Computer-Assisted Quality Assurance in an HIV Serology Laboratory

A computer-based quality assurance programme for an HIV-1 serology laboratory is described. The programme was designed to minimise transcription errors and to provide rapid feedback on laboratory performance. Similar systems could readily be introduced to any laboratory with access to simple computing facilities.

Seroprevalence and incidence of genital ulcer infections in a rural Ugandan population

OBJECTIVES

To determine age-sex specific seroprevalence and incidence rates of Treponema pallidum, Haemophilus ducreyi, and HSV-2; to assess the association between HIV-1 status and incidence of these STIs; and HSV-2 serostatus with number of lifetime sexual partners.

METHODS

Antibodies against HIV-1, T pallidum, H ducreyi, and HSV-2 infections were tested using approximately 1000 paired (2 year interval) sera collected from a rural adult (15-54 years) population cohort in south west Uganda.

RESULTS

Overall HIV-1 prevalence was 4.9%. Prevalence for T pallidum was 12.9% among males and 12.6% among females. The corresponding rates for H ducreyi were 9.8% and 7.3% respectively. HSV-2 prevalence rates were considerably lower in males (36.0%) than in females (71.5%), p < 0.001. Incidence rates for T pallidum per 1000 person years of observation were 8.4 for males and 12.3 for females. The corresponding rates for H ducreyi were 24.6 and 20.0 and for HSV-2 were 73.2 and 122.9 per 1000 person years of observation, respectively. The RR of HSV-2 incidence was 3.69 in HIV seropositive cases versus HIV seronegative after adjusting for age and sex. The corresponding RR for H ducreyi was 3.50 among female HIV positive cases versus negatives with no effect seen in males. Association between HIV-1 prevalence and prevalence of other STIs was significant (Mantel-Haenszel test) for H ducreyi (p = 0.01) and for HSV-2 (p = 0.004) but not for T pallidum (p > 0.4). HSV-2 prevalence was associated with number of lifetime sexual partners (females, p = 0.003; males, p = 0.08).

CONCLUSIONS

The results have provided a reliable estimate of the magnitude of the STI problem and demonstrated an association between HIV-1 status and serology of other STIs in a general rural population in sub-Saharan Africa. The study has also highlighted a correlation between HSV-2 seropositivity and number of reported lifetime sexual partners.

Mortality associated with HIV-1 infection over five years in a rural Ugandan population: cohort study

OBJECTIVE

To assess the impact of HIV-1 infection on mortality over five years in a rural Ugandan population.

DESIGN

Longitudinal cohort study followed up annually by a house to house census and medical survey.

SETTING

Rural population in south west Uganda.

SUBJECTS

About 10,000 people from 15 villages who were enrolled in 1989-90 or later.

MAIN OUTCOME MEASURES

Number of deaths from all causes, death rates, mortality fraction attributable to HIV-1 infection.

RESULTS

Of 9777 people resident in the study area in 1989-90, 8833 (90%) had an unambiguous result on testing for HIV-1 antibody; throughout the period of follow up adult seroprevalence was about 8%. During 35,083 person years of follow up, 459 deaths occurred, 273 in seronegative subjects and 186 in seropositive subjects, corresponding to standardised death rates of 8.1 and 129.3 per 1000 person years. Standardised death rates for adults were 10.4 (95% confidence interval 9.0 to 11.8) and 114.0 (93.2 to 134.8) per 1000 person years respectively. The mortality fraction attributable to HIV-1 infection was 41% for adults and was in excess of 70% for men aged 25-44 and women aged 20-44 years. Median survival from time of enrollment was less than three years in subjects aged 55 years or more who were infected with HIV-1. Life expectancy from birth in the total population resident at any time was estimated to be 42.5 years (41.4 years in men; 43.5 years in women), which compares with 58.3 years (56.5 years in men; 60.5 years in women) in people known to be seronegative.

CONCLUSIONS

These data confirm that in a rural African population HIV-1 infection is associated with high death rates and a substantial reduction in life expectancy.

HIV-1 disease progression and AIDS-defining disorders in rural Uganda

BACKGROUND

The majority of people infected with HIV-1 live in Africa, yet little is known about the natural history of the disease in that continent. We studied survival times, disease progression, and AIDS-defining disorders, according to the proposed WHO staging system, in a population-based, rural cohort in Uganda.

METHODS

In 1990 we recruited a random sample of people already infected with HIV-1 (as prevalent cases) detected during the initial survey round of a general-population study to form a natural-history cohort. Individuals from the general-population cohort who seroconverted between 1990 and 1995 (incident cases) were also invited to enroll. Participants were seen routinely every 3 months and when they were III.

FINDINGS

By the end of 1995, 93 prevalent cases and 86 incident cases had been enrolled. Four patients in the prevalent group were in stage 4 (AIDS) at the initial visit. During the next 5 years, 37 prevalent cases progressed to AIDS. Seven incident cases progressed to AIDS and the cumulative progression to AIDS at 1, 3, and 5 years after seroconversion was 2%, 6%, and 22%, respectively. The cumulative probability of AIDS at 4 years from entering stages 1, 2, and 3 was 11%, 33%, and 58%, respectively. There were 47 deaths among prevalent cases and seven among incident cases during follow-up. The cumulative mortality 4 years after patients entered stages 1, 2, 3, and 4 was 9%, 33%, 56%, and 86%, respectively. The median survival after the onset of AIDS was 9.3 months.

INTERPRETATION

Our results are important for the setting of priorities and rationalisation of treatment availability in countries with poor resources. We found that progression rates to AIDS are similar to those in developed countries for homosexual cohorts and greater than for cohorts infected by other modes of transmission. However, we have found that the rates of all-cause mortality are much higher and the progression times to death are shorter than in developed countries.

An HIV-1 natural history cohort and survival times in rural Uganda

OBJECTIVE

To describe a population-based rural cohort of HIV-1-seropositive and seronegative individuals established in 1990 in south-west Uganda, and determine survival times in the cohort.

