Biomedical subjects

O Tomori

Publications and source records attributed to O Tomori.

At least 19 recordsLinked to original sources

PubMed1999

Impact of yellow fever on the developing world.

Yellow fever (YF) has remained a disease of public health importance since it was first described in the fifteenth century. At different periods in human history, YF has caused untold hardship and indescribable misery among populations in the Americas, Europe, and Africa. It brought economic disaster in its wake, constituting a stumbling block to development. Yellow fever is an arboviral infection with three epidemiological transmission cycles between monkeys, mosquitoes, and humans. It is an acute infectious disease characterized by sudden onset, with two phases of development separated by a short period of remission. The clinical spectrum of YF varies from a very mild, nonspecific, febrile illness to a fulminating, sometimes fatal disease with pathognomonic features. In severe cases, jaundice and bleeding diathesis with hepatorenal involvement are common. The fatality rate of severe YF is 50% or higher. Despite landmark achievements in the understanding of the epidemiology of YF and the availability of a safe, efficacious vaccine, YF remains a major public health problem in both Africa and South America, where annually the disease affects an estimated 200,000 persons, causing an estimated 30,000 deaths. Since the 1980s epidemics of YF in Africa have affected predominantly children under the age of 15 years. The failure to control YF arises from a misapplication of public health strategies and insufficient political commitment by governments in YF endemic areas, especially in Africa, to control the disease.

Adolescent↗

PubMed1999

The reemergence of Ebola hemorrhagic fever, Democratic Republic of the Congo, 1995. Commission de Lutte contre les Epidémies à Kikwit.

In May 1995, an international team characterized and contained an outbreak of Ebola hemorrhagic fever (EHF) in Kikwit, Democratic Republic of the Congo. Active surveillance was instituted using several methods, including house-to-house search, review of hospital and dispensary logs, interview of health care personnel, retrospective contact tracing, and direct follow-up of suspect cases. In the field, a clinical case was defined as fever and hemorrhagic signs, fever plus contact with a case-patient, or fever plus at least 3 of 10 symptoms. A total of 315 cases of EHF, with an 81% case fatality, were identified, excluding 10 clinical cases with negative laboratory results. The earliest documented case-patient had onset on 6 January, and the last case-patient died on 16 July. Eighty cases (25%) occurred among health care workers. Two individuals may have been the source of infection for >50 cases. The outbreak was terminated by the initiation of barrier-nursing techniques, health education efforts, and rapid identification of cases.

Adolescent↗

PubMed1999

Serologic survey among hospital and health center workers during the Ebola hemorrhagic fever outbreak in Kikwit, Democratic Republic of the Congo, 1995.

From May to July 1995, a serologic and interview survey was conducted to describe Ebola hemorrhagic fever (EHF) among personnel working in 5 hospitals and 26 health care centers in and around Kikwit, Democratic Republic of the Congo. Job-specific attack rates estimated for Kikwit General Hospital, the epicenter of the EHF epidemic, were 31% for physicians, 11% for technicians/room attendants, 10% for nurses, and 4% for other workers. Among 402 workers who did not meet the EHF case definition, 12 had borderline positive antibody test results; subsequent specimens from 4 of these tested negative. Although an old infection with persistent Ebola antibody production or a recent atypical or asymptomatic infection cannot be ruled out, if they occur at all, they appear to be rare. This survey demonstrated that opportunities for transmission of Ebola virus to personnel in health facilities existed in Kikwit because blood and body fluid precautions were not being universally followed.

Adult↗

PubMed1997

Mutational changes in the hemagglutinin of equine H3 influenza viruses result in the introduction of a glycosylation site which enhances the infectivity of the viruses.

The complete amino acid sequences of the hemagglutinin (HA) glycoprotein of three equine-2 influenza viruses from tropical Africa are presented in comparison with that of a well characterized European equine-2 virus (Suffolk/89) and a consensus sequence from the database. The sequences of the tropical African viruses were deduced from the complete nucleotide sequences of their HA genes reported earlier. Mutational changes in the nucleotide sequences resulted in amino acid changes in the HA which led to the introduction of a new asparagine-linked (N-linked) glycosylation site in two viruses. This new glycosylation site enhanced the infectivity of these viruses as investigated by plaque assay, virus titration in embryonated chicken eggs and tunicamycin treatment. The role of N-linked glycosylation of influenza virus HA glycoprotein in virus infectivity, antigenicity and immunogenicity is discussed in the light of the results of our previous and present investigations.

