The prevalence and economic importance of bovine fasciolosis in Kenya--an analysis of abattoir data.

A retrospective study covering a period of 10 years (1990-1999) was carried out using post mortem meat inspection records at the Veterinary Department Headquarters at Kabete to determine the prevalence and economic importance of bovine fasciolosis in Kenya. Meat inspection records from abattoirs in 38 districts distributed over seven out of the eight provinces of Kenya were examined. Prevalence of fasciolosis was calculated as the number of cattle found to be infected with Fasciola, expressed as a percentage of the total number of cattle slaughtered. Using the average weight and market price of a bovine liver, the monetary loss occasioned by condemnation of Fasciola infected livers was calculated. A survey was also carried out at Dagoretti slaughterhouse complex in Nairobi to determine the relative occurrence of F. gigantica and F. hepatica in slaughtered cattle. Cattle slaughtered at Dagoretti slaughterhouse originate from all parts of the country. A total of 5,421,188 cattle were slaughtered in the seven provinces of Kenya during the 10-year period and 427,931 (8%) of these cattle were infected with Fasciola. The region with the highest prevalence of fasciolosis was Western Province (16%) followed, in descending order, by Eastem Province (11%), Nyanza Province (9%), Rift Valley Province (8%), Central Province (6%), Nairobi Province (4%) and Coast Province (3.5%). The total economic loss incurred by the country during the 10-year period as a result of condemnation of the infected livers was approximately US$2.6 million. The total annual economic losses during this period ranged from approximately US$0.2-0.3 million. The highest total economic losses for the 10-year period were recorded in Western Province (US$0.8 million) and Central Province (US$0.7 million). A total of 1584 cattle originating from five provinces of Kenya were slaughtered at Dagoretti slaughterhouse over a period of two months of which 147 (9.3%) were infected with liver flukes. All the liver flukes obtained from the infected livers were identified as F. gigantica. It is concluded that fasciolosis is prevalent in cattle in all provinces of Kenya, that it causes great economic losses as a result of condemnation of infected livers, and that F. gigantica is the main species of liver flukes affecting cattle in Kenya. Local climatic factors, cattle trade, rustling and population numbers, and the presence of the snail intermediate hosts are probably the main factors influencing the incidence of the disease in the various regions of the country.

Bacteriological qualities of indoor and out-door drinking water in Kibera sub-location of Nairobi, Kenya.

OBJECTIVES: To compare the bacteriological quality of out-house (tank or standpipe) water and in-house drinking water (storage containers) and determine the risk factors influencing it. DESIGN: A cross-sectional study. SETTING: The study was carried out in Kibera slums located 7 km southwest from the Nairobi City centre. SUBJECTS: Water samples from twenty outside tanks/standpipes and sixty from in-house water storage containers. MAIN OUTCOME MEASURES: Pour plate method was used to enumerate total bacterial counts in water, while the multiple tube technique was used to determine faecal coliform (FC) and faecal streptococci (FS) numbers. A questionnaire and environmental observation were used to determine the risk factors influencing bacteriological quality of water. RESULTS: The mean total bacterial counts (TBC) for out-house water was 46.6 per 100 ml while that for in-house water was 818.2 per 100 ml. Faecal coliforms were isolated from 7 (35%) standpipes and 57 (95%) in-house storage containers. The mean faecal coliform count was 93 and 103.4 per 100 ml for out-house and in-house water, respectively. The counts were significantly higher in the latter. Faecal streptococci were isolated from 2 (10%) standpipes and 37 (61.7%) in-house storage containers. The mean faecal streptococci counts were 35 and 65 per 100 ml for out-house and in-house water sources, respectively. Escherichia coli was isolated in 2 (10%) of out-house water and 30 (50%) of in-house. Of these, four were enteropathogenic, serotype 011 from one out-house water source and serotypes 011, 011, 0112ac from in-house water sources. CONCLUSIONS: Bacteriological contamination of water at the source with a further deterioration between the collection points and homes was observed. A defective water delivery system and inadequate environmental sanitation were a potential source of contamination for out-house water. Scoops were a major source of contamination for stored water.

Tetracycline residue levels in cattle meat from Nairobi salughter house in Kenya.

Two hundred and fifty beef samples were collected from five slaughterhouses in and around the city of Nairobi. The beef animals were sourced from various parts of the country. Samples of 50-100 grams were collected randomly from the liver, kidney and muscle of different beef carcasses. The samples collected were processed using multiresidue analytical methods that included liquid-gas partitioning and set-pat C18 cartridges chromatographic clean up. Chlortetracycline and oxytetracycline detection was done using Knauer Model 128 HPLC with an electron capture detector. Out of the 250 samples that were analyses for tetracycline residues 114 (45.6%) had detectable tetracycline residues. Of the 114 samples with detectable tetracycline residues, 60 (24%) were liver samples, 35 (14%), were kidney samples and 19 (7.6%) were muscle samples. The mean (p>0.05) residue levels of tetracycline for the five slaughterhouses studied were as follows: Athi River 1,046 micro g/kg, Dandora 594 micro g/kg, Ngong 701 micro g/kg, Kiserian 524 micro g/kg and Dagoretti 640 micro g/kg. Of the 250 samples analysed 110 (44%) had oxytetracyclines while 4 (1.6%) had chlortetracyclines. The mean residue levels of the detected tetracyclines were higher than the recommended maximum levels in edible tissues. This study indicates the presence of tetracycline residues in the various edible tissues. Regulatory authorities should ensure proper withdrawal periods before slaughter. This study indicates the presence of tetracycline residues in the various edible tissues. Regulatory authorities should ensure proper withdrawal period before slaughter of the animals.

