Achievements of schistosomiasis control in China

The control of schistosomiasis has been spectacularly successful in terms of controlling endemicity and severity of the disease during the last 50 years. It can be categorized into two stages. From 1955 through 1980, the transmission-control strategy had been widely and successfully carried out. By the end of 1980, the epidemic of schistosomiasis was successfully circumscribed in certain core regions including areas at the middle and low reaches of the Yangtze River and some mountainous areas in Sichuan and Yunnan provinces, where control of schistosomiasis had been demonstrated to be very difficult to be sustained. Therefore, since 1980, schistosomiasis control in China has been modified to employ a stepwise strategy, based on which morbidity control has been given priorities and if possible transmission control has been pursued. However, since snail-ridden areas remain unchanged so far, reinfections occur frequently. This necessitates a maintenance phase to consolidate the achievements in the control of schistosomiasis. In the mean time, we are challenged with some environmental, social and economical changes in terms of controlling schistosomiasis. Successfully controlling schistosomiasis in China is still a long-term task but will be achieved without doubt along with the economic development and the promotion of living and cultural standard of people.

The role of the scientific research in the control of schistosomiasis in endemic areas

The way the researches established the lines of direction for considering fight against schistosomiasis on the double aspect of transmission and morbidity control is outstanding. Chemotherapy in the morbidity control is emphasized. The research priorities for schistosomiasis control are mentioned.

Long-term outcomes of school-based treatment for control of urinary schistosomiasis: a review of experience in Coast Province, Kenya

Urinary schistosomiasis remains a significant burden for Africa and the Middle East. The success of population-based control programs will depend on their impact, over many years, on Schistosoma haematobium reinfection and associated disease. In a multi-year (1984-1992) control program in Kenya, we examined risk for S. haematobium reinfection and late disease during and after annual school-based treatment. In this setting, long-term risk of new infection was independently associated with location, age, hematuria, and incomplete treatment, but not with sex or frequency of water contact. Thus, very local environmental features and age-related factors played an important role in S. haematobium transmission, such that population-based control programs should optimally tailor their efforts to local conditions on a village-by-village basis. In 2001-2002, the late benefits of earlier participation in school-based antischistosomal therapy were estimated in a cohort of formerly-treated adult residents compared to never-treated adults from the same villages. Among age-matched subjects, current infection prevalence was lower among those who had received remote therapy. In addition, prevalence of bladder abnormality was lower in the treated group, who were free of severe bladder disease. Treatment of affected adults resulted in rapid resolution of infection and any detectable bladder abnormalities. We conclude that continued treatment into adulthood, as well as efforts at long-term prevention of infection (transmission control) are necessary to achieve optimal morbidity control in affected communities.

Specific schistosomiasis treatment as a strategy for disease control

The great hope for schistosomiasis treatment began with the development of oxamniquine and praziquantel. These drugs can be administered orally in a single dose and have a high curative power with minor side effects. In this study, we carried out a field experiment involving a population of 3,782 people. The population was examined at four localities in Minas Gerais within the valleys of the Doce and Jequitinhonha Rivers. In this cohort, there were 1,790 patients infected with Schistosoma mansoni (47.3%) and we showed that only 1,403 (78.4%) could be treated with oxamniquine in a single dose of 12.5-20 mg/kg orally. The other 387 (21.6%) were not treated during the first stage because of contraindications (pregnancy or impeditive diseases), absences or refusals. It was observed that, on average, 8.8-17% of the infected patients continued to excrete S. mansoni eggs at the end of the 2nd month after treatment and 30-32% of the cohort was infected by the end of the 24th month. In one of the areas that we followed-up for a total of 30 years, the prevalence of the infection with S. mansoni fell from 60.8-19.3% and the hepatosplenic form of the disease dropped from 5.8-1.3%. We conclude that specific treatment of schistosomiasis reduces the prevalence of infection in the short-term and the morbidity due to schistosomiasis in medium to long-term time frames, but does not help to control disease transmission.

Lymph scrotum: an unusual urological presentation of lymphatic filariasis. A case series study

Lymphatic filariasis (LF) causes a wide range of clinical signs and symptoms, including urogenital manifestations. Transmission control and disability/morbidity management/control are the two pillars of the overall elimination strategy for LF. Lymph scrotum is an unusual urological clinical presentation of LF with important medical, psychological, social and economic repercussions. A retrospective case series study was conducted on outpatients attended at the National Reference Service for Filariasis, in an endemic area for filariasis (Recife, Brazil), between 2000 and 2007. Over this period, 6,361 patients were attended and seven cases with lymph scrotum were identified. Mean patient age was 45 years (range, 26 to 64 years). Mean disease duration was 8.5 years (range, two to 15 years). All patients had evidence of filarial infection from at least one laboratory test (parasitological, antigen investigation or "filarial dance sign" on ultrasound). Six patients presented histories of urological surgery. The authors highlight the importance of the association between filarial infection and the inadequate surgical and clinical management of hydrocele in an endemic area, as risk factors for lymph scrotum. Thus, filarial infection should be routinely investigated in all individuals presenting urological morbidity within endemic areas, in order to identify likely links in the transmission chain.

