Parasitological Screening Research Articles

Efficacy of praziquantel against urinary schistosomiasis and reinfection in Senegalese school children where there is a single well-defined transmission period.

BackgroundHuman schistosomiasis is a significant health problem in Sub-Saharan Africa. In Niakhar, West central Senegal, the transmission of S. haematobium occurs seasonally between July and November. No control measures have been implemented despite high prevalence reported in previous studies. This aim of this study was to i) determine the current prevalence of S. haematobium in children at Niakhar, ii) assess the efficacy of one dose of PZQ (40 mg/kg) against S. haematobium and iii) monitor reinfection.MethodsThe current study was carried out in a cohort of 329 children aged five to 15 years enrolled from six villages in Niakhar to determine the efficacy of one dose of PZQ, as well as reinfection. Parasitological screening was performed in June 2011 to determine the baseline prevalence of S. haematobium, and then a single dose of PZQ was administered to all selected subjects in the transmission season in August 2011. The efficacy of PZQ treatment and reinfection were monitored respectively five weeks after in September 2011 and from February to March 2012.ResultsAt baseline, the overall prevalence and the heavy intensity of infection were 73.2 % and 356.1eggs/10 ml of urine. Significant differences in the prevalence and intensity of S. haematobium infection were noted between villages. A single dose of PZQ significantly reduced the prevalence of S. haematobium infection from 73.2 % to 4.6 % and the geometric mean intensity of infection from 356.1 to 43.3 eggs/10 ml of urine. The cure rates ranged from 89.4 % to 100 %. The egg reduction rates also ranged from 77.6 % to 100 %. Two to three months after the period of transmission, the overall rate of reinfection was 12.6 % and was significantly higher in male children than in female children. The overall prevalence at this period was 13.8 %, which was significantly lower than the prevalence at baseline (73.2 %).ConclusionThe Niakhar study area remains a hot spot of urinary schistosomiasis in Senegal with differences in transmission between villages. This study suggests that when transmission is strictly seasonal, Praziquantel shows the expected efficacy in reducing the prevalence and intensity of infection, but also a significant effect on the occurrence of reinfection.

Discovery of carbohybrid-based 2-aminopyrimidine analogues as a new class of rapid-acting antimalarial agents using image-based cytological profiling assay.

New antimalarial agents that exhibit multistage activities against drug-resistant strains of malaria parasites represent good starting points for developing next-generation antimalarial therapies. To facilitate the progression of such agents into the development phase, we developed an image-based parasitological screening method for defining drug effects on different asexual life cycle stages of Plasmodium falciparum. High-throughput screening of a newly assembled diversity-oriented synthetic library using this approach led to the identification of carbohybrid-based 2-aminopyrimidine compounds with fast-acting growth inhibitory activities against three laboratory strains of multidrug-resistant P. falciparum. Our structure-activity relationship study led to the identification of two derivatives (8aA and 11aA) as the most promising antimalarial candidates (mean EC50 of 0.130 and 0.096 μM against all three P. falciparum strains, selectivity indices >600, microsomal stabilities >80%, and mouse malaria ED50 values of 0.32 and 0.12 mg/kg/day, respectively), targeting all major blood stages of multidrug-resistant P. falciparum parasites.

