Epidemiologic surveillance of hydatidosis in the Patagonian region, Argentina: 1983-1988

The results of a control program of hydatid disease in five jurisdictions of the Patagonian Region in Argentina are presented. The information is glossed in rates of infection in man (95 x 100,000 in 1988 and 15 x 100,000 in 1983), dogs (21.6% in 1983 and 3.1% in 1988) and sheep (16.6% in 1983 and 2.6% in 1988). Factors that condition the endemic situation of hydatidosis in the region are discussed.     

Epidemiology of hydatidosis in the province of Sassari, Italy

Cystic echinococcosis is endemic in certain parts of the world, including Sardinia, Italy. It was performed a study in the province of Sassari in order to evaluate the incidence of the infection in man and the effects of control programs since 1964 to 2002. Data obtained by surgical records, hospital discharge forms, radiological and pathological files were collected using a case report form. During the years 1964-2002, 2702 new cases were identified (average annual incidence: 17 per 100,000) and 1981 (73.3%) were submitted to surgical treatment. In 57.3% municipalities no cases were observed during the years 1998-2002. Males are more affected (56.2%), mostly farmers-shepherdess (68.6 per 100,000) and pensioners (59.6 per 100,000). Control measures led to a significant decline in the incidence rate of hydatidosis during the period 1964-2002, dropping by 27.6 per 100,000. The mean age of surgical patients increased during the years of surveillance, such as the surgical liver/lung ratio as a consequence of a cohort effect. The durability of control programs is the corner stone for obtaining a significant decrease of this infection.     

Human hydatidosis in Chile. Seroprevalence and estimate of the number of infected people

Chile is located in the southwestern border of South America. The country is 4,329 km long and 96-342 wide. From north to south it is divided into five marked different biogeographical zones: deserts, steppes, bushes, forests (cattle raising) and austral (sheep raising). Population (June 1999) 15,017,760 (14.6% rural). Human hydatidosis is endemic in Chile. According to Ministry of Health information about 320 cases are registered each year. In order to find out the likely prevalence of human hydatidosis in Chile, a series of serosurveys was carried out in 1988-1997 throughout the total country. By using the indirect hemagglutination reaction and ELISA for hydatidosis (tests with good sensibility and specificity) 60,790 unselected apparently healthy persons: 41,399 from urban areas (16,428 blood donors, 13,894 delivering mothers and 11,077 middle grade schoolchildren) and 19,361 from rural areas--from randomly selected family groupings--were studied. A total individuals 82 (136/100,000) resulted positive: 36 (87/100,000) urban and 46 (241/100,000) rural, being the prevalence higher in rural areas, particularly in the southern austral zone (mean 1068/100,00). These figures agree with those observed in clinical epidemiological studies. In conformity with the present results, in the whole country 17,002 individuals should have hydatidosis: 10,318 urban and 6,784 rural. All these possible infected people, not necessarily should present pathology in the future, as it has been observed in autopsies from unselected individuals, performed at the Medico-Legal Service in Santiago, in whom 71.3% of diagnosed hydatosis with hydatid cysts in many different locations, was an autopsy finding.     

Seroepidemiological study of human hydatidosis, by means of an indirect hemagglutination test in Rio Negro County, X Region, Chile, 1989-1990

Rio Negro Country (40 degrees 48'-40 degrees 50' South lat.; 73 degrees 12'-73 degrees 13' West long.), is located in the province of Osorno, South of Chile. It has a population of 18,031 inhabitants, with 39% in rural areas. The basic economic activity is cattle raising (cows, pigs). According to reports, prevalence of human hydatidosis in 1988 was 11.1 per 100,000. In order to contribute to a better knowledge of human hydatidosis in Rio Negro County, an indirect hemagglutination test (IHAT) was performed to 509 randomized persons. Five (1.0%) individuals resulted positive.     

