Prospective study of incidence of juvenile diabetes mellitus over 10 years in Dar es Salaam,Tanzania.

OBJECTIVE--To ascertain the annual incidence of diabetes requiring treatment with insulin in children and adolescents aged 0-19 years in Dar es Salaam, Tanzania, during a 10 year period from 1 January 1982 to 31 December 1991. DESIGN--Prospective registration at a major urban hospital of all patients with newly diagnosed diabetes who were resident in Dar es Salaam. SETTING--Muhimbili Medical Centre, Dar es Salaam, Tanzania. PATIENTS--86 patients: 45 male, 41 female. RESULTS--The annual incidence of juvenile diabetes for both sexes was 1.5 per 100,000 population aged 0-19 years (95% confidence interval 1.3 to 1.7). Incidence per 100,000 population per year increased with age: 0.6 (0.0 to 0.13) in the age group 0-4 years, 0.5 (0.3 to 0.7) at 5-9 years, 2.2 (1.8 to 2.6) at 10-14 years, and 3.4 (2.9 to 3.9) at 15-19 years. CONCLUSION--Juvenile diabetes mellitus is fairly rare in sub-Saharan Africa. If environmental factors such as infection and material deprivation were important determinants of insulin dependent diabetes in Africans, as they may be in Europeans, much higher rates would have been expected unless genetic factors possibly exert a protective role. The eightfold greater incidence in African Americans than in Tanzanians may be related to greater genetic admixture in African Americans with people from countries in Europe with a high incidence.     

Cerebrospinal fluid and serum biomarkers of cerebral malaria mortality in Ghanaian children

Background

Successful malaria vector control depends on understanding behavioural interactions between mosquitoes and humans, which are highly setting-specific and may have characteristic features in urban environments. Here mosquito biting patterns in Dar es Salaam, Tanzania are examined and the protection against exposure to malaria transmission that is afforded to residents by using an insecticide-treated net (ITN) is estimated.

Methods

Mosquito biting activity over the course of the night was estimated by human landing catch in 216 houses and 1,064 residents were interviewed to determine usage of protection measures and the proportion of each hour of the night spent sleeping indoors, awake indoors, and outdoors.

Results

Hourly variations in biting activity by members of the Anopheles gambiae complex were consistent with classical reports but the proportion of these vectors caught outdoors in Dar es Salaam was almost double that of rural Tanzania. Overall, ITNs confer less protection against exophagic vectors in Dar es Salaam than in rural southern Tanzania (59% versus 70%). More alarmingly, a biting activity maximum that precedes 10 pm and much lower levels of ITN protection against exposure (38%) were observed for Anopheles arabiensis, a vector of modest importance locally, but which predominates transmission in large parts of Africa.

Conclusion

In a situation of changing mosquito and human behaviour, ITNs may confer lower, but still useful, levels of personal protection which can be complemented by communal transmission suppression at high coverage. Mosquito-proofing houses appeared to be the intervention of choice amongst residents and further options for preventing outdoor transmission include larviciding and environmental management.     

Impact of Community-Based Larviciding on the Prevalence of Malaria Infection in Dar es Salaam,Tanzania

Background

The use of larval source management is not prioritized by contemporary malaria control programs in sub-Saharan Africa despite historical success. Larviciding, in particular, could be effective in urban areas where transmission is focal and accessibility to Anopheles breeding habitats is generally easier than in rural settings. The objective of this study is to assess the effectiveness of a community-based microbial larviciding intervention to reduce the prevalence of malaria infection in Dar es Salaam, United Republic of Tanzania.

Methods and Findings

Larviciding was implemented in 3 out of 15 targeted wards of Dar es Salaam in 2006 after two years of baseline data collection. This intervention was subsequently scaled up to 9 wards a year later, and to all 15 targeted wards in 2008. Continuous randomized cluster sampling of malaria prevalence and socio-demographic characteristics was carried out during 6 survey rounds (2004–2008), which included both cross-sectional and longitudinal data (N = 64,537). Bayesian random effects logistic regression models were used to quantify the effect of the intervention on malaria prevalence at the individual level. Effect size estimates suggest a significant protective effect of the larviciding intervention. After adjustment for confounders, the odds of individuals living in areas treated with larviciding being infected with malaria were 21% lower (Odds Ratio = 0.79; 95% Credible Intervals: 0.66–0.93) than those who lived in areas not treated. The larviciding intervention was most effective during dry seasons and had synergistic effects with other protective measures such as use of insecticide-treated bed nets and house proofing (i.e., complete ceiling or window screens).

