopolis and Ravena. The hepatointestinal form was associated with age, and individuals under 15 years of age presented risk of infection 8.85 times higher than adults. Multivariable analysis of the factors involved in transmission of the disease showed that Lavapes was independently associated with infection. In that area, poor sanitary conditions and the proximity of houses to streams infested with S. marsoni cercariae facilitated infection of neighborhood women while performing domestic activities, as well as men digging sand from the streams for construction. These results show the focal nature of transmission of the endemic requiring specific intervention for effective control of disease.     

我院真菌感染的调查

目的 了解某医院真菌感染及其耐药情况，为临床治疗提供依据。方法 采用回顾性调查方法，对全院2001年1～12月分离出的268株真菌进行鉴定及药敏分析。结果 全年分离出真菌14种共268株，其中白色念珠菌131株(48．88％)，热带念珠菌76株(28．36％)，光滑念珠菌23株(8．58％)，近平滑念珠菌15株(5．60％)；以上四种共245株，占91．42％。药物敏感实验结果显示，真菌对不同药物有不同程度的耐药，以酮康唑最高。结论 在268株医院内感染真菌中，主要为白色念珠菌与热带念珠菌，对酮康唑的耐药性较高。     

1979—1988年我国人间鼠疫及防治对策

本文分析了1979~1988年中国人间鼠疫疫情。十年中,在四种类型鼠疫自然疫源地、行政区划的六个省、自治区24个县发生鼠疫病人99例,死亡55例,病死率为55.56%。其中90%以上鼠疫患者、全部肺鼠疫病人及死亡病例均发生在中国西部旱獭疫源地。剥食、接触疫獭和其它染疫动物是动物鼠疫传入人间的主要途径。据疫情分析,提出了今后防治对策。     

重症监护病房深部真菌感染回顾性分析

目的分析重症监护病房(ICU)患者深部真菌感染的常见菌种、好发部位及耐药性,并探讨其危险因素。方法2006年1月-2007年3月入住ICU患者所送的各类感染标本进行真菌培养分离菌株,鉴定采用API 20CAUX,Rosco纸片扩散法测定药敏性。结果共检出真菌123株,以白色假丝酵母菌检出率最高(34.1%),其次为光滑假丝酵母菌(26.8%)、热带假丝酵母菌(18.7%);所有分离的菌株对两性霉素B、制霉菌素敏感,对氟康唑、伊曲康唑及酮康唑部分耐药;长期使用广谱抗菌药物、留置导管、老年患者诱发真菌感染率高。结论假丝酵母菌属是ICU院内获得性真菌感染的主要病原菌;感染的主要部位在下呼吸道;两性霉素B、制霉菌素敏感性仍较好,但其毒性较大;三唑类药物对白色假丝酵母菌及热带假丝酵母菌也有较高的敏感性,但光滑假丝酵母菌、克柔假丝酵母菌对三唑类药物具有较高的耐药率;合理使用抗菌药物,减少不必要的诊疗操作,早发现、早诊断、早治疗是防治深部真菌感染的关键。     

Biomphalaria glabrata in Haiti

Biomphalaria glabrata, an intermediate host for Schistosoma mansoni, was first reported in Haiti in 1891 at one location in the Départment du Nord and in 1977 it was reported at several sites in one additional watershed. Our study identifies two additional locations each on a different watershed plus a third possible site. A wide but discontinuous distribution of the snail on the north coast of Haiti is confirmed (no autochthonous infections with S. mansoni have been reported). While there are many possible explanations for this discontinuous distribution, a role for the competitor Thiara granifera in shaping the current distribution of B. glabrata is suggested. The incursion of B. glabrata into Haiti is not recent but at the same time is not expanding.     

Intra-household clustering of hepatitis C virus infection in Karachi, Pakistan

Transmission rates of hepatitis C virus (HCV) infection through non-sexual household contacts have been considered to be very low. This study evaluated intra-household clustering of cases of HCV infection in a low socio-economic community in Karachi, Pakistan. Serum samples from 341 household contacts of 86 thalassaemic HCV-seropositive children were evaluated for antibodies to HCV using an ELISA. Spatial analysis of data was carried out to test for intra-household clustering. Seventy of 341 (20.5%) household contacts were HCV-seropositive. Of the households studied, 44.2% (38/86) had one or more contacts who tested HCV-seropositive. Ecological analysis of variables at household level showed that in households where HCV-seropositive index thalassaemic children were male HCV tended to be transmitted to one or more familial contacts. Spatial analysis with an asymptotic score test of the null hypothesis of no extra within-family infectivity revealed that there was a significant tendency of HCV infection to cluster within a household (score statistic = 19.44, P=0.032). The results showed that non-sexual household exposure may play a role in efficient HCV spread to household contacts of HCV-infected persons and needs further evaluation.     