Hydatidosis in the province of La Pampa, Argentina, 1998

Echinococcus granulosus is the agent that causes the classical hydatidosis or cystic echinococcosis. The most spread cycle in South America is the sheep-dog cycle, and offers favorable conditions for the development of the parasite. As the province of La Pampa shows an endemic presence with notification of cases and infected dogs, the present work has the aim of contributing to the study of the distribution and prevalence of the disease in the district of Maracó, La Pampa, Argentina. Dogs of 36 farms that had ovines, were dosed with arecoline hydrobromide at a dose of 3.5 mg/kg. Dogs from 27 (75%) farms resulted positive to Tenia sp. and 3 (8.3%) to E. granulosus. Blood samples were taken to all the people living in all the inquired farm and were processed by the ELISA test for hydatidosis. A retrospective survey on cases of human hydatidosis attended in the Hospital of General Pico, head if the sanitary region, and in two private clinics was performed. Analysis of clinical records indicated 11 cases operated during the period 1996/1997 (annual incidence rate of 6.8 per 100,000 inhabitants). It is of public health interest to fulfill epidemiologic investigations in other districts of the Province of La Pampa with the aim of delimitating the endemic distribution within the province and also organizing surveillance systems on human hydatidosis.     

Epidemiology of human hydatidosis in the IX Region of la Araucania, Chile 1991-1998

In the region of la Araucania, located in the south of Chile (37 degrees 24'-39 degrees 34' South lat.), the economy is based in cattle raising and agriculture. The cases of human hydatidosis, mortality and notification registered in la Araucania 1991-1998 are reviewed. The rate for hydatid disease is 38.5 per 100,000 population. Liver (47.1%) and lung (40.7%) were the most affected viscera. Days in hospital, 11-20 the 56.1%. Disease in female is 51.1%. The mortality rate is 0.8 per 100,000, the most frequently affected county is Imperial. The age group 15-44 years is the most affected. The notification rate is 8.74 per 100,000 population. The rate for hydatid disease is higher than the rate of notification, then necessarily there exist a subnotification. We think that it is necessary to investigate the serological prevalence of hydatidosis in the population of the IX Region Araucania.     

An elderly man with cholestatic jaundice due to biliary hydatidosis

Hydatid disease is found throughout the world, with a higher prevalence in the Mediterranean area. In Spain, the most endemic regions are Rioja and Aragon, with rates above 10 cases/100,000 inhabitants, followed by Castilla-La Mancha and Castilla y Leon (5-10 cases/100,000 inhabitants). This parasitic disease is caused by the larval stage of Echinococcus granulosus (EG) and the main organs affected are the liver and the lung (85 % cases). We present a case of obstructive jaundice and secondary cholangitis due to a biliary hydatidosis. Abdominal computed tomography scan showed dilatation of the entire biliary tract. The technique used for diagnosis and treatment was endoscopic retrograde cholangiopancreatography.     

Distribution of surgical hydatidosis in Tunisia, results of 2001-2005 study and trends between 1977 and 2005

We have performed an exhaustive retrospective study in all surgical wards (54 services in 35 hospitals) which usually carry out surgical treatment of hydatic cysts in the country, covering the period between January 2001 and December 2005, in order to determine the annual surgical incidence of human cystic hydatidosis in Tunisia. A total of 6249 surgical interventions were recorded during the period 2001-2005. The highest proportion was recorded in the hospitals of Tunis District (42.9%). The service of thoracic surgery from Ariana hospital occupies the first rank (95%). The yearly incidence rate varies between 11 and 13.6 per 100,000. Calculated over the 5 years period, the incidence rate is 63.2 per 100,000 inhabitants, which means an average yearly incidence rate of 12.6 per 100,000 [12.28-12.99]. Governorates of the North West and the Western Central regions of the country are the most endemic area with an average annual incidence rates varying between 19.2 and 33.9 per 100,000, which is at least once and half higher than the national level. After 30 years (1977-2005), the average annual incidence rate slightly dropped, from 15 to 12.6 per 100,000, proving that such zoonosis remains a problem of public health in Tunisia. In order, to control in more or less short term this heavy burden disease and public health expenditure, the only efficient way is the prevention of the diseases with a mass treatment campaign of dogs, principal host of the parasite.     

