Mara Region Research Articles

Incidence of injuries and mortality in the leopard tortoise, Geochelone pardalis, in northern Tanzania

Observations were made of injuries and mortality in the leopard tortoise (Geochelone pardalis) in northern Tanzania between October 1993 and June 1996. Tortoise injuries were more frequent at unprotected (15.3%) than at protected sites (4.7%). Fire was the most frequent cause, accounting for 44.0% of the injuries. Of the animals encountered, 12.9% were found dead. Dead animals were encountered more frequently at protected (25.4%) than at unprotected sites (8.3%). Carapace injuries (6.8%) and road kills (5.1%) were the only causes of mortality identified. Mortality was higher in adults (13.9%) than in immature animals (5.5%), and in females (13.9%) than in males (6.4%). Mortality was more frequent at the Arusha Region (46.8%) than at the Mara Region sites (7.6%). Tanzania Journal of Science Volume 27 (2001), pp. 101-106

Contagious bovine pleuropneumonia in Tanzania: current status.

CBPP reappeared in Arusha, Northern Tanzania in 1990, having been introduced from Kenya. The disease spread rapidly to Mara region through rustling of sick or infected animals. In November 1992, an unrelated outbreak occurred in Kagera, having spread from Southern Uganda. Up to the end of December 1994, the disease appeared to be confined to Kagera and Arusha. In January 1995, CBPP was observed in Morogoro region, south of the central railway line. Thereafter, the disease spread through western Tanzania. More recently, further disease has occurred in the Southern Highlands and Central regions. The contaminated area now stretches roughly between latitudes 1 degree and 9 degrees S and longitudes 30 degrees and 37 degrees E, with a cattle population of about 10 million. The direct losses incurred as a result of animal mortality, and vaccination campaign and disease surveillance costs have been assessed at over US$11 million. Indirect losses resulting from chronic disease are much more difficult to assess but are believed to be even higher. Control of the disease has been through restricting animal movements and a mass vaccination campaign. Uncontrolled animal movement during transhumance, trade, cattle thefts and vaccination breakthroughs facilitated the spread of the disease.

Genetic variability of human immunodeficiency virus type 1 in rural northwest Tanzania.

Initial findings are reported on the genotype variation of HIV-1 in the Mara region of northwest Tanzania where the overall prevalence of HIV-1 was 7.3% during 1989-90. HIV-1 sequences from eight peripheral blood mononuclear cell specimens are reported. Seven specimens were collected in 1994 from residents of rural villages in the area while the eighth specimen was collected in 1987 from a person who originally lived in the Mara region moved to Kigoma Tanzania for several years then returned to the Mara region after developing AIDS. The genetic variability of the HIV-1 env Tanzania specimens is consistent with the pattern of increasing sequence divergence observed in that region of the world. The authors stress that sequence differences observed in comparison with older Tanzanian HIV specimens need to be followed up with greater numbers of sequences in order to determine the direction of change and eliminate sampling bias.

Edible plants of Mara Region, Tanzania

Fifty‐three cultivated food plants and 38 species of edible wild fruits and leafy vegetables were identified during the course of ethnobotanical interviews with 51 informants of Musoma and Tarime Districts, Mara Region, Tanzania, and an accompanying dietary survey of Tarime District. An additional 35 potentially edible species of fruits, leafy vegetables and underground plant portions were identified by searching the East Africa Herbarium, Nairobi, for specimens from Mara Region of species known to be used as food in neighbouring areas of East Africa.

Rural Tanzanian Youths' First Intercourse Is Early, Number of Partners High

Investigators interviewed 400 men and 478 women aged 15-49 in seven villages in the North Mara region of Tanzania an area where most people work as subsistence farmers and fishermen to measure patterns of sex behavior among different social and demographic groups stratified by sex age tribe religion and education. 68% of the participants were of Luo ethnicity 47% were Catholic and 45% were Protestant. 65% of men and 82% of women were currently married with 29% of men and 52% of women in polygamous unions. Only 16 men and 20 women all younger than 17 at the time of the survey had never had sex. Otherwise the mean age at first intercourse was 15.8 years for men and 14.9 years for women. Among men aged 40-49 years 16.8 was the mean age at first intercourse compared to 13.8 among 15-19 year-olds. Among women the largest single proportion initiated intercourse at ages 14-16 regardless of their current age. On average the younger the individual at first intercourse the greater is the mean number of sex partners. The oldest groups of participants reported having had fewer lifetime partners than did younger groups especially the men. 78% of men and 37% of women reported ever having five or more partners during their lifetime. 71% of men and 93% of women reported having either one or no sex partner during the month preceding the survey. Men and women averaged 4.3 and 1.5 partners respectively during the year preceding the survey; 6.0 and 1.8 partners over the previous two years; and 7.8 and 2.4 partners over the past five years. Men and women reported engaging in vaginal intercourse 2.4 and 1.7 times per week respectively. As the number of sex partners increases so does the total number of sexual episodes. Among those with comparatively more sex partners however the number of acts of intercourse per partner is lower than among those with fewer partners or those in monogamous relationships. The rate of partner change was greatest in the younger age groups. The researchers stress the need to teach children about HIV transmission and AIDS before they become sexually mature.

