Epidemiological survey of the prevalence of intestinal parasites among schoolchildren in Sari, northern Iran

Parasitic infection is highly prevalent throughout the developing countries of the world. Research on the prevalence of intestinal parasitic infections in various geographic regions is a prerequisite for the development of appropriate control strategies. A cross-sectional study was conducted to determine the prevalence of intestinal parasitic infections among schoolchildren in public primary and secondary schools in the urban areas of Sari, Mazandaran province, northern Iran. The study was conducted from November 2009 to June 2010. A total of 1100 stool samples from 607 males and 493 females aged 7-14 years were examined by direct wet mounting, formalin-ether concentration, and Ziehl-Neelsen and trichrome permanent staining methods. A parental questionnaire for common risk factors was completed for each participant. Mono- or poly-parasitism was detected in 367 (33.3%) of the children (32.6% of males and 34.2% of females). Various species of protozoan or helminth infections were detected: Blastocystis hominis seemed to be the most prevalent parasite (13.5%) followed by Giardia lamblia (10.6%), Entamoeba coli (7.2%), Endolimax nana (1.5%), Enterobius vermicularis (2.2%), Trichostrongylus sp. (2.1%) and Strongyloides stercoralis (1.6%). The prevalence of intestinal parasite infections in females was slightly higher than in males, though without a statistically significant difference (p=0.56). No age association was detected, and a slightly lower positive association with increasing age was observed (p=0.33). A significant association was observed with parents' educational level, household income and practice of hand washing before meals (p<0.01). Although paediatric pathogenic intestinal parasite infections are not more prevalent in this geographical area than in other regions, improvements in personal hygienic conditions and behavioural characteristics is important to completely control parasitic infections in schoolchildren in northern Iran.     

Malaria in the central health district of Dakar (Senegal). Entomological, parasitological and clinical data

We previously investigated malaria in the southern health district of the city of Dakar, which includes the oldest neighborhoods. In this study, we investigated malaria in the central health district, corresponding to the central area of the conurbation. The study was carried out at 12 sites, from March 1996 to February 1997. The sites were selected such that the entire district was covered and included 2 sites in the shanty town and three in an old village that has been absorbed into the city. We carried out prospective monthly entomological analyses with a view to identifying the vectors and the mode of transmission of malaria. We also carried out clinical and parasitological follow up to determine the incidence of parasitemia and of bouts of malaria. Insects were collected overnight from humans and the insects remaining the next morning in 10 bedrooms in the health district were collected. For clinical and parasitological follow up, families were visited at home once per week and their clinical state was assessed. Blood smears were taken to facilitate the detection of bouts of malaria. Body temperature was measured and we checked for the presence of organisms in the blood systematically during the last weekly visit of each month. For a total of 308 collections at night from human volunteers and 1,395 bedroom collections of residual fauna, we obtained 12,879 Culicidae females, 199 (1.5%) of which were anopheles mosquitoes, with Culex quinquefasciatus accounting for 98% of the remaining mosquitoes. As in the southern district, A. arabiensis was the only species of the A. gambiae complex collected. Anopheles mosquitoes accounted for only 0.3 bites per man per night and 0.07 females per room. They were therefore poorly represented in this district and were not detected at all at five sites. They were found in large numbers only during the rainy season, especially in September, when they accounted for 2.25 bites per man per night and 0.3 females per room at 3 sites in an undeveloped zone in which 81.4% of all the anopheles mosquitoes were collected. The parturition frequency of the biting females was 32.6% and that of the females collected in houses was 50.0%. None of the A. arabiensis females dissected (98.5% of those collected) carried Plasmodium sporozoites. The clinical and parasitological follow up concerned 2,583 individuals, aged from 1 month to 80 years, from 285 families resident in Dakar who volunteered for the study; 41.9% of these individuals were less than 15 years old and 92.2% had been living in Dakar for more than 2 years. Thick and thin blood smears taken monthly showed the frequency of the parasite to be 1.0% and that of gametocytes to be 0.1%. P. falciparum was the only parasite detected in the subjects. Plasmodium infections were observed in all age groups, with a frequency of 0.4% (adults over the age of 20 years) to 1.6% (children under two years of age). Parasitized subjects were detected in every month of the study, with a frequency of 0.4% (in January) to 1.9% (in December). The largest number of cases detected in a three-month period (38.8% of all cases) was that for October to December, the three-month period immediately after the rainy season (July to September). Parasite frequency, which was no higher than 1. 2% at 10 sites, was clearly higher at two sites in the shanty town (3.8 and 6.8%), mostly inhabited by immigrants from rural areas. At the end of the study year, satisfactory weekly follow up was considered to have been achieved for 1,067 of the participants. The annual incidence of parasitemia in this cohort was 5.1% and that of malaria was 2.4%. Incidence did not vary significantly with age and was between 1.8% and 7.6% for parasitemia and between 0.8% and 3.5% for malaria. However, significant differences in incidence were observed between areas. Incidence was higher at the two sites in the shanty town, with rates of 12.1% and 36.5% for parasitemia and 6.1% and 15.9% for malaria. (ABSTRACT TR     