Trends in coronary artery bypass grafting in Ontario from 1981 to 1989.

OBJECTIVES: To determine the trends in overall and age-specific rates of coronary artery bypass grafting (CABG) in Ontario from 1981 to 1989 and to assess whether relative resource scarcity, as manifested in waiting lists, resulted in obvious age-related or sex-related changes in utilization. DESIGN: Computerized compilation of hospital discharge abstracts from the Hospital Medical Records Institute. All separations for every other year from Apr. 1, 1981, to Mar. 31, 1990, were included. Procedures rather than patients were the unit of analysis (repeat procedures were double-counted if associated with separate hospital admissions). SETTING: Ontario acute care hospitals offering CABG. PATIENTS: People aged 20 years and over who underwent one or more CABG procedures. RESULTS: The overall rate of CABG increased by 31% in the study period, plateauing only between 1983 and 1985. By 1989-90 the rate was 66.03 per 100,000. The highest annual increase in the rate was among people aged 65 to 74 years, at 17.61 procedures per 100,000, as compared with 4.64 per 100,000 among people 75 years and over. In 1989-90 those aged 65 and over represented 37% of the total caseload. The overall male:female ratio did not change significantly throughout the study period. CONCLUSIONS: Since the CABG utilization rate continues to increase in Ontario, recent waiting lists must be due to a disproportionate growth in demand. There was no convincing evidence of age-related or sex-related discrimination in allocating this limited resource. Supply-demand mismatch was driven above all by the continued increase in CABG use among elderly people.     

Echinococcosis: An Economic Evaluation of a Veterinary Public Health Intervention in Rural Canada

Echinococcosis is a rare but endemic condition in people in Canada, caused by a zoonotic cestode for which the source of human infection is ingestion of parasite eggs shed by canids. The objectives of this study were to identify risk factors associated with infection and to measure the cost-utility of introducing an echinococcosis prevention program in a rural area. We analyzed human case reports submitted to the Canadian Institutes for Health Information between 2002 and 2011. Over this 10 year period, there were 48 cases associated with E. granulosus/E. canadensis, 16 with E. multilocularis, and 251 cases of echinococcosis for which species was not identified (total 315 cases). Nationally, annual incidence of echinococcosis was 0.14 cases per 100 000 people, which is likely an underestimate due to under-diagnosis and under-reporting. Risk factors for echinococcosis included female gender, age (>65 years), and residing in one of the northern territories (Nunavut, Yukon, or Northwest Territories). The average cost of treating a case of cystic echinococcosis in Canada was $8,842 CAD. Cost-utility analysis revealed that dosing dogs with praziquantel (a cestocide) at six week intervals to control cystic echinococcosis is not currently cost-effective at a threshold of $20,000-100,000 per Quality Adjusted Life Year (QALY) gained, even in a health region with the highest incidence rate in Canada ($666,978 -755,051 per QALY gained). However, threshold analysis demonstrated that the program may become cost-saving at an echinococcosis incidence of 13-85 cases per 100,000 people and therefore, even one additional CE case in a community of 9000 people could result in the monetary benefits of the program outweighing costs.     

Insulin dependent diabetes in childhood and material deprivation in northern England, 1977-86.

OBJECTIVE--To determine the incidence of insulin dependent diabetes in the Northern region of England in children less than 16 years old in the period 1977 to 1986 and to relate the incidence data to an index of deprivation. DESIGN--Retrospective analysis of hospital case records identified from the regional health authority''s computer; validation of the primary source with hospital clinic registers and community paediatric registers. SETTING--Northern region, excluding South Cumbria District Health Authority (659,300 children under 16 in 1981). PATIENTS--All children diagnosed with insulin dependent diabetes before the age of 16 and resident in the region at time of diagnosis. MAIN OUTCOME MEASURES--Incidence rates for the 10 year period and analysis of incidence rates within categories of deprivation. RESULTS--919 incident cases were identified. The validation procedure covered 54% of all cases identified and gave 95% completeness of ascertainment. The average annual incidence over the 10 year period was 14.8/100,000 for girls and 13.4/100,000 for boys. The annual incidence for the most and least deprived areas of the region was 18.7/100,000 (95% confidence interval 16.2 to 21.5) for boys and 7/100,000 (5.6 to 8.8) for girls. There was a highly significant trend (p less than 0.001) of decreasing incidence with decreasing level of deprivation. CONCLUSIONS--In the north of England the incidence of childhood diabetes is related to material deprivation.     

