Plague epidemiology and control in eastern and southern Africa during the period 1978 to 1997

Human plague is one of the important re-emerging zoonotic diseases threatening public health in some African, Asian and South American countries. During the period 1978 to 1997, Africa reported the largest numbers of plague cases and deaths in the world. During the decade 1978 to 1987, 19 countries reported 10 537 cases. Ten of the countries and 41.9% of the reported cases were in Africa. At least 14.5% of the cases reported in Africa died. Similarly, during the decade 1988 to 1997, 22 countries, 12 of which were in Africa, reported a total of 17,674 cases and 1,465 deaths. Of these, 11,711 cases of which 9.6% died, were reported from Africa.     

Observations on the current status of plague endemicity in the western Usambara mountains, north-east Tanzania

Epidemiological investigations were executed at 6 locations in the western Usambara mountains in north-east Tanzania from November 1980 to May 1982. Rodent, human and dog sera were checked for agglutinating plague antibodies, using the passive haemagglutination test. Fraction I plague antigen was similarly tested for in rodent organ macerates. Bubo aspirates and rodent organ-smears were microscopically examined for plague bacilli. A total of 257 rodents and 191 fleas were collected. Rattus rattus, Praomys natalensis and Arvicanthis niloticus were the commonest rodent species. Flea ectoparasites mostly comprised of Xenopsylla brasiliensis and Dinopsyllus lypusus. Specific plague antibodies were detected in 2.8%, 10% and 2.9% of the rodents examined in November 1980, November 1981 and May 1982 respectively. Similarly, plague antibodies were found in 0.6%, 1.2% and 0.5% of the human sera tested in September 1981, November 1981 and May 1982 respectively. All the dog sera were negative. The results suggested past contact with plague and existence of a persistent plague focus in the area. Health education for villagers, maintenance of a plague surveillance programme and regular seminars for medical and health personnel in the area were recommended in order to prompt early detection, reporting and control of an outbreak.     

Obesity and regional fat distribution in Kenyan populations: Impact of ethnicity and urbanization

Background: Obesity is increasing rapidly in Africa, and may not be associated with the same changes in body composition among different ethnic groups in Africa.

Objective: To assess abdominal visceral and subcutaneous fat thickness, prevalence of obesity, and differences in body composition in rural and urban Kenya.

Subjects and methods: In a cross-sectional study carried out among Luo, Kamba and Maasai in rural and urban Kenya, abdominal visceral and subcutaneous fat thicknesses were measured by ultrasonography. Height and weight, waist, mid-upper arm circumferences, and triceps skinfold thickness were measured. Body mass index (BMI), arm fat area (AFA) and arm muscle area (AMA) were calculated.

Results: Among 1430 individuals (58.3% females) aged 17–68 years, abdominal visceral and subcutaneous fat, BMI, AFA and waist circumference (WC) increased with age, and were highest in the Maasai and in the urban population. AMA was only higher with increasing age among males. The prevalence of overweight (BMI ≥ 25) (39.8% vs. 15.8%) and obesity (BMI ≥ 30) (15.5% vs. 5.1%) was highest in the urban vs. rural population.

Conclusion: Abdominal visceral and subcutaneous fat thickness was higher with urban residency. A high prevalence of overweight and obesity was found. The Maasai had the highest overall fat accumulation.     

Responsibility as a dimension of HIV prevention normative beliefs: measurement in three drug-using samples

The concept of responsibility was derived originally from principles of morality, as part of a network of rights, duties and obligations. HIV risk-related studies have suggested that a sense of responsibility for condom use to protect a partner is a potentially important predictor of condom use in drug-using populations. We created a four-item scale measuring Self responsibility to use condoms and Partner's responsibility to use condoms. Data were collected from three drug-using samples: crack smokers, HIV seropositive crack smokers in an intervention study in Houston, Texas, and Tanzanian heroin users in Dar es Salaam. Data indicated that the four responsibility items had high alpha coefficients in each sample, and that there were moderate to high intercorrelations between equivalent self and partner responsibility items. There were significant differences in scale scores between the crack smokers and the HIV positive crack smokers and the Tanzanian samples, but no significant differences between the HIV positive and Tanzanian samples. Comparing within the first crack-smoker sample those who were HIV positive and negative showed significant differences in the direction of higher beliefs in responsibility to use condoms in the HIV positive group. These data suggest that responsibility is measurable, holds similar psychometric properties across three samples differing in culture and HIV serostatus, and that condom use responsibility is conceptualized as a measure of general responsibility rather than as a reciprocal self/partner responsibility.     

