Population-based analysis of ocular Chlamydia trachomatis in trachoma-endemic West African communities identifies genomic markers of disease severity.

BACKGROUND: Chlamydia trachomatis (Ct) is the most common infectious cause of blindness and bacterial sexually transmitted infection worldwide. Ct strain-specific differences in clinical trachoma suggest that genetic polymorphisms in Ct may contribute to the observed variability in severity of clinical disease. METHODS: Using Ct whole genome sequences obtained directly from conjunctival swabs, we studied Ct genomic diversity and associations between Ct genetic polymorphisms with ocular localization and disease severity in a treatment-naïve trachoma-endemic population in Guinea-Bissau, West Africa. RESULTS: All Ct sequences fall within the T2 ocular clade phylogenetically. This is consistent with the presence of the characteristic deletion in trpA resulting in a truncated non-functional protein and the ocular tyrosine repeat regions present in tarP associated with ocular tissue localization. We have identified 21 Ct non-synonymous single nucleotide polymorphisms (SNPs) associated with ocular localization, including SNPs within pmpD (odds ratio, OR = 4.07, p* = 0.001) and tarP (OR = 0.34, p* = 0.009). Eight synonymous SNPs associated with disease severity were found in yjfH (rlmB) (OR = 0.13, p* = 0.037), CTA0273 (OR = 0.12, p* = 0.027), trmD (OR = 0.12, p* = 0.032), CTA0744 (OR = 0.12, p* = 0.041), glgA (OR = 0.10, p* = 0.026), alaS (OR = 0.10, p* = 0.032), pmpE (OR = 0.08, p* = 0.001) and the intergenic region CTA0744-CTA0745 (OR = 0.13, p* = 0.043). CONCLUSIONS: This study demonstrates the extent of genomic diversity within a naturally circulating population of ocular Ct and is the first to describe novel genomic associations with disease severity. These findings direct investigation of host-pathogen interactions that may be important in ocular Ct pathogenesis and disease transmission.

Determinants of condom use in 24,000 prostitute/client contacts in The Gambia.

OBJECTIVE: To determine the factors that influence condom use among prostitutes and their clients in The Gambia. DESIGN: A cohort of 181 prostitutes working in seven bars and several rural markets in The Gambia were monitored daily for 14 months. A sample of 747 clients of these prostitutes was also questioned. MAIN OUTCOME MEASURE: Proportion of sexual contacts for which a condom was used. RESULTS: Data on 24,181 sexual contacts reported by the prostitutes indicated condom use varied according to type of partner (from 84% with clients to only 4% with regular partners). Condom use with clients varied according to location (from 91% in high-class bars to 59% in rural markets), decreased from 91% with the first client of the evening to 37% with the tenth client, and from 75% with clients paying higher charges (> D19) to 52% with those paying lower charges (< D20). Condom use was not related to the socio-demographic characteristics of the prostitutes. Clients reported lower condom use than prostitutes. Clients aged 20-24 years were least likely to use condoms, while white collar workers, traders, and those paying higher charges, were more likely to use condoms. CONCLUSIONS: The level of condom use in this cohort of prostitutes was high but not consistent. Condom use was determined more by the type of establishment and the characteristics of clients, than by any fixed tendency among the prostitutes. Thus, education campaigns should be directed as much to clients as to prostitutes. In The Gambia, 'lower-class' bars and those in rural areas where prostitutes work should be a priority target.

Sexual mixing patterns in Uganda: small-time urban/rural traders.