The control of viral diseases in the developing countries with the use of existing vaccines]

In developing countries, every year about 70 million measles cases occur with 1.5 million deaths, over 200,000 children contract paralytic poliomyelitis, 50 million people get infected with viral B hepatitis causing over 1 million deaths, and several thousand people perish because of yellow fever according to WHO data. At the present time, there are 12 vaccines against viruses: vaccines against German measles and mumps in addition to the above. The universal immunization program (UIP) of WHO targets measles and polio. In 1989, a WHO resolution envisioned a 90% immunization coverage by the year 2000. Measles vaccination is recommended for children aged 9-23 months, since most children have maternal antibodies during the first 3-13 months of age. The Edmonston-Zagreb vaccine provided seroconversion of 92, 96, and 98% for 18 months vs. the 66, 76, and 91% rate of the Schwarz vaccine. In the US, measles incidence increased from 1497 cases in 1983 to 6382 cases in 1988 to over 14,000 cases in 1989, prompting second vaccination in children of school age. The highest incidence of polio was registered in Southeast Asia, although it declined from 1 case/100,000 population in 1975 to .5/100,000 in 1988. Oral poliomyelitis vaccine (OPV) provides protection: there is only 1 case/2.5 million vaccinations. Hepatitis B has infected over 2 billion people. About 300 million are carriers, with a prevalence of 20% in African, Asian, and Pacific region populations. Plasmatic and bioengineered recombinant vaccine type have been used in 30 million people. The first dose is given postnatally, the second at 1-2 months of age, and the 3rd at 1 year of age. Yellow fever vaccine was 50 years old in 1988, yet during 1986-1988 there were 5395 cases with 3172 deaths in Africa and South America. Vaccination provides 90-95% seroconversion, and periodic follow-up vaccinations under UIP could eradicate these infections and their etiologic agents.     

Epidemiology of Echinococcus granulosus in Arbil province, northern Iraq, 1990-1998

During the period 1990-1998, 99 cases of human cystic hydatidosis (12.4 cases per year) were surgically treated at the two main hospitals in Arbil province, northern Iraq, and from this the human occurence for the province was estimated to be 2 per 100,000 inhabitants. In the same area, 1270 sheep, 550 goats and 320 cattle were examined at slaughter for hydatid cysts and prevalence rates were found to be 15.0%, 6.2% and 10.9%, respectively. A decreasing tendency in livestock prevalences was found towards the end of the study period. As in humans, most of the hydatid cysts in livestock were located in the liver. Fertility of sheep cysts, i.e. those containing protoscoleces, was found to be significantly higher (64%) than that of goats (35.7%) and cattle (29.8%). The percentage of fertile cysts containing viable protoscoleces varied between 63 and 82% in the livers and between 72 and 79% in the lungs of the different animal species. A total of 97 stray dogs were examined post-mortem in the years 1991, 1992 and 1998, and Echinococcus granulosus worms were found in the intestines of 48 dogs (49.5%). High worm burdens (> 1000) were observed in 37% of the dogs, medium worm burdens (200-1000) in 41%, and low worm burdens (< 200) in 22%. In 1998, the prevalence of canine echinococcosis (24.3%) was found to be significantly lower than in 1991 (70.4%) and 1992 (60.6%). The prevalence of human hydatidosis did not differ significantly over the years, but the study confirmed that hydatidosis is endemic in northern Iraq, and that housewives, labourers and farmers appear to be at the greatest risk of infection.     