DESIGN

Prospective cohort study.

METHODS

Participants were recruited from a large population study, and invited to attend a clinic every 3 months. They were seen by clinicians who administered detailed medical questionnaires and undertook a physical examination.

RESULTS

By the end of 1995, 390 (79%) of the 491 people asked to enrol in the natural history cohort (NHC) had done so. Ninety-three were prevalent cases of HIV infection detected during the initial survey round of the general population cohort in 1989/1990, 66 were subsequent incident cases, 177 were age-matched HIV-negative controls and 54 were HIV-negative spouses of HIV-positive individuals. Twenty participants seroconverted in the NHC. The age-standardized mortality rates per 1000 person-years for the prevalent, incident, and negative cases were 156.5 [95% confidence interval (CI), 115.8-211.4], 35.0 (95% CI, 16.4 75.0) and 13.5 (95% CI, 7.3-25.1), respectively. The median survival time from enrolment to death for the prevalent cases was 4.5 years (95% CI, 3.5- > 5.2); > 5.4 years from seroconversion for the incident cases; and > 5.2 years from enrolment for the HIV-negative cases. The 5-year cumulative survival for prevalents, incidents and HIV-negative participants was 46%, 83% and 94%, respectively.

CONCLUSIONS

We have described an NHC of HIV-positive and HIV-negative participants which is representative of the general population. The NHC was established over 5 years ago; it is continuing and we are maintaining good compliance rates. Survival probabilities in the cohort were lower than most other reported studies.

Proportion of HIV infections attributable to other sexually transmitted diseases in a rural Ugandan population: simulation model estimates

BACKGROUND

Unprotected heterosexual contact in the presence of other sexually transmitted diseases (STD) enhances the probability of HIV transmission. The objective of this study was to estimate the proportion of HIV infections attributable to STD in rural Uganda.

METHODS

Simulation modelling scenarios of the transmission dynamics of HIV infection and of ulcerative and non-ulcerative STD were employed to address this objective, drawing on data from a specific rural population cohort of 10,000 in south-west Uganda.

RESULTS

In simulations of the initial 10-year period of the HIV epidemic (1980-1990), over 90% of HIV infections were attributed to STD. Even given conservative assumptions about the prevalence of STD and about their enhancing effects on HIV transmission, STD played a critical role in the rapid and extensive spread of HIV infection. The role of STD decreased with progression of the HIV epidemic.

CONCLUSIONS

In developing countries, control of the spread of HIV infection may benefit substantially from successful STD intervention programmes, and particularly in areas where HIV infection is not already well established.

Incidence of HIV-1 infection in adults and socio-demographic characteristics of seroconverters in a rural population in Uganda: 1990-1994

BACKGROUND

To evaluate HIV-1 incidence among adults and socio-demographic risk factors in a rural population in Uganda, a prospective cohort study was carried out.

METHODS

All consenting adult residents in a cluster of 15 neighbouring villages of the Masaka District of south-west Uganda have been participating in annual socio-demographic and serological surveys since November 1989. Those who had a negative serostatus when they were first tested and had at least one serostatus assessment during the 4 years of follow-up (1990-1994) have been evaluated for HIV-1 seroconversion. Incidence rates have been calculated per 1000 person-years of observation and socio-demographic characteristics assessed for association with recent seroconversion.

RESULTS

At the baseline survey, of 4175 adults with assessable serostatus (79% of all censused adults), 342 (8.2%) were seropositive. During 12588.2 person-years of follow-up 89 seroconversions were identified corresponding to an incidence rate of 7.1 (95% CI: 5.6-8.5). Overall rates were highest in females aged 20-24 years (15.2) and in males aged 20-44 years (11.6). There was a significant interaction between age and sex; the ratio of the rate in females to that in males decreased from 3.3:1 to 0.5:1 with increasing age. Rates for males aged > or = 20 years were four times higher than those for younger males. Other significant socio-demographic correlates with risk included not belonging to the majority tribe, non-Muslim religion and length of stay on compound of less than 10 years. Incidence rates did not show any clear trends with time.

CONCLUSION

These findings further emphasize the need for targeted interventions.

The orphan problem: experience of a sub-Saharan Africa rural population in the AIDS epidemic

An assessment of the prevalence of orphans and the magnitude of their problems and the extent to which HIV-1 is contributing to this was done in a rural population in South-West Uganda with an HIV-1 seroprevalence of 8% among adults. Slightly over 10% of children aged less than 15 years were reported to have lost one or both parents. Loss of the father alone (6.3%) was more common than loss of the mother alone (2.8%). Generally orphans were living with their surviving parent or other relatives but it was also noted in this study that some children with both parents alive lived with relatives as part of the extended family system. HIV-1 seroprevalence rates were higher among orphans than among non-orphans and were up to 6 times higher in the 0-4 year age group. Seropositivity rates were also higher among surviving parents of orphans than among parents of non-orphans. No significant difference in mortality between orphans and non-orphans was observed. During a 3-year follow-up period a total of 169 children became orphans and 43% of these cases resulted from the death of an HIV-1 positive parent. There was a limited effect on school attendance by orphanhood. The HIV-1 epidemic has substantially increased the number of orphans in this community, a finding which is probably typical of many other sub-Saharan African countries. It appears that these orphans were generally well looked after within the community. This coping capacity may, however become overstretched if the epidemic evolves further.

Verbal autopsy as a tool for diagnosing HIV-related adult deaths in rural Uganda

BACKGROUND

In general, information on the causes of adult deaths in developing countries is scarce. More specifically, relatively little is known about the effect of HIV-1 associated disease on adult mortality in general populations. In this study we have used a verbal autopsy technique to ascertain whether adult deaths were associated with HIV-1 in a rural population with a prevalence of HIV-1 infection of 8%, and used HIV-1 antibody status to validate the verbal autopsy findings.