Brazilian contributions to epidemiological aspects of schistosomiasis mansoni

A review of epidemiological aspects of endemic areas for schistosomiasis, especially in Brazil, will be presented. These studies, performed by several authors from different states of the country, have been very useful in indicating the relative efficacy of control measures. For example quoting only one aspect, specific treatment was demonstrated by Brazilian researches to be the most important individual tool for morbidity control. More recently the study of risk factors in endemic areas has been seen to be a very important approach when transmission control is the final goal.

Chemoresistance of Plasmodium falciparum and Plasmodium vivax parasites in Brazil: consequences on disease morbidity and control

In Brazil, malaria still remains a clinically important febrile syndrome for local populations and travelers, occurring mostly in the Amazon Basin. This review aims to report the main efforts employed to control this disease since the 1940s and the emergence of Plasmodium falciparum and Plasmodium vivax chemoresistance to chloroquine and sulphadoxine-pyrimethamine among other drugs. Additionally, in vivo, in vitro and molecular studies as well as malaria chemoresistance consequences on disease morbidity and policy treatment guidelines were commented.

Risks of endemicity, morbidity and perspectives regarding the control of Chagas disease in the Amazon Region

Chagas disease, in the Amazon Region as elsewhere, can be considered an enzootic disease of wild animals or an anthropozoonosis, an accidental disease of humans that is acquired when humans penetrate a wild ecosystem or when wild triatomines invade human dwellings attracted by light or searching for human blood. The risk of endemic Chagas disease in the Amazon Region is associated with the following phenomena: (i) extensive deforestation associated with the displacement of wild mammals, which are the normal sources of blood for triatomines, (ii) adaptation of wild triatomines to human dwellings due to the need for a new source of blood for feeding and (iii) uncontrolled migration of human populations and domestic animals that are already infected with Trypanosoma cruzi from areas endemic for Chagas disease to the Amazon Region. Several outbreaks of severe acute cases of Chagas disease, as well as chronic cases, have been described in the Amazon Region. Control measures targeted to avoiding endemic Chagas disease in the Amazon Region should be the following: improving health education in communities, training public health officials and communities for vector and Chagas disease surveillance and training local physicians to recognise and treat acute and chronic cases of Chagas diseases as soon as possible.

Morbidity of Chagas heart disease in the microregion of Rio Negro, Amazonian Brazil: a case-control study

A case-control study on the morbidity of Chagas heart disease was carried out in the municipality of Barcelos in the microregion of the Rio Negro, state of Amazonas. One hundred and six individuals, who were serologically positive for Trypanosoma cruzi infection, as confirmed by at least two techniques with different principles, were matched according to age and sex with an equal number of seronegative individuals. The cases and controls were evaluated using an epidemiological questionnaire and clinical, electrocardiograph and echocardiograph examinations. In the seroepidemiological evaluation, 62% of the interviewees recognised triatomines and most of them confirmed that they had seen these insects in the piassava plantations of the riverside communities of the Negro River tributaries. Of the seropositive patients, 25.8% affirmed that they had been stung by the triatomines and 11.7% denied having been stung. The principal clinical manifestations of the seropositive individuals were palpitations, chest pain and dyspnoea upon effort. Cardiac auscultation revealed extrasystoles, bradycardia and systolic murmurs. The electrocardiographic alterations were ventricular extrasystoles, left and right bundle branch block, atrioventricular block and primary T wave alterations. The echocardiogram was altered in 22.6% of the seropositive individuals and in 8.5% of the seronegative individuals.

