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.

Hepatitis B surface antigen (HbsAg) in the sera of medical, nursing and microbiology students in Ibadan, Nigeria.

A total of 331 serum samples collected from medical students, student nurses, microbiology students, and patients presenting with Pyrexia of Unknown Origin (PUO) were tested for the presence of Hepatitis B surface Antigen (HbsAg). While only seven (14.0%) of 50 microbiology students (mean age 24.0 years) tested positive for HbsAg, six (6.7%) of 89 student nurses (mean age 21.6 years) and 13 (13.5%) of 95 medical students (mean age 24.3 years) in the clinical phase of their study were found to have HbsAg in their sera. Also, 10 (10.3%) of 97 patients with PUO (mean age 25.4 years), a group of patients from whom medical personnel are most likely to often collect blood for laboratory studies, were found to have HbsAg in their sera. No significant difference was found in the prevalence of HbsAg among the different groups examined in this study (P>0.05). The result of the study thus shows that medical and nursing students, unlike what is known for practising nurses, physicians and surgeons are not at a higher risk of HBV transmission than students of botany and microbiology. Likewise, patients with PUO do not constitute a group that is more likely to transmit HBV to medical personnel than other groups of patients. Vaccination against hepatitis B virus during the early period of medical and nursing training may therefore go a long way to reduce the high prevalence of hepatitis B virus infection previously reported among practising health personnel in Nigeria.

Low seroconversion rates to measles vaccine among children in Nigeria.

The Nigerian Expanded Programme on Immunization (EPI) was assessed with particular reference to measles immunization. Of 150 children who received measles vaccine at the Institute of Child Health, University of Ibadan, Nigeria, 82 (54.7%) seroconverted. The immune response was directly related to the titre of the vaccines used. Vaccines whose titres were 10(-1) to 10(1.7) stimulated immune responses in 0-25% of vaccinees, those with titres in the range 10(-2.1) to 10(-2.5) stimulated responses in 12-47.6%, while those with titres of 10(-2.7) to 10(-3.4) stimulated responses in 87.5-100% of vaccinees. Only one of the vaccines used had a titre that met the minimum WHO required standard of log 10(-3) TCID50 at the point of vaccination.

PIP: During April 1989-February 1990, in Nigeria, health workers took blood samples from 284 children aged at least 9 months from across the socioeconomic spectrum who received measles vaccine at the Institute of Child Health of University College Hospital in Ibadan to examine seroconversion rates to lyophilized and diluted measles vaccines. This was done to evaluate the Nigerian Expanded Programme on Immunization (EPI). 16 (5.6%) had measles antibodies before vaccination. 52.8% (150) of the children returned for post-vaccination screening. 54.7% seroconverted. 86.5% of children who seroconverted had low-level antibody titers. Five of the seven children who had measles antibodies before vaccination and who had returned for post-vaccination screening had a reduced antibody titer. The other two had an increased titer. Only one of the vaccines had a titer meeting the minimum standard set by the World Health Organization (log 10-3TCID50). The immune response depended on the titer of the vaccine. For example, the Morbilvax vaccine of batch 33A13 had the highest titer (10-3.4) and stimulated the greatest immune response (93.3%), while all the batches with a titer of 10-1-1.7 (except one) stimulated no immune response. The vaccines were not stable at 45 degrees Celsius but were relatively stable at 37 degrees Celsius and -70 degrees Celsius. These findings show that low vaccine titers were responsible for the low seroconversion rates. The researchers advise EPI managers to evaluate the cold chain, to examine storage conditions, to randomly test vaccines before use, and to use highly heat-stable vaccines.

Low seroconversion rates to measles vaccine among children in Nigeria

The Nigerian Expanded Programme on Immunization (EPI) was assessed with particular reference to measles immunization. Of 150 children who received measles vaccine at the Institute of Child Health, University of Ibadan, Nigeria, 82 (54.7%) seroconverted. The immune response was directly related to the titre of the vaccines used. Vaccines whose titres were 10(-1) to 10(1.7) stimulated immune responses in 0-25% of vaccinees, those with titres in the range 10(-2.1) to 10(-2.5) stimulated responses in 12-47.6%, while those with titres of 10(-2.7) to 10(-3.4) stimulated responses in 87.5-100% of vaccinees. Only one of the vaccines used had a titre that met the minimum WHO required standard of log 10(-3) TCID50 at the point of vaccination