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Biomedical subjects

P Odermatt

Publications and source records attributed to P Odermatt.

17 recordsLinked to original sources

Control of Schistosoma mekongi in Cambodia: results of eight years of control activities in the two endemic provinces.

In Cambodia, schistosomiasis is transmitted in the provinces of Kratie and Stung Treng where approximately 80000 individuals are estimated to be at risk of infection. The baseline prevalence of infection was estimated to be between 73% and 88%, and cases of severe morbidity (hepatosplenomegaly, puberty retardation) and mortality were very common. In 1994, the Ministry of Health of Cambodia started schistosomiasis control applying universal chemotherapy with praziquantel (40mg/kg). The coverage of the programme was between 62% and 86% for 8 years. This simple control measure resulted in the control of the disease: no cases were reported in 2004 and only three cases were reported in 2005. In addition, there are no longer reports of cases of severe morbidity due to schistosomiasis. Since the beginning of the control programme, a single dose of mebendazole (500mg) has been combined with praziquantel during the mass chemotherapy; as a result the prevalence of Ascaris lumbricoides and hookworms dropped from 74.5% to 10% and from 86% to 40% respectively. The experience in Cambodia demonstrates that, with political commitment, control of parasitic diseases is achievable even in a situation of minimal resources. The programme represents a successful model for other developing countries.

Adolescent↗

[Anaemia in a school of rural Cambodia: detection, prevalence, and links with intestinal worms and malnutrition].

According to WHO, half of the world's children suffers from anaemia, which is a silent and neglected endemic resulting from three major causes: iron deficiency intestinal worms and malaria. A two month transversal study was conducted in a rural primary school in Battambang Province, Cambodia, in a malaria-free area. The main objective of the study was to assess the prevalence of anaemia and two of its possible driving factors, intestinal parasites and general malnutrition; a secondary objective was to assess the accuracy of haemoglobin colour scale, an easy and cheap visual technique compared to spectrophotometry used as the reference. Among 168 school children (average age: 11), the prevalence rates of moderate and severe anaemia were 24% and nil respectively; average haemoglobin was 12.6 g/dl. These results compared favourably with previous data from Cambodia. In our study's conditions, the haemoglobin colour scale grossly overestimated the anaemia prevalence: 83 vs. 24%, specificity 22%. Despite its simplicity and very low cost, this technique appeared inaccurate. Anaemia was independently associated with Ancylostoma carriage (p = 0.05), and stunting (p = 0.01), which prevalences were 54% et 40% respectively; and this, despite a mebendazole 500 mg dose given 9 months prior to the study as part of a regular deworming school program. Although periodical mass deworming in schools does not prevent early Ancylostoma reinfection, it may reduce the severity of anaemia. It therefore appears fully justified, and may be strengthened, notably by switching from mebendazole to albendazole.

Ancylostomiasis↗

[Pleuro-pulmonary paragonimiasis].

Paragonimiasis is a food borne zoonosis due to a trematode belonging to the genus Paragonimus. Although present throughout the world, about 90% of the cases occur in Asia where around 20 million people are infected. The parasitic cycle is complex with two different intermediate hosts. Man is infected by ingesting the raw or undercooked flesh of the second host - a freshwater crab or prawn - or possibly of a paratenic mammal host (wild boar), which contains the infective larval stage metacercariae that reaches the lung which is the main target organ. Epidemiological, pathological, and clinical aspects are reviewed. The main symptoms are protracted cough, and recurrent "benign" hemoptysis. Abnormal pleuro-pulmonary imaging features are constant, but protean and non-specific, leading to frequent confusion with tuberculosis. Diagnosis is easily achieved by ova search in the sputum or pleural fluid, or by serology. Evolution is usually considered benign, although not well known. Finally, praziquantel is the effective first choice treatment. Some paradoxical aspects of this disease are underlined such as: underdiagnosis despite a very simple diagnostic procedure, or opposite tendencies according to location, either extinction or re-emergence.

Animals↗

The WHO dose pole for the administration of praziquantel is also accurate in non-African populations.

In 2001, WHO developed a pole for the administration of praziquantel without the use of weighing scales, with encouraging results in African populations. In the present study, the pole was tested on height/weight data from 9354 individuals from 11 non-African countries. In more than 98% of the individuals (95% CI 97.8-98.4) the pole estimated an acceptable dosage (30-60 mg/kg), a performance statistically similar to that observed in African populations. Reproducing the present pole in the form of a strip of paper and including it in each container of praziquantel would greatly facilitate the administration of the drug in large-scale interventions.

