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.

The evaluation of non-specific cellular immunological parameters amongst children with Schistosoma haematobium infection in Nigeria.

This study used the leucocyte migration index to assess cellular immune function in children with urinary schistosomiasis. Migration inhibitory factor was produced (with other lymphokines) by sensitizing mitogens. The production of antigen-induced migration inhibitory factor in vitro correlated with the in vivo state of cellular hypersensitivity of the lymphocyte donor. The percentage positive leucocyte migration rate using three mitogens was least with inactivated measles haemagglutinin virus (IMV) and highest with Bacillus Calmette-Guerin (BCG) in the control group, while highest with tuberculin purified protein derivative (PPD) and least with IMV in the test group. The measurement of the migration index of leucocytes comparing the control with lightly- and heavily-infected children on activation using three mitogens was significantly reduced, except in the case of the control versus lightly-infected children using IMV. Using IMV, the leucocyte migration index for control versus lightly-infected children and heavily-infected children was significant (p > 0.002 and p < 0.001, respectively). Using BCG the difference between controls and lightly- and heavily-infected children were significant (p < 0.02). PPD showed no significant difference in leucocyte migration between control and the lightly- or heavily-infected children. In all leucocyte migration index decreased with intensity of infection except in the case of PPD (p < 0.002 for BCG; p < 0.001 for the IMV). There was a significant correlation between egg count and leucocyte migration index; for BCG (r = -0.20, p < 0.005); for IMV (r = -0.3, p < 0.001); for PPD (r = -0.38,p < 0.001). Patients with schistosomiasis infection can express normal and effective cellular immune responses to non-schistosomal antigens and also have equal immunological ability to combat pathogens as S. haematobium-free controls.

Evaluating the laboratory techniques used in the diagnosis of sputum-producing-patients suspected of Mycobacterium infection.

Because of the susceptibility of HIV-infected persons to Mycobacterial infections, more sensitive diagnostic technique are being employed to detect Mycobacterium spp from clinical specimens. This study was therefore carried out to evaluate the sensitivity of methods used for the diagnosis of mycobacterial infections among sputum producing patients. Sputum samples from 160 patients were examined for Mycobacterium spp using direct smear microscopy, concentrated smear microscopy, and cultural method. The cultural technique detected the highest number of positives, 62 (38.8%), followed by concentrated smear technique,, 41 (25.6%) while direct smear technique detected only 24 (15.0%). The results show that cultural technique should be employed for the diagnosis of Mycobacterium in order to avoid false negative results. However, concentrated smear technique should always be carried out, so that treatment could commence immediately in obviously positive cases.

Prevalence of transmissible blood infections among blood donors at the University of Maiducuri Teaching Hospital, Maiduguri, Nigeria.

Before the advent of the Acquired Immune Deficiency Syndrome (AIDS), many countries of the world transfused blood without seriously considering the potential risks of transmission of infectious agents. Even after it was shown that the Human Immunodeficiency virus(HIV) could be transmitted through blood and blood products, many hospitals and clinics in Nigeria still continue to transfuse unscreened blood. This study was therefore initiated to highlight the risks of transmitting infectious agents through blood transfusion and the category of infectious agents which could be transfused in blood in this area. A total of 364 healthy blood donors were counselled, bled and screened for HIV-1, HIV-2, HBsAg, Treponema pallidum, Plasmodium falciparum and microfilaria. The results show that the three most common infections transmissible through blood transfusion are Hepatitis B(14.9%), HIV-1 (5.8%) and P.falciparum (4.1%). Thirteen of the 364 blood donors (3.6%) and antibodies to T. pallidum. There were no donors with HIV-2 or filarial infection. Infection of donors by hepatitis B virus (HBV), T. pallidum and HIV-1 was not significant dependent on promiscuity, polygamy, previous blood transfusion or local surgery. However, there was a significant difference between donors with no risk factors and those with risk factors with regard to seroprevalence to HBV, T. pallidum and HIV-1 (p = 0.0053). The results confirm that transfusion of unscreened blood carries severe risks of transmitting serious infectious agents and that is a need to enforce laws for transfusing blood in Nigeria. Meanwhile, in the absence of screening facilities, proper counselling of blood donors in order to ascertain their risk behaviour should be used to select donors and reduce this risk.