Amebic liver abscess: epidemiology, clinical features, and outcome.
Amebic liver abscess (ALA) is a serious, but readily treatable form of hepatic infection. In order to understand the clinical features of this condition in the United States, we reviewed the medical histories of 56 patients with ALA at two large San Francisco Hospitals from 1979 to 1994. Patients were divided into the following groups based on the presumed manner in which they had acquired ALA: those born or raised in the United States, with a history of travel to an endemic area (Tr-ALA); those from an endemic area, but living in the United States for less than one year (En-ALA); and those neither from nor having traveled to an endemic area (N-ALA). We found distinct clinical patterns in patients from different epidemiological groups. Patients with Tr-ALA were a decade older than those from endemic regions, were more likely to be male, and tended to have an insidious onset. Furthermore, compared to patients with En-ALA, those with Tr-ALA were more likely to have hepatomegaly (P < 0.0001) and large abscesses (ALA > 10 cm; P < 0.01). One third of the patients studied had no associated travel history or endemic origin as risk factors. Of these, 63% had a condition consistent with severe immunosuppression, such as infection with the human immunodeficiency virus (HIV), malnourishment with severe hypoalbuminemia, or chronic infection. In patients with N-ALA, the presence of a presumed immunosuppressed state increased significantly, as compared to patients with endemic or travel risk factors for ALA. During the last five years of the study, one third of all patients diagnosed with ALA were HIV positive (including 2 with a new diagnosis of AIDS), many of whom were discovered to be HIV-infected only after presentation with ALA. We conclude that travel to and origin in an endemic area are important risk factors for the development of ALA, and patients in these different epidemiological groups appear to have distinct clinical features. Further, in the absence of recognized risk factors, the development of ALA may suggest an immunocompromised host. (+info)
Acute Chagas' disease in western Venezuela: a clinical, seroparasitologic, and epidemiologic study.
A clinical, parasitologic, and serologic study carried out between 1988 and 1996 on 59 acute-phase patients in areas of western Venezuela where Chagas' disease is endemic showed 19 symptomatic patterns or groups of symptoms appearing in combination with different frequencies. The symptomatic pattern with the highest frequency was that showing simultaneously fever, myalgia, headache, and Romana's sign, which was detected in 20% of the acute-phase patients. Asymptomatic individuals and patients with fever as the only sign of the disease made up 15% and 11.9% of the total acute cases, respectively. Statistical correlation analysis revealed that xenodiagnosis and hemoculture were the most reliable and concordant of the five parasitologic methods used; these two methods also showed the highest proportions in detecting any clinical symptomatic pattern in acute-phase patients. A similar high reliability and concordance was obtained with a direct agglutination test, an indirect immunofluorescent antibody test, and an ELISA as serologic tests, which also showed a higher proportion of positive detection of clinical patterns than parasitologic methods (P < 0.001). It is recommended that individuals coming from endemic areas showing mild and/or severe clinical manifestations should be suspected of being in contact or having been in contact with Trypanosoma cruzi, be referred for parasitologic and serologic evaluations to confirm the presumptive clinical diagnosis of acute Chagas' disease, and start specific treatment. The epidemiologic implications of the present findings are discussed and the use of similar methodology to evaluate other areas where Chagas' disease is endemic is suggested. (+info)
Treatment of malarial acute renal failure by hemodialysis.
We studied 112 patients with malarial acute renal failure (ARF) during the period 1991-1997 at Bangkok Hospital for Tropical Diseases (Mahidol University, Bangkok, Thailand). Hemodialysis was performed in 101 (90.2%) of these patients. The mean number of times the patients were hemodialyzed was 6.5 (range = 1-27). Ninety-three (83.0%) patients were oliguric and the remainder were nonoliguric. Patients who had oliguric renal failure required more hemodialyses and had more complications than the nonoliguric patients. The oliguric patients had an eight-fold higher risk of requiring six or more hemodialyses (95% confidence interval = 1.2-53.9, P = 0.0008). The overall mortality rate was 10.7% (12 of 112). Eleven of the patients who died were jaundiced and eight of them had cerebral malaria with a Glasgow Coma Score < or = 8. We conclude that hemodialysis is a useful treatment for oliguric and nonoliguric ARF from severe malaria, particularly when initiated early in the course of the illness. (+info)
Mortality due to schistosomiasis mansoni: a field study in Sudan.
Although schistosomiasis affects 200 million persons, 20 million of whom have advanced disease, little is known about the mortality pattern in areas of endemic schistosomiasis mansoni. In an attempt to assess the mortality rates in an endemic area in Sudan, we conducted two demographic surveys in a village in the Gezira area. Clinical, sonographic, and parasitologic examinations were performed in a randomly selected sample of 25% of the population in 1987 and 1994. One of us asked each head of household about the names, sex, and age of family members. Particularly, we asked about death in the family if any, history of schistosomiasis, abdominal swelling, and hematemesis. Possible causes of death were ascertained by reviewing medical records in the village dispensary and the district hospital. There were 42 deaths in the village. Four males died of hematemesis secondary to portal fibrosis. The crude mortality rate of schistosomiasis was is 51/100,000/year. The overall schistosomiasis fatality rate per year was 1/1,000 infected persons, but was as high as 11/100/infected patients with bleeding varices. These findings showed the impact of schistosomiasis on public health in this economically important region of Sudan. (+info)
The role of humic substances in drinking water in Kashin-Beck disease in China.
