Molluscicidal effect of Piper guineense.

The study was undertaken to assess the dosage-mortality ratio and toxic effects of Piper guineense fruit extracts on the adults of Biomphalaria pfeifferi, the snail intermediate host of Schistosoma mansoni, which causes intestinal schistosomiasis. The result showed significant toxic effects with crude ethanol and hot water fruits extracts. The estimated lethal dose concentration by arithmetic method (LC(50) and LC(90)) using both crude ethanol and hot water fruit media extracts were found to be (0.10 ± 0.04, 0.9 ± 0.2) mgl(-1) respectively for ethanolic extract and (5.0 ± 1.4, 8.5 ± 0.7) mgl(-1) respectively for hot water extract. Ethanolic extract was more potent than hot water extract. An all or none phenomenon appeared characteristic of the biological activity of these extracts. There was significant decrease in oviposition rate (p < 0.02). The extract from the fruits of this tropical plant holds promise in the control of Biomphalaria pfeifferi.

Seroconversion of children following natural measles infection and vaccination.

OBJECTIVE: To evaluate the relationship between measles virus (MV) antibodies (abs) in sera and breast milk of nursing mothers, their contributions in seroconversion of children (0-9 months) post vaccination, prevalence of prevaccination measles abs in sera of children brought for measles vaccination and seroconversion rate in vaccinees from nursing and lactating mothers. Also to determine the potency of vaccines available in Nigeria in relation to seroconversion. METHODS: One hundred and twenty pre- and post-vaccination sera and breast milk samples were collected from each nursing mother while corresponding number of finger prick pre- and post-vaccination sera samples were collected from children on filter papers. These were tested for mv abs using serological techniques. RESULTS: Eighty (20.0%) mothers had measles haemagglutination inhibition (HI) abs in sera and 88 (27.2%) had mv HI abs in breast milk. Eight (2.0%) children who had prevaccination mv abs in sera came from mv ab negative mothers. Forty-four (37.0%) came back for post vaccination sera, sero-converted while 76 (63.3%) gave low sero-conversion rate of 37.0%. Results showed that mv abs in sera or breast milk of mothers did not interfere with mv vaccination in children. The low sero-conversion rate obtained was due to low vaccine potency with titres ranging between (log10-10 - log10-2.5)TCID/per dose, besides non-specific antiviral substances exhibited virus neutralizing activity. CONCLUSION: Poor sero-conversion due to loss of passive immunity arose from undernourishment while low ab titres came with natural infection. This suggested mv vaccination did not immunize following natural mv infection or any other previous immune status.

Some aspects of epidemiology of filth flies: Musca domestica, Musca domestica vicina, Drosophilia melanogaster and associated bacteria pathogens in Ekpoma, Nigeria.

Between January 2005 and December 2005, including the wet and dry seasons, 1,358 filth flies (Musca domestica, 737 [54.3%]; M. domestica vicina 556 [41%]; and Drosophilia melanogaster 65 [5%]) were caught by quadrant samplings using nets twice each month (early and later) in each of the various sites with varying sanitary conditions in Ekpoma, Nigeria. These sites were markets, hospitals, houses/human habitations, pit latrines, stalls of local food vendors, abattoirs/slaughterhouses, and dairy farms. These filth flies were studied for their potential to carry bacterial species. The identified filth flies were found to carry bacterial pathogens, with each harboring 2-10 bacteria. Seven bacterial species and their load namely, Escherichia coli (189 x 10(10) organisms per milliliter), Proteus species (210 x 10(10) organisms per milliliter), Streptococcus species (192 x 10(10) organisms per milliliter), Klebsiella species (213 x 10(10) organisms per milliliter), Salmonella species (386 x 10(10) organisms per milliliter), Staphylococcus species (163 x 10(10) organisms per milliliter), and Serratia macenscens (5.0 x 10(10) organisms per milliliter) were isolated. The highest mean bacterial load for all bacteria isolated from pooled flies was 200 x 10(10) organisms per milliliter. The mean bacterial loads of 150, 90, and 10 x 10(10) organisms per milliliter were recorded for M. domestica, M. domestica vicina, and D. melanogaster, respectively. Approximately 15(4)-23(6) bacterial colonies per fly were recorded. The total number of bacteria isolated from flies caught in the dairy farms were higher than those isolated from flies caught in any other studied sites. Lower prevalence of associated bacterial pathogens was established from flies caught in areas where hygienic conditions prevailed. Salmonella species was the most prevalent bacterial pathogen isolated amongst the flies that perched on dairy products sampled. Bacterial load was most prevalent during the wet season. Resistances of some bacterial pathogens to common available antibiotic drugs shown by zone of inhibition (

Urinary tract pathology in Schistosoma haematobium infected rural Nigerians.

