Prevalence and frequency of Giardia lamblia in children aged 0 to 60 months with and without diarrhoea.

Stool specimen results from children with diarrhoea and without diarrhoea, in a rural village community in Kenya, were analysed in order to compare prevalence and age frequency distributions of Giardia between the 2 groups. There was evidence for 2 age-related prevalence peaks for Giardia in children 60 months and below. Furthermore, there appeared to be a clear Giardia-diarrhoea relationship in the age group of 19 to 24 months.

PIP: Stool specimen results were analyzed from children with diarrhea and without diarrhea in a rural village in Kenya, Nderu, to compare the prevalence and age frequency distributions of Giardia between the two groups. Data for Giardia were available from the National Diarrhea Control Program (NDCP) for the period September 1985 to September 1986 for 608 diarrhea specimens. These data were compared to those from 408 stool specimens collected during four cross-sectional surveys in Nderu between July 1985 and October 1986 from children aged 0-60 months without diarrhea in 60 families. The impact of Giardia in childhood morbidity in communities where the organism is endemic remains elusive. The major problems encountered when defining the morbidity of Giardia in an endemic setting are the limitations of applying epidemiological methods where the organism is so frequent, and the phenomenon of poly-parasitism making it very difficult to pinpoint the effects of a single organism. It was nonetheless determined that a significant proportion of childhood diarrhea, at least among 19-24-month olds, is associated with and probably caused by Giardia. This increase in prevalence of Giardia in the 19-24-month group apparently leads to a second peak of Giardia-induced diarrhea at 37-48 months. This second peak is difficult to interpret.

Longitudinal study of young children in Kenya: intestinal parasitic infection with special reference to Giardia lamblia, its prevalence, incidence and duration, and its association with diarrhoea and with other parasites.

84 young children from a rural community, Nderu, in Kenya, were each followed for up to 10 months, from January to November 1987. Their ages ranged from 10 to 28 months over the period of study. Stools were obtained once a week, as were reports from the mothers about presence of abdominal complaints, including diarrhoea. A total of 2258 stools and 1873 reports were collected. 9 parasites were commonly encountered of which Giardia lamblia was the most frequent at 44.7%. The overall estimated number of new Giardia episodes per year per child was 2.77 +/- 2.22 SD and the mean estimated duration of infection was 75.25 +/- 73.84 SD days per child. The mean proportion of positive visits per child was 0.42 +/- 0.25 SD. Giardia trophozoites, Trichomonas hominis, Chilomastix mesnili, Entamoeba histolytica, Blastocystis hominis and Hymenolepis nana were all significantly associated with unformed stools and reports of diarrhoea. There was a significant probability of finding Giardia in stool within +/- 2 weeks of a report of diarrhoea. Poly-parasitism was common and several paired associations were significantly positive, particularly between species of amoebae. Quantity of Giardia in stool (expressed as a 0 to 5+ score) was suppressed both by type and number of other parasites present.

Intestinal parasites in a rural community in Kenya: cross-sectional surveys with emphasis on prevalence, incidence, duration of infection, and polyparasitism.

A cross-sectional survey of intestinal parasitic infection in a rural community, Nderu, in Kiambu District, Kenya, was carried out in 1985 by examining 1129 individuals from 203 households (about 25% of the total population). This was followed by 3 more cross-sectional surveys, in January, May and October 1986, of 56 families comprising 461 individuals, who had also participated in the first survey. In the first survey, 81.4% of the sample was positive for at least one intestinal parasite and 78% was positive for intestinal protozoa. 72.7% of those infected had multiple infections. The prevalence of most of the protozoa increased with age but that of Giardia lamblia peaked in the 0 to 4 year class at 35.5%. Females were infected more often with several of the protozoa, but males with Ascaris. People living in larger households were more often infected with Entamoeba histolytica and Iodamoeba butschlii, while the opposite was true of H. nana and tended to be for Giardia. Significant positive associations between parasite species were common at all surveys, especially among the amoebae. The majority of negative associations were for Giardia. Unformed stools were significantly associated with Giardia, Blastocystis, and trophozoites of Trichomonas hominis and Chilomastix mesnili. Endolimax nana and Entamoeba coli were found more often in formed stools. Estimates of daily incidence, and duration of infection in days, were calculated for 11 parasites. The longest mean estimated duration of infection for any species was 237 +/- S.D. 151.4 days for H. nana and the shortest was 41.6 +/- S.D. 0.4 days for T. hominis.

Bancroftian filariasis in Kenya. V. Mass treatment given by members of the local community.

Diethylcarbamazine citrate was given for a total of 13 days to all people above one year of age in the following areas: (1) Mambrui, a town with a population of about 1300; (2) Jaribuni, a rural area with a population of about 1500; (3) The towns and villages on the islands off the north coast of Kenya with a population of over 20 000. The people were not weighed, but the daily dose was calculated according to age, being approximately 6 mg kg-1; drug taking was not supervised. The drug was mainly distributed by local people who also treated the side-effects; a doctor remained available in the background for consultation and advice. In Mambrui and Jaribuni, where baseline data had been collected, the number of infective larvae per 1000 vector-mosquitoes had decreased by more than 90% in the six to 12 months period after the campaign. Two years after the campaign, the microfilaria rate in Mambrui had dropped by 75%; in Jaribuni, a reduction of 75% was recorded in men, but in women it was only 48%. The overall rates after the mass treatment were 5.3 and 9.3% in Mambrui and Jaribuni, respectively. On the islands to the north, particularly good results were obtained in the village of Siyu, where the highest elephantiasis rate had been recorded; three years after the campaign, the microfilaria rate there had fallen to 3.6%, while none of 48 children under ten were found infected. The spectacular results in Lamu town may have been partly due to excellent mosquito control in preceding years. However, no control was achieved on the remote island of Ndau, probably because the treatment team left before the side-effects had disappeared, causing many people to stop the course of tablets. Thus, on the East African coast it is possible and cheap to control Bancroftian filariasis by mass treatment campaigns carried out by local, non-medical personnel.