Towards an effective poliovirus laboratory containment strategy in Nigeria.

BACKGROUND: The Global Commission for the Certification of the Eradication of Poliomyelitis will declare the world free of wild poliovirus transmission when no wild virus has been found in at least 3 consecutive years, and all laboratories possessing wild poliovirus materials have adopted appropriate measures of containment. Nigeria has made progress towards poliomyelitis eradication with the latest reported WPV type 1 on 21 Aug 2016 after 2 years without any case. This milestone achievement was followed by an inventory of biomedical laboratories completed in November 2015 with the destruction of all identified infectious materials. This paper seeks to describe the poliovirus laboratory containment process in Nigeria on which an effective containment system has been built to minimize the risk of virus re-introduction into the population from the laboratories. METHODS: A national survey of all biomedical facilities, as well as an inventory of laboratories from various sectors, was conducted from June-November 2015. National Task Force (NTF) members and staff working on polio administered an on-site questionnaire in each facility. Laboratory personnel were sensitized with all un-needed materials destroyed by autoclaving and incineration. All stakeholders were also sensitized to continue the destruction of such materials as a requirement for phase one activities. RESULTS: A total of 20,638 biomedical facilities were surveyed with 9575 having laboratories. Thirty laboratories were found to contain poliovirus or potentially infectious materials. The 30 laboratories belonged to the ministries of health, education, defence and private organizations. CONCLUSIONS: This article is amongst the first in Africa that relates poliovirus laboratory containment in the context of the tOPV-bOPV switch in alignment with the Global Action Plan III. All identified infectious materials were destroyed and personnel trained to continue to destroy subsequent materials, a process that needs meticulous monitoring to mitigate the risk of poliovirus re-introduction to the population.

Transmission dynamics and control of Ebola virus disease outbreak in Nigeria, July to September 2014.

We analyse up-to-date epidemiological data of the Ebola virus disease outbreak in Nigeria as of 1 October 2014 in order to estimate the case fatality rate, the proportion of healthcare workers infected and the transmission tree. We also model the impact of control interventions on the size of the epidemic. Results indicate that Nigeria's quick and forceful implementation of control interventions was determinant in controlling the outbreak rapidly and avoiding a far worse scenario in this country.

Yellow fever: the recurring plague

It is a significant hazard to unvaccinated travelers to these endemic areas. Virus transmission occurs between humans, mosquitoes, and monkeys.

Progress towards polio eradication: an African perspective.

Despite daunting competing health priorities, Africa has made significant progress in polio control. Northern and Southern Africa appear to be polio-free and may shortly be certified as such; however, polio still remains endemic in West and Central Africa and the Horn of Africa. Countries "in difficult circumstancess", wracked by major civil wars, have particularly low routine vaccine coverage, although NIDS have been carried out during negotiated days of tranquillity. AFP surveillance has also improved, although the quality of stool specimens is still far from ideal. There is, nevertheless, an extraordinary political commitment to the eradication campaign. Lessons from the history of polio in the continent need to be heeded in designing end-game strategies. Obstacles on the path to successful eradication are undoubtedly more formidable on the African continent--perhaps the most serious of all are the continuing wars. International political commitment and focussed and empowering developmental aid are urgently needed.

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.

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.

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.

Human immunodeficiency virus types 1 and 2 infection in some rural areas of Nigeria.

The prevalence of human immunodeficiency virus types 1 and 2 in rural areas of Nigeria was estimated using 1089 sera collected in 18 locations from 1992 to early 1994. The sera were tested with Enzyme linked Immunosorbent Assay (ELISA) and confirmed by Western Immunoblotting technique. Overall, 13 (1.2%) of the 1089 sera were positive for antibodies to HIV-1 and HIV-2. Prevalence of 0.6% and 0.8% were obtained for HIV-1 and HIV-2 respectively. The highest prevalence of HIV-1 and HIV-2 (50.0%) were found in Zuhlrrua and Umubuzu. A seroprevalence of 1.2% was obtained for both male and female groups tested. The highest prevalence of HIV was found among individuals 30-39 years age group. An overall increase in prevalence of HIV-1 and HIV-2 infection was obtained over the three years during which samples were collected for this study (0.7% in 1992, 1.0% in 1992 and 3.4% in 1994). In addition, two sera were positive for both HIV-1 and HIV-2. The detection of antibodies to HIV-1 and HIV-2 in the rural areas where blood samples were collected for this study shows that both viruses are widespread in the rural communities of Nigeria.

A survey for antibodies to Lassa virus among health workers in Nigeria.

A study was conducted among 552 health workers at 6 health facilities in Nigeria. Lassa virus immunoglobulin (Ig) G antibody was detected in 12.3%, using an enzyme-linked immunosorbent assay. Antibody prevalence in the 6 health centres ranged from 1.2% to 27.3%. Prevalences were higher in primary and secondary health facilities than in tertiary centres. Seroprevalences ranged from 1.7% to 23.7% among different occupational groups of health workers; the highest observed antibody prevalence was among ward aids. Lassa virus IgM antibody, indicating recent infection, was present in 6 of the health workers, 5 of whom were ward aids and one was a nurse. All of the health workers with specific IgM came from a single facility in Lafia, sampled during an outbreak of Lassa fever.

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.

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.

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.

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.

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.

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.

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.

Circulation of poliovirus among risk groups in Ibadan, Nigeria.

Faecal samples collected from 114 fully vaccinated pre-school children and 32 unvaccinated infants in Ibadan, Nigeria, were assayed for poliovirus in Hep-2 and RD cell cultures. 8 strains of poliovirus type 1 were isolated from 146 samples--3 from 32 unvaccinated children aged less than 40 d and 5 from 114 fully vaccinated children aged between 9 and 60 months. Studies using Sabin and wild monoclonal antibodies and the polymerase chain reaction confirmed 7 of the 8 isolates to be of the wild type, a possible source of infection among vaccinated children.

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.

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.

PIP: To identify epidemiologic and clinical patterns associated with human immunodeficiency virus (HIV) infection in sexually transmitted disease (STD) patients in Nigeria, serologic testing was performed on 581 men and women seen at Ibadan's Special Treatment Clinic during 1989-90. Of these, 37 (6.4%) were confirmed HIV-positive; 21 (3.6%) had HIV-1 antibodies and the remaining 16 (2.8%) had HIV-2 antibodies. Peak HIV incidence (24 cases, or 65%) was in the 21-30 year age group; the male to female ratio was 1.01 to 1.00. Presenting symptoms in HIV-positive cases included urethral discharge, vaginal discharge, dysuria, and genital ulcers. The prevalences of gonococcal infection, nonspecific urethritis and cervicitis, genital ulcer disease, and trichomoniasis were 27.0%, 18.9%, 16.2%, and 10.8%, respectively, among HIV-infected STD patients; none of the associations between specific STDs and HIV were statistically significant. Only 1 patient had developed clinical signs of acquired immunodeficiency syndrome (AIDS). The 6.4% prevalence rate detected among STD patients in this study was considered high since HIV is new to Nigeria (436 cases reported to date). Overall, these findings suggest that the AIDS epidemic is in an early stage in Nigeria and the major mode of HIV transmission is heterosexual sex. Routine HIV screening for high-risk groups in Nigeria, including STD patients, is recommended.

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.