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A A Buck

Publications and source records attributed to A A Buck.

29 records · Page 2Linked to original sources

Microfilaruria in onchocerciasis. A clinical and epidemiological follow-up study in the Republic of Chad.

Microfilariae of O. volvulus were recovered from the urine of 11% of the residents of a village in the Republic of Chad where onchocerciasis was holoendemic. A follow-up study of the same population 3 years after the original investigation revealed that microfilaruria was still present and that living microfilariae of O. volvulus could be recovered from small urine samples obtained by high catherization of the ureters. Radiological changes consistent with chronic pyelitis were found in 4 out of 14 persons with microfilaruria who were examined by retrograde pyelography. The recovery of microfilariae in the urine was associated with the intensity of the infection, as determined by counts of microfilariae in skin snips and the number of onchocercomata. A systematic comparison for differences between onchocerciasis patients with and without microfilaruria revealed that the microfilaruria patients had a low weight: height ratio, deficient antibody responses in indirect haemagglutination tests with O. volvulus antigen, elevated serum aminotransferase levels, and reduced systolic blood pressure.

Adolescent↗

Community diagnosis of Bancroftian filariasis.

The objective of this study was to find the best tests for efficiently estimating the true prevalence of Bancroftian filariasis in endemic areas. The study population comprised 427 people over 10 years of age in an endemic village in Egypt. Four tests were evaluated; a standardized clinical examination, night blood examinations for microfilariae (50 microL thick films and 1 mL membrane filtration), and a test for circulating filarial antigen. 191 subjects (44.75%) had at least one positive test and were considered to have filariasis. The sensitivities of clinical examination, thick films, membrane filtration and antigen testing for filariasis were 16%, 50%, 64%, and 88%, respectively. Relative to membrane filtration of night blood, the filarial antigen test had a sensitivity of 97.5%, a positive predictive power of 71%, and a negative predictive power of 99%. None of the blood tests was a sensitive indicator of clinical filariasis; 69% of clinical cases were negative in all 3 blood tests and would have been missed if clinical examinations had not been done. Therefore, we recommend a combination of clinical examination and the filarial antigen test (with optional examination for microfilariae of those with positive antigen tests) for community diagnosis of Bancroftian filariasis in endemic areas.

Adolescent↗

Efficient assessment of filariasis endemicity by screening for filarial antigenaemia in a sentinel population.

We have previously reported that a monoclonal antibody-based antigen detection assay (AD12) is sensitive and specific for Bancroftian filariasis in Egypt. The purpose of the present study was to demonstrate the use of this assay in a sentinel population as a means of efficiently screening for filariasis endemicity. Antigen testing was performed with finger-prick blood collected during the day from 743 schoolchildren (ages 11-16 years). The school draws students from 5 villages in Qalubia Governorate, 35 km north-east of Cairo, Egypt. The prevalence of filarial antigenaemia in the school was 17.2%. Antigenaemia rates in children from the 5 villages were 29, 20, 18, 17, and 10% (non-uniformity significant by chi 2 analysis, P = 0.02). These data agree with Ministry of Health rankings of relative endemicity for these villages based on prior night blood surveys. The village with the highest antigen prevalence in children was surveyed one year before the present study. Prevalence rates of antigenaemia and microfilaraemia at that time for a different sample of children aged 11-16 years were 33% and 22%, respectively. We conclude that antigen detection in schoolchildren of this age group is an efficient means of assessing filariasis endemicity in Egypt.

Adolescent↗