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Biomedical subjects

A Nasidi

Publications and source records attributed to A Nasidi.

At least 19 recordsLinked to original sources

Subtype G and multiple forms of A/G intersubtype recombinant human immunodeficiency virus type 1 in Nigeria.

Multiple human immunodeficiency virus type 1 (HIV-1) genetic subtypes, intersubtype recombinants, and group O have been found in west central Africa. In Nigeria, where HIV-1 prevalence is rising rapidly, characterization of HIV-1 strains has been limited. Each of three full-length genome sequences acquired to date shows evidence of recombination: two are largely subtype G with subtype A segments in the midgenome accessory region; the third, IbNG, is subtype G with the long terminal repeats and two segments of pol from subtype A. In this study, peripheral blood mononuclear cells obtained in 1994-1995 from 10 patients hospitalized in northeastern Nigeria were evaluated by sequencing of the complete envelope and, from 7 patients, a portion of gag. Four patients harbored subtype G viruses and six patients had recombinant viruses. Two had strains sharing the A/G recombinant structure of IbNG. Two had a previously undescribed recombinant, mostly subtype A, whose carboxyl-terminal gp41 could not be classified. An A/G recombinant different from IbNG but similar to CA1, a Cameroonian strain, was found in one patient. The remaining patient had a strain that was otherwise subtype G but shared an unclassified carboxyl-terminal gp41 segment with the CA1-like strains. Other subtypes and group O were not found.

Base Sequence

Prognostic scores for use in African meningococcal epidemics.

Current WHO guidelines for the case management of meningococcal infections during epidemics in developing countries often cannot be applied, largely because of the limited health resources in such countries. Several scoring scales based on clinical and laboratory features in numerous combinations have been developed for the management of meningococcal infections in developed countries, and these have facilitated early identification of patients with fulminant disease and thus early intervention and reduction in mortality. Unfortunately such scoring scales are not appropriate for use in developing countries. We identified hypotension, tachycardia, tachypnoea, delay in capillary refill time, coma, absence of neck stiffness and petechiae and/or purpura as simple prognostic factors of meningococcal disease. Two scores were developed: score I, which includes all seven prognostic factors, had a sensitivity and specificity of 80% and 94%, respectively. Score II, which excluded hypotension, had a sensitivity and specificity of 73.3% and 89.7%, respectively. Quick and simple scoring scales are therefore not only applicable but useful for the case management of patients in meningococcal epidemics in developing countries.

Adolescent

First clinical experiences with a new ovine Fab Echis ocellatus snake bite antivenom in Nigeria: randomized comparative trial with Institute Pasteur Serum (Ipser) Africa antivenom.

During the past decade, effective snake antivenoms have become scarce in northern Nigeria. As a result, many patients severely envenomed by the saw-scaled or carpet viper (Echis ocellatus), which is responsible for more than 95% of the snake bites in the region, did not receive effective treatment and mortality and morbidity increased. To combat this crisis, a new monospecific ovine Fab antivenom (EchiTab) is being developed. Its theoretical advantages over conventional equine F(ab')2 antivenom are a more rapid tissue penetration and larger apparent volume of distribution (the volume of [tissue] fluid in which the the antivenom would be uniformly distributed to achieve the observed plasma concentration). In a preliminary study, two vials (20 ml; 1.0 g of protein) of EchiTab rapidly and permanently restored blood coagulability and cleared venom antigenemia in seven envenomed patients. Four experienced early reactions that responded to epinephrine. In a randomized comparative trial of one vial (10 ml; 0.5 g protein) of EchiTab or four ampules (40 ml; 2.12 g of protein) of Institute Pasteur Serum (Ipser) Africa polyspecific F(ab')2 antivenom, there were fewer reactions, but only 36% and 35% of patients, respectively, showed permanent restoration of coagulability, with the remainder requiring further doses. This suggests that 0.5 g (one vial) of EchiTab is approximately equivalent to 2.12 g (four ampules) of Ipser Africa antivenom, and that a higher initial dose will be required for most patients. Measurements of circulating venom and antivenom levels reflected the clinical events.

Adolescent

Review of cases of nosocomial Lassa fever in Nigeria: the high price of poor medical practice.