OBJECTIVE: To document the extent to which rural and urban-based male traders have sexual contacts away from their place of residence. METHODS: Fifty-one traders (46 who travel by bicycle and five others) kept daily diaries of all their journeys and sexual contacts for a total of 584 person-weeks. Twenty-five were resident in a trading town where HIV prevalence was about 40% and 26 lived up to 25 km away in rural areas where HIV prevalence was approximately 8%. RESULTS: A total of 2147 return trips were made (mean, 3.7 per week). Eighty per cent were between the trading town and the surrounding rural area. A total of 1377 sexual contacts were recorded (mean, 2.3 per week); 95% of the contacts of urban-based men occurred in the town, 3% in other urban areas and 2% in a rural area. For rural-based men 82% of sexual contacts took place in their home village, 14% in a neighbouring village, 2% in the trading town and 3% in other urban centres. CONCLUSION: Despite considerable economic interaction there is very little sexual mixing between the town and surrounding rural areas. This may explain why the high HIV prevalence found in some trading towns in Africa has not diffused out to rural areas.

The effects of post-test counselling on condom use among prostitutes in The Gambia.

OBJECTIVES: To determine the effect of counselling on condom use by prostitutes. DESIGN: Cohort study. SETTING: Field-based study in The Gambia. PARTICIPANTS: Thirty-one (12 HIV-positive and 19 HIV-negative) prostitutes. INTERVENTIONS: Post-test HIV counselling. MAIN OUTCOME MEASURES: Levels of condom use. RESULTS: Overall, counselling had no effect on condom use. CONCLUSIONS: Scarce resources should be directed towards providing condoms in bars rather than counselling.

PIP: HIV infection is much more prevalent in prostitution than in the general population of the Gambia (26.2 vs. 1.7%, respectively, in 1988). The short-and long-term effects of counseling on condom use by prostitutes was examined by determining condom use in 29 prostitutes, 11 HIV-positive (group 1) and 18 HIV-negative (group 2), before and 1 month after counseling and in 31 prostitutes, 12 HIV-positive group 3) and 19 HIV-negative (group 4), before and 2-5 month after counseling. HIV-positive women were told that reinfection would increase their chances of developing AIDS as well as lead to transmission of the virus. 3515 sexual contacts were recorded before counseling, 1252 after 1 month, and 4949 at 2-5 months later. Group 1 women reported an 89.3% rate of use before counseling; 1 month later, 9 maintained their rate, 1 increased use from 56 to 81%, and 1 decreased use from 31 to 26%. Group 2 women had 88% use before and, in 11 of the 12 women, 90% use after counseling; the 12th woman reduced use to 66% and was observed to increase her alcohol intake significantly. In both groups, 4 increased use and 3 reduced use. In Group 3, condom use declined insignificantly from 89.3 to 83.5%. 4 women maintained 90% use, 6 reduced use, and 2 increased it. Group 4 women decreased use insignificantly from 88% before to 84.4% after counseling. 8 women maintained original levels of use, 4 increased, and 7 decreased (1 from 90% to as low as 17%). In groups 3 and 4, 74% had 90% use precounseling; this fell to 69% at 1 month and 36% at 2-5 months after counseling, a significant decrease in usage. In all of the prostitutes, condom use increased in the first month after counseling and fell 2-5 months later. Counseling, therefore, failed to increase overall condom use. Possible reasons for this failure include the Senegalese backgrounds of many of the women (they were accustomed to health checks and free condoms); the low number of AIDS deaths in the Gambia, which keeps the disease a distant possibility instead of a pressing reality for the prostitutes; and the consideration of condom use as primarily a method to prevent contraction of the traditional sexually transmitted diseases. When resources are scarce, it may be more important to provide free condoms in bars frequented by prostitutes than to provide counseling.

Molecular epidemiological analysis of HIV in sexual networks in Uganda.

