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Biomedical subjects

S K Lwanga

Publications and source records attributed to S K Lwanga.

15 recordsLinked to original sources
PubMed1991

Evaluation of a standardized survey design proposed for use in epidemiological research on AIDS.

A Monte Carlo model simulating actual populations was employed to evaluate the precision in estimation of a standardized sampling method proposed by the Global Programme on AIDS of the World Health Organization, for general use in collecting population-based data on HIV seroprevalence. It appears that in real populations, where there is likely to be 'pocketing' of infection, the proposed methodology will generally fail to provide estimates accurate to within 1% of the true population value. However, if the primary objective of a particular survey is to construct confidence intervals that include the true population HIV seroprevalence rate, then this survey method appears to be a reasonable choice. This study also suggests that selection of only one adult per household improves the precision of resulting estimates. However, since selection of only one adult per household would require that more households be visited, any gain in precision would need to be weighed against the likely increase in cost of household visits.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Estimation and projection of adult AIDS cases: a simple epidemiological model.

Many HIV/AIDS (acquired immunodeficiency syndrome) models have been developed to help our understanding of the dynamics and interrelationships of the determinants of HIV (human immunodeficiency virus) spread and/or to develop reliable estimates of the eventual extent of such spread. These models range from very simple to very complex. WHO has developed a simple model for short-term projections of AIDS, details of which are presented here along with results obtained using the model to estimate and project AIDS cases for the USA, sub-Saharan Africa, and south/south-east Asia. WHO has also developed, based on the model described in this paper, a computer program (Epi Model), which will enable the user to easily change the values of any of the variables required by the WHO model.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Multiple infections in cases of cervical cancer from a high-incidence area in tropical Africa.

The presence of several infections was determined in tissue and serum samples from 34 cases and 23 controls seen in 1984-85 at Mulago Hospital in Kampala, Uganda. When assessing single infections, association with cervical cancer could be shown for 5 agents, namely by Southern blot assay for human papillomavirus types 16 and 18 (HPV), and by serological tests at varying levels of antibody titres, for herpes simplex virus type I and/or 2 (HSV), cytomegalovirus (CMV), Epstein-Barr virus, viral capsid antigen (EBV-VCA), and Chlamydia trachomatis (CLT). Due to interaction, HSV and CMV were associated with cervical cancer only when infection by both of these agents was demonstrable. In the assessment of the simultaneous presence of these 5 infections, moderately high antibody titres were taken as the cut-off point for infection by HSV, CMV, EBV-VCA, and CLT. This showed that 3 and 4 infections at a time were seen in the majority of the cases in contrast to the controls with essentially no more than 2 such infections. A linear trend in the rise of risk for cervical cancer was noted with increasing number of infections.

Antibodies, Viral↗
PubMed1985

A computer simulation of the EPI survey strategy.

A Monte Carlo simulation study was designed to evaluate the sample survey technique currently used by the Expanded Programme on Immunization (EPI) of the World Health Organization. Of particular interest was how the EPI strategy compared to a more traditional sampling strategy with respect to bias and variability of estimates. It was also of interest to investigate whether the estimates of population vaccination coverage were accurate to within 10 percentage points of the actual levels. It was found that within particular clusters, the EPI method was particularly sensitive to pocketing of vaccinated individuals, but the more traditional method gave more accurate and less variable results under a variety of conditions. However, the stated goal of the EPI, of being able to produce population estimates accurate to within 10 percentage points of the true levels in the population, was satisfied in the artificially created populations studied.

Child, Preschool↗
PubMed1980

Long-term experience with Burkitt's lymphoma in Uganda.

The cumulative results and long-term follow-up of all patients with Burkitt's lymphoma treated at the Uganda cancer Institute Kampala are reported. The annual admission rate is 29. The tumor patients commonly present with jaw swelling (72%), abdominal swelling (56%) and central nervous system involvement (30%). Complete response rate is achieved in a high proportion of patients (81%). About 50% of these relapse, equal numbers relapsing before and after 3 months. The most important factor influencing remission duration and survival is disease stage. Other important factors are treatment protocols and, to a lesser extent, the type of relapse. Central nervous system relapse does not necessarily augur poor prognosis as second remissions and long-term survival can be achieved with appropriate therapy. Presently 25% of all treated patients have survived free of disease well beyond 5 years.

Adolescent↗
PubMed1978

Childhood Hodgkin's disease in Uganda: a ten year experience.

Between 1967 and 1977, 48 patients with Hodgkin's disease under 16-years-old were treated with MOPP chemotherapy alone at the Uganda Cancer Institute because radiotherapy facilities are not available. Thirty-eight percent had early stage disease (stages I-IIIA). Prolonged first remissions were achieved in 74% of 42 complete responders. Of 11 patients who relapsed, 5 had prolonged second remissions induced by MOPP. Three patients were lost to follow-up and 15 of the remaining 45 died: 12 of these from progressive Hodgkin's disease, 2 from unrelated causes and 1 from Burkitt's lymphoma after 4 months remission from Hodgkin's disease. Acturial survival for all patients is 67% (75% for stages I-IIIA and 60% for stages IIIB-IV). Treatment complications included Herpes zoster and gynaecomastia. The latter is probably related to gonadal dysfunction. All stages of childhood Hodgkin's disease can be successfully managed with MOPP chemotherapy alone.

Adolescent↗
PubMed1977

Cerebrospinal irradiation of Burkitt's lymphoma. Failure in preventing central nervous system relapse.

Twenty-two patients with Burkitt's lymphoma in complete remission induced by either cyclophosphamide or a combination of cyclophosphamide, oncovin and methotrexate were randomized to receive or not to receive prophylactic cerebrospinal irradiation. Six of 11 irradiated patients relapsed with tumour of the central nervous system as compared to 4 of 11 controls. Relapse frequency appeared to be related to stage of disease on admission. It is concluded that irradiation does not prevent relapse.

Brain↗
PubMed1977

Hepatitis B surface antigen (HBsAg) subtypes in Uganda. A preliminary report.

Hepatitis B surface antigen positive sera for 34 African residents in Uganda were analysed for antigenic determinants and ethnic groups. Twenty four of the subjects belonged to Bantu ethnic groups and the rest to non-Bantu ethnic groups. Nineteen of the Bantu had antigenic subtype adw and only one of the non-Bantu had subtype adw. The association between subtypes and ethnic groups was found to be statistically significant (p less than 0.01). The results in this preliminary report agree with reports from West Africa of a high preponderance of hepatitis B surface antigenic subtype ayw among the non-Bantu West Africans.

Africa↗