Epidemiological changes of paediatric urolithiasis in Tunisia

Background: The clinical and biological characteristics of urolithiasis in children are still evolving in our country. Since the eighties no study has been conducted to determine incidence of urolithiasis in Tunisia. Aim: To define the current status of urolithiasis inTunisian children. Methods: The records of 414 children with urolithiasis treated between 1983 and 2007 were found in a multi-centric study which took into consideration to age, sex, and history diagnosis and physical, laboratory, and radiologic findings. Clinical and biological date were performed in 344 cases. Stone analysis was performed by spectrophotometry. Results: The incidence of paediatric urolithiasis has steadly decreased from 0.7/ 10 000 of the child population / year in 1991-1994 to 0.1 cases/10 000 children/ year in 2007. There was a continuous decrease in bladder stone over the past 25 years (47.1% in 1982-1986 Vs 10.2% in 2002-2007). Stones were homogeneous in 31.4% of cases. The main component was calcium oxalate stones in 36.4% of the cases. Since the eighties the increase of oxalates stones (15.6% in eighties Vs 51.5% actually) were with depends to purines and struvite stones. Conclusion: Epidemiologic characteristics of the urinary lithiasis (sex, age, localization and composition) have changed in Tunisia, due to the the improvements of standard of living. The occidentalization of the nutritional practices and the receding of the culinary traditions gave birth to new risks of urolithiasis characterized by the emergence of calcium oxalate stones.     

Epidemiological data concerning one year of a malaria surveillance pilot project in Southern Rhodesia

Few factual data have been published on the problem of disappearing malaria due to Plasmodium falciparum in Africa. In Southern Rhodesia a surveillance project has been under way since January 1961. The author describes malaria surveillance procedures, methods, organization and costs for the year 1962-63 and presents data relevant to a sparsely populated part of rural Africa where a surveillance visitor can cover a population of only some 3500 by monthly house-to-house visits. Through such visits, and through special surveys, an annual blood examination rate of 25% was achieved in the area at fairly low cost.     

Risk factors for intestinal invasive amebiasis in Japan, 2003-2009

We determined yearly change in prevalence and risk factors for amebic colitis caused by intestinal invasive amebiasis among persons who underwent endoscopy and assessed differences between HIV-positive and HIV-negative persons in Japan. A total of 10,930 patients were selected for analysis, of whom 54 had amebic colitis. Prevalence was in 2009 (0.88%, 12/1360) compared with 2003 (0.16%, 3/1904). Male sex (odds ratio [OR] 8.39, 95% CI 1.99-35.40), age <50 years (OR 4.73, 95% CI 2.43-9.20), history of syphilis (OR 2.90, 95% CI 1.40-5.99), and HIV infection (OR 15.85, 95% CI 7.93-31.70) were independent risk factors. No differences in risk factors were identified between HIV-positive and HIV-negative patients. Contact with commercial sex workers was a new risk factor among HIV-negative patients. Homosexual intercourse, rather than immunosuppressed status, appears to be a risk factor among HIV-positive patients.     

Epidemiological, parasitological and molecular aspects of Giardia duodenalis infection in children attending public daycare centers in southeastern Brazil

The purpose of this study was to determine the prevalence, associated risk factors and genotype of Giardia duodenalis infection in children attending public daycare centers in the city of Araguari, state of Minas Gerais, Brazil. Fecal samples were collected from 245 children aged 0-5 years, and questionnaires were asked about sociodemographic and hygiene-related characteristics. At the daycare centers where children tested positive, fecal samples were collected from the staff handling food, and from family members and domestic animals. Positive samples were analyzed at the dehydrogenase glutamate (gdh) locus to determine the genotype. The prevalence of G. duodenalis was 51.8%, and drinking unfiltered and unboiled water (OR 2.12, CI 1.26-3.69, p<0.001) and washing hands only with water (OR 2.14, CI 1.19-4.04, p<0.001) were related risk factors. No association was found between test-positive children and their family members, domestic animals and food handlers. An analysis of the sequences of 30 samples revealed that they all belonged to genotype B.     

Facts, projections, and gaps concerning data on aging

In 1900, approximately 25 percent of all deaths occurred in people 65 years of age and over, while today the age at death has been pushed back so that, by 1980, 30 percent of deaths occurred in those over age 80. The greatest declines in age-specific mortality for those 65 and over occurred from 1920 to 1945 and since 1970. Illness and disability rise with age, and there is some evidence that rates of disability in all age groups may be increasing. Measurement of morbidity and disability is the area where data are weakest and our needs for data are perhaps greatest. Agreement is needed on the use, limitations, and interpretations of surveys and of data relating to functional status. In a few years, medical students and physicians will be computer literate. We should plan now for a better utilization of the already available Federal data sets as well as implementation of computerized health care information on individual patients. Some modifications of privacy legislation will probably be necessary in order for physicians to give better care to their patients, and to provide epidemiologic research opportunities in critical areas of public health needs. Caution is urged in order to maintain credibility in health promotion by avoiding overstatement of knowledge in areas where scientific evidence is weak or lacking. Better utilization and development of epidemiologic and statistical information as well as basic research in chronic diseases are urged to prepare for the year 2025, when there will be some 60 million Americans age 65 and over--about 20 percent of the total population.     