Low prevalence of risk factors for coronary heart disease in rural Tanzania.

A community-based survey was used to assess the prevalence of risk factors for coronary heart disease (CHD) in rural Tanzanians. In all, 8581 subjects (3705 men, 4876 women) aged > or = 15 years in eight villages in three regions in rural Tanzania representing a range of socioeconomic deprivation were studied. The main outcome measures were serum cholesterol and triglyceride level, blood pressure and prevalence of dyslipidaemia, hypertension, smoking, overweight, impaired glucose tolerance (IGT) and diabetes; as well as ECG changes. Mean serum cholesterol levels in men were 4.2, 3.4 and 3.7 mmol/l, and in women 4.4 3.6 and 3.9 mmol/l in Kilimanjaro, Morogoro and Mara regions respectively. In Kilimanjaro region 17.4% of men and 19.0% of women had values above 5.2 mmol/l compared with only 5.0% and 6.7% in Morogoro region and 4.8% and 6.9% respectively in Mara region. Systolic and diastolic blood pressures increased with age in both men and women in all three regions with the most marked increase in Kilimanjaro region and the smallest rise in Mara region. Mean age-adjusted values were highest in Kilimanjaro region (124/75 mm Hg, and 125/76 mm Hg in men and women respectively) and lowest in Mara region (120/70 mm Hg in men and 118/68 mm Hg in women). Hypertension was found in 6.6% of men and 7.5% of women in Kilimanjaro region, 3.3% and 4.7% in Morogoro, and 2.6% and 3.4% in Mara region. Cigarette smoking was found in 42.6% of men in Kilimanjaro region, 28.2% of Morogoro region and 8.6% in Mara region. Less than 4% of women smoked in all three regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaemia is a major public health problem in Tanzania

In Tanzania health workers surveyed 10037 adults (=or> 15 years old) in rural villages in the Morogoro Rural District (a poor rural area) Kilimanjaro region of Hai District (the most wealthy rural area in the study) Mara region (a poor rural area) and in the urban areas of Manzese and Kimara in Dar es Salaam to determine the prevalence of anemia in adults. The prevalence of anemia in males (hemoglobin [Hb] < 13 g/dl) and in females (Hb < 12 g/dl) varied from 29.8% in Kilimanjaro to 79.9% in Mara and 25.8% in Kilimanjaro to 80.5% in Morogoro respectively. Anemia was always more prevalent in Morogoro and Mara than in Kilimanjaro or Dar es Salaam. When the researchers used Hb levels of less than 11 g/dl for males and less than 10 g/dl prevalence ranged from 3.1% in Kilimanjaro to 26.3% in Morogoro for men and 2.1% in Kilimanjaro to 26.8% in Morogoro for women. Mean Hb levels were 13.2 g/dl in Kilimanjaro 11.9 g/dl in Dar es Salaam 11.1 g/dl in Morogoro and 11.1 g/dl in Mara. The 5537 nonpregnant women had a consistently higher mean Hb level than did the 257 pregnant women (11.7 g/dl vs. 10 g/dl). Men in the older age groups had a higher prevalence of anemia in all areas except Mara than did younger men especially 65-year-old and older men. Age was not a factor in women however. Mean prevalence of anemia in males and females in the poorer rural areas was much higher than mean prevalence of anemia in males and females in other East African countries. Since anemia reduces maximum oxygen transport the high levels of anemia in Tanzania may impede work performance. Further anemia contributes to poor health also reducing work performance. These findings show that anemia is a major public health problem in Tanzania.

MarA locus causes decreased expression of OmpF porin in multiple-antibiotic-resistant (Mar) mutants of Escherichia coli.

