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Biomedical subjects

K M De Cock

Publications and source records attributed to K M De Cock.

At least 109 records · Page 6Linked to original sources
PubMed1994

Feigned HIV infection/AIDS: malingering and Munchausen's syndrome.

Feigned HIV infection or acquired immunodeficiency syndrome (AIDS), in which people mimic infection with or disease due to HIV, accounted for 1.7% of admissions to our specialist HIV unit in Central London over a 5 year period. Of 12 patients with feigned HIV/AIDS, 11 were HIV antibody-negative, and one refused testing. Presenting histories were sometimes grandiose, unusually tragic, or unlikely in relation to the patients' healthy appearance, and often included admissions to other specialist HIV units. Substance abuse was suspected in over half of the patients described, a higher frequency than that observed in our HIV-infected patient population. The possibility of feigned HIV/AIDS should be remembered in persons with self-reported HIV infection. Recognition of this condition is important to avoid costly and potentially dangerous investigation and therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Excluding blood donors at high risk of HIV infection in a west African city.

OBJECTIVE: To examine the potential impact of deferral of blood donors at high risk of HIV infection in a west African city where blood is screened for HIV antibodies but no other special measures are taken to protect the blood supply. DESIGN: Cross sectional study. SETTING: National Blood Transfusion Centre and Project RETRO-CI, an international collaborative AIDS research project, Abidjan, Côte d'Ivoire. SUBJECTS: 1257 male first time blood donors. INTERVENTIONS: Blood donors were interviewed about demographic and behavioural characteristics and tested for HIV antibodies by enzyme immunoassay and, if positive, synthetic peptide based tests. MAIN OUTCOME MEASURES: HIV antibody status in relation to presence of behavioural risk factors; calculation of sensitivity, specificity, and predictive values of specific criteria for excluding HIV infected donors. RESULTS: The overall prevalence of HIV infection was 11.4%. The most important risk factors for HIV positivity were prostitute contact and being aged 30-39 years. For identifying seropositive donors individual criteria had sensitivity, specificity, and positive predictive values ranging from 15% to 98%, 38% to 91%, and 17% to 30% respectively. Prostitute contact in the past five years would have excluded 31% of all donors and 73% of HIV infected donors. 27% of those excluded would have been HIV positive. CONCLUSIONS: The widespread assumption that donor deferral is not feasible in sub-Saharan Africa needs reassessment. In Abidjan this approach was well accepted and potentially effective. Donor deferral requires evaluation as a strategy for improving blood safety in resource poor areas with high rates of HIV infection.

Adolescent↗
PubMed1993

Epidemiology and transmission of HIV-2. Why there is no HIV-2 pandemic.

Although human immunodeficiency virus type 1 (HIV-1) and HIV-2 share modes of transmission, their epidemiologic characteristics differ and international spread of HIV-2 has been very limited. Recently, the prevalence of infection with HIV-1 but not HIV-2 has increased rapidly in different West African countries, where HIV-2 was probably present earlier. Among 19,701 women of reproductive age tested in Abidjan, Ivory Coast, between 1988 and 1992, the prevalence of HIV-1 infection increased from 5.0% to 9.2%, while that of HIV-2 declined from 2.6% to 1.5%. Differences in viral load may be responsible: reported results of virus culture and polymerase chain reaction assays suggest that at high CD4+ T-lymphocyte counts viral load is lower in HIV-2-infected than in HIV-1-infected persons; the efficacy of heterosexual and perinatal transmission of HIV-2 is less efficient than that of HIV-1 at this stage. At low (< 0.20 x 10(9)/L [< 200/microL]) CD4+ T-lymphocyte counts, virus isolation is equally successful for both viruses, and the efficacy of heterosexual transmission is similar. Differences in HIV-1 and HIV-2 natural history are reflected in differences in viral load, that for HIV-2 being lower until immunodeficiency is severe. Differences in viral load throughout most of the natural history of infection appear to correlate with lower transmissibility of HIV-2 than HIV-1, and are the likeliest explanation for their markedly different global epidemiology.

Adolescent↗
PubMed1993

Rapid and simple screening and supplemental testing for HIV-1 and HIV-2 infections in west Africa.