Answer to December 2012 Photo Quiz

Answer: Cyclospora cayetanensis. Cyclospora cayetanensis is an intestinal coccidian protozoon that has emerged as a significant human infectious agent worldwide, causing self-limiting gastroenteritis in immunocompetent hosts. Human-to-human spread of the parasite occurs indirectly via the environment through oocysts in contaminated water, food, or soil. The parasite has a cosmopolitan distribution and is endemic in tropical and subtropical areas (3). The parasite is commonly limited to travelers to Latin America, the Indian subcontinent, and Southeast Asia, including China (4); therefore, infection with Cyclospora cayetanensis is known as traveler's diarrhea (5). Cyclospora cayetanensis is an important cause of waterborne and food-borne outbreaks due to imported fruits and vegetables from developing countries. The underreporting of infection with this parasite likely occurs because standard examinations for ova and parasites may not include the identification of Cyclospora oocysts. This oversight is at least partly due to the lack of awareness of this disease among the public and medical workers (1). The following criteria have been established for the diagnosis of cyclosporiasis (by the CDC in 1997): detection of oocysts in stool, intestinal fluid, or small bowel biopsy specimens by microscopic examination; demonstration of oocyst sporulation; and detection by molecular methods (not a routine parasitology screening tool) (2). Cyclospora cayetanensis oocysts are spherical and between 8.0 and 10 μm in diameter, with a 50-nm-thick wall and an outer threadlike coat, which is referred to as a wrinkle by some researchers (see Fig. 1a and b in the photo quiz). Diagnostic tests also include phase-contrast microscopy, modified acid-fast staining with variable staining (from pale to red) (see Fig. 1c and d in the photo quiz), and autofluorescence with UV illumination. Ova and parasite exams typically include only direct and concentrated microscopic exams and trichrome stains without modified acid-fast staining or autofluorescence testing. Multiple stool specimens collected on subsequent days are required because parasites are shed intermittently. Of note, two of our patient's specimens were positive, and one was negative. The treatment for Cyclospora infection is a 7-day course of oral trimethoprim-sulfamethoxazole, which proved to be effective for our patient. Health care providers should evaluate Cyclospora infection in patients presenting long-lasting diarrheal illness and order the appropriate tests for this parasite. (See page 3821 in this issue [doi:10.1128/JCM.00256-12] for photo quiz case presentation)

Overcoming Language and Cultural Barriers: A Graphical Communication Tool to Perform a Parasitological Screening in Two Vulnerable Populations From Argentina

This is an exploratory study of the application of a support tool for the detection of asymptomatic subjects carrying enteric parasites in two vulnerable populations in Argentina: a shantytown in the city of Buenos Aires and a rural Wichí indigenous community in the province of Chaco. The ethnic and cultural diversity, high illiteracy rate, and language barriers called for the development of an auxiliary resource to explain stool sample collection procedures. In individual interviews with each family, the authors used two instructional guidance leaflets in comic strip format depicting the procedures. They evaluated the acceptance of the graphical communication tool on the basis of the number of retrieved samples. Percentages of respondent families were 72.2% and 66.7%, respectively. Definitive validation of these instruments would allow their use in community studies, community service learning experiences, and research on aboriginal communities that would otherwise be excluded from studies on health status.

WPŁYW SYSTEMU UTRZYMANIA NA WYSTĘPOWANIE PASOŻYTÓW JELITOWYCH U ŚWIŃ

The aim of the study was to compare the intestinal parasite fauna occurring in pigs kept in different rearing conditions (group A – extremely extensive, B – extensive and C – intensive). In the period between March and July 2010, 345 samples of faeces from piglets (125), weaners (60), fatteners (94) and sows (66) were collected and tested, using standard coproscopic methods. Six parasitic species, belonging to phylum Nematoda (Strongyloides ransomi, Ascaris suum, Oesophagostomum dentatum, Trichuris suum) and to phylum Apicomplexa (Isospora suis and Eimeria debliecki) were diagnosed. Eggs of Toxascaris leonina, a parasitic roundworm mostly affecting the members of the Canidae and Felidae families, not encountered in pigs until now, were found in the faeces of fatteners. The highest level of parasite invasion was recorded in pigs from group A and B; they were multi-species invasions. Parasitic species found in faeces not only bring economic losses, but they may also be dangerous for human health and life, which indicates the necessity to implement parasitological screening protocols, especially in the extensive rearing conditions.