OBJECTIVE: To investigate the suitability of HIV sequence analysis, based on the p17 region of the gag gene, to characterize the sexual networks in and around a trading town in south-west Uganda. METHODS: Blood samples were obtained from 54 HIV-seropositive members of three distinct sexual networks and phylogenetic analysis carried out on proviral DNA sequences obtained from the p17 region of gag from 53 individuals. RESULTS: Despite documented evidence of very little sexual mixing between residents of the trading town, fishing village and surrounding rural area, there was no evidence of clustering of sequences associated with place of residence. More strikingly, known sexual partners failed to show significantly related sequences, and the two pairs of sequences that did show significant similarity came from individuals who had no known social or sexual contact. CONCLUSIONS: Sequence analyses such as those described here have proved effective in confirming or identifying epidemiological links not only following single transmission events but also within risk groups. However, the results from Uganda contrast markedly with those from Europe and the United States. The length of time that the community has been infected, the number of occasions when the virus has been introduced and the high degree of partner change may contribute to the lack of supportive evidence for sociological studies of sexual networks in Uganda.

Analogues of diverse structure are unable to differentiate native melatonin receptors in the chicken retina, sheep pars tuberalis and Xenopus melanophores.

1. The pineal hormone melatonin exerts its biological effects through specific, high affinity G-protein coupled receptors. Recently, three melatonin receptor subtypes (Mel1a, Mel1b and Mel1c) have been cloned. Neither the cloned subtypes, nor the native receptors have yet been compared in a detailed pharmacological analysis. 2. The present study examined the structure-activity relationships of a series of 21 melatonin analogues, by comparing their potency on the pigment aggregation response in Xenopus laevis melanophores with their affinity in radioligand binding competition studies in chicken retina and sheep pars tuberalis (PT), two tissues in which melatonin is known to mediate a biological response. 3. All but four of the analogues were full melatonin receptor agonists producing a concentration-related redistribution of pigment granules in cultured Xenopus melanophores. The remaining analogues produced little pigment aggregation at 10 microM. 4. Saturation studies with 2-[125I]-iodomelatonin identified a single binding site in the chicken retina and sheep PT membranes, with a KD of 36.6 +/- 2.8 and 37.3 +/- 4.3 pM, and a maximal number of binding sites (Bmax) of 16.6 +/- 0.5, and 40.1 +/- 1.7 fmol mg-1 protein, respectively. 5. Comparison of the potency/affinity of the analogues for the binding sites gave a highly significant correlation in each case, retina/melanophore, r = 0.97 (P < 0.001, n = 17), PT/melanophore, r = 0.97 (P < 0.001, n = 17) and PT/retina, r = 0.98 (P < 0.001, n = 21). 6. Despite their large range in affinity and structural diversity these melatonin agonists were unable to distinguish between melatonin receptors in the chicken retina, sheep pars tuberalis and Xenopus melanophores.

Regional lung deposition of a technetium 99m-labeled formulation of mometasone furoate administered by hydrofluoroalkane 227 metered-dose inhaler.

BACKGROUND: A new inhaled suspension formulation of mometasone furoate (MF), a potent corticosteroid with minimal systemic availability, has been developed for the treatment of asthma. This formulation is delivered by metered-dose inhaler (MDI) using the nonchlorofluorocarbon propellant hydrofluoroalkane 227 (HFA-227). OBJECTIVE: The primary goal of this study was to determine the respiratory tract deposition of this formulation of MF. A secondary objective was to measure plasma concentrations of MF and a putative metabolite, 6-X-OH MF, to determine the systemic exposure to corticosteroid. METHODS: This was a single-dose, open-label study in which 200 microg of technetium 99m (99mTc)-radiolabeled MF was administered to patients with asthma. Gamma scintigraphy was used to quantify lung, oropharyngeal, stomach, and MDI mouthpiece deposition patterns of MF. RESULTS: Eleven patients, aged 21 to 47 years, with a history of asthma were enrolled in and completed the study. The mean (+/- SD) whole lung deposition of MF was 13.9%+/-5.7% of the metered (ex-valve) dose. The central lung zone received 5.3%+/-2.8% of the dose; the intermediate zone received 4.7%+/-1.9%; and peripheral lung deposition was 4.0%+/-1.5%. The mean (+/- SD) ratio of peripheral to central lung deposition was 0.8+/-0.2. Oropharyngeal deposition was 79.1%+/-8.7% of the ex-valve dose, with 6.3%+/-7.8% deposited on the MDI mouthpiece and 0.7%+/-0.5% exhaled. The majority of plasma samples taken for analysis of MF and 6-13-OH MF concentrations were below the limit of quantification (50 pg/mL) in all patients after inhalation of 200 microg 99mTc-labeled ME CONCLUSION: The lung deposition of MF when administered via HFA-227 MDI is comparable to the 10 to 20% lung deposition seen with other corticosteroid suspension for- mulations administered by MDI that have demonstrated effectiveness in the treatment of asthma.