老年慢性阻塞性肺疾病继发肺真菌病的危险因素研究

目的探讨慢性阻塞性肺疾病（COPD）患者继发医院肺部真菌感染的危险因素。方法采用病例对照研究方法,回顾性分析52例COPD继发肺部真菌感染患者的临床资料,并随机选择同期住院的未继发肺部真菌感染的52例COPD患者作为对照,分析其危险因素。结果52例医院肺部真菌感染患者感染菌种包括：白假丝酵母菌40例(76.92%),光滑假丝酵母菌3例(5.77%),热带假丝酵母菌7例(13.46%),毛霉菌属及曲霉菌属各1例(1.92%)。单因素分析结果显示,广谱抗菌药物使用时间＞14 d、累计全身使用肾上腺糖皮质激素＞500 mg、低蛋白血症、Ⅱ型呼吸衰竭、机械通气及合并糖尿病与COPD患者发生医院肺部真菌感染有关。多因素Logistic回归分析结果显示,累计全身使用肾上腺糖皮质激素＞500 mg、广谱抗菌药物使用时间＞14 d、机械通气、合并Ⅱ型呼吸衰竭是COPD患者继发医院肺部真菌感染的重要危险因素。结论了解COPD继发医院肺部真菌感染的危险因素,有助于针对性地采取防控措施,减少深部真菌感染的发生。     

Influenza in Poland in 2000

In 2000 the number of cases of influenza and influenza-like illness (ILI) registered in Poland amounted to 1,596,920 (68.1% of 1999 cases). The highest influenza incidence was reported in ?ódzkie voivodship (9,388.8 cases per 100,000). Among children aged 0 to 14 years the number of influenza and ILI cases amounted to 408,495 (incidence 5,518.8 cases per 100,000) and was 25.5% of the total number of cases recorded in 2000. The number of patients referred to hospital was 7,028 and 358 persons died due to influenza and its complications. No influenza strains were isolated in 2000. Immunofluorescence test confirmed infection with influenza type A in 39 patients, while with type B--in 2 patients. Sero-surveys carried out in the epidemic season 2000/2001 showed that the highest antihemagglutinin antibody levels were produced for influenza strain A(H3N2) and B. The highest antibody titers were recorded in the age group 15-25, while the lowest levels--in the age group 0-3 years.     

Infection rates from Covid-19 in Great Britain by geographical units: A model-based estimation from mortality data

This study estimates cumulative infection rates from Covid-19 in Great Britain by local authority districts (LADs) and council areas (CAs) and investigates spatial patterns in infection rates. We propose a model-based approach to calculate cumulative infection rates from data on observed and expected deaths from Covid-19. Our analysis of mortality data shows that 7% of people in Great Britain were infected by Covid-19 by the last third of June 2020. It is unlikely that the infection rate was lower than 4% or higher than 15%. Secondly, England had higher infection rates than Scotland and especially Wales, although the differences between countries were not large. Thirdly, we observed a substantial variation in virus infection rates in Great Britain by geographical units. Estimated infection rates were highest in the capital city of London where between 11 and 12% of the population might have been infected and also in other major urban regions, while the lowest were in small towns and rural areas. Finally, spatial regression analysis showed that the virus infection rates increased with the increasing population density of the area and the level of deprivation. The results suggest that people from lower socioeconomic groups in urban areas (including those with minority backgrounds) were most affected by the spread of coronavirus from March to June.     

Scarlet fever in Poland in 2002

Following the last epidemic in 1995 the scarlet fever incidence in Poland has been gradually decreasing, on average 20% per year. The downward trend continued in 2002, the overall incidence rate being 10.6 per 100,000. It was the lowest incidence registered in Poland since the introduction of mandatory reporting of scarlet fever in 1918 (the lowest so far registered incidence rates were 15.2 in 2001 and 17.5 in 1918). Spatial distribution of cases was relatively even--incidence ranged from 5.0 per 100,000 in ?ódzkie voivodeship to 25.1 in opolskie voivodeship. As observed previously incidence in the urban areas (12.0) was significantly higher then in the rural areas (8.4) and the incidence in men (11.7) exceeded the incidence in women (9.6). The majority of cases occurred in children and adolescents younger then 15 years (mode--6 years). Two percent of cases were hospitalized. There were no deaths due to scarlet fever reported in 2002.     

Estimate of HIV prevalence in pregnant women by means of spatial analysis in Southern Brazil

Spatial analysis techniques were used to estimate the interurban differential HIV prevalence among pregnant women in the city of Porto Alegre, Southern Brazil. The estimates were produced through the spatial smoothing of residence pinpoints with live newborns and HIV infected pregnant women for the year of 2003. The overlay of high prevalence areas in city slums was identified. This finding confirms the intensification of AIDS epidemic among poor urban populations, and indicates areas where basic care and educational strategies should be reinforced.     

Plague metapopulation dynamics in a natural reservoir: the burrow system as the unit of study

The ecology of plague (Yersinia pestis infection) in its ancient foci in Central Asia remains poorly understood. We present field data from two sites in Kazakhstan where the great gerbil (Rhombomys opimus) is the major natural host. Family groups inhabit and defend burrow systems spaced throughout the landscape, such that the host population may be considered a metapopulation, with each occupied burrow system a subpopulation. We examine plague transmission within and between family groups and its effect on survival. Transmission of plague occurred disproportionately within family groups although not all gerbils became infected once plague entered a burrow system. There were no spatial patterns to suggest that family groups in close proximity to infected burrow systems were more at risk of infection than those far away. At one site, infection increased the chances of burrow-system extinction. Overall, it is useful to consider the burrow system as the unit of study within a much larger metapopulation.