Bancroftian filariasis in a Philippine village: clinical, parasitological, immunological, and social aspects.

The distribution and effects of Bancroftian filariasis in 535 inhabitants of a Philippine village were investigated. Clinical, parasitiological, immunological, and socioeconomic assessments were made. A history of acute lymphatic inflammation and the presence of inguinal lymphadenopathy were common. Lymphatic obstructive disease, defined as leg edema, hydrocele, or an epididymal cyst, was more common in men than women and increased progressively with age. The prevalence and intensity of microfilaremia rose with age in males, whereas the prevalence but not the intensity of infection increased with age in females. The prevalence of immunological responsiveness, as assessed by skin reactivity to microfilarial antigen and serum antibodies to adult filarial worms, increased with age in both males and females. There was no relationship between either microfilaremia or obstructive disease and the ability to work or have children, but both were more common in heads of households with the lowest socioeconomic scores. Epidemiological factors which may have contributed to these findings are discussed. (author's modified)     

Ethical implications of clinical trials in Tunisia

Clinical trials are necessary for medical advancement. They must respect legal obligations. Ethical questions related to protection of the human being's rights are yielded by these trials. Joining research to medical core is problematical in consideration of patient's consent to clinical trial. Exclusion by the Tunisian law of persons under age, pregnant or breast-feeding women from medical experimentation in the aim of protecting them against clinical research adverse events or abuses is ethically questionable since it deprives them from a possible medical progress. So why not to involve them in clinical research when there is an expected benefit, after bringing them protection as vulnerable persons like we should do for instance for the elderly, handicapped persons or prisoners. Legal creation of research ethics committees is important for the respect of experimentation rules on human beings.     

Epidemiologic,clinical and cytohematologic characteristics of adult acute lymphoblastic leukemia in Tunisia

Through a national retrospective study, the authors report the clinical and hematological characteristics of 124 acute lymphoblastic leukemia of the adult diagnosed during 5 years (1993-1997). The national prevalence is of 0.28/100.000 inhabitants/year. The sex-ratio is of 1.3. Sixty six per cent of patients were 16-35 years of age, and only 10% of them were more than 60 years of age. A tumoral syndrome was present at 71% of the cases with peripheral adenopathies in 55%, splenomegaly in 40%, hepatomegaly in 19% and a mediastinal tumor in 18% of the cases. The bone pain were rarely signaled (10%) and neuro-meningeal affection was found in only 3% of cases. There was no testicular lesions. The white blood cells count was less than 30.000/mm3 in 60% whereas an important hyperleucocytosis superior than 100.103/mm3 was observed in 20% of the cases. Anemia and thrombopenia were noted in 94% and 90% of the cases respectively. Acute lymphoblastic leukemia typing by cytological study of Bone marrow according to the Fransh-American-Britain criteria (FAB) had found 43%, 48% and 4% for type 1,2 and 3 respectively. In 5% of the cases the type of the acute lymphoblastic leukemia was not precised (diagnosis based on the Bone biopsy).     

Epidemiological study of Enterobacteriaceae resistance to colistin in Sfax (Tunisia)

Objectives

The authors had for aim to monitor Enterobacteriaceae resistance to colistin, during 6 years (2005–2010), and to study the epidemiology of Enterobacteriaceae resistant strains isolated in the Sfax region (Tunisia).

Design

This retrospective study was carried out in the microbiology laboratory, at the Habib Bourguiba teaching hospital in Sfax. All strains of colistin resistant Enterobacteriaceae isolated from patients were studied.

Results

One hundred and twenty one strains of colistin resistant Enterobacteriaceae were isolated from 93 patients. Klebsiella pneumoniae was the most frequent species (60.2%), followed by Enterobacter cloacae (26.9%), and Escherichia coli (12.9%). Thirteen strains (E. cloacae) were heteroresistant to colistin. Eighty one isolates (87.1%) were resistant to third generation cephalosporins. The rate of resistance to colistin ranged from 0.09% for E. coli to 1.2% for K. pneumoniae, and 1.5% for E. cloacae. A progressively increasing colistin resistance was observed for K. pneumoniae. Most resistant strains were isolated from urine in the urology department. Previous exposure to colistin was reported in 59.2% of patients. Pulsed field gel electrophoresis typing revealed different clones.

Conclusions

Colistin resistance in Enterobacteriaceae is a worrying phenomenon in Sfax. It is related to polyclonal diffusion. Continuous epidemiological monitoring and a rational use of colistin are necessary to limit the spreading of these colistin resistant strains and to maintain this antibiotic's effectiveness.