Demographic characteristics of a rural area in Kenya in 1974-80

A longitudinal, epidemiological study was carried out in a rural area of Kenya with a population of about 28,000 between 1974 and 1980. Population registration during this time showed that population growth was very high between 1974 and 1978 (4.4%/year) and much lower in 1979 and 1980 (1.1%). Natural increase was nearly as high as in Kenya as a whole (3.7%) in this period. Fertility was somewhat lower than in all Kenya (the crude birth rate was 46/1000) while mortality was substantially lower (7/1000). These rates are believed to be genuine and not due to under reporting of infant deaths. The most likely reason for these low infant mortality levels is the existence of favorable economic, social and hygienic conditions in the area compared to other parts of Kenya. The adult mortality rates are low too, in particular for the population aged 65 and over. The main reason is the overestimation of ages, in particular of women in the older age brackets, which has led to too large a denominator of the age specific rates in these age groups. Levels of temporary and permanent migration are high and probably characteristic for many parts of Kenya. Of the 19% of the registered population absent when visited by the fieldworkers, there were more males (23%) than females (14%). The % of absenteeism is higher for males between 20-59 years old, and also for females between 15 and 30. About 3% of the population is away for a short time, visiting relatives, attending weddings and funerals or occupied as traders. The large majority of absentees (14%) consists of temporary labor migrants and family members accompanying them. Many are gainfully employed in Nairobi and other towns in Kenya; some are farmers who seasonally move to another farm which they own outside the area. Others are wives and children who temporarily join their husbands, or polygamous men who are temporarily staying with another wife outside the area. All permanent movements to and from the study area, as well as within it, show that on average migration inwards and outwards balanced each other in the 7-year period. The gross migration rate is substantially higher for females than for males. This is due to family related reasons: marriage, divorce, separation. Other categories of migrants are those families who establish a new business or farm elsewhere, teachers and pastors who are transferred, and farm laborers, housemaids and servants. Poor economic conditions of 1979/80, due to a drop in coffee prices and poor harvests of coffee, maize and beans, led to more emigration and less immigration.     

Birth interval, mortality and growth of children in a rural area in Kenya

The impact of the length of birth intervals on mortality and growth of children from the perinatal period to 2 years in the Northern Division of Machakos District, Eastern Province, Kenya, were analyzed. There are 2 types of birth intervals: 1) the prospective birth interval--between the birth concerned (the 1st birth of the interval pair) and the subsequent birth; and 2) the retrospective birth interval--between the birth considered (the 2nd of the interval pair) and the preceeding birth. This study includes 3019 women who had at least 1 live birth between April, 1974 and April, 1981. They gave birth to 6778 children (including stillbirths). Births occurring in 1974 are excluded in the analysis because of considerable underregistration. 102 stillbirths and 213 deaths in the 1st 2 years are analyzed. They have been grouped into deaths during the perimatal period; the 1st year after the 1st week of life (infant period); and the 2nd year of life. The most convient method of analysis of the relation between retrospective birth interval and mortality is multivariate analysis, as the intermedicate biological and behavioral factors through which birth intervals can affect health are simultaneously influenced by other variables like maternal age and birth order; the log linear model is applied here. The probability of dying is the dependent variable. The impact of short prospective intervals are closely associated. Only infant and child deaths occurring after the conception of the next child are included. The size of cohorts in which these deaths occur can be calculated with a life table approach. The mortality probability between 5 and 12 months for children with short prospective intervals is .034. This is higher than the corresponding rate for all children in the area (P0.05). It is shown that children with short retrospective or prospective birth intervals do not run a greater risk of mortality or growth retardation than children with longer intervals, neither during the perinatal period nor during the 1st 2 years of life.     

Childhood malnutrition and growth in a rural area of Western Kenya

An anthropometric survey was carried out on 1,383 school students aged 5-17 years in Suba district (a rural area of western Kenya). Body size and proportion were computed from height, weight, sitting height, arm circumference, and skinfolds. The aim of the study was to evaluate patterns of growth and nutritional status of the Luo population by assessment of the prevalence and trends of malnutrition among children and adolescents. Very few age-groups show significant sex differences for height, body weight, and arm muscle area. However, there are several differences in skinfold thicknesses and arm circumference, always with higher mean values in girls. Analysis of the nutritional status (weight-for-age, height-for-age, and BMI-for-age) shows significant differences among the age-groups in both sexes. Boys present lower Z-scores than girls and there are higher percentages of malnourished subjects (stunted and underweight) among the males. The Luo data were compared with those of other African populations. Their body dimensions, nutritional status, and growth are similar to those of the other sub-Saharan samples. In conclusion, the Luo children are generally undernourished at the older ages: adolescents (11-16 years of age) show the most severe undernutrition and the highest percentages of undernourished subjects. In addition to the higher risk of undernutrition in teenagers, an emerging problem of over-nutrition is evident among the younger age-groups, with a higher prevalence in females. These findings are discussed in light of sexual dimorphism in sensitivity to adverse environmental conditions.     