OBJECTIVE: To evaluate a combination of rapid tests as a strategy for screening and supplemental testing of serum for HIV-1 and/or HIV-2 antibodies. DESIGN: Cross-sectional evaluation. SETTING: Projet RETRO-CI, an AIDS research project in Abidjan, Côte d'Ivoire. METHODS: Serum specimens were collected from 1000 consecutive women giving birth in an Abidjan maternal and child health centre and from 185 hospitalized patients. All serum specimens were tested for HIV-1 and HIV-2 antibodies by whole-virus enzyme immunoassay; repeatedly reactive specimens were further tested by virus-specific Western blot and synthetic peptide-based tests. This was the reference strategy against which the algorithm under evaluation was compared. All specimens were subsequently tested by a mixed (HIV-1 and HIV-2) recombinant antigen-based test (Abbott Testpack), followed, if positive, by a rapid synthetic peptide-based test (Genetic Systems Genie) as a supplemental test. RESULTS: According to the reference strategy the prevalence of HIV-1 and/or HIV-2 infection was 13% among the pregnant women and 78% among the hospitalized patients. Compared with the reference strategy, the combination of rapid tests was associated with a sensitivity of 99.6%, a specificity of 99.9%, and positive and negative predictive values of 99.6 and 99.9%, respectively. Four per cent of HIV-2-positive and 1% of HIV-1-positive specimens were considered dually reactive by the rapid test combination. CONCLUSIONS: Synthetic peptide-based tests provide an alternative to Western blots for supplemental testing for HIV-1 and HIV-2. This combination of rapid tests offers performance characteristics comparable to an enzyme immunoassay and Western blot-based strategy, without requiring running water, electricity, or a well-developed laboratory. High-quality serodiagnosis of HIV-1 and HIV-2 infections is possible at the most peripheral levels of the health-care system in developing countries, the limiting factors being the costs of tests and training of staff.

AIDS Serodiagnosis↗
PubMed1993

Clinical research, prophylaxis, therapy, and care for HIV disease in Africa.

By the end of the century, citizens of resource-poor countries will constitute 90% of the world's human immunodeficiency virus (HIV)-infected people. Clinical management of such persons in developing countries has been neglected; most AIDS research has concentrated on epidemiology, and donor agencies have generally invested in the prevention of HIV infection. The heavy burden of HIV disease in Africa requires that care for AIDS be addressed, and prevention and care should be seen as interrelated. Prevention and treatment of tuberculosis, the commonest severe infection in persons with AIDS in Africa, illustrate this interrelationship. We outline priorities for applied research on the management of HIV disease in a resource-poor environment, and discuss prophylaxis, therapy for opportunistic diseases, terminal care, and use of antiretroviral therapy. Research should define the standard of care that can realistically be demanded for HIV disease in a resource-poor environment. Research and public health programs for AIDS in developing countries must address AIDS care and attempt to reduce the widening gap between interventions available for HIV-infected persons in different parts of the world.

AIDS-Related Opportunistic Infections↗
PubMed1992

Risk of HIV infection from transfusion with blood negative for HIV antibody in a west African city.

OBJECTIVE: To estimate the risk of infection with HIV (HIV 1 or HIV 2, or both) from transfusion of a screened unit of blood in a high prevalence area in west Africa. DESIGN: Retrospective cohort study for January-July 1991. SETTING: National Blood Transfusion Centre, Abidjan, Côte d'Ivoire. SUBJECTS: Repeat donors (5831 units of blood) and first time donors (5076 units) in the first five months of 1991. MAIN OUTCOME MEASURES: Prevalence and estimated incidence of HIV infection in repeat and first time donors; estimated rate of potentially infected, HIV antibody negative units; and rate of (false negative) potentially infected units assuming a laboratory test sensitivity of 99%. RESULTS: Overall HIV prevalence was 11.0% in first time donors and 2.1% in repeat donors. In the first seven months of 1991, 29 HIV antibody positive (27 HIV 1, 1 HIV 2, 1 dually reactive) donors with a seronegative unit of blood earlier in the year were identified; 26 had donated blood eight weeks or less before their estimated dates of seroconversion and may have been infectious (minimum rate 26/5831 (4.5/1000 potentially infected units)). Estimated incidence of infection in repeat donors was 1.2-2.5%. Laboratory test insensitivity would result in an estimated 1.1/1000 false negative units from first time donors and 0.2/1000 units from regular donors. The overall rate of potentially infected units (all donors, seroconversions, and errors) was estimated at 5.4-10.6/1000. CONCLUSIONS: The risk of HIV infection from a single unit of blood remains substantial (5.4-10.6/1000 units). To prevent infection from blood transfusion in areas of high incidence and prevalence of HIV all but absolutely essential transfusions should be avoided, and donors with low incidence of HIV infection should be selected.