Failure to offer parasitology screening to vulnerable migrants in France: Epidemiology and consequences

The "Consultations de Diagnostic et d'Orientation" (CDO), created in 1998 by the Paris Health Department, are medical consultations for vulnerable populations, which are held in municipal clinics, free of charge. More than two-thirds of CDO patients come from Africa. Our study was designed to assess and analyze whether these clinics offered consulting migrants screening for intestinal parasitic and Schistosoma haematobium infections.Material and methodsThis retrospective study included all immigrants attending CDO for the first time at four Parisian municipal free clinics during 2003. Univariate and multivariate analysis adjusted for age, sex, and geographic origin were conducted. An interview with one of the CDO physicians provided qualitative data to round out the quantitative data from the record analysis.ResultsThe study included 503 migrants eligible for screening for intestinal parasitic infections because they come from regions where these infections are endemic; among them 481 were also eligible for urine screening for Schistosoma haematobium (SH). The sociodemographic characteristics for the entire sample (not significantly different from the 481-person subgroup) were: sex ratio (M/W): 4:1; more than 50% were 35 years old or younger; and more than 50% had no health insurance coverage. Overall, around 80% came from sub-Saharan Africa, around 16% from North Africa or the Middle East, and 4.5% from Asia or South America. Screening for intestinal or urinary parasitic infections was not offered to 3 outof 5 migrants from endemic areas. Screening for intestinal parasites was offered lessoften to migrants from regions other than sub-Saharan Africa, to those older than 35years of age, and to those without abdominal symptoms. Schistosoma haematobium urine screening was proposed less often to those from North Africa or the Middle East, to those older than 35 years of age, and to those without either abdominal or genitourinary symptoms. Microscopic examination of urine for Schistosoma haematobium was performed for 171 patients; 22 positive results were reported, with viable SH eggs (13%). Microscopic examination of stool for ova and parasites was performed for 161 patients; 32 had positive results (20%). These included 14 cases of Entamoeba histolytica/dispar (our laboratory cannot distinguish the 2 strains).DiscussionThe failure to offer screening affects sub-Saharan Africans less than other migrants, perhaps because of a particular visibility due to their mass (they are the most prominent subgroup of migrants) or their higher frequency of abdominal/genitourinary symptoms. Nevertheless, more than 50% of them were not asked to undergo parasite screening, although they are the group with the highest rate of intestinal/urinary parasitosis. The most common and dangerous parasite found was Schistosoma haematobium; we do not know the pathogenicity of the Entamoeba found. Reasons for the frequent failure to suggest these screenings may include that physicians consider parasitosis as diseases of secondary importance, or have forgotten its symptoms, epidemiology, cycles, means of diagnosis, or treatment. Patients accepted the screening well when it was offered. Reasons during the course of consultation might have included insufficient time for pre-test counselling, some difficulties in communicating with the patient in French, or an overriding request or complaint from the patient. We propose the following strategy for parasite screening in CDO: standard "stool ova and parasite exams" proposed to any migrant in France for less than 5 years except sub-Saharan Africans, who should receive presumptive anti-parasite treatment instead; microscopic examination of urine for Schistosoma haematobium for sub-Saharan Africans from endemic regions. This detection can avoid - if treatment is early enough - severe uronephrological complications, which are rare but costly from a health care perspective (bladder tumor, renal failure). Physicians in non-tropical settings must remember to consider parasite infections when they see patients from endemic regions.

Detection and Differentiation of Coccidian Oocysts by Real-Time PCR and Melting Curve Analysis

Rapid and reliable detection and identification of coccidian oocysts are essential for animal health and foodborne disease outbreak investigations. Traditional microscopy and morphological techniques can identify large and unique oocysts, but they are often subjective and require parasitological expertise. The objective of this study was to develop a real-time quantitative PCR (qPCR) assay using melting curve analysis (MCA) to detect, differentiate, and identify DNA from coccidian species of animal health, zoonotic, and food safety concern. A universal coccidia primer cocktail was designed and employed to amplify DNA from Cryptosporidium parvum, Toxoplasma gondii, Cyclospora cayetanensis, and several species of Eimeria, Sarcocystis, and Isospora using qPCR with SYBR Green detection. MCA was performed following amplification, and melting temperatures (T(m)) were determined for each species based on multiple replicates. A standard curve was constructed from DNA of serial dilutions of T. gondii oocysts to estimate assay sensitivity. The qPCR assay consistently detected DNA from as few as 10 T. gondii oocysts. T(m) data analysis showed that C. cayetanensis, C. parvum, Cryptosporidium muris, T. gondii, Eimeria bovis, Eimeria acervulina, Isospora suis, and Sarcocystis cruzi could each be identified by unique melting curves and could be differentiated based on T(m). DNA of coccidian oocysts in fecal, food, or clinical diagnostic samples could be sensitively detected, reliably differentiated, and identified using qPCR with MCA. This assay may also be used to detect other life-cycle stages of coccidia in tissues, fluids, and other matrices. MCA studies on multiple isolates of each species will further validate the assay and support its application as a routine parasitology screening tool.