Preventive oncologic check-ups in the District Sumperk, 1975-1986: the description of a database

From 1975 through 1986, repeated preventive oncologic check-ups were carried out in the District Sumperk. In the course of the check-ups, 49,426 persons were examined. The examinations were aimed at surveillance of initial stadium of cancers as well as at detection of other serious chronic diseases. The results of the check-ups form a large database suitable for a number of epidemiological analyses. In this article, methods of the data collection are described, individual data items are characterized and their summary is presented in tables. Utilization of the database is proposed in specified types of epidemiological studies.     

Afrotropical sand fly-host plant relationships in a leishmaniasis endemic area,Kenya

The bioecology of phlebotomine sand flies is intimately linked to the utilization of environmental resources including plant feeding. However, plant feeding behavior of sand flies remains largely understudied for Afrotropical species. Here, using a combination of biochemical, molecular, and chemical approaches, we decipher specific plant-feeding associations in field-collected sand flies from a dry ecology endemic for leishmaniasis in Kenya. Cold-anthrone test indicative of recent plant feeding showed that fructose positivity rates were similar in both sand fly sexes and between those sampled indoors and outdoors. Analysis of derived sequences of the ribulose-1,5-bisphosphate carboxylase large subunit gene (rbcL) from fructose-positive specimens implicated mainly Acacia plants in the family Fabaceae (73%) as those readily foraged on by both sexes of Phlebotomus and Sergentomyia. Chemical analysis by high performance liquid chromatography detected fructose as the most common sugar in sand flies and leaves of selected plant species in the Fabaceae family. Analysis of similarities (ANOSIM) of the headspace volatile profiles of selected Fabaceae plants identified benzyl alcohol, (Z)-linalool oxide, (E)-β-ocimene, p-cymene, p-cresol, and m-cresol, as discriminating compounds between the plant volatiles. These results indicate selective sand fly plant feeding and suggest that the discriminating volatile organic compounds could be exploited in attractive toxic sugar- and odor- bait technologies control strategies.     

Differing burden and epidemiology of non-Typhi Salmonella bacteremia in rural and urban Kenya, 2006-2009

Background

The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change.

Methods

As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006–2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured.

Results

NTS accounted for 60/155 (39%) of blood culture isolates in the rural and 7/230 (3%) in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children <5 years old. The NTS-to-typhoid bacteremia ratio in the rural site was 4.6 and in the urban site was 0.05. S. Typhimurium represented >85% of blood NTS isolates in both sites, but only 21% (urban) and 64% (rural) of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman''s correlation, p = 0.018 for children, p = 0.16 adults). In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy.

Conclusions

NTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa.     

Participatory investigations of bovine trypanosomiasis in Tana River District, Kenya

Participatory research on bovine trypanosomiasis was conducted with Orma pastoralists in Tana River District, Kenya. The use of participatory methods to understand local perceptions of disease signs, disease causes, disease incidence by cattle age group, seasonal patterns of disease and preferences for indigenous and modern control methods are described. Results indicated that local characterization of diseases called gandi and buku by Orma pastoralists was similar to modern veterinary knowledge on chronic trypanosomiasis and haemorrhagic trypanosomiasis (due to Trypanosoma vivax), respectively. The mean incidence of gandi varied from 10.2% in calves to 28.6% in adult cattle. The mean incidence of buku varied from 3.1% in calves to 9.6% in adults. Pearson correlation coefficients for disease incidence by age group were 0.498 (P < 0.01) and 0.396 (P < 0.05) for gandi and buku, respectively. Informants observed cases of trypanosomiasis in 24.1% of cattle (all age groups); these cases accounted for 41.8% of all sick cattle during the preceding 12-month period. Eight indigenous and three modern trypanosomiasis control methods were identified. Results indicated that an integrated approach to trypanosomiasis control based on private, individual action was well established in the assessment area. When presented with four different trypanosomiasis control methods, community representatives selected 'better use of trypanocides' as the most preferred intervention and 'community-based tsetse control' as the least preferred intervention. This finding prompted researchers to modify the original project activities. Constraints facing the sustainability of community-based tsetse control are discussed.     

