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Vol.4 No.4 – 17 : Evaluation of circulating antigen in urine technique for diagnosis of Schistosoma haematobium infection

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By : Ahmed Abdelhalim Yameny

Society of Pathological Biochemistry and Hematology, Egypt

Ahmed A. Yameny (Email: dr.ahmedyameny@yahoo.com)

DOI: 10.21608/jbaar.2018.155494

Abstract

Background : Diagnosis of urinary and intestinal schistosomiasis by detecting circulating Schistosome antigens in serum and urine have been developed and assessed to dissolve problems with parasitological diagnosis in low endemic areas or for early diagnosis, this study aimed to evaluate commercially available kit, using circulating antigen in urine as alternative for microscopic testing of urine to diagnose S.haematobium infection Subjects and methods: This study is a cross-sectional study designed to evaluate circulating antigen a commercially available kit was used for determine urinary schistosomiasis  in the study population, this performed on 50 positive S.haematobium samples and 50 negative samples for individuals matching in age and sex , in addition, urine microscopic examination was done for detection of S.haematobium eggs by sedimentation centrifugation and nuclepore filteration techniques. Results :  The results showed that circulating antigen kit in urine had a sensitivity of 56% and specificity of 76%.. PPVs was 70% whereas NPVs was 63.3 %. As for diagnostic efficiency, it was 66%, where the area under the curve (AUC) was sufficient 0.63 . Conclusion and Recommendations: Years ago this commercial kit used in our study and in all medical laboratories in Egypt for detection of schistosome antigen in urine is called schistofast bilharzial antigen in urine , this study showed low sensitivity (56%) and lowe specificity (76) than expected resuls for detection of circulating antigen and they are generally more expensive than microscopic examination.

Evaluation of circulating antigen in urine technique for diagnosis of schistosoma haematobium infection-converted

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Vol.3 No.4 – 9 : The Validity of Haematuria and Proteinuria by chemical reagent strip for diagnosis of Schistosoma haematobium infection

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By : Ahmed Abdelhalim Yameny

Society of Pathological Biochemistry and Hematology, Egypt

Ahmed A. Yameny (Email: dr.ahmedyameny@yahoo.com)

Abstract

Background : Urinary schistosomiasis is a chronic water-borne disease that affect the life of millions of people globally especially the rural areas of developing countries, Microscopic examination can quantify the intensity of the S.haematobium infection, however it is relatively insensitive especially in situations involving low level infections. Hematuria and proteinuria have been considered as alternatives for microscopic testing of urine to diagnose S.haematobium infection, and as a single tool in large-scale control programs. Subjects and methods : This study is a cross-sectional study designed to evaluate haematuria and proteinuria by chemical reagent strip for determine urinary schistosomiasis in the study population, to overall sample was 1000 patients of different ages in addition, urine microscopic examination was done for detection of S.haematobium eggs by sedimentation centrifugation and nuclepore filteration techniques. Results : The results showed that haematuria by chemical reagent strips had a sensitivity of 27.8% and specificity of 63.4%. When proteinuria was considered, sensitivity increased to 67.1% also specificity increased to 80.7%. When both haematuria and proteinuria was considered, sensitivity was 45.2% and specificity 85.9%. sensitivity in between the previous results. PPVs ranged between 6.13% and 22.9% whereas NPVs ranged between 91.1% and 96.6%. As for diagnostic efficiency, it was best for both haematuria and proteinuria (83.1%) followed by proteinuria 79.6% and least for haematuria (60.7%), where the area under the curve (AUC) was sufficient for both haematuria and proteinuria 0.61 and good for proteinuria( 0.71),where it was not useful for haematuria (0.48). Conclusion and Recommendations : Most previous studies showed blood in urine or microhaematuria is more important than protein and used chemical reagent strips to detect microhaematuria and not protein. While this study showed detect of protein by chemical reagent strip is more important than microhaematuria by chemical reagent strip, and statistical parameters tested were higher with proteinuria than haematuria .The sensitivity, specificity, positive and negative predictive value, likelihood ratio for positive results, diagnostic efficiency and area under the curve all were higher in proteinuria than haematuria. The sum of proteinuria and haematuria had more specificity . In this study we demonstrate that the use of urine reagent strips for both proteinuria and haematuria might be considered for the diagnosis of S. haematobium where microscopy is unavailable.