Prevalence and demographic factors of stimulant use.

The use of stimulants for recreation purposes has increased considerably during the 20th century. Cocaine was first considered to be a drug of potential abuse during the First World War but was only perceived as a serious threat when it became widely used in socially and economically deprived urban areas of the USA in the 1980s. Use of amphetamines was common among certain occupational groups as a means of remaining alert until the 1950s, when they were seen to be abused by a small minority of recreational users. Controls were then introduced in most developed countries. The public health issue of stimulant use is that of finding a balance between the prevention of serious social or personal harm caused by abuse of these drugs while not impeding their beneficial use.

Nasal and hand carriage of Streptococcus pneumoniae in children and mothers in the Tari Basin of Papua New Guinea.

Nasal and hand carriage of Streptococcus pneumoniae was looked at in 55 families. Overall nasal carriage was 61% (83% in children and 33% in mothers). Hand carriage was 14%. Just over half of the mothers who carried pneumococcus were concordant with their infants.

A malaria control trial using insecticide-treated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, west Africa. 1. A review of the epidemiology and control of malaria in The Gambia, west Africa.

Malaria was recognized as an important cause of death among early European visitors to The Gambia, but the infection was first studied systematically in the local population only in the 1950s. Studies undertaken in the village of Keneba at that time showed that nearly all children under the age of 5 years had parasitaemia throughout the year. More recent surveys in rural areas of The Gambia have shown much lower levels of parasitaemia, probably as a result of a decline in rainfall in The Gambia during the past 30 years and because of an increase in the availability of anti-malarial drugs. Nevertheless, community surveys and reviews of hospital statistics show that malaria is still one of the most important causes of death among Gambian children; about 1 in 25 rural Gambian children die from malaria before reaching the age of 5 years. Until recently, malaria control in The Gambia relied upon prompt treatment of clinical attacks, first with quinine and more recently with chloroquine, and upon some limited vector control in the capital, Banjul. However, during the past few years, it has been shown that mortality in rural children can be reduced substantially by means of chemoprophylaxis given by village health workers. Bed nets (mosquito nets) are used widely in The Gambia and epidemiological surveys have shown an association between the use of bed nets and protection against malaria. This observation led to a series of small scale intervention trials.(ABSTRACT TRUNCATED AT 250 WORDS)

Social and environmental factors associated with the risk of child mortality in a peri-urban community in The Gambia.

A group of 479 children born in a peri-urban West African community during a two-year period was studied in an attempt to identify social and environmental factors associated with the risk of dying in early childhood. Comparison of the characteristics of the 17 children that had died with those of the 462 survivors suggested an increased risk among the children of self-employed women, and among children living in compounds in which animals were kept. Of 500 mothers who were studied (including some whose children were born elsewhere), 145 had experienced at least one child death. When these 145 women were compared with the remaining 355, several factors related to living conditions, maternal education and health knowledge were found to be associated with the risk of child mortality.

PIP: These are the results of a study on infant and child mortality in Bakau, the Gambia. The study, carried out in 1982, concerned 479 children, 17 of whom died. Factors associated with mortality include self-employment of mother, presence of animals in the compound where the child lived, maternal education, and health knowledge.

Food and water hygiene and diarrhoea in young Gambian children: a limited case control study.