METHODS

All adult deaths in the population cohort that occurred between December 1990 and November 1993 were identified through a monthly death registration system. Approximately 2 months after death, a relative of the deceased was interviewed by a trained nurse, and questionnaires were assessed by at least two independent clinicians; all were unaware of the HIV serostatus of the deceased.

RESULTS

A total of 155 adult deaths was assessed, i.e. 53% of all recorded adult deaths. Of those assessed half were HIV-1 positive. In all 47% of deaths were classified as HIV-related. The overall specificity and positive predictive value of the verbal autopsy tool were both 92%; in those aged 13-44 years (83 adults) the corresponding values were 85% and 95% respectively. The verbal autopsy estimated HIV-1 attributable mortality fraction was similar to the calculated fraction based on prospective data.

CONCLUSIONS

The results of this study suggest that verbal autopsy studies may assist in providing data on HIV-associated mortality in general populations and may be useful as surveillance tools.

HIV-1 infection in a Ugandan town on the trans-African highway: prevalence and risk factors

All adult residents (aged 13 years or more) of 154 randomly selected households in 3 urban and one semi-rural ward of a town in South West Uganda on the trans-African highway were invited to participate in a socio-demographic, behavioural and medical survey. An unambiguous HIV-1 serostatus was obtained for 389 (80%) adults. The overall sero-prevalence rate was 40.4%; all age groups except males aged 13-19 years had infection rates in excess of 20%. Rates above 50% were found in females aged 20-34 years and males aged 35-44 years. For females seropositivity rates increased steeply with increasing numbers of lifetime sexual partners up to a maximum of 3; in contrast, for males rates continued to increase with increasing numbers of partners. The risk of infection amongst those with only one reported partner was 17%. A high proportion of males (14%) and females (18%) reported a history of genital ulcer disease within the previous 6 months; on examination genital lesions were observed in 12% of all participants. Interventions with a single focus are unlikely to have much impact in such a situation and a strategy is suggested which includes 3 components, namely improved STD control, a reduction in partner change and an increase in condom utilization.

Post-natal incidence of HIV-I infection among children in a rural Ugandan population: no evidence for transmission other than mother to child

We conducted a prospective cohort study to determine the post-natal incidence of and possible transmission routes for HIV-I infection in rural Ugandan children. The cohort consisted of the population of a cluster of 15 villages in Masaka District, south-west Uganda, and was enrolled in 1989-1990 through a demographic and serological survey. During the period 1991-1993 the population was resurveyed annually. A total of 5492 children aged 0-12 years were enrolled; of these, 41 (0.7%) were seropositive infants. A total of 3941 (72%) children were HIV-negative on enrolment and had at least one follow-up specimen. During 8596 person-years of observation only I seroconversion was observed, an incidence rate of 0.12 (95% CI 0.00-0.35) per 1000 years of observation. The transmission of HIV was most probably through breast milk. The case corresponds to a rate of 1.1 per 1000 in households with one or more HIV-positive adults (874 years of observation); no incident case was observed in households with only seronegative adults (6423 years of observation). Thus, HIV infection among children aged 0-12 years in this population is virtually exclusively the result of mother-to-child transmission. No infections were observed attributable to parenteral exposure, non-sexual casual or household contact, or insects.

Modelling the impact of alternative HIV intervention strategies in rural Uganda

OBJECTIVE

To assess the likely impact on HIV incidence of increased condom use, a reduction in casual sexual partners, treatment programmes for other sexually transmitted diseases (STD) and combinations of these in rural Uganda.

METHODS

A simulation model for the transmission dynamics of HIV infection and STD was employed, drawing on data from a rural population cohort in South-West Uganda with an HIV prevalence of 9% among adults in 1990.

RESULTS

For the scenario most consistent with data from the study population, 39% of all adult HIV infections were averted, in the 10 years from 1990, when condoms were used consistently and effectively by 50% of men in their contacts with one-off sexual partners (such as bar girls and commercial sex workers). Reducing by 50% the frequency of men's sexual contacts with one-off partners averted 68% of infections. Reducing by 50% the duration of all STD episodes averted 43% of infections. Combining these three interventions averted 82% of all adult infections in the 10 years from 1990.

CONCLUSION

A substantial proportion of HIV infections may be averted in general populations through interventions targeted only on less regular sexual partnerships.

Human immunodeficiency virus (HIV-1) seropositivity among children in a rural population of south-west Uganda: probable routes of exposure

Serological studies on 7796 rural Ugandans showed 377 (4.8%) were HIV-1 antibody-positive, of whom 343 (8.2%) were adults, ten (0.4%) 5-12-year-olds and 24 (1.7%) under 5 years of age. Serological tests done on 18 mothers of the under-5s showed 17 to be HIV-1-positive. One mother was persistently negative. Her child had a history of multiple injections. Structured interviews with parents or guardians of the ten HIV-1-seropositive children aged 5-12 years to determine possible sources of exposure revealed that six were vertically infected and that blood transfusion, injections and sexual exposure each accounted for one case. It was not possible to identify a source of exposure in one instance. There was no evidence that casual household contact or scarifications played a role in the transmission of HIV-1 in children in this population. Our data show that in this rural population HIV-1 seropositivity in children is mainly associated with seropositivity in the mothers and that HIV-1 infection in children aged between 5 and 12 years is rare.