Mar (multiple antibiotic resistant) mutants of Escherichia coli express chromosomally mediated resistance to a variety of structurally unrelated hydrophilic and hydrophobic antibiotics. Insertion of transposon Tn5 into the marA locus at min 34.05 on the chromosome completely reverses the Mar phenotype (A. M. George and S. B. Levy, J. Bacteriol. 155:531-540, 1983). We found that among changes in the outer membrane of Mar mutants, porin OmpF was greatly reduced, although Mar mutants were more resistant than cells lacking only OmpF. Transduction of the marA region from a Mar strain, but not a wild-type strain, led to loss of OmpF. P1 transduction of marA::Tn5 into a Mar mutant partially restored OmpF levels. Therefore, OmpF reduction required a mutation in the marA region. Mar mutants of an ompF-lacZ operon fusion strain expressed 50 to 75% of the beta-galactosidase activity of the isogenic non-Mar parental strain, while Mar mutants of a protein fusion strain expressed less than 10% of the enzyme activity in the non-Mar strain. These changes were completely reversed by insertion of marA::Tn5. The responsiveness of OmpF-LacZ to osmolarity and temperature changes was similar in Mar and wild-type strains. Although some transcriptional control may have been present, OmpF reduction appeared to occur primarily by a posttranscriptional mechanism. The steady-state levels of ompF mRNA were twofold lower and the mRNA was five times less stable in the Mar mutant than in the wild-type strain. Expression of micF, which lowers ompF mRNA levels, was elevated in Mar strains, as revealed by a micF-lacZ fusion. Studies with strains deleted for the micF locus showed that the marA-dependent reduction of OmpF required an intact micF locus. Our findings suggest that the marA locus directly or indirectly increases micF expression, causing a posttranscriptional decrease in ompF mRNA and reduced amounts of OmpF.

Transmission of a Theileria species to cattle by the ixodid tick, Amblyomma cohaerens Donitz 1909.

Amblyomma cohaerens nymphs, which had been collected as engorged larvae from African buffalo (Syncerus caffer) in the Mara region of Kenya, transmitted a theilerial parasite to a steer. Macroschizonts were detected in the regional lymph node of this steer 12 days after tick application and were subsequently detected for 3 days at low levels of parasitosis. The macroschizonts were large and had numerous nuclei, being morphologically unlike any other theilerial schizonts described previously from cattle in Eastern and Southern Africa, but they resembled the macroschizont of T. barnetti Brocklesby 1965 from a buffalo also obtained in the Mara region. Piroplasms morphologically indistinguishable from T. mutans were first detected in the blood of the steer on the sixty-first day after tick application. The steer showed a significant rise in antibody titre to only T. mutans (Aitong) piroplasm antigen, using the indirect fluorescent antibody test. There was no evidence that this parasite was pathogenic. The intraerythrocytic piroplasms proved to be blood-transmissible to a splenectomised calf. Although the parasite showed affinities to T. barnetti and T. mutans (Aitong) definite conclusions regarding its identity must await further transmission experiments.

Observations on the Subgenus Argas (Ixodoidea: Argasidae: Argas) 12. Argas {A.) africolumbae: variation, bird hosts, and distribution in Kenya, Tanzania, and South and South-West Africa1

Argas (A.) africolumbae type material was from a hospital and a house with nests of the Cape Rock Pigeon in 2 localities and from a granite outcrop with Bald Ibis nests in a 3rd locality of Transvaal, South Africa. Subsequent collections recorded here are from 1 locality in South-West Africa, 4 in Eastern and Rift Valley Provinces of Kenya, and 8 in Mwanza, Shinyanga, and Mara Regions of Tanzania. Newly recorded or confirmed hosts are the African Rock Martin (2 subspp.), Red-rumped Swallow, Striped Swallow, Tropical Cliff Chat, and Speckled Pigeon and/or Red-winged Starling. The ticks rest within or near the stick or mud nests of these birds in buildings (houses, hospital) or against rock faces of cliffs or caves and feed only or chiefly during the host nesting season. Notable differences arc observed in size of individual adults and larvae in population samples from large-sized and small-sized hosts; larval setal counts and measurements also differ in host-related samples. The possibility of host-specific races (?subspecies) should be investigated. In preliminary studies of the life cycle (using domestic pigeons as hosts), more than 10 months elapsed between the final of 2 female blood meals and oviposition. F1 adults emerged after 2 or occasionally 3 nymphal instars 20 to 25 weeks after eggs were deposited. Larvae fed for ca 10 days, nymphs and adults for ca 15 min.

Phagocytosis of Trypanosoma (Nannomonas) congolense by circulating macrophages in the African buffalo (Syncerus caffer)

Nineteen African buffalo were short in the Mara region of Kenya. Leucocytes were separated from the buffalo samples by sedimentation and centrifugation. In leucocyte smears of six buffalo, trypanosomes were detected and in two of them, high levels of phagocytosis of Trypanosoma (Nannomonas) congolense by circulating macrophages were demonstrated.