Blood Donors↗
PubMed1992

Prevalence of HIV-1 and HIV-2 mixed infections in Côte d'Ivoire.

We have investigated the cause of dual serological reactivity to human immunodeficiency virus (HIV) types 1 and 2, a common occurrence in West Africa. Serum specimens from 111 individuals from Côte d'Ivoire classified by commercial western blot as HIV-1 (n = 15), HIV-2 (32), and dually reactive (64) were further tested by more specific serological tests (a synthetic peptide enzyme immunoassay [Pepti-LAV 1/2] and western blots prepared from antigen in which oligomeric forms of the transmembrane protein were disrupted by trichloroacetic acid [WB-TCA]). Peripheral blood mononuclear cells were tested for HIV-1 and HIV-2 with the polymerase chain reaction (PCR) and virus culture. Of 104 samples that were concordant by both WB-TCA and Pepti-LAV, 82 (79%) were confirmed by PCR results. Virus culture was concordant with serology for specimens (35/38) in which any virus was detected. Our findings indicate that mixed HIV-1/HIV-2 infections are common in Côte d'Ivoire, and suggest that natural infection by one HIV type does not prevent heterologous infection.

Blotting, Western↗
PubMed1992

HIV-1 and HIV-2 infections in men attending sexually transmitted disease clinics in Abidjan, Côte d'Ivoire.

OBJECTIVE: (1) To determine the prevalence of HIV-1 and HIV-2 infections and associated risk factors in men attending Abidjan's three sexually transmitted disease (STD) clinics; (2) to examine the use of such sites for epidemiological surveillance. DESIGN: Cross-sectional study. SETTING: Abidjan's two main STD clinics (Clinics A and T), and the University Hospital Dermatology outpatients clinic. PATIENTS: Consecutive patients with genitourinary symptoms. MAIN OUTCOME MEASURES: Prevalence of reactivity to HIV-1, HIV-2, and both viruses; descriptive characteristics of clinic attenders; clinical diagnoses of STD; risk factors associated with HIV-1 and HIV-2 positivity. RESULTS: The overall prevalence of HIV (HIV-1 and/or HIV-2) infection was 21% (250 out of 1169; 16% HIV-1, 2% HIV-2, 3% dual reactivity). Overall prevalence varied by clinic: University Hospital Dermatology outpatients clinic, 39%; Clinic T, 19%; Clinic A, 10%. Men with STD had an overall prevalence of 31% (155 out of 506), compared with 14% in men without physical signs of STD (odds ratio 2.6, 95% confidence interval 2.0-3.6). The highest prevalence, 46%, was in men with genital ulcer disease. Risk factors associated with HIV-1 as well as with HIV-2 infection after multivariate analysis were a history of sex with prostitutes, lack of circumcision, being unskilled, and a history of prior genital ulcer. Current genital ulcer, current STD and positive Treponema pallidum haemagluttination assay were associated with HIV-1 and dual reactivity. CONCLUSIONS: Risk factors for HIV-2 infection in men attending Abidjan STD clinics were broadly similar to those for HIV-1 infection. HIV-1 infection was more strongly associated with current STD. Important differences between the three clinics were observed in STD prevalence and type, and HIV seroprevalence. Such differences should be taken into account in the planning of HIV serosurveillance in STD clinics.

Adolescent↗
PubMed1992

Immunological comparison of HIV-1-, HIV-2- and dually-reactive women delivering in Abidjan, Côte d'Ivoire.