During the annual rainy season epidemic of diarrhoea in The Gambia, two groups of urban children were identified, one of which remained completely free of diarrhoea and another in which diarrhoeal prevalence exceed 30% over a period of three months. Microbiological studies on the food and water consumed by these children during one day showed widely varying degrees of contamination in both groups. No difference was observed in levels of contamination, faecal or otherwise, between the two groups. The real problem seemed to lie in accounting for the freedom from diarrhoea of some children rather than explaining possible causes of morbidity in others.

PIP: During the annual rainy season epidemic of diarrhea in the Gambia, 2 groups of urban children were identified, 1 of which remained completely free of diarrhea and another in which diarrheal prevalence exceeded 30% over a period of 3 months. Microbiological studies on the food and water consumed by these children during 1 day showed widely varying degrees of contramination in both groups. No difference was observed in levels of contamination, fecal or otherwise, between the 2 groups. The real problem seems to lie in accounting for the freedom from diarrhea seen in some children rather than in explaining the possibel causes of morbidity in others.

Alternative measures of diarrhoeal morbidity and their association with social and environmental factors in urban children in The Gambia.

Diarrhoeal morbidity was studied during a 15-week period of the rainy season in 244 children aged 6 to 35 months in an urban Gambian community. The average prevalence of diarrhoea was 12.0% and the mean number of episodes per child varied between 2.4 and 2.9 depending on the definition of an episode. The number of chronic episodes lasting 14 d or more was tripled when 7 rather than one diarrhoea-free days were required to define a new episode. Neither prevalence nor the number of episodes varied significantly with age or sex. There was little association between the social and environmental characteristics of the children and diarrhoeal morbidity. The implications of using differing measures of diarrhoeal morbidity are discussed.

A malaria control trial using insecticide-treated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, west Africa. 4. Perceptions of the causes of malaria and of its treatment and prevention in the study area.

Perceptions of the causes of malaria, its treatment and prevention were studied among 996 adults, selected randomly from 73 villages and hamlets in a rural area of The Gambia. Structured questionnaires and other interview techniques were used for data collection. Malaria has no specific name in the study area; it is referred to commonly as Fula kajewo (Fula fever). Only 28% of the respondents knew that mosquitoes transmitted malaria. However, most people believed correctly that August to October was the main malaria season. Eighty-six per cent of the subjects were bed net users. The majority of nets were produced locally, usually white in colour and made of sheeting fabrics. Usage of nets was correlated with ethnic group, age and polygamy but not with education, income, occupation or ownership of certain items which indicate high social status. Analysis of expenditure on mosquito coils indicated that non-users of nets spent 43% more on coils than did users. Bed nets have been used for a long time in the study area; 98% of users saw their parents using them during their childhood.

PIP: In the Gambia, malaria specialists at the Medical Research Council Laboratories oversaw interviews of 996 men and women from, 73 villages and hamlets on the south bank of the River Gambia to learn their perceptions of the causes of malaria and of its treatment and prevention. No specific local term for malaria existed. The most common term used by all ethnic groups, except the Fulas, was Fula kejewo (Fula fever). Just 28% of all adults knew that mosquitoes transmit malaria. Men were more likely to know the real cause of malaria than women (p .001). Knowledge about the cause of malaria increased with education p =.01). Most people (90%) knew that malaria transmission occurs most often during August-October. 86% of adults and 81% of their children less than 10 years old used bed nets. Girls were more likely to sleep under bed nets than boys (p = .005). Local tailors made most bed nets with either second hand or new fabrics. They tended to be made of sheeting fabrics and white in color. Most adults were willing to treat their bed nets with the insecticide permethrin to protect against mosquitoes. Ethnic group (Fulas less likely, p .001), age (older people more likely, p .001), and polygamy (p = .002) were correlated with bed net use. Education, income, and occupation or ownership of items indicating high social status were not correlated with bed net use. Nonusers of bed nets spent 43% more on mosquito coils, used to smoke out mosquitoes from rooms before going to sleep, than did users (p = .001). Almost all adults (98%) remembers their parents using bed nets when they were children. The bed nets users who were at least 70 years old said that the Mandinkas mainly used bed nets. These findings should prove useful to the government as it develops a national impregnated bed net program to control malaria in rural areas.