Mortality in a cadmium polluted area in Japan

A 15-year follow-up study of 3178 inhabitants (1424 men and 1754 women) living in the cadmium (Cd) polluted Kakehashi River basin was conducted. The results clarified effects on mortality of renal dysfunction induced by Cd indicated by urinary beta-2-microglobulin (beta2-MG), total protein, glucose, and total amino acids. This study used Cox's proportional hazard model. The mortality risk ratio of urinary beta2-MG positive (>= 1000 microg/gCr) subjects was significantly increased in both sexes: 1.35 for men and 1.73 for women. The increased mortality ratio of the urinary protein positive (>= 10 mg/dl) subjects was also significant for both sexes, with risk ratios of 1.82 for men and 2.01 for women. Only the women showed significantly increased mortality of the urinary glucose positive (>= 20 mg/dl) subjects and amino acids positive (> = 300 microg/gCr) subjects. When the subjects were divided into four categories according to urinary beta2-MG, <300, 300-1000, 1000-10000, >= 10000 microg/gCr, the mortality risk ratios were increased in proportion to the increase of urinary beta2-MG in both sexes. These results suggest that mortality of Cd-exposed subjects increased with increasing excretion of four urinary markers of renal tubular dysfunction, and in proportion to increases in the amount of urinary beta2-MG excretion including under 1000 microg/gCr.     

Leucostasis, an underestimated cause of death in leukaemia

Massive sludging of leukaemic cells in blood vessels is a frequent and often lethal complication of leukaemia. In a retrospective clinicopathological study on the causes of death in 52 patients with acute myeloid leukaemia and myeloproliferative disease, pulmonary leucostasis was found in 40% of the patients. In many of these patients the vessels of the heart, brain and testes were also involved. In search for signs and symptoms specific for leucostasis, the clinical records of the 21 patients with leucostasis (the study group) were compared to those of 20 patients without leucostasis (the control group). Dysfunction of the organs most affected by leucostasis, namely lungs, heart and brain, was found more often in the study group than in the controls, but the combination of unexplained fever with cardiopulmonary and/or central nervous system failure occurred almost exclusively and in half of the patients with leucostasis. Leucostasis occurs predominantly, but not exclusively, in patients with high leucocyte counts, and especially, but again not exclusively, when the leucocyte counts rise sharply.     

Effects of drought on child health in Marsabit District,Northern Kenya

This study uses five years of panel data (2009–2013) for Northern Kenya’s Marsabit district to analyze the levels and extent of malnutrition among children aged five and under in that area. We measure drought based on the standardized normalized difference vegetation index (NDVI) and assess its effect on child health using mid-upper arm circumference (MUAC). The results show that approximately 20 percent of the children in the study area are malnourished and a one standard deviation increase in NDVI z-score decreases the probability of child malnourishment by 12–16 percent. These findings suggest that remote sensing data can be usefully applied to develop and evaluate new interventions to reduce drought effects on child malnutrition, including better coping strategies and improved targeting of food aid.     

Misclassification, correlation, and cause of death studies

Relatives may tend to die of the same cause. A model is proposed specifying the degree of this association, simultaneously allowing for misclassification of cause of death. These mistakes usually degrade any existing correlation structure, the effects being marked when error rates reach between 20% to 30%. It is then that the search for associations becomes very difficult indeed, and results misleading. This is an example of a wider malaise that can afflict analysis of association, and the developments here apply to two-by-two contingency tables in general.     