OBJECTIVES: To compare the basic immunological changes induced by HIV-1 and HIV-2 infection and to assess the immune status of subjects serologically reactive to both HIV-1 and HIV-2 (dually-reactive). DESIGN: Immune parameters were studied cross-sectionally in women delivering in Abidjan, Côte d'Ivoire, West Africa, where HIV-1 and HIV-2 are endemic. In this area, a significant number of sera from infected individuals are reactive to both HIV-1 and HIV-2. SUBJECTS AND METHODS: Two hundred and twenty-eight women delivering in a major maternity clinic were screened for HIV-1 and HIV-2 using an enzyme-linked immunosorbent assay. Seropositivity was confirmed by Western blot. The immune parameters studied were CD4+ and CD8+ lymphocyte subsets, immunoglobulin (Ig) serum levels, neopterin and beta 2-microglobulin (beta 2M) serum levels. RESULTS: Similar but less pronounced immune changes were present in HIV-2-reactive subjects compared with HIV-1- and dually-reactive subjects. The observed differences between the HIV-seropositive groups could not be explained by differences in age or disease stage but paralleled differences in the frequency of persistent generalized lymphadenopathy (PGL). The intermediate immune profile of HIV-2-reactives (between seronegatives and HIV-1- and dually-reactives) was most clearly reflected by the number of CD8+ lymphocytes, the CD4:CD8 ratio and the IgG serum level. Median neopterin and beta 2M levels, though significantly increased in all HIV-seropositive groups, did not differ significantly between HIV-2-, HIV-1- and dually-reactives. CONCLUSIONS: HIV-2 infection is associated with typical HIV-related immunological changes. Immunologically, dually-reactives resemble HIV-1-reactives more closely than HIV-2-reactive subjects.

Adult↗
PubMed1992

HIV infection and primary resistance to antituberculosis drugs in Abidjan, Côte d'Ivoire.

OBJECTIVE: To determine the prevalence of Mycobacterium tuberculosis resistance to antituberculosis drugs, and to relate this resistance to HIV serologic status. DESIGN: Cross-sectional prevalence study. SETTING: The two major outpatient tuberculosis clinics in Abidjan, Côte d'Ivoire, West Africa. PATIENTS: Sixty individuals with newly diagnosed pulmonary tuberculosis and sputum smears positive for acid-fast bacilli. MAIN OUTCOME MEASURES: HIV serologic status and in vitro testing for susceptibility of M. tuberculosis isolates to antituberculosis drugs. RESULTS: M. tuberculosis was isolated from 82% (49 out of 60) of sputum specimens. Thirty-five per cent (17 out of 49) were obtained from HIV-seropositive and 65% (32 out of 49) from HIV-seronegative patients. There was no statistically significant difference in the proportion of resistant isolates from HIV-seropositive versus HIV-seronegative patients, although the relatively small sample size limited power. Of the total number of isolates, 17% were resistant to isoniazid; resistance was less to streptomycin (7%), rifampin (2%), pyrazinamide (0%), and ethambutol (0%). Eighteen and 21% of mycobacterial isolates from HIV-seropositive and HIV-seronegative individuals, respectively, were resistant to one or more of these drugs. CONCLUSIONS: Surveys of this type are useful in planning and evaluating tuberculosis preventive therapy in individuals with dual infection.

AIDS-Related Opportunistic Infections↗
PubMed1992

Pneumocystis carinii pneumonia. An uncommon cause of death in African patients with acquired immunodeficiency syndrome.

Admissions and deaths in a pulmonary medicine ward in Abidjan, Cote d'Ivoire, West Africa, were evaluated over a 6-month period in 1989 with systematic autopsies on all patients who died. Of 473 patients admitted, 38% were HIV-1 seropositive, 4% were HIV-2 seropositive, and 14% reacted to both viruses. A total of 100 patients (21%) died, and deaths were twice as frequent in HIV-seropositive compared with HIV-negative patients. The pathology of 78 autopsies showed that the predominant cause of death in HIV-seropositive patients was disseminated tuberculosis (40%). Cancer was the cause of death in 64% of HIV-negative patients. Pneumocystosis was found in only 9% of HIV-seropositive autopsies. Since Pneumocystis carinii is an uncommon cause of death in this population, prophylaxis for P. carinii pneumonia is not warranted for HIV-infected patients in Africa. In contrast, research on chemoprophylaxis for tuberculosis is urgently required.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Risk of tuberculosis in patients with HIV-I and HIV-II infections in Abidjan, Ivory Coast.