Social and environmental factors associated with diarrhoea and growth in young children: child health in urban Africa.

This study investigates the relationship between social and environmental variables and diarrhoea and growth in children aged between 6 and 36 months in an urban area of The Gambia, West Africa. The social and environmental conditions of 493 children were observed and recorded over a period of 12 months. Two hundred and seventy-seven children were under weekly diarrhoea surveillance for a 15 week period during the wet season and 322 children had anthropometric measurements taken in May and September. Computer analysis was used to determine association between single and multiple environmental and social factors and diarrhoea prevalence and growth. The results of the diarrhoea surveillance showed that there was considerable variation between individual children. Thirty children had no diarrhoea during the period of surveillance and 30 had diarrhoea for over 24% of the time, with 2 children having diarrhoea for more than 50 days out of a total of 105. None of the social and environmental variables recorded showed a significant relationship with diarrhoea prevalence. The anthropometric measurements showed that at the end of the wet season, in September, 23% of children in this age group were less than 90% of the National Centre for Health Statistics standards of height for age and several of the variables recorded showed a statistically significant association with this measurement.

Prostitutes and their clients: a Gambian survey.

The social backgrounds and working behaviour of 248 prostitutes in urban and rural areas of The Gambia were investigated. Prostitutes were found to be highly mobile, moving frequently between a number of working locations in The Gambia and neighbouring Senegal, from which most of them originated. The educational level of prostitutes and the standard of living of their natal families were above average. Prostitutes worked on average four days a week and had between two and three clients a night. Condoms were used in up to 80% of contacts. 795 clients of prostitutes were interviewed and found to be on average of low educational and occupational status. Half were non-Gambian and most were currently travelling or living away from home.

Sexual networks in Uganda: mixing patterns between a trading town, its rural hinterland and a nearby fishing village.

The study was based in south-west Uganda where significant differences in HIV prevalence have been found between urban and rural areas. Longitudinal data collected in a diary format was used to determine the extent to which high-risk men and women living in a truck stop/trading town had sexual contact with people from surrounding rural areas and a nearby fishing village. Study participants were 143 men, 75 of whom were resident in the town, 40 in a fishing village and 28 in rural areas, and 81 women, of whom 47 were resident in the town, 25 in the fishing village and 9 in a rural area. During 1687 man weeks the 143 men made 3149 trips and had 5189 sexual contacts. Ninety-two per cent of these sexual contacts occurred in the man's current place of residence and 21% were with a new partner. The 81 women participated for 1280 women weeks during which they recorded 6378 sexual contacts. Women who lived in the fishing village and the rural area had around 90% of their contacts with local men while those who lived in the town fell into 3 categories: women who charged a relatively high price for commercial sex had only 11% of contacts with men living in the town, while those who charged a tenth of the price had 71% of contacts with town men. The small number of women who fell into an intermediate category, in terms of price, had sexual contact with a wide variety of men. These findings show that there is little scope for HIV infection to spread between different residential or occupational groups. This may help to explain how large differences in HIV seropositivity between neighbouring localities can be maintained for long periods, despite considerable social and economic mixing between groups and high levels of sexual partner change within groups.

