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Biomedical subjects

L Savioli

Publications and source records attributed to L Savioli.

At least 73 records · Page 4Linked to original sources
PubMed1992

Evaluating measures to control intestinal parasitic infections.

Intestinal parasitic infections are among the most common infections of humans in developing countries, but the resources available for their control are severely limited. Careful evaluation of control measures is essential to ensure that they are cost-effective. The evaluation of the effects of control on intestinal helminths and intestinal protozoa requires an understanding of the different epidemiological patterns of these two groups of parasites. The transmission dynamics and morbidity associated with the major helminth infections (Ascaris lumbricoides, Trichuris trichiura and the hookworms) are dependent on the size of the worm burdens. Thus the important parameter for evaluating the impact of control on morbidity and transmission is the intensity of infection, which can be assessed by determining the mean density of parasite eggs in faecal specimens. Estimation of intensity is subject to systematic errors, however, due to the complex pattern of worm burden distributions. The frequency distribution of burdens is highly overdispersed, and individuals exhibit predisposition to particular levels of infection. Furthermore, mean intensity is age-dependent, in a species-specific manner, and is clustered spatially and within families. These complex patterns imply that the estimation of intensity is exceptionally sensitive to the size and demographic structure of the population sample selected for assessment. They also have the effect that prevalence estimates, the most commonly used measures of infection in communities, can seriously mislead. Paradoxically, prevalence is least useful where infection is most common because the relationship between prevalence and intensity is most markedly non-linear when the prevalence is high. Thus in areas where control is most needed, evaluation using prevalence might suggest that control had failed while evaluation by intensity would, correctly, show the measure of success. With the major protozoan infections (Entamoeba histolytica, Giardia duodenalis and Cryptosporidium parvum) an estimate of intensity is of little value and the central parameter for evaluation is prevalence. Prevalence does exhibit age and spatial heterogeneity, which may be species-specific, so there remains a need to ensure a consistent sample structure, although this is less critical than for the helminths. The major constraint on evaluating the control of protozoan infections is the need to identify pathogenic species and, in some cases, pathogenic strains. Harmless commensal protozoans are ubiquitous and often morphologically very similar to pathogens, but their control is both unnecessary and impracticable. Species such a E. histolytica appear to exist as strains with differing pathogenicity, thus control will be cost-effective only if the focus is on pathogenic strains. Effective diagnosis is therefore central to the evaluation of the control of protozoan infections.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Control of morbidity due to Schistosoma haematobium on Pemba Island: egg excretion and hematuria as indicators of infection.

The variability of Schistosoma haematobium egg excretion using a quantitative syringe filtration technique and the variability of hematuria detected visually and by reagent strips were studied in a population of 520 subjects from the village of Pujini (Pemba Island, Zanzibar, Tanzania) for 6 consecutive days. A high degree of day-to-day variability of egg excretion within subjects was found both in the whole population and in the 5-19 year age group. Subjects with 1 urinary egg count of greater than or equal to 50 eggs/10 ml urine were not similarly classified in 36-61% of the other 5 examinations and 4-16% of their other examinations were negative. Gross hematuria had a specificity of almost 100%, when related to a positive filtration on any day, and was closely related to egg counts of greater than or equal to 50 eggs/10 ml urine. The finding of a strongly positive reaction for hematuria on a given single day was closely associated with the subject having a high egg count (greater than or equal to 50 eggs/10 ml urine) on at least one of the 6 days of the study. At the primary health care level, single highly positive semiquantitative values for hematuria were a more useful diagnostic indicator than a single egg count to select patients with heavy infections for selective population chemotherapy.

Adolescent↗
PubMed1990

Measurement of schistosomiasis-related morbidity at community level in areas of different endemicity.

Among the indicators of schistosomiasis morbidity currently used in control programmes, ultrasound has been found to be a safe, non-invasive and efficient technique for detecting schistosomiasis-related lesions and for assessing the effect of treatment on their resolution. Three case-studies from East Africa, in areas of different endemicity for Schistosoma haematobium, using ultrasound are described and their results related to indirect measurements of the disease (e.g., haematuria, egg counts). This review reveals that cross-sectional ultrasound surveys can be used to quickly assess subsamples of populations in areas of different endemicity, in order to make decisions about sampling strategies in control programmes. The association between the intensity of infection and urinary tract abnormalities is reviewed and evaluated. One case study provides information on the resolution of S. haematobium-related uropathy after treatment; this information is crucial in order to maintain low levels of morbidity in a community. The role of ultrasound is further discussed, particularly as a tool to complement and validate indirect morbidity control measurements. The validation of such indirect measurements for use as a basis for public health decisions is important because they can be carried out by existing health care services in many areas.