Clinical observations on acute poliomyelitis

During the years of the polio epidemics, most patients with the poliovirus had little or no paralysis. In those with paralytic polio, the extent of involvement of the anterior horn cells was often underestimated. Thus, patients with post-polio syndrome now often report that a limb was uninvolved; however, the original record will show clear evidence of initial paralysis that improved so that the patient no longer recognized the weakness. The epidemics were associated with great anxiety involving the patients, their families and all of society. Treatment was for the most part ineffective and was sometimes confused or inappropriate. Patients developed coping techniques that have been singularly useful and effective. These coping techniques often include strategies that require maximal athletic development of little-used muscles. The coping techniques developed by post-polio patients would be of great benefit to patients with other forms of disability. Review of the medical histories, biographies, and autobiographies of patients who had severe disability because of poliomyelitis reveals that they adopted firm convictions about their disease and their recovery. We must be aware of these convictions if we are to treat their later disabilities. These convictions include the belief that their condition can only improve, that their improvement is related primarily to the willingness of the patient to engage in exercise, and that improvement is more a thing of the spirit than of medication. Associated with this conviction is denial--often concurred with by the family--of the extent of the disability. Furthermore, the confusion of physicians that patients witnessed during the great epidemics suggests to patients that physicians can be of little help to them now. Convictions that were invaluable to patients who were young and vigorous become a liability when aging and progressive weakness supervene. Patients who had adapted to muscle weakness through great physical and emotional effort are unable to continue functions they had regained. However, such patients cannot accept that they do not continue to improve. Some become depressed, but this is unusual.

Migration and HIV-1 seroprevalence in a rural Ugandan population

OBJECTIVE

To study the association between change of residence and HIV-1 serostatus in a rural Ugandan population.

DESIGN

A longitudinal cohort study.

METHODS

As part of the annual surveillance of a population cohort of approximately 10,000 individuals in a rural subcounty of southwest Uganda, information has been collected for all adults on change of residence over a 3-year period and its association with HIV-1 serostatus. Sera were collected by a medical team during home visits. Antibody testing was performed at the Uganda Virus Research Institute using two independent enzyme immunoassay systems and Western blot when appropriate.

RESULTS

At the fourth survey-round, age and sex-standardized seroprevalence rates were 7.9% overall; the rate was 5.5% for 2,129 adults who had not changed address since the first survey, 8.2% for 336 who moved within the village, 12.4% for 128 who moved to a neighbouring village, 11.5% for 1,130 who had left the area and 16.3% for 541 who had joined the study area during the previous 3 years (P << 0.001, 4 degrees of freedom). We also observed an inverse relationship between years lived at the present house at the time of the first survey and both seroprevalence and subsequent seroincidence rates. The reported numbers of lifetime sexual partners were higher in those who changed residence.

CONCLUSION

Change of residence is strongly associated with an increased risk of HIV-1 infection in this rural population and is likely to be the result of more risky sexual behaviour among those who move. These findings have important implications for the design of AIDS control programmes and intervention studies.

Methods used to study household coping strategies in rural South West Uganda

This paper describes the data collection methods used in a longitudinal study of the coping strategies of 27 households in three villages in the study area of the MRC/ODA Research Programme on AIDS in Uganda. After pre-testing and piloting, 9 local interviewers made regular visits to the 27 study households over a period of just over one year. The households were purposively selected to represent different household types and socioeconomic status categories. Data were obtained through participant observation using a checklist to ensure systematic collection of data on household activities. Debriefing sessions with the interviewers after the visits provided opportunities for the discussion of the findings and exploration of themes for further study. On the basis of the study findings, and data from the Programme's general study population survey rounds, broad indicators of household 'vulnerability' were identified. A participatory appraisal technique, 'well-being ranking', was used at the end of the study in order to test the viability of the chosen indicators. It is proposed that the example of the research method, which relied on local people not only as interviewers but also as co-investigators in the research, be used to guide future research approaches. The participation of the study community at every stage of research and design, as well as monitoring and evaluation of supportive interventions, is strongly encouraged.

Recognition, treatment seeking behaviour and perception of cause of malaria among rural women in Uganda

This study was conducted in order to understand how women in rural Uganda recognise malaria, their treatment-seeking behaviour when malaria is suspected and how the perception of cause may influence this behaviour. Focus group discussions and semi-structured interviews were held with women selected from the general population and from women attending health clinics for both preventive and curative services. The main finding of this study was that the word used for malaria in the local language, omusujja, covered a broad symptom complex which did not consistently correspond to the clinical case definition of malaria. Since there was no specific word for 'malaria', the study was broadened to encompass omusujja. The women reported that omusujja was an important health problem which had various causes, including poor diet, environmental conditions, and the bites of mosquitoes. The symptoms associated with omusujja were quite varied and ranged from generally 'feeling unwell' to a specific fever diagnosis (usually in children) of 'a rise in body temperature'. Women recognised that omusujja posed a particular threat to pregnant women. Preventive actions recommended by the women were in line with their perceptions of cause. The respondents usually mentioned the use of herbs as the first treatment action, followed by the purchase of tablets from shops, with the final recourse being the formal health sector if the previous actions had not effected a cure.(ABSTRACT TRUNCATED AT 250 WORDS)

Seroprevalence and incidence of sexually transmitted diseases in a rural Ugandan population

The aim of the study was to determine in a rural population the age- and sex-specific prevalence and incidence rates of serological reactivity of 5 common sexually transmitted diseases (STDs) and their association with HIV-1 antibody status. Of the adult population of two villages (529 adults aged 15 years or more) 294 provided an adequate blood specimen both on enrollment and at 12 months. The sera were tested at 3 collaborating laboratories for antibodies against HIV-1, Treponema pallidum, Haemophilus ducreyi, Chlamydia trachomatis and herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). A sample of 45 children were tested for HSV-1 and HSV-2. Seroprevalence rates in adults on enrollment were 7.8% for HIV-1, 10.8% for active syphilis, 10.4% for H. ducreyi, 66.0% for C. trachomatis, 91.2% for HSV-1 and 67.9% for HSV-2. Males were significantly more likely than females to be seropositive for H. ducreyi (15.6% versus 6.6%), but less likely to be HSV-2 antibody positive (57.0% versus 74.4%). Reactivity to H. ducreyi, C. trachomatis and HSV-2 rose with increasing age. In contrast, active syphilis showed no age trend. All STDs tended to be more common in those HIV-1 seropositive. Incidence rates over the 12 months were nil for HIV-1, 0.5% for syphilis, 1.2% for H. ducreyi, 11.3% for C. trachomatis, and 16.7% for HSV-2. The results of this exploratory study indicate that all STDs included are common in this rural population. The high HSV-2 prevalence rate among adolescents suggests that HSV-2 may be an important risk factor for HIV-1 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer-assisted quality assurance in an HIV serology laboratory

A computer-based quality assurance programme for an HIV-1 serology laboratory is described. The programme was designed to minimise transcription errors and to provide rapid feedback on laboratory performance. Similar systems could readily be introduced to any laboratory with access to simple computing facilities.