Adolescent↗

A new test to improve the training quality of wheelchair racing athletes.

STUDY DESIGN: Validation of a new wheelchair racing test. OBJECTIVE: To assess the reproducibility of test parameters at different, subjectively chosen, intensity levels in wheelchair racing athletes. SETTING: Swiss Paraplegic Centre, Nottwil, Switzerland. SUBJECTS: We tested 11 (eight male, three female) young competitive wheelchair racing athletes. Their age was 20.5+/-6.4 years, height 164.7+/-16.3 cm and weight 54.1+/-9.2 kg. Average weekly training time was 6.8+/-2.7 h. All had been engaged in regular training for over 3.9+/-2.8 years. METHODS: Within a period of 3+/-1 days, every athlete completed two identical tests in their own racing chair on a training roller. The tests consisted of five 1500 m bouts at routine training intensities of 1 (warm-up) up to 5 (race speed), with a rest of 2 min between each bout. The athletes were blinded to all the collected data during the whole of the test, except for indications of the 500, 1000 and 1500 m markers. We measured the overall time (for 1500 m), average speed, stroke frequency, heart rate, rate of perceived exertion (RPE) and the concentration of lactic acid for all five intensity bouts. In order to get a measure on how reproducible these intensity levels were, we compared the two tests of each athlete with each other, and calculated the root-mean-squared coefficients of variation (CV) for all measured parameters during every bout. RESULTS: CVs of the measured data show that the most reproducible values were found for bout 5 (2.6-7.9%); except for the lactic acid parameter. The heart rate (CV: 3.1-6.4%) and stroke frequency (CV: 6.5-7.9%) parameters reached rather constant values throughout all five bouts. Lactic acid concentrations showed very high CVs (16.8-29.7%). CONCLUSION: We conclude that this test is, with the exception of the lactic acid measurements, well reproducible, and particularly suitable for young wheelchair athletes. We find it to be a helpful tool for improving awareness for the individual training intensities, and for pursuing the development of the training process, as particularly the high-intensity bouts are well reproducible.

Adolescent↗

Evaluation of sprint exercise testing protocols in wheelchair athletes.

STUDY DESIGN: Comparison of five different exercise testing protocols with different speeds on a treadmill with seven wheelchair athletes. OBJECTIVE: To determine which speed and duration in an exercise protocol is best to test wheelchair athletes performing sprint races on a track. SETTING: Swiss Paraplegic Centre, Nottwil, Switzerland. METHODS: Three elite and four junior wheelchair athletes (18.7+/-6.8 years, 52.1+/-9.7 kg and 165.3+/-19.3 cm) performed five different exercise testing protocols at different speeds on a treadmill until exhaustion. Maximal effort treadmill (0.7% incline) testing protocols were performed using three timeframes. The first was focussing on short duration tests (S1 and S2) where incremental increases in velocity (0.42 and 0.1 m.s(-1)) were required from a stationary start. The second were medium duration tests (M1 and M2) where the athlete started at their 200 m and 800 m personal best time (mean velocities) and then had the velocity increased 1 km.h(-1) by every 10 and 60 s respectively. The long duration test (L) started at 14 km.h(-1) and velocity was increased by 2 km.h(-1) every 120 s. Maximal heart rate, maximal concentration of lactate, maximal speed, and maximal duration of the test were measured. RESULTS: The highest concentration of lactate and the highest heart rates were measured in the longest tests. CONCLUSION: During maximal effort testing wheelchair athletes are able to produce higher lactate concentrations when tested for longer duration. Post test lactate assessments provide little information in short duration testing protocols. Sequential lactate assessments post-test may provide additional information on the rate of recovery for middle distance wheelchair athletes and warrants further investigation.

Adolescent↗

Epidemiology and control of mekongi schistosomiasis.

Since the first case of Schistosoma mekongi infection was reported in 1957, control measures have been implemented in Laos and in Cambodia. Operational research provided the necessary information on parasite epidemiology and the associated morbidity in order to develop adequate control measures. S. mekongi transmission occurs in rocky banks of the river according to a seasonal cycle. Common daily activities of villagers living in the endemic areas constitute the risk factors for infection. The potential role of an animal reservoir is not fully understood. Severe disease is associated with advanced infection status. Signs and symptoms of portal hypertension dominate the clinical situation, and death is usually due to bleeding from ruptured esophageal varices. Schistosomiasis control in both Laos and Cambodia was based on universal treatment campaigns and resulted in a dramatic fall in the prevalence of the infection and in morbidity control. However, even if the disease and the infection have been satisfactorily controlled, transmission still occurs, and in very limited areas the prevalence reaches rates of more than 15%. Today, 60000 people are estimated to be still at risk of infection in Laos and about 80,000 in Cambodia. The new challenge in schistosomiasis control in endemic areas along the Mekong river is to consolidate the results, to establish a sensitive and reliable surveillance system, and finally to adapt control strategies to the low endemic situation. The impoverished nature of the region makes the possibility of sanitation unfeasible, and external support is still needed to sustain activities in the near future and to enable the substantial reduction of risk behaviors.