Adolescent↗
PubMed1989

Urinary schistosomiasis on Pemba Island: low-cost diagnosis for control in a primary health care setting.

In the 1970s and early 1980s indirect diagnosis of urinary schistosomiasis, using urinalysis reagent strips for proteinuria and haematuria, was proposed as a possible alternative to the more accurate but very time-consuming parasitological methods. The recent experience o f the Schistosomiasis Control Programme for Pemba Island, which used a combination of (1) observations o f grossly bloody urine specimens, (2) results from reagent strips for measuring haematuria, and (3) treatment with praziquantel, is the first large-scale example o f a simple, inexpensive and promising alternative for controlling the morbidity caused by this parasite.

Journal Article↗
PubMed1989

Signet ring cell carcinoma in a Schistosoma-infested bladder: case report and histochemical study.

A case of signet ring cell carcinoma of the urinary bladder with concomitant Schistosoma haematobium infection is reported with a histochemical study of mucous secretion. This rare kind of tumor differentiation in Schistosoma-related neoplasms may suggest that the tumor-promoting stimuli, acting on reserve cells of bladder epithelium, do not determine the tumor differentiation pattern as strictly as currently thought.

Adenocarcinoma, Mucinous↗
PubMed1989

Control of morbidity due to Schistosoma haematobium on Pemba Island: programme organization and management.

A programme to control urinary schistosomiasis was initiated on Pemba island in January 1986 with the objectives of eliminating morbidity due to S. haematobium by utilizing a primary health care approach of strengthening the existing health care delivery system and creating a sound basis for future control of other parasitic and communicable diseases. The plan of action included training of rural health assistants to undertaken an intervention phase targeted to schools for selective population chemotherapy surveys at six-month intervals during the first two years, using indirect diagnostic techniques (observation of gross haematuria and detection of microscopic haematuria by chemical reagent strips) to identify individuals for treatment with praziquantel at a dose of 40 mg/kg body weight. The evaluation of the indirect techniques indicated that both sensitivity and specificity of the chemical reagent strips to detect infection were greater than 90%. After three selective population chemotherapy surveys, the prevalence of gross haematuria was reduced by 94.2% (15.8% to 0.9%) and both gross and microscopic haematuria were reduced by 76.4% (54.1% to 12.8%) among school children. Community involvement and health education were stressed in this programme. The use of dispensary laboratories to maintain control of urinary schistosomiasis is now being evaluated.

Adolescent↗
PubMed1987

A case of falciparum malaria acquired in Italy.

The first case of Plasmodium falciparum malaria acquired in Italy after the eradication of the disease is reported. The P. falciparum strain was sensitive to chloroquine in vitro and in vivo. It seems most likely that an infective mosquito of tropical origin was responsible for transmission.

Adult↗
PubMed1986

Treatment of lower respiratory tract infections with ceftriaxone and cefotaxime. A comparative study.

The microbiological and clinico-therapeutic efficacy and safety of ceftriaxone were compared with those of cefotaxime in an open randomized trial. Fifty-four adult hospitalized patients (37 males and 17 females) suffering from either acute bronchopneumonia (19) or acute exacerbations of chronic bronchopneumonia (35) have been investigated. Four patients were withdrawn from the trial. Underlying diseases were present in 41 patients. Ceftriaxone was administered at a once-a-day dose of either 1 or 2 g (in 13 and 14 patients, respectively) and cefotaxime at a 2 g twice daily dosing regimen (27 patients), both antibiotics being given for 7-12 days. In the ceftriaxone group, 15 out of the 27 patients were cured (55%) and 9 had a favourable clinical response for a total satisfactory response rate of 88%. The causative pathogen was eliminated in 18 (66%) patients. The results obtained in the cefotaxime group did not differ significantly, but 2 patients were excluded from the study because of in vitro resistance of the causative pathogen isolated. Both drugs were well tolerated: no relevant laboratory changes were registered. The results indicate that ceftriaxone at a dosage of 2 or 1 g daily is at least as effective as cefotaxime given daily at a dosage of 4 g in the treatment of severe lower respiratory tract infections.

