PubMed Health⌕ Search

Biomedical subjects

T Romig

Publications and source records attributed to T Romig.

28 records · Page 2Linked to original sources

Portable ultrasound scanner versus serology in screening for hydatid cysts in a nomadic population.

3553 nomads in Turkana, a remote area of north-west Kenya, were screened for hydatid cysts by a portable ultrasound scanner and by serology. 198 (5.6%) proved to have liver or upper abdominal cysts. In the group screened by both techniques (2644) 174 (6.6%) cases of hydatidosis were detected by ultrasonography and 76 (2.9%) by serology. Ultrasonography gave immediate results and was less expensive and more acceptable and educationally valuable to the people. This non-invasive rapid technique also provided important clinical information about the cysts. The prevalence data thus obtained will contribute to the surveillance of a hydatid control programme.

Abdomen↗

Hydatid disease: research and control in Turkana. II. The role of immunological techniques for the diagnosis of hydatid disease.

Immunological studies have been applied to the immunodiagnosis of human hydatidosis in Turkana and for the specific identification of Echinococcus eggs, particularly in regard to their potential for the assessment of a hydatid control programme in the north-west of the District. A high rate of false negatives has been obtained with sensitive antibody tests for proven hydatid patients in Turkana and presents problems for prevalence estimation in the population. A seroepidemiological study using specific antibody detection indicated a 2.17% seropositive rate, and by using a portable ultrasound 67% of antibody positives were confirmed as having liver/abdominal cysts. An enzyme immunoassay test for specific circulating antigen, often associated with circulating immune complexes, was positive in sera in 75% of hydatid patients who were antibody-negative. The formation of specific circulating immune complexes may contribute directly to the production of a state of false negativity. These studies indicate that by combining tests for antibodies and antigens together with ultrasound, the true prevalence of human hydatidosis in Turkana is at least 5%. Characterization of Echinococcus antigens recognized by human antisera from Turkana and British hydatid patients indicates that both groups recognize the same major protein antigens in cyst fluid and protoscoleces. The results of assaying anti-oncospheral antibodies in people living in the high prevalence area of north-west Turkana compared to people in areas of low prevalence indicates that most of the people in the high prevalence area are probably infected (challenged) with Echinococcus eggs. This observation suggests that there may be a high level of acquired resistance. A species-specific immunofluorescence test using an anti-Echinococcus monoclonal antibody has been developed which can specifically identify oncospheres artificially hatched from Echinococcus eggs. This test will be applied to the problem of identification of Echinococcus eggs in the environment and in dog faeces, with a view to studying the epidemiology of the disease and for use in assessment of the hydatid control programme.

Animals↗

Hydatid disease: research and control in Turkana, IV. The pilot control programme.

A pilot programme to control hydatid disease in north-west Turkana district was started in October 1983 with an intensive educational campaign. This was followed by control and treatment of the dog population to reduce the prevalence of Echinococcus granulosus, thereby reducing the infective pressure on man. Surveillance is by mass annual sero-epidemiological and ultrascan surveys of the nomadic Turkana within the control region and by arecoline purging of the dogs. Some of the recent advances in research on hydatid disease in subject areas such as immunodiagnosis, chemotherapy and epidemiology have been incorporated into the present programme, and their relevance to this and other similar programmes is discussed.

Animals↗

Hepatitis delta virus infection in Kenya. Its geographic and tribal distribution.

In 1982-1984, an epidemiologic survey of the prevalence of hepatitis B virus surface antigen (HBsAg) in circulating blood (HBs-antigenemia) and of hepatitis delta virus infection was performed in Kenya. The distributions of hepatitis B virus and the delta virus were shown to be very variable. In southern Kenya, only two of 202 sera from HBsAg-positive individuals with no known liver disease and none from 123 HBsAg-positive patients with hepatitis B-related liver disease were positive for delta antibody. In contrast, in northern Kenya, there was an overall prevalence of delta antibody in healthy individuals of 31%. The distribution of delta infection is discussed in relation to lifestyle, ethnic group, and geographic area.