Humans↗

[The role of common starlings (Sturnus vulgaris) in the epidemiology of bacterial, potentially human pathogenic, disease agents].

Since a long time a public garden in Basel is known as a site for overnight accommodation and assembly of starlings. The birds cause an immense faecal contamination of the park and the neighbouring district. A nursery and a primary school are directly affected. To evaluate the health risk coming from the starlings droppings for the population, particularly for the children and to assess the role of starlings in the transmission of diseases to humans and in the epidemiology of human diseases the presence of human bacterial pathogens in the faeces of starlings was determined. Some of the isolated strains were further typed and compared to strains of human origin. C. jejuni, L. monocytogenes and C. psittaci were most often found. The typing of some C. jejuni and L. monocytogenes isolates showed a great variety of geno-, sero- respectively phage types that did not belong to the strains most often found in isolates of human origin. Starlings can harbour human pathogens and therefore a potential risk of infection comes from their droppings. It seems however rather improbable, that these birds present a constant direct source of infection for human beings.

Animals↗

[A foci of Schistosomiasis mekongi rediscovered in Northeast Cambodia: cultural perception of the illness; description and clinical observation of 20 severe cases].

In 1992 a foci of Schistosomiasis mekongi was rediscovered in the province of Kracheh in Northeast Cambodia. Severe clinical signs due to portal hypertension, which were frequently observed in this population, allowed the discovery of this 'forgotten' focus. Elements of the perception of the population and clinical observations of 20 severe cases due to S. mekongi infections are presented. Interviews with patients and villagers of the area of Kracheh showed severe psychosocial impact including fear from death, infirmity and invalidity. The symptoms of schistosomiasis were well known by the population and were reported to have increased in frequency in the last two decades. They have received traditional names and specific traditional treatment. The description of the clinical cases illustrates the severe pathology, which was observed in the hospital of Sambour, in the north of the province of Kracheh. It shows the pathogenic potential of S. mekongi in all age groups (from 7 to 58 years old): cachexia, hepatosplenomegaly, stunting and retardation of puberty, decompensation of portal hypertension with ascites and rupture of oesophagual varicies. The efficacy of the treatment in the severe stages varies. A follow-up after 30 months showed that 5 patients died, 5 initially improved but then relapsed, 3 remained unchanged and only 5 patients clearly improved. Two patients could not be followed-up. The clinical observations and interviews show severe pathology with impact at both individual and community level. The infection with S. mekongi is the main factor but additional concomitant factors are responsible for this fact. At a certain stage of the disease the prognosis for successful treatment is very low. These observations show the importance of the foci in the Province of Kracheh, Cambodia and underline the need for a long-term global intervention.

Adolescent↗

Foci of Schistosomiasis mekongi, Northern Cambodia: II. Distribution of infection and morbidity.