OBJECTIVE: To investigate two hospital outbreaks of Lassa fever in southern central Nigeria. SETTING: Hospitals and clinics in urban and rural areas of Imo State, Nigeria. DESIGN: Medical records were reviewed in hospitals and clinics in both areas. Patients with presumed and laboratory confirmed Lassa fever were identified and contracts traced. Hospital staff, patients, and local residents were questioned, records were carefully reviewed, and serum samples were taken. Serum samples were assayed for antibody specific to Lassa virus, and isolates of Lassa virus were obtained. RESULTS: Among 34 patients with Lassa fever, including 20 patients, six nurses, two surgeons, one physician, and the son of a patient, there were 22 deaths (65% fatality rate). Eleven cases were laboratory confirmed, five by isolation of virus. Most patients had been exposed in hospitals (attack rate in patients in one hospital 55%). Both outbreak hospitals were inadequately equipped and staffed, with poor medical practice. Compelling, indirect evidence revealed that parenteral drug rounds with sharing of syringes, conducted by minimally educated and supervised staff, fuelled the epidemic among patients. Staff were subsequently infected during emergency surgery and while caring for nosocomially infected patients. CONCLUSION: This outbreak illustrates the high price exacted by the practice of modern medicine, particularly use of parenteral injections and surgery, without due attention to good medical practice. High priority must be given to education of medical staff in developing countries and to guidelines for safe operation of clinics and hospitals. Failure to do so will have far reaching, costly, and ultimately devastating consequences.

Clinical Competence

Prevalence of human immunodeficiency virus (HIV) antibodies in tuberculosis patients in Lagos, Nigeria.

To establish the prevalence of HIV antibodies in patients with pulmonary tuberculosis, 536 new cases presenting with symptoms of bronchopulmonary disorders were randomly selected from the six referral chest clinics in Lagos and screened for tuberculosis and HIV infections. Sputum and serum samples were obtained from all the patients. The sputum samples were examined for acid-fast bacilli (AFB) by both microscopy and culture. The sera were screened for HIV-1 and HIV-2 antibodies by ELISA and confirmed by Western blot (WB). Of the 536 cases studied, 188 (35%) were positive for AFB while 13 (2.4%) were seropositive for HIV. Correlation between the AFB and HIV results revealed that 10 (5.3%) of the 188 AFB positives were also seropositive for HIV as compared to 3 (0.9%) in the 348 AFB negative cases. The difference in the HIV seroprevalence rates in the two groups was statistically significant (P < 0.001). The recorded higher frequency of HIV infections in the AFB positives strongly suggested some level of interaction between TB and HIV infections in Lagos. Infections with HIV-2 were more prevalent than HIV-1 in the patients with HIV and TB. No case of dual infection with HIV-1 and HIV-2 was recorded in this group of patients. However, in the 3 HIV-seropositive patients within the control group (non-tuberculosis patients), 2 (67%) were positive for both HIV-1 and HIV-2 while 1 (33%) was positive for HIV-2 only. Mycobacterium tuberculosis (70%), M. avium (20%) and M. kansasii (10%) were the mycobacteria strains isolated from the HIV/TB infected patients.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Opportunistic Infections

Should yellow fever vaccine be included in the expanded program of immunization in Africa? A cost-effectiveness analysis for Nigeria.

The cost-effectiveness of preventive yellow fever vaccination versus emergency mass vaccination campaigns for epidemic control remains a matter of controversy. Until recently, Nigeria and other anglophone countries in West Africa most severely afflicted by yellow fever epidemics have followed a policy of emergency control. The effects of including yellow fever 17D vaccine in the Expanded Program of Immunization (EPI) on the immune status of the Nigerian population was studied under conservative assumptions of vaccine coverage and efficacy. The model defined the age-specific prevalence of immunity resulting from vaccination of infants and from natural endemic infection beginning in 1991 and extending over a time horizon of 35 years. The data were used to predict the number of cases and deaths during hypothetical epidemics in 2006 and 2026, representing the historic periodicity of epidemics. A second model was used to demonstrate that a > or = 60% prevalence of immunity would preclude epidemic yellow fever transmission; under base case assumptions, this prevalence would be reached after 18 years of initiating routine yellow fever vaccination in the Guinea savannah zone, the region most often affected by epidemics. Using assumptions based on data from other African countries, the cost of adding yellow fever vaccine to the existing EPI was estimated as +0.65 per fully immunized child, whereas the cost of emergency vaccination in the face of an epidemic was estimated as +7.84/person. Vaccine coverage rates achievable by the EPI were modeled on recent successes with measles vaccine, and began in 1991 at 60%. The effective vaccine coverage rate in an emergency campaign was taken as 10%, based on recent experience. For an epidemic of moderate size in 2006 (morbidity similar to the documented outbreak in 1987), the cost-effectiveness of emergency mass immunization for control of hypothetical yellow fever epidemics was two-fold higher ($381/case and $1,904/death prevented) than that of the EPI ($763/case and $3,817/death prevented). However, despite its higher cost, the efficiency of the EPI was seven-fold greater in terms of cases and deaths prevented. In large epidemics, such as that occurring over successive years (1986-1991) in Nigeria, cost-effectiveness of the EPI exceeded that of emergency control. The EPI may also play an important role in the prevention of endemic yellow fever. Assuming annual rates of endemic yellow fever predicted by serologic surveys, routine vaccination would significantly reduce morbidity and mortality at cost-effectiveness ratios within the range for other diseases prevented by the EPI, including polio, tetanus, and diphtheria.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent

Demographic characteristics of retroviral infections (HIV-1, HIV-2, and HTLV-I) among female professional sex workers in Lagos, Nigeria.