Amino Acid Sequence↗

PubMed1997

Does neuroanatomy predict ECT response?

1. Structural neuropathologic abnormalities have been associated with severe psychiatric illnesses, including bipolar disorder, major depressive disorder, and schizophrenia. In the latter, ventricular enlargement has been variably associated with symptom severity and poor treatment response. In patients with severe depressive disorders, the relationship between cortical and subcortical pathology and ventricle enlargement, symptom severity, and response to treatment is far from clear. 2. The present study investigated the relationship between structural CNS pathology, symptom severity and treatment response in patients undergoing ECT. It was hypothesized that patients with greater neuroanatomic abnormalities would demonstrate greater initial symptom severity and poorer response to ECT. 3. The subjects were 57 patients with unipolar or bipolar depression admitted for ECT treatment. Symptom severity was quantified using the Hamilton Depression Rating Scale (HRSD) at baseline and post-ECT. 4. Lateral and third ventricle-brain ratio (LVBR, 3VBR) were determined from CT scans and cortical atrophy was rated by a faculty neuroradiologist. 5. Contrary to our first hypothesis, structural pathology was not associated with baseline symptom severity. In terms of treatment response, the number of treatments required to achieve benefit was correlated with larger 3VBR; CT variables were not related to total post-treatment or change in HRSD score. Third ventricle enlargement may be an index of generalized pathology or regional brainstem abnormalities that influence ECT response rate by limiting individual seizure efficacy or neurochemical responsiveness, thereby necessitating a greater number of ECT treatments, without significant impact on overall response.

Atrophy↗

PubMed1997

Overview of poliomyelitis in the African Region and current regional plan of action.

The African Region of the World Health Organization includes a diverse membership of 48 countries and territories that has made substantial progress toward controlling poliomyelitis. The coverage with three doses of oral poliovirus vaccine among 1-year-old children reached 58% in 1995, a substantial increase from 49% in 1993, and the incidence of poliomyelitis decreased from 5126 cases in 1980 to 1597 in 1995. To interrupt poliovirus circulation, 29 countries planned to conduct either national immunization days (25 countries) or subnational immunization days (4 countries) during 1996. To ensure the success of these efforts, high-level political commitment has been obtained in many countries, and the campaign to "Kick polio out of Africa" is supported by some of the most respected African politicians. Provided the necessary resources can be obtained from internal and external sources, the African Region may be able to achieve the eradication of poliomyelitis by the year 2000 or shortly thereafter.

Africa↗

PubMed1996

Yellow fever: a decade of reemergence.

Since the 1980s, yellow fever has reemerged across Africa and in South America. The total of 18 735 yellow fever cases and 4522 deaths reported from 1987 to 1991 represents the greatest amount of yellow fever activity reported to the World Health Organization (WHO) for any 5-year period since 1948. There is an excellent vaccine against yellow fever. At present, a high proportion of travelers to at-risk areas are reported to be immunized, reflecting widespread knowledge about the International Health Regulations. In South America, yellow fever remains an occupational hazard for forest workers, who should be immunized. However, Aedes aegypti mosquitoes are now present in urban areas in the Americas (including southern parts of the United States), and there is concern that yellow fever could erupt in explosive outbreaks. In Africa, a large proportion of cases have occurred in children. The WHO, the United Nations Children's Fund (UNICEF), and the World Bank have recommended that 33 African countries at risk for yellow fever add the vaccine to the routine Expanded Programme on Immunization; studies show that this would be highly cost-effective. To date, financing yellow fever vaccine has been a major problem for these countries, which are among the poorest in the world. For this reason, WHO has launched an appeal to raise $70 million for yellow fever control in Africa.

Africa↗

PubMed1996

Clinical and pathological features of Nigerian equine encephalitis.

Thirteen cases of a disease with a low morbidity and very high mortality in horses in Nigeria are described; the disease is characterised by fever (rectal temperature > or = 40 degrees C), generalised muscle spasms, ataxia, increased respiratory and heart rates and terminal lateral recumbency. The illness generally lasts three to five days but durations of 12 to 30 hours have been observed. Laboratory investigations, including histopathology and serology suggest a viral aetiology, possibly an alphavirus of the equine encephalitis group.