Questionnaire As A Tool For Identification Of High Risk Communities In Urinary Schistosomiasis Research

A study of Schistosomiasis haematobium infection in all the fifteen primary schools in Agulu town, Anaocha Local Government Area of Anambra State, was conducted using questionnaire. Out of the fifteen schools, 7 had pupils with urinary schistosomiasis infection. Ten villages out of 20 in the town were indicated to contribute individuals that attend the 7 schools. Umuowelle Primary School ranked first with a positivity rate of 54.2 % for response “yes” to “blood in urine” and 40.3 % for “Bilharziasis/schistosomiasis”. To rate the diagnostic performance of the questionnaire parasitological urine screening was also conducted in all the schools. The results showed that using questionnaire as a diagnostic tool is highly specific (87.5 %) and sensitive (87.5 %). Questionnaire administration was also shown to be cheaper, with a cost 7 times less than parasitological urine screening as well as being time saving. The diagnostic performance of the questionnaire was good in view of its preliminary screening function.

The Effects Of Season And Distance On The Prevalence And Intensity Rates Of Urinary Schistosomiasis In Agulu-Lake Area Of Anambra State, Nigeria

A survey of the effects of season, and distance to water source on the prevalence and intensity rates of Schistosoma haematobium infection in Agulu community of Anambra State was conducted using the primary schools in the town, using parasitological screening approach. Prevalence was similar in both the dry and rainy season months. Seven out of the 15 Primary schools surveyed had pupils with infection. Prevalence in schools with infection ranged from 4.1- 55.2 % during the dry season to 3.3-55.6 % during the rainy season. Prevalence and geometric mean egg count were highest in the 10-14 years age group in all the schools and in both dry and rainy seasons. Geometric mean of egg count / 10ml urine (intensity) decreased from 22.5 egg/10 ml in dry season to 10.7 egg/10 ml in wet season. Prevalence rates and intensity showed significant decrease with increase in the distance from the village to the lake. The implications of these are discussed .

Severe haemoptysis associated with seizures in a dog

CASE HISTORY: A 7-year-old, sterilised male German Shepherd dog was presented with a history of three episodes of severe haemoptysis and associated dyspnoea within a 3-week period. A generalised tonic-clonic seizure was witnessed preceding the third episode. CLINICAL FINDINGS: Thoracic radiographs revealed a severe bilateral alveolar lung pattern of the caudodorsal lung fields; extension into the left cranial lung lobe was present but pulmonary vessels were within normal size limits. Frank blood was the only abnormality present at bronchoscopy. A coagulation profile, parasitological screening, thoracic and brain computed tomography (CT), and cerebrospinal fluid (CSF) cytological analysis did not identify any abnormalities. DIAGNOSIS: Haemoptysis due to either severe neurogenic pulmonary oedema or rupture of the pulmonary capillaries secondary to seizures was considered a possible diagnosis. The primary generalised seizures were attributed to late-onset idiopathic epilepsy diagnosed by exclusion of other causes. CLINICAL RELEVANCE: This is the first known case report describing severe haemoptysis associated with seizures in a dog.