Conclusion

A large-scale community-based larviciding intervention significantly reduced the prevalence of malaria infection in urban Dar es Salaam.     

Diabetes in tropical Africa: a prospective study, 1981-7. I. Characteristics of newly presenting patients in Dar es Salaam,Tanzania, 1981-7.

OBJECTIVE--To study the clinical characteristics of newly diagnosed diabetic patients in tropical Africa. DESIGN--Prospective study of all newly diagnosed diabetic patients registered at a major urban hospital between 1 June 1981 and 31 May 1987. SETTING--Muhimbili Medical Centre, Dar es Salaam, Tanzania. PATIENTS--1250 Patients: 874 men, 376 women. RESULTS--272 (21.8%) Patients had diabetes requiring insulin, 825 (66.0%) had diabetes not requiring insulin, and 153 (12.2%) had diabetes of uncertain type. Most patients (1103, 88.2%) presented with the classic symptoms of diabetes. The peak time of presentation of diabetic patients requiring insulin was at age 15 to 19 years. Male manual workers and peasant farmers with diabetes not requiring insulin presented at a significantly older age and had a lower body mass index than sedentary office workers. Forty six (18.1%) of the patients requiring insulin diabetes and 111 (14.4%) not requiring insulin had first degree relative with diabetes. Twenty seven per cent of patients were underweight (body mass index less than 20 kg/m2) and 14.6% were obese (body mass index greater than 30 kg/m2). Hypertension was diagnosed in 211 (26.7%) of 791 patients not requiring insulin. Nine (3.3%) of those requiring insulin may have had the protein deficient type of diabetes related to malnutrition. The fibrocalculous variety of diabetes related to malnutrition was not observed. CONCLUSIONS--Newly presenting diabetic patients in Tanzania with diabetes requiring insulin are older at presentation than those in Britain; most diabetic patients present with diabetes not requiring insulin and a smaller proportion of Tanzanian patients are obese. Most have a lower socioeconomic state than diabetic patients in Britain. There are often delays in diagnosis in Tanzania, and there is a higher incidence of death shortly after presentation.     

Hypertension in sub-Saharan Africa: cross-sectional surveys in four rural and urban communities

Background

Cardiovascular disease (CVD) is the leading cause of adult mortality in low-income countries but data on the prevalence of cardiovascular risk factors such as hypertension are scarce, especially in sub-Saharan Africa (SSA). This study aims to assess the prevalence of hypertension and determinants of blood pressure in four SSA populations in rural Nigeria and Kenya, and urban Namibia and Tanzania.

Methods and Findings

We performed four cross-sectional household surveys in Kwara State, Nigeria; Nandi district, Kenya; Dar es Salaam, Tanzania and Greater Windhoek, Namibia, between 2009–2011. Representative population-based samples were drawn in Nigeria and Namibia. The Kenya and Tanzania study populations consisted of specific target groups. Within a final sample size of 5,500 households, 9,857 non-pregnant adults were eligible for analysis on hypertension. Of those, 7,568 respondents ≥18 years were included. The primary outcome measure was the prevalence of hypertension in each of the populations under study.The age-standardized prevalence of hypertension was 19.3% (95%CI:17.3–21.3) in rural Nigeria, 21.4% (19.8–23.0) in rural Kenya, 23.7% (21.3–26.2) in urban Tanzania, and 38.0% (35.9–40.1) in urban Namibia. In individuals with hypertension, the proportion of grade 2 (≥160/100 mmHg) or grade 3 hypertension (≥180/110 mmHg) ranged from 29.2% (Namibia) to 43.3% (Nigeria). Control of hypertension ranged from 2.6% in Kenya to 17.8% in Namibia. Obesity prevalence (BMI ≥30) ranged from 6.1% (Nigeria) to 17.4% (Tanzania) and together with age and gender, BMI independently predicted blood pressure level in all study populations. Diabetes prevalence ranged from 2.1% (Namibia) to 3.7% (Tanzania).