Parasitological investigation assessing the ova of Schistosoma haematobium in the urine of 138 volunteers in Ihieve-Ogben, Edo State, Nigeria revealed 43 positive results (31.2%). Children had a higher prevalence of urinary schistosomiasis 30 (41.1%) than their adult counterparts 13 (20.0%) and this difference was statistically significant (t = 8.89, p > 0.01). More volunteers had light intensity of infection 27 (19.6%) than heavy infection 16 (11.6%) and this difference was statistically significant (chi2 = 22.90, p>0.05). Ultrasonographic investigations carried out on these 43 S. haematobium infected volunteers revealed ten pathological conditions, including abnormal wall thickness 24 (55.8%), abnormal shape 30 (69.8%), irregular bladder wall 12 (27.9%), masses 10 (23.3%), pseudopolyps 2 (4.7%), echogenic particles 30 (69.8%), residual volume 12 (27.9%), calcifications 24 (55.8%), hydroureter 10 (23.3%) and hydronephrosis 8 (18.6%) when compared to control subjects which lacked bladder and kidney abnormalities. These pathological conditions were slightly more common in the volunteers with heavy infection than those with light infection, but this difference was not statistically significant (t = -2.19, p < 0.02). More pathological conditions were found in children than in adults; this finding was statistically significant (t = 3.23, p > 0.03). Hydronephrosis and hydroureter were not found in the volunteers with light intensity of infection.

CD4(+), CD8(+), immunoglobulin status and ocular lesions among some onchocerciasis-infected rural Nigerians.

CD4(+), CD8(+), immunoglobulin status and ocular lesions of some onchocerciasis-infected rural Nigerians as manifested by the presence of microfilariae in their skin snips and some chronic symptoms of the parasitic infestation were evaluated. The highest mean CD4(+) and mean microfilarial (mff) load of 560 +/- 20.46 unit cells/microl and 20 mff/mg were recorded among the individuals within the second decade of life, while the least mean CD4+ and mff load of 307.20 +/- 11.23 unit cell/microl and 6.5 mff/mg occurred among volunteers after 60 years of age. The highest mean CD8(+) of 388.00 +/- 23.71 unit cells/microl occurred at the third decade of life. The individuals above 60 years had the least mean CD8(+) of 350.25 +/- 11.90 unit cells/microl. The volunteers had mean CD4(+) of 372.45 +/- 109.02 unit cells/microl and mean CD8(+) of 359.42 +/- with an overall CD4(+):CD8(+) ratio of 1.04. The mean CD4(+) and mean CD8(+) had positive correlation with the mean microfilarial load (r = 0.52 and r = 0.40), respectively. The mean IgE, IgG, lgA, IgM, and IgD were 2,074.82 +/- 823.09, 19.36 +/- 2.49, 3.88 +/- 0.26, 3.59 +/- 0.38, and 0.29 +/- 0.19 mg/dl, and these immunoglobulins negatively correlated with the mean microfilarial load at r = -0.02, r = -0.15, r = -0.82, r = -0.37, and r = 0.26, respectively. Among these immunoglobulins evaluated, only mean IgE (2,074.82 +/- 823 ng/ml) was statistically different from the control subjects (0 mg/dl) at t = 3.39, P < 0.05. In all, the prevalence of the visual impairment and lesions were low. Among the six visual lesions, namely, cataract, choroidoretinitis, iridocyclitis, glaucoma, sclerosing keratitis, and optic atrophy encountered in Egoro-Eguare, only optic atrophy and sclerosing keratitis was reported among the children. The female adults had the highest prevalence of reduced vision 20(43.5%). Also, the prevalence of choroidoretinitis (2.2%) and iridocyclitis (2.2%) were the least prevalent ocular lesions reported among these female adults. The depletion of the CD4(+) contributed to the low prevalence of visual impairment and lesions in this locality. The depleted CD4(+), CD8(+), and the lower values of IgA, IgM, and IgG contributed in the maintenance of chronicity of onchocerciasis in Egoro-Eguare, Nigeria.

Human immunodeficiency virus type-1 (HIV-1) and the associated clinical features among sero-positive Nigerian subjects.

Enzyme Linked Immunosorbent Assay (ELISA) and Westernblot were employed to analyze sera collected from one thousand and fifty (1050) patients who tested HIV positive type-1. Out of this, 95 (9.1%) of the patients were less than 2 years old, 102 (10.0%) were aged between 2-15 years old while 813 (77.4%) were aged above 15 years. For any age group, the ratio of male to female was 1:1 except that there was excess of males below 5 years. There were four (4) most frequent signs and symptoms observed. These were loss of weight or malnutrition, generalized lymphadenopathy, chronic watery diarrhoea and chronic chest infections. Loss of weight was recorded in 65.0% of the seropositive patients in all age groups. Generalized lymphadenopathy was seen in 35.0% of all the age groups but was most frequent in 36.1% of those less than 2 years. Chronic watery diarrhoea (42.8%) was frequent in patients less than 2 years and less frequent in 18.0% of older children between 1-15 years. Chronic chest infections were least frequent in 25.0% of adults above 15 years old and highest frequency was observed in 53.0%, children less than 2 years. Forty patients had incomplete documentations and children of pediatric ages had acutely overt clinical manifestation of HIV (1&11) attributable to undeveloped immune competence.