Rapid assessment of endemicity of loaisis in Ini and Ibiono Ibom Local Government Areas, Akwa Ibom State, Nigeria

Rapid Assessment of Loaisis (RAPLOA) was conducted in a total of 13 meso-endemic and hyper-endemic villages in Ini and Ibiono Ibom Local Government Areas of Akwa Ibom State, Nigeria, to identify villages that could be at risk of Severe Adverse Events (SAEs) following treatment with ivermectin in areas where onchocerciasis and loaisis are co endemic. Common names for loiasis namely Utung Eyin (eye worm) and Ubiak Eyin (eye pain) were found to exist in all the 13 villages. A total of 970 people aged 15 years and above were interviewed according to RAPLOA guidelines. Eleven of the 13 villages had RAPLOA rates of less than 40% and are therefore at low risk of experiencing SAEs. Two villages, Anananmong and Ikot Adaha, with RAPLOA rates of 40% and 40.5% respectively, are at high risk of Loa loa SAEs following treatment with ivermectin. Parasitological screening of blood samples showed that only 10 (1.03%) of 970 persons examined were positive for Loa loa microfilariae with prevalence range of 0-3.8% (median 1.25%). Intensity of infection was low with individual microfilariae load ranging from 20 to 3,200 mf/ml while Community Microfilariae Load (CMLF) was 0-8.9 mf/ ml (1.61mf/ml). There was no demonstrated relationship between RAPLOA > 40% and Very High Microfilarial Loads (VHML) in the two communities with RAPLOA of 40% and above. Based on the above results, it is advice that provision must be made to ensure that severe adverse reactions are quickly detected and managed during mass treatment with ivermectin in Anananmong, Ikot Adaha, and neighbouring villages. Keywords: ochocerciasis, loasis, co-endemic, treatment, ivermectin. Nigerian Journal of Parasitology Vol. 27 2006: pp. 85-90

Fatness and overweight in women and children from riverine Amerindian communities of the Beni River (Bolivian Amazon)

Obesity is a worldwide public health problem impacting not only industrialized nations but also developing countries. The main objective of this paper was to analyze risk factors for overweight among Amerindian children and their mothers. Data were collected in 15 Amerindian riverside communities from the Beni River (Bolivia). The total sample was of 195 mothers and 452 children, 0-15 years of age. Information about family activity and dietary patterns was collected, and a clinical examination was performed. Stool samples were collected in children for parasitological screening. Anthropometric measurements, including weight, height, arm circumference, and four skinfolds, were taken. A bioelectrical impedance analysis was performed in mothers. In total, 12.2% (95% confidence interval (CI(95%)) 9.1-15.9%) of the children were considered overweight; less than 1% were overtly obese International Obesity Task Force (IOTF) criteria. Among their mothers, 35.3% (CI(95%), 28.7-42.5%) were overweight (BMI (weight/height (2)) >25 kg/m(2)), and 5% (CI(95%), 2.5-5.1%) were obese (BMI >30 kg/m(2)). BMI was moderately related to anthropometric indices of body composition in children, but was highly correlated with fatness in mothers. The risk of overweight was not associated with environmental factors in children. In mothers, there was a significant relationship between BMI, health status, and dietary diversity score. There was a moderate association in boys between fatness and the BMI of their mothers (R(2) = 0.12, P < 0.001), but not in girls. These findings suggest a trend toward accumulation of fat related to possible changes at the economic and agricultural levels, even in remote rural areas.

Serological and Parasitological Screening of Trypanosoma cruzi Infection in Mothers and Newborns Living in Two Chagasic Areas of Mexico

Maternal-fetal transmission of Trypanosoma cruzi generally occurs in 2-12% of pregnant infected mothers. This transmission form has been poorly studied in Mexico where only one case of congenital infection published in 1998 has been reported. We screened 145 mothers and their delivered babies in two hospitals of endemic regions in Mexico (states of Chiapas and Veracruz) searching for anti-T. cruzi antibodies and circulating parasites by hemoculture and PCR. In Poza Rica, Veracruz, 3/85 (3.5%) mothers were seropositive for T. cruzi infection and in Palenque, Chiapas, 3/60 (5%) cases. In total 6/145 (4.1%) were seropositive subjects. Although cord blood samples of delivered babies from seropositive mothers have IgG anti-T. cruzi antibodies, none presented PCR and positive hemoculture. Although a high relative seroprevalence of T. cruzi infection in pregnant women was detected, no case of vertical transmission was recognized. Undoubtedly, further studies of large samples are necessary to evaluate maternal transmission risk in Mexico.