In 1990/1991, 885 prostitutes residing in 11 of the 12 Local Government Areas (LGAs) of Lagos State, Nigeria, participated in a cross-sectional study to determine current seroprevalence of antibodies to human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2), and human T-cell lymphotropic virus type I (HTLV-I). The overall prevalence of HIV-1 was 12.3%, of HIV-2, 2.1%, and of HTLV-I, 2.8%. HIV-1 seropositivity did not vary significantly by age, socioeconomic class, or nationality, but HIV-1 seroprevalence was significantly elevated for prostitutes resident in the Port area of Lagos which serves as a crossroads for international and national commerce (OR = 2.3; 95% CI = 1.1, 4.6). HIV-2 infection was significantly associated with low socioeconomic class (OR = 3.7; 95% CI = 1.2, 10.8) and non-Nigerian nationality (OR = 6.7; 95% CI = 2.5, 18.4). Prevalence of HTLV-I infection increased significantly with age (OR = 2.3; 95% CI = 1.0, 5.3). The high seroprevalence of HIV-1 in this survey, compared with previous surveys reported in the last several years and the correlation between high prevalence and areas of international commerce suggest that HIV-1 is spreading in this area of Nigeria. Intensified prevention campaigns are needed to address this possible emerging epidemic.

Adolescent

Trial of economical regimens of suckling mouse brain rabies vaccine for postexposure prophylaxis in Lagos, Nigeria.

The suckling mouse brain rabies vaccine, recommended for production and routine use in Nigeria from our previous study, was investigated in the present study in an effort to reduce the cost of antirabies treatment in the country. This is needed for economic reasons. Instead of seven daily doses followed by three boosters, we tried five daily doses followed by three boosters, with or without equine hyperimmune serum given on day 0 (40 IU per kg body weight). Fifty dog-bite, victims, aged 3-81 years, were placed on this regimen, 25 with serum and 25 without serum, according to the history of the case. The serum had no effect on the kinetics of antibody development and both serum and vaccine were well tolerated. The geometric mean titres (GMTs) of antirabies antibodies in the sera of recipients of vaccine alone on days 10, 28 and 90 were 3.05 equivalent units ml-1 (EU ml-1), 4.35 EU ml-1 and 2.54 EU ml-1 respectively. Among those who had received antiserum and vaccine the titres were respectively 3.19 EU ml-1, 4.35 EU ml-1 and 3.02 EU ml-1. Of the 50 subjects, 49 showed detectable antibodies by day 28, and all the 50 survived. This regimen is therefore recommended for further trial in countries where rabies is endemic but potent antirabies vaccines are scarce and expensive. Another 23 subjects, considered not to be at risk of rabies, were given a one-tenth dose, two-site intradermal inoculation of the same vaccine on days 0, 3, 7, 14, 28 and 90.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Epidemic yellow fever in eastern Nigeria, 1986.

An epidemic of yellow fever occurred in the eastern part of Nigeria during the second half of 1986. Oju, in Benue State, was the most heavily affected region, but yellow fever also occurred in surrounding areas, particularly Ogoja, in Cross River State. In Oju, the mean attack and mortality rates were 4.9% and 2.8%, respectively. Sex and age specific rates were highest in males and in the 20-29 yr age group. The overall case fatality rate was approximately 50%. Diagnosis was confirmed by IgM capture enzyme-linked immunosorbent assay (ELISA) and complement fixation (CF) tests. Entomological investigations implicated Aedes africanus as the epidemic vector. Oju alone probably had about 9800 cases of yellow fever with jaundice, and some 5600 deaths. Outbreaks of this nature could be prevented by inclusion of yellow fever in the Expanded Programme on Immunisation, in areas subject to recurrent epidemics.

Adolescent

AIDS: a faltering step.

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Acquired Immunodeficiency Syndrome

Anti-rabies treatment of dog-bite victims in Lagos, Nigeria: trial of suckling mouse brain and fetal bovine kidney cell rabies vaccines.