PIP: In southwest Uganda, there is concern that sexual mixing between rural areas with low HIV prevalence and urban areas with high HIV prevalence will produce uniformly high rates of HIV. To determine the extent of such mixing, a prospective study was conducted in a trading town on the trans-African highway with a steady flow of male truckers, an agricultural hinterland to the west, and a fishing village to the east. A total of 143 men recruited largely from bars and 81 women reported to be sexually promiscuous kept records of their sexual contacts over a 6-month period. During 1687 man-weeks of observation, the men made 3149 road trips and had 5189 sexual contacts; 92% of these contacts occurred in the men's place of residence and 21% involved a new partner. 59% of town men's sexual contacts, 61% reported by men in the fishing village, and 52% of those in rural areas involved casual partners. An additional 6378 sexual encounters were recorded during 1280 woman-weeks. Close to 90% of women's sexual contacts in the 2 rural areas involved local men. Among the highest-paid town commercial sex workers, only 11% of sexual contacts involved men from the town; in contrast, 71% of sexual encounters among town women who charged only 10% the price of their more expensive counterparts were with local men. Serologic testing of a subset of 75 men and 52 women yielded HIV prevalences of 28% and 52%, respectively. The distinct sexual networks identified in this study suggest it is unlikely that rates of HIV infection in the rural areas will reach those in nearby trading towns.

Social aspects of AIDS-related stigma in rural Uganda.

In the process of collecting sexual behaviour data through in-depth interviews, 24 respondents offered information on stigma related to HIV-1 infection. Observations of social relations in public places and families of infected individuals were made. The findings suggest that although HIV/AIDS-related stigma has had adverse effects on treatment seeking behaviour of PWAs and coping mechanisms of their families, a more tolerant attitude is starting to emerge in this area. Probably, due to improvements in counselling services and home care schemes for those with AIDS. This supports the call for increased investments in counselling and community development aimed at caring for people with AIDS (PWAs).

Diagnostic splenectomy for visceral leishmaniasis.

A 57-year-old-man with a history of malaise, fever, night sweats and shortness of breath presented a diagnostic challenge to his medical team. He was pancytopaenic and had splenomegaly on admission but other investigations, including bone marrow aspiration, proved inconclusive. After the patient deteriorated clinically, the general surgical team was requested to perform a diagnostic splenectomy. The histology of this showed infection with visceral leishmaniasis. He recovered completely with Amphotericin treatment. Although this is a rare condition, particularly for the general surgeon, this case highlights the difficult position surgeons are often put in when performing major surgery diagnostically.

A three-year follow-up survey of demographic changes in a Ugandan town on the trans-African highway with high HIV-1 seroprevalence.

A 1991 serosurvey in a Ugandan trading town on the trans-African highway reported a 40 per cent HIV-1 prevalence in adults. Three years later in a repeat survey of the 531 adults resident in 1991, 279 (53%) were still present, 196 (37%) had left and 56 (11%) had died. There were 138 new residents and 46 children had become adults, making a total of 463 adults in 1994, 13 per cent less than 1991. Most immigrants (91%) came from the surrounding rural district whereas 38 per cent of emigrants went to an urban area. A significant inverse association between wealth and seropositivity was found for women but not men. Of the original residents 157 were known to be HIV-1 positive in 1991; 31 (20%) had died compared to 10 (4%) of the 232 known to be seronegative, representing an HIV-1 attributable mortality fraction of 60 per cent.

PIP: A 1991 serosurvey was conducted in 1991 in a small trading town-truck stop on the trans-African highway in Masaka district, Uganda, to assess the level of HIV-1 seroprevalence among residents. 531 adults aged 13 years or older living in 154 randomly selected households were censused and a clear HIV-1 test result obtained for 389. 157 were HIV-1 positive and 232 seronegative. A higher number of lifetime sex partners, being married, and being a woman aged 20-34 years or a man aged 35-44 years were positively associated with being HIV-infected. A repeat survey of the 531 adults resident in 1991 was conducted in 1994 to find that 279 were still present, 196 had left, and 56 had died. Of the original residents, 31 known to be HIV-1-positive had died, compared to 10 of the 232 known seronegative. There were 138 new residents and 46 children had become adults, for a total 463 adults in 1994. 91% of immigrants came from the surrounding rural district, while 38% of emigrants moved to an urban area. A significant inverse association between wealth and seropositivity was found for women but not men.