Animals↗

PubMed1996

Rift Valley fever in Nigeria: infections in domestic animals.

Between 1986 and 1989, 2,255 sera collected from six domestic animal species in Nigeria were tested for antibodies to Rift Valley fever (RVF) virus. In addition, a longitudinal study was carried out from July 1987 to December 1988, using ten sentinel flocks on four farms at Ibadan and Ile-Ife, to determine the activity of RVF virus (RVFV). All samples were tested for haemagglutination-inhibiting antibodies and positive sera were further screened, using the plaque reduction neutralisation test. Of 2,255 samples, 259 (11.5%) had haemagglutination-inhibiting and neutralising antibodies, as follows: sheep (18.7%), goats (10.4%), cattle (10.2%), horses (9.8%) and camels (3.3%). The highest prevalence of RVFV antibody was found in the plateau area (18.4%). Animals aged three years or more had a higher prevalence of antibodies to RVFV. Longitudinal studies showed seroconversion to RVFV in ten of the 210 animals which were kept under observation (4.8%). All seroconversions occurred during the wet season. The results of this study indicate that the infection of animals with RVFV is widespread in Nigeria.

Abattoirs↗

PubMed1996

Rift Valley fever in Nigeria: infections in humans.

Between 1985 and 1989, a total of 3,121 human sera collected from different population groups in six ecological zones of Nigeria were tested for the presence of antibodies to Rift Valley fever (RVF) virus by the haemagglutination-inhibition test. All reactive sera were further tested by the plaque reduction neutralisation test and specific RVF immunoglobulin M (IgM) assay. A total of 461 sera (14.8%) demonstrated haemagglutination-inhibiting antibody and 390 of the 461 initially reactive sera (84.6%) revealed neutralising antibodies. A significantly higher exposure to the virus was found among livestock workers and wildlife rangers than in other categories of people tested. The rate of positive reactions was higher in adults of 30 years or more than in younger age groups. Of 461 sera tested for specific RVF IgM, 107 gave positive results (23.2%). The highest prevalence of RVF IgM was found among livestock and forestry workers. In the longitudinal survey, an RVF virus infection rate of 6.7% was demonstrated. The infection rate was significantly higher during the wet season than during the dry season of the same year.

Adolescent↗

PubMed1996

Experimental infection of three Nigerian breeds of sheep with the Zinga strain of the Rift Valley Fever virus.

Experimental infection of three indigenous breeds of sheep in Nigeria, namely the West African Dwarf (WAD), Yankasa and Ouda resulted in fatal disease with the Zinga Rift Valley Fever virus. Infected sheep of the three breeds responded by pyrexia within 24 h of infection, that lasted 6 to 7 days, but peaked between day 2 and 4 post-infection. Viraemia coincided with pyrexia and peaked (10(9) PFU/ml) 3 days p.i. in Yankasa and WAD sheep, but with highest titre (10(7.5) PFU/ml) in Ouda sheep. Zinga Rift Valley Fever virus infection of sheep was characterised by hyperactivity, watery and mucoid nasal discharges, projectiles and bloody diarrhoea, external haemorrhage and clinical manifestations of nervous disorders. Viraemia was followed by low level of antibody development in all the infected sheep. Haemotological changes included a sharp fall in the PCV, Hb concentration and total RBC count during the course of the disease. These changes were most severe in the Yankasa, followed by WAD and Ouda breeds. There were thrombocytopaenia, prolongation of prothrombin and clotting times in all the infected sheep. There was also progressive leucopaenia associated with lymphopaenia. The total protein and albumin levels were depressed, but the globulin level rose from day 5 p.i. The changes in the serum biochemical constituents included sharp and progressive increase in the level of alanine aminotransferase and aspartate aminotransferase. The sodium level decreased gradually while that of potassium was initially stable but later increased until the infected animals died. There was a significant increase in the level of blood urea nitrogen from day 3 p.i. that continued until the infected animals died. Gross and microscopic examinations of the carcasses of the infected sheep showed significant lesions in many organs, including disseminated intravascular coagulation.

Animals↗

PubMed1995

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↗

PubMed1995

Clinico-epidemiological patterns of HIV infection in STD patients in Ibadan.