Drug use careers and blood-borne pathogen risk behavior in male and female Tanzanian heroin injectors

Injection drug use in sub-Saharan Africa is a relatively new phenomenon that expands the repertoire of human immunodeficiency virus (HIV)-associated risk behaviors in Africa. We carried out a study of 537 injection drug users (56% men and 44% women) in Dar es Salaam, Tanzania, to examine their HIV risk behaviors and their drug-using careers that had culminated in injecting heroin. Data were collected in 2005-2006 using the Swahili version of the Tanzanian AIDS Prevention Project questionnaire. Marijuana, alcohol, and heroin were the first drugs reported for both men and women. Most drug milestones appeared in a similar order for men and women. Mandrax, khat, and injecting appeared close to one another in chronological time for both men and women, suggesting they were introduced into the country and appeared on the drug scene at about the same (real) time. Drug careers for women were shorter than for men, and time from first use of heroin to first injection was shorter for women. Years of injecting suggested that injecting had increased in males approximately five years prior to data collection, with males injecting earlier, but females being increasingly introduced to injecting in the previous two years. Injecting appears at a mean of five years (men) and three years (women) into their heroin-using career. Heroin use appears to occur in binges, with women being more likely to have sex during a binge. In this sample, more than 90% of women but only 2% of men reported ever trading sex for money. More than 90% of men and women reported using new needles for injection. These data confirm that heroin injecting is well established in large cities in east Africa, and that HIV prevention in the region must now include drug injectors and other drug users.     

Anxiety and depression strongly associated with sexual risk behaviors among networks of young men in Dar es Salaam,Tanzania

This study tested the association between mental health scores and sexual risk behaviors among male members of social groups known as “camps” in Dar es Salaam, Tanzania. Anxiety and depression were measured using the HSCL-25 and condom use and sexual partner concurrency were assessed through self-report. A total of 1113 sexually active men with an average age of 27 years were included in the analyses. Higher anxiety and depression scores were significantly associated with both condom use (Anxiety AOR?=?0.58, 95% CI: 0.44, 0.77; Depression AOR?=?0.60, 95% CI: 0.47, 0.77) and concurrency (Anxiety AOR?=?2.32, 95% CI: 1.73, 3.12; Depression AOR?=?2.08, 95% CI: 1.60, 2.70). The results of this study provide information salient to the development of effective HIV prevention interventions targeting populations with high burdens of anxiety and depression. The feasibility and effect of integrating mental health promotion activities into HIV prevention interventions should be explored.     

Cleaning effectiveness of chewing sticks among Tanzanian schoolchildren.

The oral hygiene of habitual chewing stick and toothbrush users who participated in an oral health education (OHE) programme in schools was evaluated. The study comprised all chewing stick users (n = 45) in standard 4 in 8 randomly selected experimental schools and all chewing stick users (n = 17) in standard 4 in 4 randomly selected control schools. Each chewing stick user was randomly matched with a toothbrush user of the same sex, age and school. Their ages ranged from 10 to 13 years with a mean of 11.5 years. The children in standard 4 of the 8 experimental schools received OHE. Among many topics aiming to improve oral health of children, the practice of systematic brushing was taught. The children practised weekly brushing sessions in schools under the supervision of instructed teachers. At baseline, the chewing stick users exhibited statistically significant more plaque, but their gingival condition was comparable with their matched toothbrush counter-parts. After 3 months, the chewing stick and the toothbrush users in the experimental schools, had reduced their plaque and gingival bleeding scores significantly to the same extent, whereas no substantial changes in oral hygiene occurred in the control group. The findings show that schoolchildren who participated in a school programme that emphasizes effective toothbrushing were able to improve their oral hygiene regardless of whether they were habitual chewing stick or toothbrush users.