Mortality by cause of death in a rural area of Machakos District, Kenya in 1975-78.

This paper examines mortality by cause of death in a rural area of Machakos district in Kenya. The cause-of-death data collected between 1975 and 1978 were likely to be of fairly good quality. The number of deaths was higher among infants and children. Infectious diseases and diseases of the respiratory system were the leading causes of death among children below 5 years of age. Next in prominence were the causes ascribed to congenital anomalies and perinatal conditions. Among adolescents and young adults, injury and poisoning, together with tuberculosis and other infectious and parasitic diseases, were the leading causes of death. Degenerative diseases, especially diseases of the circulatory system and neoplasms and respiratory illness, were responsible for the majority of deaths among the older population.

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

PIP: 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.^ieng

Pertussis in a rural area of Kenya: epidemiology and results of a vaccine trial.

Pertussis surveillance was carried out from 1974 to 1981 among a population of 24 000 in the Machakos district of Kenya by fortnightly or monthly home visits. The diagnosis was verified by a physician according to standard criteria including bacteriological and haematological findings. Since not all cases could be diagnosed with certainty, each case was scored from 0 to 3 according to the probability of pertussis. During the surveillance a vaccine trial was carried out: 436 children receiving two diphtheria-pertussis-tetanus (DPT) immunizations 6 months apart were compared with 466 children receiving the conventional three doses 3 months apart.The agglutinating antibody response was determined in approximately 100 children in the trial at 1 month, 2 years, 3(1/4) years and 4(1/4) years after completing the immunizations. The results showed no difference in titres between the 2-dose and 3-dose groups at one month after the last immunization. Waning of antibodies proceeded more rapidly in the 2-dose group, the differences between both groups becoming statistically significant after 2 years.Two epidemic waves of pertussis occurred during the seven years of surveillance. A third epidemic did not materialize, possibly because of increased herd immunity due to the immunizations. The case fatality rate was 1% and was highest (2.6%) among infants. During the 4 years following completion of the immunizations, 36 children in the vaccine trial, based on the cumulative probability of pertussis, yielded 16.7 cases. The number of "cases" so defined did not differ significantly between the two immunized groups, although there was a suggestion of greater protection with the 3-dose schedule. Compared with the observed number of "cases" among 1281 children of the same birth cohorts not included in the trial, the reduction among the trial children (both immunized groups) was 54%.

Machakos project studies. Agents affecting health of mother and child in a rural area of Kenya. XXI. Antenatal and delivery care.

Traditional and modern antenatal and delivery care is described for women who delivered during 1975 and 1976 and who belonged to the study population of the Machakos project studies. During their pregnancy 84% of the women had visited at least once an antenatal clinic. When asked during pregnancy 56% of the women stated that they intended to deliver in hospital but only 26% ultimately did so. Hospital delivery seemed to depend mostly on opportunity and habit. Of the special risk factors for complications of pregnancy and delivery only previous caesarean section and low height, and to a lesser degree primiparity, operated in favour of hospitalisation. Abdominal massage, given by traditional midwives, was the main form of traditional antenatal care; it was used mainly for abdominal pain. There was little interference during labour of deliveries attended by traditional midwives and few harmful practices were discovered. Their factual knowledge and understanding of anatomy and physiology of pregnancy and delivery was limited. Suggestions are given on how to promote hospital delivery among those women who require this for medical reasons.

Agents affecting health of mother and child in a rural area of Kenya. XVII. Population growth in 1974-1978.

Demographic information was collected on a fortnightly basis between 1974 and 1978 in the framework of the Machakos Project. Results reported here deal with population size and increase on a de jure and de facto basis, population composition by age and sex, and crude birth and death rates. The results show that the study area is characterized by somewhat lower fertility than the national average of Kenya and much lower mortality. In addition, there is net-in-migration into the study area and the overall result is very rapid population increase. It is argued that underreporting of births and deaths, has been kept to a minimum due to the design that was used together with the use of several control measures.

Agents affecting health of mother and child in a rural area of Kenya. XVIII. Fertility, mortality and migration in 1975-1978.

The results reported here are based on age-specific rates and are, therefore, more sensitive and meaningful as indicators of fertility and mortality than the crude rates mentioned in the previous article. The results confirm that, compared to world standards, the study area is characterized by a high level of fertility and a fairly low level of mortality. Fertility and mortality are, however, lower in the study area in comparison to Kenya as a whole. Another characteristic is high population mobility which is of two types: temporary migration of absent members of the population, and permanent in- and out-migration.

PIP: This demographic study is a continuation of the 1st study and focuses on data pertaining to age-specific fertility and mortality rates between 1975 and 1978. Epidemiological and demographic data were obtained by means of fortnightly visits by male fieldworkers to the households in the Machakos District. Total fertility rate of the area was 7260/1000 women or 7.3 children per woman; fertility was constant during the study period. Infant mortality varied from 41 to 62, averaging 49.1. Male mortality was higher in all age groups than female mortality. In-migration was somewhat more common (78/1000 annually) than out-migration (71/1000), with incidence of both types higher for women than for men. This was attributed to the fact that many women leave their parental homes during the years after marriage or after the birth of a child. Other reasons were separation from spouse and divorce. Compared to the world standards, the Machakos area has a high level of fertility and a fairly low level of mortality; compared to Kenya as a whole, Machakos has low fevels of fertility and mortality.

Machakos Project Studies: agents affecting health of mother and child in a rural area of Kenya. XVI. The outcome of pregnancy.