Conclusion

Hypertension was the most frequently observed risk factor for CVD in both urban and rural communities in SSA and will contribute to the growing burden of CVD in SSA. Low levels of control of hypertension are alarming. Strengthening of health care systems in SSA to contain the emerging epidemic of CVD is urgently needed.     

Incidence of HIV-1 infection in a rural region of Uganda.

OBJECTIVE--To determine the incidence of infection with HIV-1 and the risk factors associated with seroconversion in three geographical strata of a rural Ugandan district. DESIGN--Serological, sociodemographic, and behavioural surveys of everyone aged 13 or more in 21 randomly selected communities at baseline and one year later. SETTING--Rural population of Rakai district, southwestern Uganda, residing in main road trading centres, secondary trading villages, and agricultural villages. SUBJECTS--In 1989, 1292 adults provided a blood sample and interview data; one year later, 778 survivors (77%) who had been seronegative at baseline provided follow up data. MAIN OUTCOME MEASURES--Incidence of HIV infection in relation to individual characteristics and risk factors, including place of residence. RESULTS--Incidence of HIV infection in all adults was 2.1/100 person years of observation (SE 0.5 (95% confidence interval 1.1 to 3.1)); in people aged 15-39 the incidence was 3.2/100 person years. Incidence was highest in men and women aged 20-24 (9.2/100 person years (3.9) and 6.8/100 person years (2.9) respectively). Risk factors significantly associated with seroconversion were age 24 and under and two or more sexual partners. Between the surveys the proportion of all respondents reporting high risk behaviour (two or more partners) significantly increased from 8.9% to 12.3%. CONCLUSIONS--Despite preventive programmes and substantial knowledge about AIDS the incidence of HIV infection remains high in this rural population. Prevention aimed at vulnerable rural communities is urgently needed to contain the HIV epidemic.     

Must diabetes be a fatal disease in Africa? Study of costs of treatment.

OBJECTIVE--To estimate the costs of diagnosis and treatment of diabetes in Tanzania. DESIGN--Costs estimated from the reported and recorded experience of patients with newly presenting diabetes in 1989-90 and of diabetic patients first seen in 1981-2. SETTING--Muhimbili Medical Centre, Dar es Salaam. SUBJECTS--464 patients (315 men and 149 women). 262 patients diagnosed during 1 September 1989-31 August 1990 (group 1) and 202 during 1 June 1981-31 August 1982 (group 2). RESULTS--The average annual direct cost of diabetes care in 1989-90 was $287 for a patient requiring insulin and $103 for a patient not requiring insulin. Purchase of insulin accounted for 68.2% ($156) of the average annual outpatient costs for patients requiring insulin. For patients not requiring insulin the cost of oral hypoglycaemic drugs and treatment of chronic complications and infections accounted for 42.5% ($29.3) and 48.8% ($33.7) of costs respectively. Cost of outpatient care of diabetic patients for the whole of Tanzania was estimated at $2.7m, *75,128 (32.2%) of which was for insulin. Doctors'' and nurses'' costs accounted for 0.2% of total costs of outpatient care. The annual direct inpatient care costs were estimated at $1.25m. Around 0.2% of the Tanzanian population aged 15 years and over used the equivalent of 8% of the total government health expenditure, which was $47,4088,382. CONCLUSION--Diabetes places a severe strain on the limited resources of developing countries. If African patients with diabetes have to pay for their treatment most will be unable to do so and will die.     

Transmission of Schistosoma bovis in Mkulwe (Mbozi District, Mbeya region, southern highlands of Tanzania)

Various populations of laboratory bred bulinid snails were exposed to miracidia of Schistosoma bovis from Mbozi. The parasite is naturally transmitted by Bulinus globosus in the area. Laboratory infection revealed a good relationship with B. forskalii and B. globosus from Mbozi and a population of B. forskalii from Dar es Salaam (infection rates 100%, 63.6% and 41.7% respectively). Populations of B. globosus and B. nasutus from Dar es Salaam were refractory. It appears that both snail species (B. globosus and B. forskalii) present in Mbozi district transmit S. bovis.     