Human rabies is common in Nigeria, a country known for rabies endemicity. Yet the supply of anti-rabies vaccines for human use (adult sheep brain origin, produced locally, and duck embryo and human diploid cell vaccines, imported) is grossly inadequate. This study involved controlled treatment of dog-bite victims with suckling mouse brain (SMBV) or fetal bovine kidney (FBKV) rabies vaccines in an effort to determine which type to recommend for production and use in Nigeria. Dog-bite victims treated were aged three to 74 years, with about equal numbers of males and females. Of the 136 patients, 116 (85.3%) completed at least the primo-series of vaccinations, and all have survived without any evidence of clinical rabies. Recipients of the SMBV showed local and generalized reactions in 11.1% and 2.5% of the cases, respectively. Recipients of the FBKV administered subcutaneously showed local and generalized reactions, in 12.5% and 9.4% of cases, respectively. There were no side effects attributable to the vaccine among patients who received the FBKV intramuscularly. By day 7, 26.7% of SMBV recipients and 28.6% of FBKV recipients showed antibody response, with titres of at least one Equivalent Unit ml-1. These percentages increased to 95.1 and 81.1, respectively, by day 14, and by day 20 (for SMBV recipients) or day 30 (FBKV recipients) the response was 100%. Titres dropped by day 90, but in no case to below 1 EU ml-1. We have concluded that both vaccines are equally efficacious and well tolerated. In view of the simple technology required, and the resultant lower cost, the SMBV is being recommended for production and use in Nigeria.

Adolescent

Urban yellow fever epidemic in western Nigeria, 1987.

A large epidemic of urban yellow fever occurred in April and May 1987 in Oyo State, western Nigeria. The principal vector was Aedes aegypti, breeding in domestic water containers. The 1987 outbreak followed an epidemic of sylvatic yellow fever in eastern Nigeria the previous year, and probably resulted from introduction of the virus by viraemic travellers. The outbreak in Oyo State ended in early July, by which time 805 cases and 416 deaths had been officially notified. However, surveys of 3 villages in the epicentre, a region with over 4 million inhabitants, indicated an infection rate of approximately 20%, a clinical attack rate of 2.9% and a mortality rate of 0.6%, suggesting that the true incidence of cases and deaths far exceeded the official reports. Yellow fever virus was isolated from persons with fully developed yellow fever as well as mild febrile illness. One virus isolate was made from blood of an individual with mild illness, who had received 17D vaccine 5 d earlier; monoclonal antibody analysis showed that the isolate was a wild-type virus. Larval indices of Ae. aegypti were very high; however, low vector competence of the Ae aegypti population may have provided a constraint on spread of the epidemic. In late 1987 a third epidemic appeared in Niger State, northern Nigeria, with 644 reported cases and 149 deaths. The vector(s) involved is (are) unknown.

Adolescent

Yellow fever vaccination and pregnancy: a four-year prospective study.

During an outbreak of yellow fever (YF) in Nigeria in 1986-1987, women at various stages of pregnancy were vaccinated against YF, either because those pregnancies were not known at the time or because they requested vaccination out of fear of acquiring the disease. This offered an opportunity to assess the safety and efficacy of YF vaccine in pregnant women and the effect of this vaccine on their newborn children. Pre-vaccination and post-vaccination serum samples from the vaccinated pregnant women were tested by enzyme-linked immunosorbent assay and by neutralization tests for antibody to YF virus. The results showed that the antibody responses of these pregnant women were much lower than those of YF-vaccinated, non-pregnant women in a comparable control group. Follow-up of these women and their newborn children for 3-4 years showed no abnormal effect that could be attributed to the YF vaccine, which suggests that vaccination of pregnant women, particularly during a YF epidemic, may not be contraindicated.

Adolescent

Bf S gene frequency in Nigerians with HIV infection.

Complement immunogenetic susceptibility to human immunodeficiency virus (HIV) infection was examined in 40 Nigerians with serological and/or clinical evidence of the infection. A mild increase in C4A null alleles (C4AQO) frequency was observed in the patient group compared to a group of healthy subjects (25 per cent vs 17 per cent) but overall the HIV infected and the reference groups did not differ significantly in the frequency of alleles of C4A or C4B. In contrast, properdin factor B (Bf) S gene frequency was significantly higher in the patients with HIV infection (p less than 0.025). There was a concomitant decrease in Bf F allele and gene frequencies (p less than 0.01, and p less than 0.05), respectively. Furthermore, blank Bf allotypes due to excessive complement consumption were detected in two asymptomatic patients. These findings suggest that Major Histocompatibility Complex (MHC) located complement genes may be important HIV infection. In particular Bf S gene or even C4AQO alleles may be permissive or influence outcome of infection with HIV.

Adult