In the province of Kracheh, in Northern Cambodia, a baseline epidemiological survey on Schistosoma mekongi was conducted along the Mekong River between December 1994 and April 1995. The results of household surveys of highly affected villages of the East and the West bank of the river and of school surveys in 20 primary schools are presented. In household surveys 1396 people were examined. An overall prevalence of infection of 49.3% was detected by a single stool examination with the Kato-Katz technique. The overall intensity of infection was 118.2 eggs per gram of stool (epg). There was no difference between the population of the east and west shore of the Mekong for prevalence (P = 0.3) or intensity (P = 0.9) of infection. Severe morbidity was very frequent. Hepatomegaly of the left lobe was detected in 48.7% of the population. Splenomegaly was seen in 26.8% of the study participants. Visible diverted circulation was found in 7.2% of the population, and ascites in 0.1%. Significantly more hepatomegaly (P = 0.001), splenomegaly (P = 0. 001) and patients with diverted circulation (P = 0.001) were present on the west bank of the Mekong. The age group of 10-14 years was most affected. The prevalence of infection in this group was 71.8% and 71.9% in the population of the West and East of the Mekong, respectively. The intensity of infection was 172.4 and 194.2 epg on the West and the East bank, respectively. In the peak age group hepatomegaly reached a prevalence of 88.1% on the west and 82.8% on the east bank. In the 20 schools 2391 children aged 6-16 years were examined. The overall prevalence of infection was 40.0%, ranging from 7.7% to 72.9% per school. The overalls mean intensity of infection was 110.1 epg (range by school: 26.7-187.5 epg). Both prevalence (P = 0.001) and intensity of infection (P = 0.001) were significantly higher in schools on the east side of the Mekong. Hepatomegaly (55.2%), splenomegaly (23.6%), diverted circulation (4. 1%), ascites (0.5%), reported blood (26.7%) and mucus (24.3%) were very frequent. Hepatomegaly (P = 0.001), splenomegaly (P = 0.001), diverted circulation (P = 0.001) and blood in stool (P = 0.001) were significantly more frequent in schools of the east side of the Mekong. Boys suffered more frequently from splenomegaly (P = 0.05), ascites (P = 0.05) and bloody stools (P = 0.004) than girls. No difference in sex was found for the prevalence and intensity of infection and prevalence of hepatomegaly. On the school level prevalence and intensity of infection were highly associated (r = 0. 93, P = 0.0001). The intensity of infection was significantly associated only with the prevalence of hepatomegaly (r = 0.44, P = 0. 05) and blood in stool (r = 0.40, P = 0.02). This comprehensive epidemiological study documents for the first time the public health importance of schistosomiasis mekongi in the Province of Kracheh, Northern Cambodia and points at key epidemiological features of this schistosome species, in particular the high level of morbidity associated with infection.

Adolescent↗

[Diarrhea in urban agricultural workers in Nouakchott in Mauritania].

Nearly 200 million people in the developing world are dependent or urban gardening for food and income. This practice has been accelerated by the droughts of recent decades which have forced more and more migrants into urban areas. Numerous potential health hazards have been attributed to urban gardening but the exact risks in Sahelian areas remain unclear. The purpose of this cross-sectional study was to evaluate the incidence of diarrhea at the Tel Zatar gardening site in urban Nouakchott, Mauritania. In addition, a case-control study was carried out to identify risk factors for diarrhea in function of gardeners' activity and living conditions. Statistical analysis was performed using univariate and logistical regression methods. The annual incidence of diarrhea ranged from 6.9 (IC95 p. 100 = 5.0-8.8) to 8.5 (IC95 p. 100 = 6.2-10.8) episodes per gardener and year. Multivariate analysis identified four significant risk factors. Two of these factors were unrelated to gardening, i.e., not having spent more than USD 3.50 the previous day (odds ratio (OR = 2.8, IC95 p. 100 = 1.01-7.81) and poor food hygiene (cooking outside (OR = 4.69, IC95 p. 100 = 1.06-20.83). The other two factors were regular consumption of raw vegetables (OR = 25.5, IC95 p. 100 = 2.0-32.0) and use of untreated well water (OR = 3.85, IC95 p. 100 = 1.08-14.29). Unprotected well water was the cause of 59.2 p. 100 of diarrheal episodes reported by gardeners at Tel Zatar. The results of this study confirm that vegetable production in urban gardens such as Tel Zatar is associated with health risks. Public health measures should address not only the garden sites but also domestic hygiene.

Adult↗

[Swarms of starlings in Basel: a natural phenomenon, a nuisance or a health risk?].

A Natural Phenomenon, Molestation or a Health Risk? For the last two decades an avenue in the centre of Basel (Altrheinweg, Klybeckquartier) is known as site for overnight accommodation and assembly of starlings (Sturnus vulgaris) during autumn. The nightly visitors cause an immense contamination that directly affects a nursery and a primary school. The aim of the present study was the evaluation of the health risk for the population due to the starlings' droppings, particularly for the children from the nursery school. Between August and December of the years 1995 and 1996 the population of starlings was observed, the contamination of the area with faeces was quantified, the presence of microorganisms in the faeces was determined and the contamination of the soil from the Altrheinweg was compared with that from other avenues and parks. Furthermore, the children attending the nursery school were monitored for possible infections due to the birds' droppings. In mid-October, when the population of starlings reached their maximum of about 15,000 birds, 1053 defecations per night and square metre were counted on an average in 1995 and 1821 in 1996. The microbiological analysis of the starlings' faeces showed a high contamination with Campylobacter spp. (1995: 95.5%; 1996: 100%), L. monocytogenes (1995: 36.5%; 1996: 26.7%) and C. psittaci (1995: 40.5%), a lower contamination with Salmonella spp. (1995: 1.0%), S. aureus (1995: 2.0%), Y. enterocolitica (1995: 1.5%) and Y. pseudotuberculosis (1995: 1.0%). Mycotic and parasitic human pathogens were not found. The contamination of the soil from the Altrheinweg with Campylobacter spp. and L. monocytogenes was significantly greater than that of the other avenues and parks in Basel. However, the investigations conducted by the school medical service showed that no infections among the children attending the nursery school could be correlated to the presence of the starlings. Even if the heavy contamination of the area with droppings of starlings presents a potential health risk, a continuous or systematic transmission of infectious agents seems rather improbable due to the contamination-avoiding behaviour of the children, the characteristics of the microorganisms involved and the climatic conditions in autumn. This situation showed however not reduce our awareness of such a potential health risk.