Application of enzyme-linked immunosorbent assay (ELISA) based on two E. granulosus antigens in the diagnosis of human hydatidosis.

A total of 180 sera consisting of 50 sera from Kenyans with surgically confirmed hydatidosis and 130 sera from individuals without hydatid disease were examined. "Antigen 880" (which is suspected to be similar to Antigen B) showed a sensitivity of 88%. No false reactions were obtained with sera from individuals with non-hydatid infections, hence a specificity of 100% was recorded with this antigen. "Antigen 346" (which is similar to Capron's "Arc 5") showed a sensitivity of 52% and a specificity of 100%. It is concluded that "Antigen 880" may be more useful than "Arc 5" in the diagnosis of human hydatidosis in Kenya due to the high sensitivity obtained with the antigen.

Purification and partial characterization of a thermo-stable lipoprotein ("antigen 880") of hydatid cyst fluid (HCF).

A purification procedure for a HCF thermo-stable lipoprotein designated as "Antigen 880" and subsequent characterization are described. The molecular weight and PI of the lipoprotein were shown to be 240,000 daltons and 4.2 respectively. The antigenic activity of "Antigen 880" was not affected by trypsinization, pepsinization and delipidization. This suggested that the antigen activity of the lipoprotein recided in both the protein and lipid moieties. Treatment of the antigen with various concentrations of iodoacetamide and dithiothreital (DTT) and subsequent assay for antigenic activity showed that the two chemicals did not affect antigenic activity. This suggested that the di-suphide bonds were not a pre-requisite to antigenic integrity of the lipoprotein. After heating HCF at temperature between 105-121 degrees C, it was shown that "Antigen 880" was the only HCF antigen which retained activity at these temperatures. Further analysis of the supernate obtained after heating concentrated HCF at a temperature of 110 degrees C for 10 minutes by use of Sephadex G-200 column showed two peaks. Antigenic activity specific for "Antigen 880" was obtained in Peak I, while no antigen activity was found in Peak II. When Peak I was analyzed using step-by-step DEAE 52 ion exchange chromatography, only one peak was eluted with 0.2M phosphate buffer, pH 8.5. This peak had antigenic activity for "Antigen 880". Analysis by disc-gel electrophoresis of the antigenic preparation obtained from the DEAE-cellulose column revealed one protein species. "Antigen 880" was shown to be stable for 10 months after incubation at pH1-11.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of human hydatid disease in surgically-confirmed cases by the use of the indirect haemagglutination test based on a thermo-stable lipoprotein and on unfractionated hydatid cyst fluid.

A total of 204 sera, taken from healthy individuals or from individuals with various parasitic and bacterial infections, were examined by the indirect haemagglutination test. The tests were carried out using either a thermo-stable lipoprotein or unfractionated hydatid cyst fluid, and a titre of 1:64 or above was considered positive. Sixty-two of 70 sera from individuals with surgically-confirmed hydatid disease showed positive reactions with the thermo-stable lipoprotein--a sensitivity of 88%. No false positive reactions were obtained with sera from healthy individuals or from individuals with parasitic or bacterial infections, and no cross-reactions were observed with sera from individuals with multiple myeloma. The lipoprotein antigen thus showed a specificity of 100%. A sensitivity of 88% was obtained with the indirect haemagglutination test using whole hydatid cyst fluid; but positive reactions were obtained from healthy individuals and from individuals with schistosomiasis, leishmaniasis, taeniasis and malaria. No cross-reactions were obtained with sera from patients with gonorrhoea, syphilis or multiple myeloma. Because of the high sensitivity and specificity shown by the thermo-stable lipoprotein ('Antigen 880'), it is considered that this antigen is more useful than unfractionated hydatid cyst fluid in the diagnosis of human hydatidosis in Kenya.

Usefulness of indirect haemagglutination (IHA) and enzyme-linked immunosorbent assay (ELISA) in the diagnosis of human hydatidosis.

This communication reports on the usefulness of the IHA test and the ELISA in the diagnosis of human hydatid disease. The study was conducted on 40 surgically confirmed cases of hydatid disease, 40 normal individuals, and sera from individuals with various parasitic infections and other conditions namely: hook-worm-8, taeniasis-5, schistosomiasis-10, malaria-15, visceral leishmaniasis-12, multiple myeloma-3, syphilis-6, and gonorrhoea-10. The results show a sensitivity of 85% and specificity of 100%. The results indicate that it is no longer scientifically rational to hold the view that the Turkana do not mount adequate immune response against Echinococcus infections.

The amino acid and fatty acid composition of the thermostable lipoprotein ("Antigen 880") of hydatid cyst fluid (HCF).

Analysis for the amino acid composition of "Antigen 880" was carried out by use of double dimension paper chromatography and Biotronik 2,000 automatic amino acid analyzer. By the double dimension paper chromatography, leucine, phenylalanine, tyrosine and alanine were identified as amino acid components of the protein moiety of "Antigen 880". In the Biotronik 2,000 automatic amino acid analyzer showed the concentration of the various amino acids to be as follows: isoleucine, leucine, tyrosine, phenylalanine, lysine and histidine were identified as amino acid constituents of "Antigen 880". Quantitative studies in Biotronik 2,000 analyzer showed the concentration of the various amino acids to be as follows: valine -0.85 mumol/ml; leucine - 0.22 mumol/ml. /ml; iso-leucine - 0.18 mumol/ml; tyrosine - 0.04 mumol/ml, and histidine - 0.02 mumol/ml. The fatty acid composition of the lipid moiety of "Antigen 880" was investigated by use of Gas-Liquid chromatography. In this method, C8:0. C10:0, C12:0, C14:0, C16:0 and C18 were identified as the fatty acid constituents of the lipid moiety of "Antigen 880".