Effect of maternal clinical chorioamnionitis on neonatal morbidity in very-low birthweight infants: a case control study

Aims: To assess the relationship between maternal clinical chorioamnionitis and neonatal outcome in preterm very-low birthweight (VLBW) infants. Methods: An observational case-control study was conducted in the Neonatology Services of 12 acute-care teaching hospitals in Spain. Between January 2004 and December 2006, all consecutive VLBW (F1500 g) infants born to a mother with clinical chorioamnionitis were enrolled. Controls were infants without chorioamnionitis matched by gestational age who were born immediately after each index case. Results: There were 165 cases and 163 controls. A significantly higher percentage of cases than controls required intubation (53% vs. 35.8%), had normal intrauterine growth (98.1% vs. 84.7%), were born in a tertiary center (inborn) (95.1% vs. 89.1%), from single gestations (76.4% vs. 65.6%) and vaginal delivery (47.3% vs. 33.3%), showed a lowerApgar score at 5 min, and presented a higher rate of earlyonset sepsis (10.4% vs. 1.2%). Older maternal age (32.5 vs. 30.8 years), premature labor (67.3% vs. 25.8%), premature rupture of membranes (61.3% vs. 25.8%), and antibiotic treatment (88.5% vs. 52.3%) were significantly more frequent among cases than controls. Conclusions: After controlling by gestational age, maternal chorioamnionitis was associated with neonatal depression and early sepsis but not with other prematurity-related complications.

Effect of maternal clinical chorioamnionitis on neonatal morbidity in very-low birthweight infants: a case control study

Aims: To assess the relationship between maternal clinical chorioamnionitis and neonatal outcome in preterm very-low birthweight (VLBW) infants. Methods: An observational case-control study was conducted in the Neonatology Services of 12 acute-care teaching hospitals in Spain. Between January 2004 and December 2006, all consecutive VLBW (F1500 g) infants born to a mother with clinical chorioamnionitis were enrolled. Controls were infants without chorioamnionitis matched by gestational age who were born immediately after each index case. Results: There were 165 cases and 163 controls. A significantly higher percentage of cases than controls required intubation (53% vs. 35.8%), had normal intrauterine growth (98.1% vs. 84.7%), were born in a tertiary center (inborn) (95.1% vs. 89.1%), from single gestations (76.4% vs. 65.6%) and vaginal delivery (47.3% vs. 33.3%), showed a lowerApgar score at 5 min, and presented a higher rate of earlyonset sepsis (10.4% vs. 1.2%). Older maternal age (32.5 vs. 30.8 years), premature labor (67.3% vs. 25.8%), premature rupture of membranes (61.3% vs. 25.8%), and antibiotic treatment (88.5% vs. 52.3%) were significantly more frequent among cases than controls. Conclusions: After controlling by gestational age, maternal chorioamnionitis was associated with neonatal depression and early sepsis but not with other prematurity-related complications.

Effect of maternal clinical chorioamnionitis on neonatal morbidity in very-low birthweight infants: a case control study

Aims: To assess the relationship between maternal clinical chorioamnionitis and neonatal outcome in preterm very-low birthweight (VLBW) infants. Methods: An observational case-control study was conducted in the Neonatology Services of 12 acute-care teaching hospitals in Spain. Between January 2004 and December 2006, all consecutive VLBW (F1500 g) infants born to a mother with clinical chorioamnionitis were enrolled. Controls were infants without chorioamnionitis matched by gestational age who were born immediately after each index case. Results: There were 165 cases and 163 controls. A significantly higher percentage of cases than controls required intubation (53% vs. 35.8%), had normal intrauterine growth (98.1% vs. 84.7%), were born in a tertiary center (inborn) (95.1% vs. 89.1%), from single gestations (76.4% vs. 65.6%) and vaginal delivery (47.3% vs. 33.3%), showed a lowerApgar score at 5 min, and presented a higher rate of earlyonset sepsis (10.4% vs. 1.2%). Older maternal age (32.5 vs. 30.8 years), premature labor (67.3% vs. 25.8%), premature rupture of membranes (61.3% vs. 25.8%), and antibiotic treatment (88.5% vs. 52.3%) were significantly more frequent among cases than controls. Conclusions: After controlling by gestational age, maternal chorioamnionitis was associated with neonatal depression and early sepsis but not with other prematurity-related complications.

Electronic control device exposure: a review of morbidity and mortality.

The use of electronic control devices has expanded worldwide during the last few years, the most widely used model being the Taser. However, the scientific knowledge about electronic control devices remains limited. We reviewed the medical literature to examine the potential implications of electronic devices in terms of morbidity and mortality, and to identify and evaluate all the existing experimental human studies. A single exposure of an electronic control device on healthy individuals can be assumed to be generally safe, according to 23 prospective human experimental studies and numerous volunteer exposures. In case series, however, electronic control devices could have deleterious effects when used in the field, in particular if persons receive multiple exposures, are intoxicated, show signs of "excited delirium," or present with medical comorbidities. As the use of electronic control devices continues to increase, the controversy about its safety, notably in potentially high-risk individuals, is still a matter of debate. The complications of electronic control device exposure are numerous but often recognizable, usually resulting from barbed dart injuries or from falls. Persons exposed to electronic control devices should therefore be fully examined, and traumatic lesions must be ruled out.