The Imo State (Nigeria) Drinking Water Supply and Sanitation Project, 1. Description of the project, evaluation methods, and impact on intervening variables.

A health impact evaluation was conducted in conjunction with the Imo State Drinking Water Supply and Sanitation Project in Nigeria. The project consisted of a package of water supply, sanitation, and health and hygiene education given by village-based workers. The evaluation was a quasi-experimental study covering pre-, peri- and post-intervention periods. Data were collected from 3 intervention and 2 control villages. Baseline surveys indicated that the intervention and control areas were similar with respect to most socio-demographic variables. Use of the improved water supply was high, although this was influenced by borehole-to-population ratios and household-to-borehole distances. Water collection time was consequently greatly reduced. Data from a small sample of households showed that borehole water became heavily contaminated during collection and storage, and that there was no significant change in consumption of water per person. Adults in 46% of household units in the intervention area were using ventilated improved pit latrines by the end of the study period. Use by young children (2-5 years old), however, was low. Limitations in the success of the health education component of the project were found. Although changes were found in knowledge, attitudes and practices related to water and sanitation, and in management of childhood diarrhoea, this occurred in both the intervention and control areas.

The Imo State (Nigeria) Drinking Water Supply and Sanitation Project, 2. Impact on dracunculiasis, diarrhoea and nutritional status.

Morbidity due to dracunculiasis (guinea worm disease) and diarrhoea in persons of all ages, and nutritional status of young children, were used as health impact indicators in the evaluation of the Imo State Drinking Water Supply and Sanitation Project in south-eastern Nigeria. Data were collected using repeated cross-sectional surveys and longitudinal follow-up. The study area was found to have a low level of endemicity of dracunculiasis. While no impact could be demonstrated on overall period or point prevalence rates in the cross-sectional surveys, a prospective longitudinal survey showed a significant reduction in the percentage of person-fortnights positive for dracunculiasis in areas served by the project, while the control areas showed no such change. In the cross-sectional surveys it was found that, in the project villages, those persons drinking only borehole water had significantly lower period prevalence rates one year later than others. Moreover, those living further from the nearest borehole had higher rates of dracunculiasis. An impact of the project on diarrhoea morbidity was found only in limited sub-groups of the population. A greater association with water availability rather than quality was suggested for rates in young children. The prevalence of wasting (less than 80% weight-for-height) among children aged less than 3 years decreased significantly over time in all 3 intervention villages; there was no such decline in the control villages.

Biotype and serogroup distribution of Campylobacter isolates from children in Nigeria.

A total of 101 Campylobacter isolates from Nigerian children with or without gastroenteritis were biotyped and serogrouped by using the Lior typing schemes (H. Lior, J. Clin. Microbiol. 20:636-640, 1984; H. Lior, D. L. Woodward, J. A. Edgar, L. J. Laroche, and P. Gill, J. Clin. Microbiol. 15:761-768, 1982). Fifty-three (52.5%) of the isolates were Campylobacter jejuni biotype I, 29 (28.7%) were C. jejuni biotype II, 10 (9.9%) were Campylobacter coli biotype I, and 9 (8.9%) were C. coli biotype II. Serogroup 36 was the most common (20.7%) in this study, in contrast with serogroup 1 (18.5%) earlier reported from Canada (Lior et al., J. Clin. Microbiol. 15:761-768, 1982).

A new scheme for serotyping group-G streptococci.

Ten antisera, prepared against nine selected strains of group-G streptococci and a strain of group-A streptococci of M-type 12, were used to serotype 102 isolates of group-G streptococci by means of precipitation reactions between the sera and hot-acid extracts of the streptococci. Fifty-six (54.9%) of the streptococci could be typed; eight serotypes were identified, of which type VIII was the most common (18.6%). The M12 and the R28 antigens, previously recorded in group-G streptococci, were not detected. The type antigens were trypsin sensitive and resembled the M antigens of group-A streptococci.

Effects of saliva and alpha-amylase on antibiotic sensitivity of bacteria.

Two hundred and ninety-six bacterial isolates were investigated for the effects of saliva and alpha-amylase on their susceptibility to ampicillin, tetracycline, chloramphenicol and gentamicin. When the test organisms were primed with normal and 'diseased' saliva there were no observable differences in the MICs of ampicillin and chloramphenicol for group-A streptococci, but alpha-amylase significantly reduced the MIC of tetracycline from 2 to 0.25 mg/1. With Staphyloccus aureus, priming with saliva and alpha-amylase had no effect on the MICs of gentamicin and ampicillin, whereas the MICs of tetracycline and chloramphenicol were increased. The effect of saliva on the susceptibility of E. coli to tetracycline was also significant; MIC50 and MIC90 were reduced from 128 to 8 and 32 mg/1 respectively. Chloramphenicol was however increased from less than 0.125 to 1 and 2 mg/1 when E. coli was primed with amylase and saliva respectively. The general significance of these observations is discussed.

Isolation of species of Yersinia from patients with gastroenteritis in Nigeria.

From patients in Nigeria with acute gastroenteritis, strains of Yersinia were isolated from 14 (1.3%) of 1082 specimens of faeces examined specifically for yersiniae by direct plating and after cold enrichment. Clinical significance was ascribed to six isolates of Y. enterocolitica (serotypes 03, 05,27 and 09) but not to seven isolates of Y. intermedia or one isolate of Y. frederikseni.

Local pattern of acute enteric bacterial infections in man--Lagos, Nigeria.

Stool specimen from 994 patients with Acute Diarrhoeal Diseases were processed for bacterial agents known to be responsible for acute diarrhoea. These were from patients seen at the Lagos University Teaching Hospital over a 9 month period. The pattern that emerged showed Shigella isolates made up by 36 flexneri; 29 boydii, 21 dysenteriae and 4 sonnei; Salmonella isolates were typhi 3, typhimurium 12, enteritidis 3, Oranienburg 9, others 8; Yersinia enterocolitica 14; Campylobacter species 20; Enterotoxinogenic E. coli 12, Vibrio cholerae 5; Enteropathogenic E. coli 35; Enterotoxinogenic E. coli 12; Enteroinvasive E. coli 5. Shigella was by far the most common with 43.6% of the isolates EPEC with 17% Salmonella 12% Campylobacter species 9.7%. Yersinia enterocolitica 6.7% ETEC 6%, Vibrio cholera 2.5% and EIEC 2.5%. The isolates are discussed in relation to age groups and seasons of the year. Oral glucose-electrolyte therapy was evaluated in 48 infants with acute diarrhoea. Pcv, electrolyte, Blood Urea, gain in body weight and fluid intake were monitored. Acceptability and effectiveness of the ORT in our Community were confirmed. There was no excess gain in body weights or puffiness of face and eyelids in the study subjects.

Differential and selective medium for isolation of Yersinia enterocolitica from stools.

A new differential and selective medium, DYS agar, was developed and evaluated from the isolation of Yersinia enterocolitica. Ther bile salts content of the medium resulted in high selectivity, and inclusion of arabinose, lysine, and arginine rendered Y. Enterocolitica very distinct from Proteus spp., Pseudomonas spp., and other members of the family Enterobacteriaceae. DYS medium was more efficient for the isolation of Y. enterocolitica from experimentally inoculated fecal specimens than MacConkey, deoxycholate-citrate, and salmonella-shigella agars. Although the medium showed selectivity similar to that of another relatively new medium. Y medium (a selective medium for Y. enterocolitica containing sodium oxalate). DYS agar was found to be superior to Y medium in terms of differentiation of Y. enterocolitica from other intestinal organisms. DYS medium is simple to prepare.