Anthelmintic Treatment Improves the Hemoglobin and Serum Ferritin Concentrations of Tanzanian Schoolchildren

AbstractTo investigate the relationships between helminth infections and iron status among school-aged children, 1,115 Tanzanian children in grades 2 through 5 were randomly assigned to treatment or control groups. The children in the treatment group were screened for infection with Schistosoma haematobium and hookworm at baseline, 3 months, and 15 months; infected children were given albendazole against hookworm and praziquantel against schistosomiasis. The control group received a placebo and did not undergo parasitological screening until 15 months after the baseline. Hematological variables were compared between the treatment and control groups. The main results were, first, that the hemoglobin concentration significantly improved after treatment for hookworm (p < .001) by 9.3 g/L in children treated for hookworm only and by 8.8 g/L in children treated for hookworm and schistosomiasis. The ferritin concentration also improved in children treated for schistosomiasis (p = .001) or hookworm (p = .019). Second, a longitudinal analysis of the data from the children in the control group showed that hookworm and schistosomiasis loads were negatively associated with hemoglobin and ferritin concentrations. Moreover, ferritin concentrations increased as C-reactive protein levels increased. Overall, the results showed that anthelmintic treatment is a useful tool for reducing anemia in areas with high hookworm and schistosomiasis endemicity. The empirical relationship between ferritin and C-reactive protein indicated that simple procedures for adjusting cutoff points for the use of ferritin as an indicator of low iron stores were unlikely to be useful in this population.

Anti-Toxoplasma gondii antibodies in patients with chronic heart failure

Chronic heart failure (CHF) involves interactions between the cardiovascular, neuroendocrine and immune systems. This study investigated the seropositivity rate for anti-Toxoplasma IgG and IgM antibodies by ELISA in patients with CHF. Ninety-seven patients with CHF and 50 healthy volunteers were selected for this investigation. The seropositivity rate for anti-Toxoplasma IgG antibodies among CHF patients (68%) was significantly higher than in healthy volunteers (36%). Thus, parasitological screening of this group of patients should be periodically performed to prevent the possible dissemination of toxoplasmosis.

Rapid assessment of Schistosoma mansoni: the validity, applicability and cost‐effectiveness of the Lot Quality Assurance Sampling method in Uganda

Rapid and accurate identification of communities at highest risk of morbidity from schistosomiasis is key for sustainable control. Although school questionnaires can effectively and inexpensively identify communities with a high prevalence of Schistosoma haematobium, parasitological screening remains the preferred option for S. mansoni. To help reduce screening costs, we investigated the validity of Lot Quality Assurance Sampling (LQAS) in classifying schools according to categories of S. mansoni prevalence in Uganda, and explored its applicability and cost-effectiveness. First, we evaluated several sampling plans using computer simulation and then field tested one sampling plan in 34 schools in Uganda. Finally, cost-effectiveness of different screening and control strategies (including mass treatment without prior screening) was determined, and sensitivity analysis undertaken to assess the effect of infection levels and treatment costs. In identifying schools with prevalences > or =50%, computer simulations showed that LQAS had high levels of sensitivity and specificity (>90%) at sample sizes <20. The method also provides an ability to classify communities into three prevalence categories. Field testing showed that LQAS where 15 children were sampled had excellent diagnostic performance (sensitivity: 100%, specificity: 96.4%, positive predictive value: 85.7% and negative predictive value: 92.3%). Screening using LQAS was more cost-effective than mass treating all schools (US$218 vs. US$482/high prevalence school treated). Threshold analysis indicated that parasitological screening and mass treatment would become equivalent for settings where prevalence > or =50% in 75% of schools and for treatment costs of US$0.19 per schoolchild. We conclude that, in Uganda, LQAS provides a rapid, valid and cost-effective method for guiding decision makers in allocating finite resources for the control of schistosomiasis.