OBJECTIVE: To examine the association between HIV-II infection and tuberculosis. DESIGN: Cross sectional study comparing the prevalence of HIV-I and HIV-II infections in patients with tuberculosis and in blood donors. SETTING: Abidjan, Ivory Coast, west Africa. PATIENTS: 2043 consecutive ambulant patients with tuberculosis (confirmed pulmonary, presumed pulmonary, or extrapulmonary) and 2127 volunteer blood donors. MAIN OUTCOME MEASURE: Prevalence of HIV-I and HIV-II infections as assessed by presence of serum antibodies. RESULTS: Overall rates of HIV infection were 40.2% in patients with tuberculosis (26.4% positive for HIV-I, 4.7% for HIV-II, and 9.0% for both); and 10.4% in blood donors (7.2% positive for HIV-I, 1.9% for HIV-II, and 1.3% for both). HIV-II infection was significantly more common in patients with all types of tuberculosis than in blood donors (97/2043, 4.7% v 40/2127, 1.9%; odds ratio 3.8%, 95% confidence interval 2.6 to 5.6). CONCLUSION: Both HIV-I and HIV-II infections are associated with tuberculosis in Abidjan. 35% of adult tuberculosis in Abidjan is attributable to HIV infection and 4% specifically to HIV-II.

Adult↗
PubMed1991

Cross-reactivity on western blots in HIV-1 and HIV-2 infections.

To examine cross-reactivity of antibodies to heterologous antigens, on HIV-1 and HIV-2 Western blots, we tested sera from 1362 consecutive tuberculosis (TB) patients and 2127 consecutive blood donors. Specimens positive on enzyme-linked immunosorbent assay (ELISA) for HIV-1 or HIV-2 were further characterized by synthetic peptide-based tests, and tested by HIV-1- and HIV-2-specific Western blots. Dual serologic reactivity on synthetic peptide tests was proportionately more frequent in HIV-positive TB patients than in blood donors, and HIV-2 reactivity less frequent. Positive HIV-1 Western blots were seen in 73-83% of specimens specifically characterized as positive for HIV-2 on synthetic peptide tests. Cross-reactivity to HIV-2 Western blots by HIV-1-positive specimens was significantly more frequent in TB patients (35%) than in asymptomatic donors (9%; P less than 0.001). Using recently recommended criteria for HIV-2 Western blot interpretation (presence of two env bands) reduced the overall proportion of HIV-1-positive specimens having a positive HIV-2 Western blot from 27.5 to 16.4%, with [corrected] minimal effect on sensitivity in the diagnosis of HIV-2 reactivity on specimens positive on synthetic peptide tests.

Blotting, Western↗
PubMed1991

Mortality trends in Abidjan, Côte d'Ivoire, 1983-1988.

To assess changes in mortality in Abidjan since the development of the AIDS epidemic, we compared official city mortality statistics and hospital fatality rates in 1983, before AIDS was recognized in Abidjan, with those in 1988. Review of records in the city's major hospitals showed that fatality rates (deaths per 1000 admissions) in adult medical patients increased by 54% between 1983 and 1988, with increases of 106 and 98% in men 20-29 and 30-39 years of age, respectively, and 199 and 42% in women of the same age ranges. Mortality rates in surgical patients showed little change, while in children they declined. Over the same period, official mortality statistics for the city showed reduced mortality rates in children and women 20-29 years of age, but an increase in mortality rates of 54% in men 20 years of age and older, and of 28% in women aged 30 years and older. HIV infection may be a major cause of the increased adult mortality documented in hospital and city records, and jeopardizes improved survival from preventive measures such as maternal and child health services.

Acquired Immunodeficiency Syndrome↗