Urban-rural contrasts in explanatory models and treatment-seeking behaviours for stroke in Tanzania

Stroke is an emerging problem in sub-Saharan Africa, about which little is known since most research to date has been based on retrospective, hospital-based studies. This anthropological work, designed to complement a large community-based project on stroke incidence, focuses on local understandings and treatment-seeking behaviours in urban (Dar-es-Salaam) and rural (Hai) areas of Tanzania. Semi-structured interviews (n=80) were conducted with 20 stroke patients, 20 relatives of stroke patients, ten traditional healers, and 30 other local residents. In contrast to common expectations, and literature that finds witchcraft beliefs to be most common in rural areas, stroke in urban Dar was widely believed to emanate from supernatural causes (demons and witchcraft), while in rural Hai, explanations drew mostly on 'natural' causes (hypertension, fatty foods, stress). These different beliefs and explanatory models fed into treatment-seeking behaviours. The first option in Hai was hospital treatment, while in Dar-es-Salaam, where belief in demons led to hospital avoidance, it was traditional healers. In both sites, multiple treatment options (serially or simultaneously) were the norm. Analysis of patient and carer narratives suggested that causation beliefs outweighed other factors, such as cost and distance, in shaping effective treatment. Three policy implications are drawn. First, as other studies have also shown, it is important to engage with, rather than dismiss, local explanations and interpretations of stroke. Stroke awareness messages need to take into account the geographical and belief systems differences. Developing an understanding of explanatory models that recognizes that local beliefs arise from dynamic processes of social interaction will be critical to designing effective interventions. Second, there is a clear role for multiple healing systems with possibility of cross-reference in the case of a chronic, disabling condition like stroke, since biomedical treatment cannot offer a 'quick fix' while traditional healers can help people come to terms with their condition. Third, issues of communication between health services and their patients are particularly critical.     

All-female broods and mimetic polymorphism in Acraea encedon (L.) (Lepidoptera: Acraeidae) in Tanzania

In some populations of the African butterfly, Acraea encedon, there are two kinds of females, one producing offspring in a normal 1:1 sex ratio, the other producing females only; in other populations the sex ratio is apparently normal. All-female broods had hitherto been mainly associated with populations in which field sampling revealed an excess of females. The all-female brood trait is described from a population at Dar es Salaam which field sampling suggested was normal, and this indicates that the trait may be much more widespread and common than had previously been supposed. This discovery also extends the known distribution of the trait across Africa from Sierra Leone to eastern Tanzania. The butterfly is also a polymorphic Müllerian mimic of Danaus chrysippus, which is a highly unusual phenomenon as Müllerian mimicry is almost invariably monomorphic. The relative frequencies of two corresponding colour forms of the two species of butterflies at Dar es Salaam adds support to the hypothesis that they are indeed Mullerian mimics. The results of breeding experiments suggest that the polymorphic forms in Acraea encedon are allelic with dominance.     

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.     

Opisthobranchiate Mollusca from Tanzania (Suborder:Doridacea)

Twenty-two species of Doridacea are described from the vicinity of Dar es Salaam, Tanzania. None is new to science, but one species of the genus Gymnodoris was too immature to be fully identified. Ten of the 22 species are known from the Hawaiian Islands, indicating that many species of dorid occur throughout the Indian Ocean and the Pacific as far as Hawaii. One species (Jorunna tomentosa) appears to be cosmopolitan, and two may possibly be confined to the coast of Africa (Chromodoris annulata and C. vicind).
Sixty-nine species of dorid have already been reported from Tanzania by Eliot. Nine species in the present collection were not found by him, so 78 are now known from the area.     

A man-eating lion (Panthera leo) from Tanzania with a toothache

Between August 2002 and April 2004, a man-eating lion killed 35 people and injured at least 9 in a 350-km² area 150 km south-west of Dar es Salaam in Tanzania. Man-eating by lions is common in Southern Tanzania, but this case was exceptional due to the high number of victims attributed to a single animal. After having been killed by game scouts and villagers, it was found to be a young adult male. Dental examination revealed a broken upper left molar where a serious abscess and caries had developed. The lion must have been in permanent pain, and this probably explains its preference for man-eating. Most man-eating lions in Tanzania are healthy animals without signs of infirmity.     