Haemophilus influenzae meningitis in Manitoba and the Keewatin District,NWT: potential for mass vaccination.

A community-based surveillance study of all central nervous system infections was carried out in Manitoba and the Keewatin District, NWT, between Apr. 1, 1981, and Mar. 31, 1984. There were 201 cases of bacterial meningitis in Manitoba over the study period, 81 (40%) caused by Haemophilus influenzae; all but one isolate tested were type b (Hib). There were nine cases of H. influenzae meningitis in the Keewatin District. The overall annual incidence rate of H. influenzae meningitis in Manitoba was 2.5/100,000; for children under 5 years the rate was 32.1/100,000. For the Keewatin District the corresponding rates were 69.6/100,000 and 530/100,000. A total of 85% and 100% of the cases of H. influenzae meningitis occurred by 24 months of age in Manitoba and the Keewatin District respectively. The age at onset was earlier in native Indian children (22 cases) and Inuit children (9 cases) than in non-native children (59 cases) (p less than 0.005); thus, vaccine prevention of Hib meningitis will likely be more difficult in native Indian and Métis children. Without evaluating the increased potential of H. influenzae vaccines to prevent nonmeningitic forms of disease, we concluded that mass childhood vaccination with polyribosylribitolphosphate (PRP) vaccine is not warranted in Manitoba or the Keewatin District. Immunogenicity studies suggest that administration of conjugated Hib vaccines such as PRP-D in infancy may prevent approximately one-third to two-thirds of cases of H. influenzae meningitis; these vaccines warrant consideration for use in mass childhood vaccination programs.     

黑龙江省森林植被碳储量及其动态变化

黑龙江省的森林资源在全国森林资源中占有较为重要的位置.利用我国第一次(1973～1976年)至第六次(1999～2003年)森林资源清查资料,以及不同树种生物量和蓄积量之间的线性关系,对黑龙江省近30年来森林碳储量进行了求和推算.结果表明,黑龙江省6次森林资源清查中森林的总碳储量分别是7.916×10⁸ t、.413×10⁸ t、.661×10⁸ t、.880×10⁸ t、6.216×10⁸ t和6.011×10⁸ t,总体呈先下降后上升的趋势,说明30年间黑龙江省的森林是CO₂的"汇";特别是1977～1981年后,黑龙江省森林碳储量呈逐渐上升趋势,说明近20年来黑龙江省森林CO₂"汇"的作用在增强.如果对现有森林进行更好地抚育和管理,黑龙江省森林作为CO₂"汇"的潜力很大.     

Analysis of some variables in patients with hydatidosis surgically treated at the Regional Hospital of Valdivia, Chile, 1976-1986

A survey of surgically treated cases of hydatidosis in the province of Valdivia, Chile, was done. Data were provided by the Regional Hospital of Valdivia, and a period of eleven years was covered (1976-1986). Disease, treatment and related data from each patient were consigned. For the analysis, the information was grouped according to: sex, age, cyst location, condition of the cyst, concomitance with another pathology, condition at time of discharge, hospitalization period and number of repeat hospitalizations. In the period studied, 197 cases of hydatidosis were surgically treated. The sex distribution was 53.3% for males and 46.7 for females; the age group 10-19 years was the most affected by the disease (19.3%). The most frequent locations of hydatid cysts were the liver (58.9%) and lungs (36.5%); the 38.6% of the patients showed complicated cysts, mainly with bacterial infections (11.7%); also, 20% of the cases presented a concomitant liver-related pathology. After the operation, 153 (77.7%) clinically recovered and 27 (13.7%) non-recovered patients left the hospital and 7 (3.5%) cases died while hospitalized. The average hospitalization period was 29 days. During 1976-1986, 24 patients were rehospitalized.     