Reference ranges for the clinical laboratory derived from a rural population in Kericho, Kenya

The conduct of Phase I/II HIV vaccine trials internationally necessitates the development of region-specific clinical reference ranges for trial enrollment and participant monitoring. A population based cohort of adults in Kericho, Kenya, a potential vaccine trial site, allowed development of clinical laboratory reference ranges. Lymphocyte immunophenotyping was performed on 1293 HIV seronegative study participants. Hematology and clinical chemistry were performed on up to 1541 cohort enrollees. The ratio of males to females was 1.9:1. Means, medians and 95% reference ranges were calculated and compared with those from other nations. The median CD4+ T cell count for the group was 810 cells/microl. There were significant gender differences for both red and white blood cell parameters. Kenyan subjects had lower median hemoglobin concentrations (9.5 g/dL; range 6.7-11.1) and neutrophil counts (1850 cells/microl; range 914-4715) compared to North Americans. Kenyan clinical chemistry reference ranges were comparable to those from the USA, with the exception of the upper limits for bilirubin and blood urea nitrogen, which were 2.3-fold higher and 1.5-fold lower, respectively. This study is the first to assess clinical reference ranges for a highland community in Kenya and highlights the need to define clinical laboratory ranges from the national community not only for clinical research but also care and treatment.     

Food of three upland game birds in Selengei Area, Kajiado District, Kenya

Foods taken by yellow-necked spurfowl, crested francolin and helmeted guinea-fowl were investigated over a 22-month period. Bulblets of sedge (Cyperus sp.) were the major plant item in the diet of all three species. Other foods were seeds and fruits of forbs, florets and fruits of grasses, leaves of forbs and grasses and insects. Insect use increased following the rains, as did the use of florets of the grasses. Except for Cyperus sp. there was little overlap of food items taken by the crested francolin and the guinea-fowl, but both were in competition with the yellow-necked spurfowl for some species of plants. This was probably due to size of food items, that is, there was a direct relationship between size of bird and size of foods taken. Forag ing habits also influence food intake.     

Management of myocardial infarction in a rural area

In an attempt to determine the most appropriate type of facility for the treatment of myocardial infarction in a rural community, the five-year experience of a practice serving 10,000 people is reviewed. This population is found to have a low incidence of myocardial infarction, a low death rate from the condition both in hospitalized patients and in the general population, and a low incidence of complications in the survivors. None of the deaths either in or out of hospital would likely have been prevented through the use of specialized facilities. It is concluded that no such facilities are necessary in this community and that other areas considering their acquisition should justify the need on the basis of their own experience and not on accounts in the literature.     

Twinning rates in a rural area of Bangladesh

In this study we investigate the incidence of twin births over a period of 16 years in a rural area of Bangladesh using data from the Demographic Surveillance System of the International Centre for Diarrhoeal Disease Research. Over the study period twinning rates fluctuated between 7.8 and 11.2 per 1000 live births. The twinning rate was strongly correlated with maternal age; the rate for mothers over 35 years of age was about 3 times higher than for mothers younger than 20 years. The variation in twinning rate with maternal age is due to the variation in dizygotic twinning; the rate of monozygotic twinning is almost constant for all ages. Twinning rates were higher in the treatment area than in the comparison area after controlling for maternal age and parity. The rates were lower for monozygotic twinning and higher for dizygotic twinning in the treatment area than in the comparison area. Seasonality was observed for both twins and singletons, but the peak for twinning precedes that for singleton births by more than a month.     

Prevalence and Causes of Ocular Morbidity in Mbeere District,Kenya. Results of a Population-Based Survey

Purpose

Ocular morbidity (OM) describes any eye disease regardless of resultant visual loss. Ocular morbidity may affect large numbers of people in low income countries and could lead to many episodes of care. However there is limited evidence about the prevalence of ocular morbidity or resulting health-seeking behavior. This study in Mbeere District, Kenya, set out to explore both these issues.

Methods

A cross-sectional household survey was conducted in 2011. Trained teams moved from house to house examining and questioning residents on ocular morbidity and health-seeking behavior. Data were collected on standardized proformas and entered into a database for analysis.

Results

3,691 people were examined (response rate 91.7%). 15.52% (95% CI 13.86–16.92) had at least one ocular morbidity in at least one eye. The leading cause was presbyopia which affected 25.11% (95% CI 22.05–28.45) of participants over 35 and increased with age. Other leading causes of OM were conditions that affected the lens (32.58%) and the conjunctiva (31.31%). No association was found between educational attainment or employment and OM. 9.63% (7.87–11.74) self-reported an ocular morbidity in the previous six months and 45.94% (95% CI 37.1–55.04) stated that they had sought treatment for the condition.

Conclusion

A large number of people were affected by an ocular morbidity in this survey. Most of these people could potentially be managed in their own communities through primary care services (e.g. those with presbyopia). Further work is required to understand the best way of providing an effective, equitable service for ocular morbidity.