An affordable, quality-assured community-based system for high-resolution entomological surveillance of vector mosquitoes that reflects human malaria infection risk patterns

ABSTRACT: BACKGROUND: More sensitive and scalable entomological surveillance tools are required to monitor low levels of transmission that are increasingly common across the tropics, particularly where vector control has been successful. A large-scale larviciding programme in urban Dar es Salaam, Tanzania is supported by a community-based (CB) system for trapping adult mosquito densities to monitor programme performance. Methodology An intensive and extensive CB system for routine, longitudinal, programmatic surveillance of malaria vectors and other mosquitoes using the Ifakara Tent Trap (ITT-C) was developed in Urban Dar es Salaam, Tanzania, and validated by comparison with quality assurance (QA) surveys using either ITT-C or human landing catches (HLC), as well as a cross-sectional survey of malaria parasite prevalence in the same housing compounds. RESULTS: Community-based ITT-C had much lower sensitivity per person-night of sampling than HLC (Relative Rate (RR) [95% Confidence Interval (CI)] = 0.079 [0.051, 0.121], P < 0.001 for Anopheles gambiae s.l. and 0.153 [0.137, 0.171], P < 0.001 for Culicines) but only moderately differed from QA surveys with the same trap (0.536 [0.406,0.617], P = 0.001 and 0.747 [0.677,0.824], P < 0.001, for An. gambiae or Culex respectively). Despite the poor sensitivity of the ITT per night of sampling, when CB-ITT was compared with QA-HLC, it proved at least comparably sensitive in absolute terms (171 versus 169 primary vectors caught) and cost-effective (153US$ versus 187US$ per An. gambiae caught) because it allowed more spatially extensive and temporally intensive sampling (4284 versus 335 trap nights distributed over 615 versus 240 locations with a mean number of samples per year of 143 versus 141). Despite the very low vectors densities (Annual estimate of about 170 An gambiae s.l bites per person per year), CB-ITT was the only entomological predictor of parasite infection risk (Odds Ratio [95% CI] = 4.43[3.027,7. 454] per An. gambiae or Anopheles funestus caught per night, P =0.0373). Discussion and conclusion CB trapping approaches could be improved with more sensitive traps, but already offer a practical, safe and affordable system for routine programmatic mosquito surveillance and clusters could be distributed across entire countries by adapting the sample submission and quality assurance procedures accordingly.     

Group Occupational Health Service in a Developing Country

In 1967 an experimental group occupational health service was set up in Dar es Salaam to provide direct service to industrial firms. Larger companies were visited by a doctor, smaller firms in rotation by auxiliaries. After three years 65 companies had joined with over 15,000 employees, and workers were attending the group dispensaries at a rate of over 250,000 visits a year. Such an approach through direct service to the working community appears to be more appropriate to a developing country than a purely advisory central occupational health unit.     

Low quality of routine microscopy for malaria at different levels of the health system in Dar es Salaam

Background

Laboratory capacity to confirm malaria cases in Tanzania is low and presumptive treatment of malaria is being practiced widely. In malaria endemic areas WHO now recommends systematic laboratory testing when suspecting malaria. Currently, the use of Rapid Diagnostic Tests (RDTs) is recommended for the diagnosis of malaria in lower level peripheral facilities, but not in health centres and hospitals. In this study, the following parameters were evaluated: (1) the quality of routine microscopy, and (2) the effects of RDT implementation on the positivity rate of malaria test results at three levels of the health system in Dar es Salaam, Tanzania.

Methods

During a baseline cross-sectional survey, routine blood slides were randomly picked from 12 urban public health facilities in Dar es Salaam, Tanzania. Sensitivity and specificity of routine slides were assessed against expert microscopy. In March 2007, following training of health workers, RDTs were introduced in nine public health facilities (three hospitals, three health centres and three dispensaries) in a near-to-programmatic way, while three control health facilities continued using microscopy. The monthly malaria positivity rates (PR) recorded in health statistics registers were collected before (routine microscopy) and after (routine RDTs) the intervention in all facilities.