Epidemiological and immunological monitoring of tetanus in Georgia (Republic)

During the period of 1961-1990 the regular immunological and epidemiological monitoring of tetanus was carried out. At the prevaccination period (1937-1960) 140 cases of tetanus were registered, 77 patients died (morbidity rate being 0.97-0.11 per 100,000 of the population with mortality rate equal to 55.6%). At the period of mass vaccinal prophylaxis (1960-1990) 56 cases were registered and 27 patients died (the corresponding values: 0.09-0.11 with 48.2% mortality). In 1981-1990 altogether 53,213 vaccinees were examined. 4,864 vaccinees (8.9%) proved to be seronegative and 43,615 vaccinees (81.9%) were found to have protective antibody titers. 4,220 pregnant women were examined; 476 women (11.2%) proved to be seronegative and 3,576 women (84.3%) were found to have protective antibody titers. Timely specific prophylaxis proved to be the only way for decreasing tetanus morbidity.     

The manifestations of an epidemic process of typhoid infection in Moscow

The work deals with the results of typhoid morbidity in Moscow for the period of 1980-1988. The morbidity rate varied from 0.98 to 0.17 cases per 100,000 of population with a tendency towards decrease. In the structure of morbidity local cases accounted for 46.8% and cases of infection contacted outside Moscow accounted for 53.2%. The morbidity level was low throughout the whole territory, only in two districts morbidity rate was significantly higher (P = 95%) than the average morbidity rate in the whole of the city. In the group of local cases morbidity had no pronounced seasonal character, in contrast to cases due to infection contacted outside the city which were mostly registered in summer and autumn. Persons aged 21-30 years were found to be the most affected age group. The general factors, and not the contact route, are supposed to play the main role in the realization of the mechanism of infection transfer. Under modern conditions, some manifestations of the epidemic process of typhoid infection can be detected only at the level of the whole city, or even the whole country.     

Recovery of the coral Montastrea annularis in the Florida Keys after the 1987 Caribbean “bleaching event”

Many reef-building corals and other cnidarians lost photosynthetic pigments and symbiotic algae (zooxanthellae) during the coral bleaching event in the Caribbean in 1987. The Florida Reef Tract included some of the first documented cases, with widespread bleaching of the massive coral Montastrea annularis beginning in late August. Phototransects at Carysfort Reef showed discoloration of >90% of colonies of this species in March 1988 compared to 0% in July 1986; however no mortality was observed between 1986 and 1988. Samples of corals collected in February and June 1988 had zooxanthellae densities ranging from 0.1 in the most lightly colored corals, to 1.6x10⁶ cells/cm² in the darker corals. Minimum densities increased to 0.5x10⁶ cells/cm² by August 1989. Chlorophyll-a content of zooxanthellae and zooxanthellar mitotic indices were significantly higher in corals with lower densities of zooxanthellae, suggesting that zooxanthellar at low densities may be more nutrientsufficient than those in unbleached corals. Ash-free dry weight of coral tissue was positively correlated with zooxanthellae density at all sample times and was significantly lower in June 1988 compared to August 1989. Proteins and lipids per cm² were significantly higher in August 1989 than in February or June, 1988. Although recovery of zooxanthellae density and coral pigmentation to normal levels may occur in less than one year, regrowth of tissue biomass and energy stores lost during the period of low symbiont densities may take significantly longer.     

Prevalence of multiple sclerosis in five rural Suffolk practices.

OBJECTIVE--To determine a point prevalence of multiple sclerosis in part of Suffolk. DESIGN--Multiple source search for patients with multiple sclerosis in five general practices. Patients were reviewed and categorised by using general practice notes. SETTING--Five rural general practices in Suffolk, 12 May 1988. SUBJECTS--31,379 patients registered with five practices. MAIN OUTCOME MEASURES--Multiple sclerosis diagnosed by a specialist. RESULTS--The search produced a provisional list of 62 eligible patients with multiple sclerosis. Review of case notes showed that 48 had probable disease, 10 early disease, and four possible disease. The probable cases gave a crude prevalence of 153/100,000 population (95% confidence interval 109/100,000 to 196/100,000). CONCLUSIONS--Although the results should be interpreted cautiously because of the small sample size, they suggest that the prevalence of multiple sclerosis in Suffolk is higher than has been estimated from hospital data.