The outcome of pregnancy of all women belonging to the study population of the Machakos project studies who delivered during 1975 and 1976 is presented. The birth-rate was 43.0 per 1,000 population per year, the fertility rate was 235 per 1,000 women 15--44 years of age per year. Unexpected low mortality rates were found; stillbirths, neonatal and infant death rates were respectively 29.8 per 1,000 total births and 22.5 and 50.0 per 1,000 live births. One maternal death occurred among the 2,223 deliveries. Maternal age of less than 25 and over 34 years, a history of previous perinatal death and breech delivery were associated with higher perinatal mortality. Parity, marital status, birth-interval and maternal height were not associated with a difference in outcome of pregnancy. The stillbirth rate among the children born in hospital (26.4%) was 4.4% compared with 2.4% among the children born at home, neonatal and infant death rates were the same. Half of all perinatal deaths were caused by either prematurity or birth trauma, 75% of all infant deaths after the first week of life were caused by infections.

PIP: This paper describes the pregnancy outcome of women who delivered in 1975 and 1976 in the area of the Machakos project near Nairobi, Kenya. The study utilized a surveillance system comprising of home visits on 3700 households by 12 fieldworkers. Total number of children born during the study period was 2246. General fertility rate was 235/1000 women of reproductive age. Birth rate was 43.0/1000. There were unexpectedly low mortality rates. Stillbirths were 29.8/1000 total births, neonatal rate, 22.5/1000 total births while infant death rate was 50.0/1000 live births. There was 1 maternal death among the 2223 deliveries. Higher perinatal mortality was attributed to maternal age of less than 25 and over 34 years, a history of previous perinatal death, and breech delivery. Differences in outcome of pregnancy were not affected by parity, marital status, birth interval, and maternal height. Stillbirth rate of hospital-born children (26.4%) was 4.4% compared with 2.4% among children born at home. Half of all perinatal deaths were caused by either prematurity or birth trauma. Infections accounted for 75% of all infant deaths after the first week of life. A subsequent paper will relate the outcome of pregnancy to antenatal and delivery care received.

Agents affecting health of mother and child in a rural area of Kenya. IX. Food intake, feeding habits and nutritional state of the Akamba infant and toddler.

PIP: A study was conducted to assess the precise diet of infants and toddlers under 3 in the Machakos District of Kenya. The study was carried out during September-December 1975 and June-September 1976, using 76 children for initial and 41 for subsequent measurements. Fieldworkers assessed breastmilk and food intake; a pediatrician and a medical nutritionist conducted the physical examinations. All body weight and food intake data are charted. Breastmilk was fed exclusively for approximately 2 months and gradually supplemented by cow's milk and a cereal. Most of the children were weaned between 16 and 24 months. Protein intake was satisfactory at all ages and only calcium and riboflavin were substantially below recommended quantities. Judging from weight-for-age and height-for-age measurements, most of the children met the Harvard nutrition standards in the 1st 6 months of life, but their progress fell off somewhat after that. Clinical examination showed 71% to be healthy and acceptably fed, 22% with a less than satisfactory physical condition, and 7% in poor physical condition. Growth deficiencies are attributed to the early decline in breastmilk quantity, the use of a watery cereal in supplementary feeding, and various nutritional and infectious diseases. Feeding practices and food quantity were considered to be generally adequate. Introduction of a higher caloric cereal would improve infant growth patterns.^ieng

Pertussis in a rural area of Kenya: epidemiology and a preliminary report on a vaccine trial.

PIP: In the course of 2 years of surveillance of whooping cough by fortnightly home visits among a population of 24,000 in a rural area of Kenya, 918 cases were observed with a peak of 218 in December 1974-January 1975. The attack rate was highest (15.8%) during the 1st year of life; for those ages 0-6 it was 12.8%. 90% of the cases occurred in children age 6 or younger. The median age was 3.5 years, the age range 1 month-13 years. Girls were significantly more affected than boys. The overall case fatality rate was 1.3% but among infants, it was 2.5 times higher. In order to contribute to the improvement of immunization coverage in countries where health resources are limited, a schedule of child immunization requiring a minimum number of contacts with the children was introduced into the study area with the aim of evaluating its effectiveness in protecting children from clinical pertussis. In this trial, the effect of 2 and 3 diphtheria-pertussis-tetanus (DPT) vaccine doses was compared. Pertussis agglutinating antibody determinations showed an equally satisfactory response after 2 and 3 DPT vaccine doses. (author's)^ieng

Agents affecting health of mother and child in a rural area of Kenya. III. The epidemiology of measles.

Between April 1974 and March 1976 surveillance of measles has been conducted by 12 fieldworkers making fortnightly home visits among a total population of 24,000 living in nearly 4000 households scattered in variable density throughout an area of 87 sq km in the northern division of the Machakos district, Kenya. The diagnosis of measles was verified by one of the project's physicians according to standardized procedures and was, whenever possible, supported by virus isolation and serum antibody level determination. Because not all reported patients were actually seen during the period of clinical manifestations, the diagnosis remained doubtful in a number of cases. Incidence and mortality figures have been estimated with 95% confidence limits based on the assumption that doubtful cases represent a probability of measles of .33 and probable cases a probability of .67. The estimated attack rate for the susceptible population 0-15 years of age was 13.5%. When related to all children--susceptible or not--the attack rate was highest in the 1-2 years age group (11%). Almost 15% of cases occurred below the age of one year, 1% below 6 months of age and 6% between 6 and 8 months. The estimated case fatality rate was 6.5%, fatality being highest between 1 and 2 years of age. For the age group 0-15 years measles accounted for 16.7% of all deaths. The estimated death rate per 100,000 total population was 113. The epidemiological pattern of measles suggests continuous re-introduction of the measles virus in a dispersed population causing micro-outbreaks of the disease in geographically widely separated spots throughout the year which tends to keep the proportion of susceptibles down and the attack rate during a protracted epidemic relatively low.