We conducted in vitro and in vivo assays in a selenium-deficient system to determine if organic matter (mainly fulvic acid; FA) is involved in a free radical mechanism of action for Kashin-Beck disease. Cartilage cell culture experiments indicated that the oxy or hydroxy functional groups in FA may interfere with the cell membrane and result in enhancement of lipid peroxidation. Experiments with rats demonstrated that toxicity from FA was reduced when the hydroxy group was blocked. Induction of lipid peroxidation by FA in liver and blood of rats was similar to that exhibited by acetyl phenyl hydrazine. FA accumulated in bone and cartilage, where selenium rarely concentrates. In addition, selenium supplementation in rats' drinking water inhibited the generation of oxy-free radicals in bone. We hypothesized that FA in drinking water is an etiological factor of Kashin-Beck disease and that the mechanism of action involves the oxy and hydroxy groups in FA for the generation of free radicals. Selenium was confirmed to be a preventive factor for Kashin-Beck disease. (+info)
Is group C meningococcal disease increasing in Europe? A report of surveillance of meningococcal infection in Europe 1993-6. European Meningitis Surveillance Group.
A surveillance system to assess the impact and changing epidemiology of invasive meningococcal disease in Europe was set up in 1987. Since about 1991, contributors from national reference laboratories, national communicable disease surveillance centres and institutes of public health in 35 European countries provided information on all reported cases of meningococcal disease in their country. We describe some trends observed over the period 1993-6. The main findings were: the overall incidence of meningococcal disease was 1.1 per 100000 population but there was some evidence of a slow increase over time and with northern European countries tending to have a higher incidence (Kendall correlation 0.5772, P < 0.001), an increasing predominance of serogroup C, and a shift in the age distribution towards teenagers and away from younger children (chi2 test for trend 44.56, P < 0.0001), although about half of the cases were under 5 years of age. The overall case fatality rate was 8.3% and the most common serosubtypes were B:15:P1.7,16 and C:2a:P1.2,5. (+info)
Clinical and epidemiological features of group A streptococcal bacteraemia in a region with hyperendemic superficial streptococcal infection.
Reports of increasing incidence and severity of invasive group A streptococcal (GAS) infections come mainly from affluent populations where exposure to GAS is relatively infrequent. We conducted a 6-year retrospective review of GAS bacteraemia in the Northern Territory of Australia, comparing the Aboriginal population (24% of the study population), who have high rates of other streptococcal infections and sequelae, to the non-Aboriginal population. Of 72 episodes, 44 (61%) were in Aboriginal patients. All 12 cases in children were Aboriginal. Risk factors were implicated in 82% of episodes (91% in adults) and there was no significant difference in the proportion of Aboriginal compared to non-Aboriginal patients with at least one risk factor. Genetic typing of isolates revealed no dominant strains and no evidence of a clone which has been a common cause of these infections elsewhere. (+info)
Proteinuria is associated with persistence of antibody to streptococcal M protein in Aboriginal Australians.
Aboriginal communities in Northern Australia with high rates of group A streptococcal (GAS) skin infection in childhood also have high rates of renal failure in adult life. In a cross-sectional study of one such high risk community, albuminuria was used as a marker of renal disease. The prevalence of albuminuria increased from 0/52 in subjects aged 10-19 years to 10/29 (32.9%) in those aged 50 or more (P < 0.001). Antibodies to streptococcal M protein, markers of past GAS infection, were present in 48/52 (92%) at ages 10-19 years, 16/32 (50%) at ages 30-39, and 20/29 (69%) in those aged 50 or more. After allowing for the age-dependencies of albuminuria and of M protein antibodies (P < 0.001) albuminuria was significantly associated with M protein antibodies (P < 0.01). Thus, 72% of adults aged 30 or more with M protein antibodies also had albuminuria, compared with only 21% of those who were seronegative. More detailed modelling suggested that although most Aboriginal people in this community developed M protein antibodies following GAS infection in childhood, the development of proteinuria was associated with the persistence of such seropositivity into adult life. The models predicted that proteinuria developed at a mean age of 30 years in seropositive persons, at 45 years in seronegative persons who were overweight, and at 62 years in seronegative persons of normal weight. We demonstrated a clear association between evidence of childhood GAS infection and individual risk of proteinuria in adult life. This study provided a strong rationale for prevention of renal disease through the more effective control of GAS skin infections in childhood and through the prevention of obesity in adult life. (+info)