Adolescent↗
PubMed1985

Mystic fevers.

Explore the source record for details and available documents.

Adult↗
PubMed1985

In vitro antibacterial activity of imipenem against Pseudomonas and Staphylococcus species. Comparison with thirteen other antimicrobial agents.

The in vitro antimicrobial activity of imipenem against recent clinical isolates of Pseudomonas spp. (94 strains) and penicillin-resistant Staphylococcus spp. (50 Staph. aureus and 50 coagulase-negative Staphylococcus) was assessed using the Mueller-Hinton agar dilution method. Results were compared with those simultaneously obtained for amikacin, netilmicin, tobramycin, norfloxacin, piperacillin, ceftazidime, ceftriaxone and azthreonam against Pseudomonas spp., and for rifampicin, clindamycin, netilmicin and cefoxitin, besides penicillin and methacillin, against Staphylococcus spp. About 50 and 90% of 84 Pseudomonas aeruginosa isolates were inhibited by concentrations of imipenem equal to or less than 2 and 8 mg/l respectively. The in vitro activity of imipenem was comparable to that of ceftazidime and norfloxacin, but superior to that of the aminoglycosides and all the other antibiotics tested, in terms of potency by weight. Among other Pseudomonas spp. only P. malthophilia (2 strains) proved resistant to imipenem. Rifampicin was the most active antibiotic by weight against Staph. aureus but imipenem was more active than clindamycin and, especially, netilmicin and cefoxitin. Imipenem was highly active also against coagulase-negative staphylococci, with some differences related to the high incidence of methicillin-resistant strains. MICs of imipenem in Mueller-Hinton broth correlated with those obtained in agar, unlike the aminoglycosides. There were no significant inoculum effects on MICs of imipenem and MBCs were within one twofold dilution of MICs in over 75% of assays.

Aminoglycosides↗
PubMed1983

Cerebral malaria treated with high doses of chloroquine.

Data concerning 11 cases of cerebral malaria treated with high doses of chloroquine base (18mg/kg/day) are reported. The risk of chloroquine resistance (already described in Tanzania) and the fact that only chloroquine is available on the island of Pemba, were the reasons for increasing the usual dose. High doses clinically seem to offer better results, only one of 11 dying (9.1%) compared with four of 30 (13.3%) in the control group given normal doses. However, the lack of significant differences between the two groups and the greater risk with high doses of chloroquine may not always justify their use to overcome a RI chloroquine resistance in adults and adolescents.

Adolescent↗
PubMedDate not supplied

Control of morbidity due to Schistosoma haematobium on Pemba island; selective population chemotherapy of schoolchildren with haematuria to identify high-risk localities.

In Pemba, Tanzania, 2 sequential surveys were made of the prevalence of haematuria in children (aged 5-19 years) in 52 schools, using direct observation of gross haematuria (bloody urine) and chemical reagent strips as indicators of Schistosoma haematobium infection. 24,462 children were examined in the first survey and 25,575 in the second, 6 months later. The prevalence of gross haematuria was initially 15.8% (3876 cases); 6 months later, after a single dose of praziquantel (40 mg/kg), it was only 2.4% (613 cases), a reduction of 84.9%. The total number of cases of haematuria (gross or otherwise) dropped similarly, from 13,920 (54%) to 6638 (26%), a 52.2% reduction. In towns the degree of reduction was positively correlated with the standard of water supply and sanitation available, and the initial prevalence of gross and total haematuria in schools was positively correlated with the prevalence 6 months later. The cost per person reduced from US$ 0.83 in the first survey to US$ 0.48 in the second (excluding field staff wages paid in local currency), the reduction being due to the reduced number of positive persons. This study has demonstrated the feasibility of using indirect techniques on a large scale for the diagnosis of S. haematobium infection to identify schoolchildren requiring treatment, and to monitor its impact on clinical morbidity in a highly endemic area.

Adolescent↗