The HIV-seropositive subjects identified among the STD Clinic patients seen at a Special Treatment Clinic between 1989 and 1990 were studied to determine the epidemiological and clinical trends of HIV infection in these patients, and to demonstrate any association between the STDs and HIV- seropositivity. Thirty-seven out of the 581 patients investigated have been confirmed HIV-seropositive by Western bolt. The prevalence of HIV infection was 6.4%. Anti-HIV-1 antibody prevalence (3.6%) was higher than that of anti-HIV-2 antibody (2.8%). The age-range of the patients investigated was from 2 weeks to 49 years, and the HIV-seropositive cases were in the age-range 15-49 years, with peak incidence of HIV infection in the 21-30 years age-bracket. The male: female ratio of HIV-seropositive subjects was practically the same (1.01:1). HIV antibody-positive cases consisted of residents from towns in both Northern and Southern Nigeria. Only one of the HIV antibody-positive cases has developed clinical AIDS-progressive weight loss fourteen months after he was found positive for HIV antibody.

Adolescent↗

PubMed1994

Sexually transmitted diseases in Ibadan in the 1990's: HIV infection--an additional dimension.

Five hundred and fifty-one patients attending the Special Treatment Clinic (STC) of the University College Hospital, Ibadan, between January 1989 and July 1990 were investigated for the common sexually transmitted diseases to determine the current relative prevalence rates of these infections. The patients were also investigated for human immunodeficiency virus (HIV) infection. Of the 551 patients, 384 (69.9%) were diagnosed as having sexually transmitted diseases. The most frequent STDs were gonococcal infections, non-specific urethritis and cervicitis and the genital ulcer diseases (GUDs) with prevalence rates 25.6%, 17.8% and 12% respectively. In addition to the common STDs, HIV infection was detected in 28 (5.1%) patients. Both HIV-1 and HIV-2 were detected as follows: HIV-1 in 16 (2.9%) patients and HIV-2 in 12 (2.2%) patients. All but one of the HIV-seropositive patients also had concurrent sexually transmitted diseases.

Adolescent↗

PubMed1992

Evaluation of measles vaccination programme conducted in two separate health centres.

Measles vaccination programmes at two vaccination centres in Ibadan, Nigeria were evaluated using the following factors as indicators: type of vaccination centre, age at vaccination, titre of vaccine, economic, health and social status of vaccinee. There was a significant association between type of vaccination centre, vaccine titre and rate of conversion. Seroconversion rates of 64 and 26% were obtained in the two vaccination centres. This was associated with the difference in the method of vaccine handling during vaccination in the centres. Higher prevalence of maternal antibody was found among children with longer breast feeding period. Results obtained suggest that the Expanded Programme on Immunization (EPI) against measles is not effective, especially in rural health centres, because of improper vaccine handling. Recommendations on how to improve measles vaccination in the EPI are highlighted.

Evaluation Studies as Topic↗

PubMed1992

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.

Antibodies, Viral↗

PubMed1990

Detection of rabies virus antibodies in fruit bats (Eidolon helvum) from Nigeria.

Fruit bats (Eidolon helvum) were collected from three different localities in Western Nigeria: Oti, Ibadan and Idanre. Fifty serum samples were analyzed using a modified rapid fluorescent focus inhibition technique against rabies, Mokola, Lagos bat and Duvenhage viruses. Twenty-five brain samples were screened for rabies and related lyssavirus antigens by direct fluorescent antibody microscopy and by an indirect fluorescent antibody technique with rabies anti-nucleocapsid monoclonal antibodies. All brain samples were negative. Two serum samples had relatively high anti-rabies activity; no neutralizing activity was detected against Mokola, Lagos bat or Duvenhage viruses.

Animals↗

PubMed1990

Detection of Mokola virus neutralising antibodies in Nigerian dogs.

Five hundred healthy Nigerian dogs were randomly selected and bled for serological detection of antibodies to lyssa-viruses, including Mokola, Lagos bat and Duvenhage viruses. The canine sera were screened for virus neutralising antibodies by a modification of the rapid fluorescent focus inhibition technique. Three serum samples were seropositive to Mokola virus but all were negative to Lagos bat and Duvenhage viruses. The three seropositive Mokola samples were also negative for rabies virus neutralising antibodies. This finding may explain occasional rabies-like canine mortalities within one year of antirabies vaccination in Nigeria.

Animals↗