Two-year HIV-1-associated mortality in a Ugandan rural population

The mortality in 15 villages in South-West Uganda was studied in relation to HIV infection. After a population census, serum samples were tested for antibodies to HIV-1. Deaths were ascertained over 2 years. Unequivocal HIV-1 serology results were available for 9389 individuals. The prevalence of infection was 4.8% for all ages and 8.2% for adults (aged 13 or more). 198 deaths were recorded during 15,725 person years of observation. Mortality among seronegative adults was 7.7 per 1000 and among seropositive adults 115.9 per 1000. The excess annual death rate associated with HIV-1 infection was 5.3 per 1000 and in adults 7.9 per 1000. Highest excess mortality was 16.9 per 1000 in the age group 25-34. Among adults, half of all deaths and among those aged 13-44 over 80% of deaths were attributable to HIV-1 infection. These results show the strong impact that HIV-1 infection is having on mortality in a rural area of Uganda where the overall HIV-1 adult prevalence rate is below 10%--a rate lower than in many other parts of East Africa.

Risk factors for HIV-1 infection in adults in a rural Ugandan community: a case-control study

OBJECTIVE

To study in depth sexual history and sexual behaviour variables as risk factors for HIV-1 infection in a rural Ugandan population.

METHODS

Following a socioeconomic and serological survey of a rural population in Masaka District, south-west Uganda, 233 randomly selected HIV-1-positive cases and 233 negative controls matched on age and village of residence, were invited in October 1990 to participate in a case-control study. A total of 132 cases and 161 controls attended for in-depth investigation including an interview about sexual behaviour.

RESULTS

The factor most strongly associated with increased risk of infection was a greater number of lifetime sexual partners, with odds ratios (OR) of 2.1 and 4.9 for those reporting 4-10 and 11 or more partners, respectively, compared with those reporting less than four partners. Having only one sexual partner did not provide complete protection, a total of seven (one male, six female) subjects reporting only one sexual partner were HIV-1-positive. Other significant factors were a history of genital ulcers [OR, 2.9; 95% confidence intervals (CI), 1.0-9.1) and not being a Muslim (OR, 5.4; 95% CI, 1.8-16.5) suggesting a possible protective effect of circumcision. There was a suggestion that those who married within the last 7 years (OR, 2.4; 95% CI, 0.9-6.1) and men exposed to menstrual blood (OR, 5.7; 95% CI, 0.7-49.8) were at an increased risk of HIV-1 infection.

CONCLUSIONS

These results confirm the predominant role of sexual behaviour in the HIV-1 epidemic. Of particular concern is the observation of HIV-1 infection among those reporting only one partner. Where HIV-1 infection is widely distributed in the general population, risk reduction strategies should, in addition to the promotion of partner reduction, place strong emphasis on safe-sex techniques.

Risk factors for HIV-1 infection in adults in a rural Ugandan community: a population study

OBJECTIVE

To determine sociodemographic risk factors associated with HIV-1 infection in a rural Ugandan population.

DESIGN

A population-based survey.

METHODS

All adult residents (aged > or = 13 years) in a cluster of 15 neighbouring villages of the Masaka District of south-west Uganda were invited to participate in a sociodemographic and serological survey. Questions relating to sexual behaviour were asked separately in an accompanying case-control study. Socioeconomic data and an unambiguous HIV-1 serostatus were obtained by house-to-house survey for 3809 (72%) of the adult population. The association between serostatus and the following variables were analysed: age, sex, marital status, tribe, religion, education, occupational group, place and frequency of travel and recent history of sexually transmitted disease.

RESULTS

Women aged 13-21 years were at a much higher risk than men of the same age [odds ratio (OR), 8.6; 95% confidence interval (CI), 3.0-24.5]. Married people aged < 25 years were twice as likely to be infected as those who were not currently married (OR, 2.3; 95% CI, 1.5-3.7). In contrast, in those aged > or = 25 years, women were at a lower risk than men (OR, 0.72; 95% CI, 0.52-0.98) as were those who were currently married compared with those who were not (OR, 0.47; 95% CI, 0.34-0.64). In both age groups those with a history of a recent genital ulcer were approximately three times more likely to be infected. Muslims had lower risks than non-Muslims (OR, 0.58 for both age groups).

CONCLUSIONS

The people most at risk of HIV-1 infection in this rural Ugandan population are young married women who had, presumably, commenced sexual activity recently.

HIV-1 incidence and HIV-1-associated mortality in a rural Ugandan population cohort

OBJECTIVE

To determine the incidence of HIV-1 infection and HIV-1-associated mortality in a rural Ugandan population.

DESIGN

A prospective cohort study.

METHODS

A cohort consisting of the population (de jure census 9820) of a cluster of 15 villages in Masaka District, south-west Uganda was enrolled between 1989 and 1990 through a demographic and medical survey. The HIV-1 seroprevalence rate was 4.8% for all ages combined and 8.2% for those aged 13 years or more. The survey was repeated after 1 year.

RESULTS

The 1-year HIV-1 incidence rate among adults was 1% [9.2 per 1000 person-years of observation; 95% confidence interval (CI), 5.5-12.9). A total of 84 deaths were observed. In adults, half of all deaths (31 out of 60) were in HIV-1-seropositive individuals. The age-adjusted overall mortality rate ratio for HIV-positive adults compared with HIV-negatives was 20.8 (95% CI, 12.0-35.7). In the 13-44 age group the corresponding rate ratios for men, women and both sexes combined were 16.3, 108.9 and 58.7, respectively. The HIV-attributable mortality fractions, i.e., the proportion of deaths that would have been avoided in the absence of HIV, were 44, 50 and 89% for adult men, adult women and adults aged 25-34 years (both sexes combined), respectively. The 1-year progression to death among HIV-1-seropositive adults was 10.3%.