Anthelmintic Treatment Improves the Hemoglobin and Serum Ferritin Concentrations of Tanzanian Schoolchildren

To investigate the relationships between helminth infections and iron status among school-aged children, 1,115 Tanzanian children in grades 2 through 5 were randomly assigned to treatment or control groups. The children in the treatment group were screened for infection with Schistosoma haematobium and hookworm at baseline, 3 months, and 15 months; infected children were given albendazole against hookworm and praziquantel against schistosomiasis. The control group received a placebo and did not undergo parasitological screening until 15 months after the baseline. Hematological variables were compared between the treatment and control groups. The main results were, first, that the hemoglobin concentration significantly improved after treatment for hookworm (p < .001) by 9.3 g/L in children treated for hookworm only and by 8.8 g/L in children treated for hookworm and schistosomiasis. The ferritin concentration also improved in children treated for schistosomiasis (p = .001) or hookworm (p = .019). Second, a longitudinal analysis of the data from the children in the control group showed that hookworm and schistosomiasis loads were negatively associated with hemoglobin and ferritin concentrations. Moreover, ferritin concentrations increased as C-reactive protein levels increased. Overall, the results showed that anthelmintic treatment is a useful tool for reducing anemia in areas with high hookworm and schistosomiasis endemicity. The empirical relationship between ferritin and C-reactive protein indicated that simple procedures for adjusting cutoff points for the use of ferritin as an indicator of low iron stores were unlikely to be useful in this population.

Fever after travel to the tropics

Fever in travellers returning from the tropics may be caused not only by tropical infection but also by travel associated non-specific infections and cosmopolitan infective diseases. A rational out-patient step by step procedure needs clinical data and a small account of laboratory investigations. A parasitological screening is mandatory. The results refer to parasitological, bacterial or viral diseases. Epidemiological aspects of the travelled country and incubation periods of tropical or other diseases have to be considered. Plasmodium falciparum infection has to be excluded first because of vital damage. Following malaria (30%) respiratory infections (11%) are common. Fever as a symptom of non-infective disease occurred in 9%. Other diseases (typhus, Dengue fever, tuberculosis) are rare but have to be considered.

Parasitology Screening of Latin American Children in a Primary Care Clinic

A screening program based in a Massachusetts community hospital primary care clinic, which included 124 children from 12 different Latin American countries, demonstrated that nearly 35% were carriers of pathogenic parasites. The large majority (83.7%) of these children were asymptomatic at the time of the examination. Although there may be considerable variation based on country of origin, the present results, as well as a review of the literature, suggest this is likely to be a common finding among children born in most regions of Latin America. Compliance with the screening process was significantly higher in groups with higher infection rates and the successive yield in those patients who submitted two or more stool samples revealed that most pathogens were identified in the first sample. School-age children were found to have the highest risk for both roundworm infections and multiple parasitic infections. For those children with identified pathogens, nearly 90% received treatment. Current trends in immigration, international adoptions, and special circumstances including day care, family shelters, and increasing numbers of human immunodeficiency virus-infected children have made an appreciation of the extent of parasitosis, and awareness of possible management approaches, an important consideration for primary care physicians in the United States.

Community-Based Questionnaires and Health Statistics as Tools for the Cost-Efficient Identification of communities at Risk of Urinary Schistosomiasis

Self-administered questionnaires, distributed by existing administrative channels to village party chairmen, head-teachers and schoolchildren, showed good diagnostic performance for the qualitative assessment of urinary schistosomiasis endemicity. At a cost 34 times below that of the WHO-recommended parasitological screening strategy, the schoolchildren's questionnaire allowed the screening of 75 out of 77 schools of a rural Tanzanian district in six weeks, and the exclusion of schools not at high risk for urinary schistosomiasis with over 90% confidence. The headteacher and party questionnaires made it possible to assess the perceived importance of a spectrum of diseases and symptoms, among which was schistosomiasis. The priority rank of schistosomiasis control was strongly correlated with the prevalence rate of the disease in the community. The questionnaires also looked for the prioritization of health among other community issues and thus contributed important information for planning at district level. Standardized monthly disease reports, sent by all primary health services, were also analysed. They allowed a zonal schistosomiasis endemicity classification.