The Validity of Haematuria and Proteinuria by chemical reagent strip for diagnosis of Schistosoma haematobium infection

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Vol.3 No.4 – 8: The validity of the Questionnaire to identify Schistosoma haematobium infection

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By : Ahmed Abdelhalim Yameny

Society of Pathological Biochemistry and Hematology, Egypt

Ahmed A. Yameny (Email: dr.ahmedyameny@yahoo.com)

Abstract

Background: Schistosomiasis is considered the most important water-based disease, Estimation of S.haematobium infection has been recognized in Egypt since ancient times, hematuria known as AAA disease. One of the symptoms of urinary schistosomiasis is visible blood in urine, since this is normally well recognized by children, the assessment of urinary schistosomiasis can be undertaken rapidly and accurately by using a simple questionnaire. This study was done to test the validity of self-reported blood in urine by questionnaire compared to parasitological methods. Subjects and methods: Across -sectional study was carried. To overall total sample was 1000 patients of different ages, data about the history of recent symptoms of schistosomiasis as haematuria and dysuria were collected. Also, urine microscopic examination was done for the detection of S.haematobium eggs by sedimentation centrifugation and nuclepore filtration techniques. Results: The results showed that haematuria by questionnaire had a sensitivity of 54.4% and specificity of 90.8%. When dysuria was considered, sensitivity increased to 75.95% but specificity decreased to 51.2%. When both self-reported haematuria and dysuria were considered, sensitivity was 68.3% and specificity 85%, in between the previous results. PPVs ranged between 11.8% and 33.6% whereas NPVs ranged between 95.9% and 96.1%. As for diagnostic efficiency, it was best for haematuria (87.9%).

Conclusion: questionnaire has a moderate sensitivity, a simple questionnaire asking “Did you have blood in urine during the last month?” and “Did you suffer from schistosomiasis during the last months?” is a validated tool that allows for a decision to be taken, a questionnaire was shown to have a very high negative predictive value 96%, so that it is safe to use it to identify communities with a low prevalence so that they can be excluded from the first phases of a control program, but microscopic examination is better and not expensive for diagnosis of urinary schistosomiasis infection.

The-validity-of-the-Questionnaire-to-identify-Schistosoma-haematobium-infection-converted.pdf

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Vol.3 No.4 – 6: Schistosomiasis haematobium Prevalence and Risk factors in EL-Fayoum Governorate, Egypt

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By : Ahmed Abdelhalim Yameny

Society of Pathological Biochemistry and Hematology, Egypt

Ahmed A. Yameny (Email: dr.ahmedyameny@yahoo.com)

Abstract

Schistosoma haematobium infection is an important water-borne disease in Egypt, its prevalence decreased to less than 0.2 % (2016). There are more than 300 villages in Egypt with a prevalence of more than 3%, especially among school children, Which require prolonged treatment and continuous examinations, The Ministry of Health and Population in Egypt has announced the start of a campaign to confirm the final elimination of schistosomiasis by 2020, this study was conducted to detect the prevalence of  Schistosoma haematobium and risk factors among 1000 patients attending Ministry of Health Laboratory Centers, in El-Fayoum Governorate by microscopic examination in rural and urban areas, the prevalence among study patients was 7.9%, an interview questionnaire was designed to obtain demographic data and risk factors, such as residential status, age,  water contact activity, occupation, and education level, the higher percentage of infection was 10.3% among 11-21 years group, infection among males was higher than that among females (9.0% vs.6. 8% respectively). The percentage of infection was 11.2 % for rural residence compared to 2.4% for urban residence, regarding occupation the higher percentage of infection was 27.6% among farmers and /or fishermen. According to contact with canal water, the percentage of infection among those who had water contact was 16.9% and only 0.9% for people with no water contact. This study, therefore, recommended that a schistosomiasis control program in these infected areas should be done to educate the population on risk factors that predispose an individual to urinary schistosomiasis and the need for proper control of snails the intermediate host besides treatment of infected people.