CONCLUSION

These results demonstrate the profound impact that the HIV-1 epidemic has on adult mortality in a rural area of Uganda where the HIV-1 prevalence and incidence rates in adults are 8 and 1%, respectively.

General and HIV-1-associated morbidity in a rural Ugandan community

OBJECTIVES

The AIDS epidemic in sub-Saharan Africa affects whole communities, adding to the already high burden of morbidity. Reports of AIDS cases are usually from hospital attenders, often diagnosed using the World Health Organization (WHO) clinical case definition. Little is known about the extent of HIV-associated morbidity in the general population. The objectives of this study were to describe the prevalence of (1) markers of general morbidity and (2) the criteria of the WHO clinical case definition for AIDS and (3) to determine the association between these markers and HIV-1 serostatus in a rural Ugandan community.

METHODS

A survey was conducted among the adult population (aged > or = 13 years) of 15 neighbouring villages in Masaka District, south-west Uganda. The survey included medical history, physical examination and testing for HIV-1 antibodies.

RESULTS

The HIV-1 seroprevalence among 4175 out of 5278 (79%) eligible adults was 8.2%. Current health problems were reported by 57.6% of adults, with increased rates in HIV-1-positive subjects, women and older people. Five of the 10 most common complaints showed significant associations with HIV-1 status, as did reported genital ulcer and vaginal discharge. The crude HIV-1 attributable disease burden in the population was 1.2% for current illness, 4.3% for previous serious illness and 9.9% for illness leading to hospital admission. Overall, 11 (3.3%) of the HIV-1-positive and nine (0.2%) of the HIV-1-negative subjects had AIDS as defined by the clinical case definition. The positive and negative predictive values and specificity were 55.0, 92.0%, and 99.8%, respectively.

CONCLUSIONS

Against a background of high general morbidity, we observed a relatively small population attribution of HIV-1-associated morbidity. The results indicate that the clinical AIDS case definition may provide a useful tool for population surveys.

Algorithms for detecting antibodies to HIV-1: results from a rural Ugandan cohort

OBJECTIVE

To evaluate an algorithm using two enzyme immunoassays (EIA) for anti-HIV-1 antibodies in a rural African population and to assess alternative simplified algorithms.

METHODS

Sera obtained from 7895 individuals in a rural population survey were tested using an algorithm based on two different EIA systems: Recombigen HIV-1 EIA and Wellcozyme HIV-1 Recombinant. Alternative algorithms were assessed using negative or confirmed positive sera.

RESULTS

None of the 227 sera classified as unequivocably negative by the two assays were positive by Western blot. Of 192 sera unequivocably positive by both assays, four were seronegative by Western blot. The possibility of technical error cannot be ruled out in three of these. One of the alternative algorithms assessed classified all borderline or discordant assay results as negative had a specificity of 100% and a sensitivity of 98.4%. The cost of this algorithm is one-third that of the conventional algorithm.

CONCLUSIONS

Our evaluation suggests that high specificity and sensitivity can be obtained without using Western blot and at a considerable reduction in cost.

Community-based HIV/AIDS research--whither community participation? Unsolved problems in a research programme in rural Uganda

Involvement of the study community in research on HIV/AIDS has presented the MRC/UVRI programme in rural Uganda with a multi-layered challenge. A typology developed in agricultural research which defines different levels of community participation in research is described where participation may be at 'contract', 'consultative', 'collaborative' and 'collegiate' level (each level indicating an increasing degree of community participation). Community involvement in the MRC/UVRI Programme is then outlined and the typology applied. It is shown that the majority of community participation in the Programme is at the contract level since the nature of the research programme as a 'foreign imposition' with 'foreign goals' has precluded the involvement of the community in much of the policy development and research planning. However, it is noted that as the Programme becomes more established in the area community influence grows and signs of community impact on policy and increased research inputs are beginning to be seen. The question is raised as to whether it is realistic to expect that externally imposed health research, particularly on sensitive topics, can ever be truly community participatory research.

When is an apparent excess of neurologic cases epidemiologically significant?

To conserve clinical and public health resources, it is necessary to screen reports from the community of an excess or cluster of cases of chronic neurologic diseases for potential epidemiologic significance, ie, to identify those clusters that may have occurred owing to the operation of an underlying etiologic cause rather than to chance alone. Traditionally, the probability that such a cluster has occurred by chance within the reporting community is computed, ignoring the fact that many other similar communities have not reported a cluster. We propose a modified approach that takes this larger universe of communities into account, thereby raising the threshold for potential epidemiologic significance. As a result, the lowest value for the ratio of observed-to-expected cases that may be considered of epidemiologic significance should be increased by factors of 2 for small clusters (one to three expected cases), 1.5 for intermediate clusters (seven to 30 expected cases), and 1.3 for large clusters (60 to 90 expected cases). Consequently, case ascertainment and full field investigations can be reserved for only those reports that, if confirmed, would represent a cluster not due to chance alone. We illustrate this with a case from our own experience.

Wohlfart-Kugelberg-Welander syndrome: serum creatine kinase and functional outcome

The medical records of 31 patients (19 male and 12 female) with clinical and electrophysiologic features of Wohlfart-Kugelberg-Welander syndrome were reviewed. The reported age at onset ranged from less than one year to 46 years, and the age at diagnosis ranged from three to 66 years. Proximal muscle weakness, especially of the lower extremities, and muscular atrophy were the predominant clinical features. Elevated serum creatine kinase levels were noted in four female and 12 male patients, and the degree of elevation was higher in the male patients (up to 32 times the upper limit of normal) than in the female patients. On initial evaluation, two patients were wheelchair-bound, whereas the others were ambulatory. On follow-up evaluation three to 32 years later (mean, 15.5 years), 11 patients used wheelchairs, although only three were wheelchair-bound. The disease followed a steady, slowly progressive course. The outcome of ambulatory status did not correlate with the initial creatine kinase determination.