Adult↗

Camponotus compressiscapus André (Hymenoptera, Formicidae) an experimental second intermediate host of Dicrocoelium hospes Looss, 1907 (Trematodes, Dicrocoeliidae).

Infection experiments showed that the African ant Camponotus compressiscapus can serve as a second intermediate host of Dicrocoelium hospes. Most of the cercariae penetrated the crop-wall and encysted in the hemocoel, whereas one or more larvae invaded the ant's central nervous system. These larvae cause behavioral changes, which increase their chance of being ingested by final hosts. Experimental infections of definitive hosts were obtained in golden hamsters, Meriones unguiculatus, guinea-pigs, and sheep.

Animals↗

Cerebral larvae in the second intermediate host of Dicrocoelium dendriticum (Rudolphi, 1819) and Dicrocoelium hospes Looss, 1907 (Trematodes, Dicrocoeliidae).

Cerebral larvae of Dicorcoelium dendriticum and D. hospes and the brains of infected ants were studied. Morphologic differences of the freed larvae could not be found, but there were evident differences in number and localization of the cerebral stages. Ants infected with D. dendriticum usually showed one "Hirnwurm" while in the majority of the ants infected with D. hospes two larvae were found. The typical localization of the "Hirnwurm" of D. dendriticum was in the ventral part of the subesophageal ganglion; almost every larva of D. hospes was found in the dorsal part of an antennal lobe. The cyst walls of the larvae were visible only in some specimens. Their thickness seemed to depend on the localization of the larva. Differences in number and localization of the larvae, and hypotheticalmechanisms how they could influence the behavior of their hosts are discussed.

Animals↗

Pastoralists and hydatid disease: an ultrasound scanning prevalence survey in east Africa.

An attempt was made to estimate the prevalence of hydatid disease in nomadic pastoralists living in eastern Africa and to identify environmental, cultural and behavioural factors which may influence Echinococcus transmission. 18,565 nomadic pastoralists, from 12 different groups living in the vast, semi-desert regions of Kenya, Sudan, Ethiopia and Tanzania, were screened for hydatid cysts using a portable ultrasound scanner. High prevalences of hydatidosis were recorded among the north-western (5.6%) and north-eastern (2.1%) Turkana of north-west Kenya, the Toposa (3.2%) of southern Sudan, the Nyangatom (2.2%), Hamar (0.5%) and Boran (1.8%) of south-west Ethiopia and northern Kenya and the Maasai (1.0%) of Tanzania. Lower prevalences were recorded amongst the southern (0.3%) and lake dwelling (0.3%) Turkana and the Pokot (0.1%) of Kenya. The disease was not found amongst the Turkana, Samburu, Dassanetch, Gabbra, Somali or Rendille screened on the east side of Lake Turkana. The scanning surveys were well accepted by the people and provided evidence for the need to expand the present hydatid control programme in Turkana to cover the whole hyperendemic focus. Such a programme must contain an educational component for, although most groups recognized hydatid cysts, there was complete lack of knowledge concerning the parasite and its mode of transmission.

Africa, Eastern↗

Evaluation of a rapid dot-ELISA as a field test for the diagnosis of cystic hydatid disease.

A rapid dot enzyme-linked immunosorbent assay (dot-ELISA) was developed as a field test for the diagnosis of cystic hydatid disease caused by Echinococcus granulosus. The 30 min test was based on the detection of antibodies to antigen B of hydatid fluid and was carried out using 50 microliters of whole blood in a field assessment in the Turkana region of north-west Kenya. Initial laboratory studies showed antigen B to be preferable to crude cyst fluid, with 94% sensitivity and 90.3% specificity for Echinococcus infections. The field test was rapid, inexpensive and simple to perform and is considered to be a useful back-up to ultrasound scanning.

Antibodies, Helminth↗