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Vol.2 No.12 – 7 : Evaluation of Health Centers Laboratory Results for Schistosoma haematobium Infection in El-Fayoum Governorate, Egypt

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By : Ahmed Abdelhalim Yameny

Society of Pathological Biochemistry and Hematology, Egypt

Ahmed A. Yameny (Email: dr.ahmedyameny@yahoo.com)

Abstract

Background : Logically ,successful treatment requires correct diagnosis based on the accuracy , reproducibility, and interpretability of investigations and examinations. The mission of health laboratory services is to provide high quality services in the right place and at the right time in respect of the needs of patients, the community  health staff including not only clinicians but also epidemiologist and environmental sanitarians. Quality is the degree to which care services influence the probability of optimal patient outcomes .” American Medical Association, 1991. Quality is never an accident . Research objective : To assess the quality of results presented  by health centers laboratories, for diagnosis of  S.haematobium in El-Fayoum Governorate. Subjects and methods: Across -sectional study was carried . This study was carried out in Ministry of  Health Laboratory Centers,in  El- Fayoum Governorate. A list of health centers was obtained from Ministry of Health (MOH). Ten Health Laboratories  were included in this study : Two central laboratories (Control Laboratory and Evaluation Laboratory)  and eight laboratories in eight  centers were chosen randomly from the list , from each laboratory 100 random urine samples were obtained and total sample size was 1000 urine samples . Results: In all centers the number of positive cases were lower than that detected by the study except in lab.1(El-Hadka health centerlaboratory), it detect one false positive case. The case was had a red blood cells in urine.And lab. No.9,(El-Sadeek primary school laboratory), there was no positive cases either by the researcher or the health center laboratories, and the total percentage of positive cases detected by health center laboratories was 67.1 % in relation to that detected by researcher.
Conclusion and recommendations : In all health centers laboratories the number of positive cases were lower than that detected by the researcher, and the total percentage of positive cases detected by health center laboratories was 67.1 % in relation to that detected by researcher. So using of Nuclepore membrane filteration technique is important for diagnosis of S.haematobium and continuous training for health centre laboratories staff is very important.

Evaluation of Health Centers Laboratory Results for Schistosoma haematobium Infection in El-converted

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Vol.1 No.6 – 12: Evaluation of Nuclepore Membrane Filtration Technique for Diagnosis of Schistosoma haematobium Infection

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By : Ahmed Abdelhalim Yameny

Society of Pathological Biochemistry and Hematology, Egypt

Ahmed A. Yameny (Email: dr.ahmedyameny@yahoo.com)

Abstract

Schistosomiasis is a parasitic disease. It is one of the most important diseases of humans in tropical and subtropical parts of the world, rapid characterization of schistosome eggs considered a key step for clinical management, diagnosis of Schistosoma haematobium is generally based on the detection of eggs in a single urine specimen, Urine filtration is one of the methods recommended by the WHO for the detection of S.haematobium. In 1976, Peters et al adapted a nuclepore filter for the diagnosis of S.haematobium eggs. They used a filter 13 mm in diameter with 8 µm pores, in another study done by Peters et al (1976), they proved that under field conditions, filtration of two 5 ml aliquots using 8 µm pore filters was very practical, if eggs of S.haematobium are present (size 150 by 60 µm), they are unable to pass through the filter and can be observed and counted under a microscope fitted with a 10x objective.

This study used both the microscopic examination techniques of urine, centrifugation sedimentation technique and Nuclepore membrane filtration technique to detect Schistosoma haematobium eggs in urine for 1000 patient samples, to evaluate each technique alone and the two techniques together. This study showed that the nuclepore filtration method more valid than the sedimentation centrifugation method, nuclepore filtration detect 77 infected cases with a sensitivity of 97.5%, but sedimentation detect 64 infected cases with a sensitivity of 81%, in this study we considered the sum of nuclepore and sedimentation as a gold standard, they detected 79 infected cases to compare them with other methods.

Evaluation-of-Nuclepore-Membrane-Filteration-Technique-for-Diagnosis-of-Schistosoma-haematobium-Infection-Final-converted

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