Antecedent medical diseases in patients with amyotrophic lateral sclerosis. A population-based case-controlled study in Rochester, Minn, 1925 through 1987

Odds ratios (ORs) were estimated for the prevalence of antecedent endocrine, metabolic, or vascular diseases among 45 patients with amyotrophic lateral sclerosis from the Rochester, Minn, population compared with 90 control subjects matched for sex, year of birth, period of observation, and residence. Hypertension occurred less frequently in male patients with amyotrophic lateral sclerosis (4%) than in control subjects (30%; OR = .10). Because of small population size, no conclusions can be drawn with respect to the following antecedent conditions: thyroid disease (OR = 1.61), coronary artery disease (OR = .58), obesity (OR = .52), diabetes (OR = 1.00), cerebrovascular disease (OR = .21), and peripheral vascular disease (OR = 1.23). The heterogeneity of antecedent thyroid disease makes it highly unlikely that any specific thyroid lesion is causally associated with most cases of amyotrophic lateral sclerosis. Hypertension may be a marker for protective factors against the development of amyotrophic lateral sclerosis in men.

Psychologic and adaptational difficulties anteceding amyotrophic lateral sclerosis: Rochester, Minnesota, 1925-1987

Comprehensive medical records of 45 amyotrophic lateral sclerosis (ALS) patients and 90 controls from the same community, matched by age, gender, and period of observation, were reviewed. Three (13%) of 23 men with ALS, 15 (33%) of 46 control men, 10 (45%) of 22 women with ALS, and 19 (43%) of 44 control women had antecedent psychologic or adaptational difficulties. The proportions of long-standing or serious conditions were comparable in all four groups. However, no man in whom ALS developed had a record of mild antecedent difficulties alone, whereas 3 would have been expected (p = 0.024).

Prevalence of HIV-1 antibody among groups of patients and healthy subjects from a rural and urban population in the Mwanza region, Tanzania

In April 1987, antibody to HIV-1 was determined in sera from 764 subjects from the Mwanza region in the north of Tanzania. Patients with a clinical suspicion of AIDS were HIV-1 antibody-positive in 65.4% (34 out of 52) and patients admitted for pulmonary tuberculosis in 25% (9 out of 36). In patients attending general outpatient departments (OPD), HIV antibody was found in 12.5% of 48 patients with a history of sexually transmitted disease (STD) and in 10.6% of 141 patients without such a history. In healthy subjects, HIV-1 antibody was present in 6% of 332 pregnant women and in 4.5% of 155 blood donors. Of the blood donors, pregnant women and OPD patients without a history of STD (628 subjects in all), 465 belonged to the rural population of the region and the majority were peasants. In this subgroup, the HIV-1 antibody prevalence was 4.8% in blood donors, 4.9% in pregnant women and 10.3% in OPD patients. This indicates a spread of HIV-1 among the population in this part of Tanzania. Further studies are needed to determine what proportion of the population is affected.

Motor neuron disease: epidemiologic studies

The etiology of motor neuron disease (MND) is unknown and treatment is limited to measures which sustain the patient. We review selected epidemiologic studies searching for a pattern in the clinical expression of MND which may reflect the operation of the underlying cause. Recognition of patterns of occurrence of MND might provide the basis for testable etiologic hypotheses for MND. In addition, recognition of the association of MND with diseases of known cause or the analogy of diseases of known cause with MND may provide further etiologic hypotheses.

Familial adult motor neuron disease: amyotrophic lateral sclerosis

We analyzed the medical records of 103 patients with familial adult motor neuron disease (MND). In the 72 families, 329 members were known to be affected. Observations were compared with the sporadic and Mariana forms of MND. Clinical and laboratory examinations of all three forms were similar in clinical course and findings, but there were minor variations in age at onset, sex ratio, survival, and the frequency with which onset occurred in the lower extremities. Recognition of the familial form still depends on diagnosis of the disease in more than one member of a family.

Amyotrophic lateral sclerosis: relationship between serum creatine kinase level and patient survival

Various laboratory tests have been used to predict the survival of patients with amyotrophic lateral sclerosis (ALS). The serum creatine kinase (CK) level is frequently elevated in patients with ALS. This study evaluates the relationship between serum CK elevation and survival in patients with ALS and points to a lack of correlation. Thirty patients with ALS, who ranged in age from 21 to 73 years, were followed up from 7 to 57 months. All patients had neurologic and psychiatric evaluations, electromyographic examinations, and serum CK measurements. The CK level was elevated in 50% of the patients. On follow-up, 20 patients had died; ten of these had had elevated CK levels. The 3-year survival from the date of the examination was 47% for patients with elevated CK levels and 40% for patients with normal levels. This difference did not have statistical significance (p greater than 0.43).

Follow-up study on amyotrophic lateral sclerosis in Rochester, Minn., 1925 through 1984

The incidence, secular trend and survivorship of amyotrophic lateral sclerosis in the Rochester, Minn., population has been investigated over a 60-year period, 1925 through 1984. The crude average annual incidence rate was 2.0 per 100,000 population. The rate, age- and sex-adjusted to the US 1970 white population, was 2.4 per 100,000 population (3.0 for men and 2.0 for women), with a male to female ratio of 1.5:1. Incidence rates after 1955 showed a small but nonsignificant increase compared to those of the former 30-year period. Median age at onset was 67.5 years; the incidence rates increased significantly with advancing age, but without a peak. Median survivorship was 23.8 months, and younger patients had a better prognosis than patients with an advanced age at onset. No change in duration of survivorship was observed over the period studied. Two of the 44 patients (4.5%) had a family history of amyotrophic lateral sclerosis.