Animals↗

[Clinical aspects and epidemiology of cryptosporidiosis in immunocompetent children].

A prospective case-control study was performed in urban and periurban areas of Basel to investigate the epidemiology of Cryptosporidium sp., an intestinal coccidian parasite. 455 children with diarrhoea, who attended paediatric and general practices, participated in the study. Oocysts of the parasite were detected in stool specimens of 21 (4.6%) patients using auramine-fluorescence and modified Ziehl-Neelson staining. Another ten infected people were found during separate investigations of outbreaks in a Kindergarten and in two families. Serial stool stains were performed to determine the period of oocyst shedding. The median duration of diarrhoea was six days and ranged from 1 to 25 days. In contrast, shedding of oocysts of Cryptosporidium sp. lasted for 12.5 days and was significantly longer than the period of diarrhoea (p = 0.02). Compared with control patients suffering from diarrhoea of other origin, respiratory symptoms were significantly (p = 0.02) more frequent in children with cryptosporidiosis (42% vs 13%). In comparison with healthy controls, prior contact with a person suffering from diarrhoea and travel to a Mediterranean country were the most important risk factors for cryptosporidiosis. An illustrative case is described in detail. It is concluded that cryptosporidial infection of the respiratory tract may also occur in immunocompetent children. The possibility of a long period of oocyst shedding is important for the planning of hygiene measures both in individuals and public health.

Adolescent↗

Symptoms and transmission of intestinal cryptosporidiosis.

Cryptosporidium spp are a cause of diarrhoea in toddlers. Symptoms and routes of transmission were investigated in a prospective case-control study in the city and surroundings of Basel, Switzerland. Twenty one (4.6%) out of 455 children with diarrhoea who attended paediatric and general practices from June to September 1988 were positive for cryptosporidium. The mothers of each case, of two controls with diarrhoea of another origin, and of two healthy controls were interviewed with a standardised questionnaire. In comparison with controls with diarrhoea of another origin, respiratory symptoms were significantly more frequent in children with cryptosporidiosis: eight of 19 (42%) compared with five of 38 (13%). In comparison with healthy controls, preceding contact with a person suffering from diarrhoea was associated with the greatest relative risk for cryptosporidiosis, followed by travel in a Mediterranean country. Transient cryptosporidial infection of the respiratory tract may be common in immunocompetent children. In the area investigated person to person transmission may account for most cases.

Case-Control Studies↗

The use of morbidity questionnaires to identify communities with high prevalences of schistosome or geohelminth infections in Tanzania.

Parasitic infections were investigated in Morogoro Rural District, Tanzania, between October 1992 and June 1993. A total of 4589 schoolchildren (aged 7-17 years) from 30 primary schools was screened for infection with Ascaris lumbricoides, Trichuris trichiura, hookworms (3456 children only), Schistosoma mansoni and S. haematobium. The children were also asked about their recent experiences of the following: diarrhoea, abdominal pain, blood in stool, perception of suffering from schistosomiasis, and worm infection and examined for spleen and liver enlargement. Among schools, there were correlations between the prevalence of S. mansoni infection and bloody stools, spleen enlargement and liver enlargement, and between S. haematobium infection and the presence of blood in urine. To exclude ecological explanations for the correlations, logistic regression was used to estimate the adjusted odds ratio (OR) for each infection and each sign or symptom. No sign or symptom was significantly associated with any geohelminth infection. Reported blood in stool was significantly associated with S. mansoni infection (OR = 1.62, P = 0.045). Reported blood in urine was significantly associated with S. haematobium infection (OR = 7.71, P < 0.001), as was reported blood in stool (OR = 11.52, P < 0.001), indicating that presence of blood in either form of excreta was related to the local term for schistosomiasis. These results support the possibility of using reported blood in stool as a means of rapid assessment for identifying communities with a high prevalence of S. mansoni infection.

Adolescent↗