Results

At baseline, 53% of blood slides were reported as positive by the routine laboratories, whereas only 2% were positive by expert microscopy. Sensitivity of routine microscopy was 71.4% and specificity was 47.3%. Positive and negative predictive values were 2.8% and 98.7%, respectively. Median parasitaemia was only three parasites per 200 white blood cells (WBC) by routine microscopy compared to 1226 parasites per 200 WBC by expert microscopy. Before RDT implementation, the mean test positivity rates using routine microscopy were 43% in hospitals, 62% in health centres and 58% in dispensaries. After RDT implementation, mean positivity rates using routine RDTs were 6%, 7% and 8%, respectively. The sensitivity and specificity of RDTs using expert microscopy as reference were 97.0% and 96.8%. The positivity rate of routine microscopy remained the same in the three control facilities: 71% before versus 72% after. Two cross-sectional health facility surveys confirmed that the parasite rate in febrile patients was low in Dar es Salaam during both the rainy season (13.6%) and the dry season (3.3%).

Conclusions

The quality of routine microscopy was poor in all health facilities, regardless of their level. Over-diagnosis was massive, with many false positive results reported as very low parasitaemia (1 to 5 parasites per 200 WBC). RDTs should replace microscopy as first-line diagnostic tool for malaria in all settings, especially in hospitals where the potential for saving lives is greatest.

     

Has mortality from melanoma stopped rising in Australia? Analysis of trends between 1931 and 1994.

OBJECTIVE--To describe recent trends in mortality from melanoma in Australia. DESIGN--An analysis of trends in age standardised and age and sex specific mortalities by year of death and median year of birth (cohort). SETTING--Australia. SUBJECTS--All deaths from melanoma registered in Australia between 1931 and 1994. RESULTS--Melanoma mortality rose steadily from 1931 to 1985. From 1959 the annual rate of increase was 6.3% in men and 2.9% in women, resulting in mortalities of 4.82 and 2.51 per 100,000 person years in 1985 and 1989, respectively. Mortalities for both sexes seem to have plateaued from June 1985 onwards. In 1990-4 the rate rose by 3.7% in men to 5.00 per 100,000 and in women it fell by 5.2% to 2.38 per 100,000. The non-significant increase after 1985 in mortality in men was restricted to those aged over 70 years of age, whereas the fall in rates in women was mostly in those aged under 55 years. This pattern was generally reflected in the state trends, though with some variation: rates for women in Queensland had peaked in the late 1970s; while rates for men in New South Wales continued to rise in 1990-4, placing them above those for Queensland. Examination of mortalities specific for age, period, and cohort for Australia as a whole showed several salient features. Rates in men rose steeply in cohorts born before about 1930; were stable in cohorts born between 1930 and 1950; and fell in more recent cohorts. Rates in women showed similar changes but about five years earlier. CONCLUSION--Melanoma mortality in Australia peaked in about 1985 and has now plateaued. On the basis of trends in cohorts it can be expected to fall in coming years.     

Sex related differences in short and long-term prognosis after acute myocardial infarction: 10 year follow up of 3073 patients in database of first Danish Verapamil Infarction Trial.

OBJECTIVE--To re-examine the prevailing hypothesis that women fare worse than men after acute myocardial infarction. DESIGN--10 year follow up of all patients with confirmed acute myocardial infarction registered in the database of the Danish verapamil infarction trial in 1979-81. SETTING--16 coronary care units, covering a fifth of the total Danish population. PATIENTS--3073 consecutive patients with acute myocardial infarction, 738 (24%) women and 2335 (76%) men. MAIN OUTCOME MEASURES--Early mortality (before day 15). For patients alive on day 15: mortality, cause of death, admission with recurrent infarction, and mortality after reinfarction. RESULTS--Early mortality increased significantly with age (P < 0.0001) but was not significantly related to sex, with a 15 day mortality of 17% in women and 16% in men. Adjustment for age and sex simultaneously revealed a significant interaction (P = 0.02) between these variables, with a greater increase with age in early mortality for men than for women (early mortality was equal for the two sexes at age 64 years). Ten year mortality in patients alive on day 15 was 58.8%. The overall age adjusted hazard ratio (95% confidence interval) for women versus men was 0.90 (0.80 to 1.01); 0.90 (0.78 to 1.04) for 10 year reinfarction (48.8%); and 0.98 (0.82 to 1.16) for 10 year mortality after reinfarction (82.3%). No difference in cause of death was found between the sexes. With a follow up of up to 10 years for patients alive on day 15 mortality, rate of reinfarction, and mortality after reinfarction increased with increasing age (P < 0.0001). CONCLUSION--Sex by itself is not a risk factor after acute myocardial infarction.