Guillain-Barré syndrome. Clinicoepidemiologic features and effect of influenza vaccine

A study of the epidemiologic and clinical features of Guillain-Barré syndrome in the population of Olmsted County, Minnesota, over the 46-year period 1935 through 1980 was conducted through the centralized diagnostic index maintained at Mayo Clinic, Rochester, Minn. A total of 48 cases were identified, giving an age- and sex-adjusted incidence of 1.8 per 100,000 person-years. The rate increased over time from 1.2 in the interval 1935 through 1956 to 2.4 in the interval 1970 through 1980. Males were affected more than females (age-adjusted rates of 2.3 and 1.2, respectively). The rate increased with age from 0.8 in those under 18 years old to 3.2 for those 60 years and older. Antecedent infectious diseases were reported in 65% of the cases. Implications with regard to the incidence of Guillain-Barré syndrome associated with the A/New Jersey/76 (swine flu) vaccine are discussed.

Brachial plexus neuropathy in the population of Rochester, Minnesota, 1970-1981

Brachial plexus neuropathy (BPN) is a clinical entity of unknown cause characterized by the acute or subacute onset of pain and weakness, with occasional atrophy of the arm muscles. Information on the incidence of the disease in a delineated population is lacking, as the data available on BPN have come essentially from case reports or selected series. Using the Mayo Clinic records-linkage system as the source of data, 579 clinical records were reviewed of Rochester, Minnesota, residents in which a diagnosis suggestive of BPN was reported for the period 1970 through 1981. Eleven cases fulfilled all criteria, providing an overall annual incidence rate of 1.64 cases per 100,000 population. An infectious disease and/or tetanus toxoid immunization preceded the onset of BPN in 4 cases. The upper brachial plexus was involved in 6 cases, the lower brachial plexus in 2, and the whole plexus in 3; in 1 case there was bilateral BPN. The neuropathy ran a mild to moderate course in 10 cases, and complete recovery was recorded in 6, with slight residua in the others. The occurrence of antecedent events and the features of the disease are supportive of the concept of an immune-mediated process.

Lack of association of A/NJ/76 (swine flu) vaccine and polymyositis

There is no indication of an increase in the number of cases of polymyositis/dermatomyositis observed and reported among the 43.3 million civilians who received the A/NJ/76 (swine flu) vaccine from October 1 to December 16, 1976, in the United States. Among nearly 1 million Army and Navy personnel who received the vaccine, there was no increase in the incidence rate of polymyositis/dermatomyositis. Furthermore, there was no indication of an increase in the number of cases of polymyositis/dermatomyositis diagnosed at the Mayo Clinic, the Cleveland Clinic, the Cleveland Metropolitan Hospital or the Massachusetts General Hospital during or following the national immunization program in 1976.

Encephalitis and aseptic meningitis, Olmsted County, Minnesota, 1950-1981: I. Epidemiology

All cases fulfilling stated criteria for encephalitis and aseptic meningitis in Olmsted County, Minnesota, for the period 1950 through 1981 were identified. This is, to our knowledge, the first such incidence and trend study in a delineated population, providing rates per 100,000 person-years of 7.4 for encephalitis (189 cases) and 10.9 for aseptic meningitis (283 cases). These are about twelve and six times higher, respectively, than the rates reported by the Centers for Disease Control. The rates have been stable over successive 5- or 10-year periods except for a recent increase in aseptic meningitis. Both conditions were more common in the summer months, in childhood, and among males. Viral identification using conventional laboratory tests has improved with time; in the period 1970 through 1981, virus type was specified in about one-fourth of the cases. The most common agents identified were California and mumps viruses in encephalitis, and entero and mumps viruses in aseptic meningitis. Antecedent and/or concurrent infections were noted in 42 and 35% of encephalitis and aseptic meningitis cases, respectively. No case due to mumps, measles, or rubella viruses has occurred since 1972, reflecting the impact of immunizations. Recovery was reported at the end of the acute phase in 95% of patients with aseptic meningitis, and there were no deaths. Seventy-eight percent of encephalitis patients recovered completely; the case fatality rate was 3.8%. Of the encephalitis cases, 2% were diagnosed initially postmortem.

Fine Structural Study of Neurofibrillary Changes in a Family with Amyotrophic Lateral Sclerosis

Lewy body-like hyaline inclusions in the soma and swollen, cord-like cell processes are characteristic alterations of the anterior horn cells in familial amyotrophic lateral sclerosis (ALS) with posterior column and spinocerebellar tract involvement. A fine structural analysis of these two structures has been performed in two brothers from a family ("C" family) previously described by Kurland and Mulder in 1955. The perikaryal hyaline inclusions consisted of accumulations of randomly oriented neurofilaments interspersed with thick linear densities associated with granular material. Some of the accumulations showed a central condensation. Cord-like, swollen neuronal processes were composed, for the most part, of numerous neurofilaments arranged parallel to the long axes. Dense structures were sometimes observed within the large bundles of filaments. They were composed of ill-defined dense, granular and fibrillar material associated with scattered vesicles and mitochondria. These dense areas were sometimes surrounded by various amounts of fine filaments, approximately 5 nm in diameter.

Rehabilitative operation for motor neuron disease: tendon transfer for segmental muscular atrophy of the upper extremities

Segmental spinal muscular atrophy of adolescence is a clinical syndrome that can be distinguished from the more common forms of motor neuron disease. A patient with this syndrome who was no longer able to care for herself is described. After selective tendon transfers in her right upper extremity, she has been able to perform many of the activities of daily living. This improved function has been maintained for more than 2 years. We suggest that transfer of tendons and muscles may be indicated in selected patients with slowly progressive muscular atrophy.

ALS and heavy metals: a pilot case-control study

We conducted a case-control study of suspected risk factors for ALS among referral patients seen at the Mayo Clinic. Responses to questions about demographic factors, diet, medical history, travel, infectious disease, and other variables were similar in ALS patients and controls. In all but a few items, the responses of the cases and controls did not differ significantly. A significant level of shared exposure to an exogenous agent or environmental insult among cases was noted mainly for heavy metals.