New enzymatic assay, parasite lactate dehydrogenase, in diagnosis of malaria in Kenya.

BACKGROUND: The unique ability of plasmodial lactate dehydrogenase p(LDH) to utilise 3-acetyl pyridine dinucleotide (APAD) in lieu of NAD as a coenzyme in the conversion of pyruvate to lactate, led to the development of a biochemical assay for the detection of plasmodial parasitaemia. Researchers have reported that p(LDH) activity of plasmodia could be used as an assessment of parasitaemia since human red blood cells do not utilise APAD in the metabolism of glucose. OBJECTIVE: To use p(LDH) for field and clinical diagnosis of malaria in endemic regions of Kenya. DESIGN: Prospective field and clinical study. SETTING: Kisumu District Hospital and Walter Reed malaria laboratory in Kenya. SUBJECTS: The study subjects were of three different categories: the healthy non-infected individuals staying out of malaria endemic region (controls group 1), the nonparasitaemic and parasitaemic non- symptomatic healthy individuals living in endemic region {both field study group 2}, the non-parasitaemic and parasitaemic symptomatic individuals living in endemic region {both clinical study group 3}. RESULTS: In the clinical studies, thin smear microscopy gave the highest sensitivity as 75.6% for plasma, while the highest specificity was 71.4%. For red blood cells, the highest sensitivity was 78.4% while specificity was 80%. In the field trials, the highest sensitivity was 89% using thin smear microscopy whereas the specificity was 45% for plasma cut off using thick smear. For red blood cells, the highest sensitivity was 79% while specificity was 66.7%. CONCLUSION: The variations in sensitivity and specificity of this assay in comparison to microscopy is a strong indication that p(LDH) may be measuring even the sequestered parasites that cannot be visualised by microscopy. The results of this study validates the use of p(LDH) as an alternative objective test for malaria diagnosis against microscopy.

Parasite lactate dehydrogenase assay for the determination of antimalarial drug susceptibility of Kenyan field isolates.

BACKGROUND: Researchers have reported that parasite lactate dehydrogenase p(LDH) could be used to determine chemo-sensitivity of plasmodia to compounds with known or presumed antimalarial activities. OBJECTIVE: To determine the drug sensitivity profiles of field adopted malaria isolates from Kisumu using p(LDH) instead of hapoxanthine assay. DESIGN: Prospective field and laboratory study. SETTING: Walter Reed, KEMRI malaria laboratory (Nairobi) and Kisumu District Hospital. SUBJECTS: Twelve field laboratory adopted isolates from Kisumu, five laboratory adopted isolates from other regions in Africa and three reference strains from Walter Reed army Institute of Research, Washington, DC. RESULTS: The p(LDH) enzyme assay was successfully used to measure the IC50 of six antimalarial drugs, chloroquine, quinine, mefloquine, dehydroartemisinin, atovaquone and halofantrine but was not successful with the four other antimalarial drugs, doxycycline, azithromycin, pyrimethamine and sulphadoxine. The Kisumu isolates tested were resistant to chloroquine and mefloquine but sensitive to quinine and the new antimalarial drugs, atovaquone, halofantrine and dehydroartemisinin. CONCLUSION: The non-radioactive p(LDH) can be used for the determination of drug sensitivity to Kenyan field isolates. It is more suited for use in a resource limited environment and may lead to more judicious prescription of new and more expensive antimalarial drugs and mitigate against the rapid spread of multi-drug resistant parasites in the East African region.

A geographic information system applied to a malaria field study in western Kenya.

This paper describes use of the global positioning system (GPS) in differential mode (DGPS) to obtain highly accurate longitudes, latitudes, and altitudes of 1,169 houses, 15 schools, 40 churches, four health care centers, 48 major mosquito breeding sites, 10 borehole wells, seven shopping areas, major roads, streams, the shore of Lake Victoria, and other geographic features of interest associated with a longitudinal study of malaria in 15 villages in western Kenya. The area mapped encompassed approximately 70 km2 and included 42.0 km of roads, 54.3 km of streams, and 15.0 km of lake shore. Location data were entered into a geographic information system for map production and linkage with various databases for spatial analyses. Spatial analyses using parasitologic and entomologic data are presented as examples. Background information on DGPS is presented along with estimates of effort and expense to produce the map information.

PIP: The global positioning satellite (GPS) network system is comprised of 24 satellites orbiting at an altitude of about 10,900 miles. The authors describe how a simple modification of GPS known as differential GPS (DGPS) can be used to produce a highly accurate base map in a tropical area. DGPS circumvents the effects of selective availability (SA) error, an intentional error component added for security purposes at each satellite, to yield a highly accurate position fix. This paper documents the use of DGPS to obtain highly accurate longitudes, latitudes, and altitudes of 1169 houses, 15 schools, 40 churches, 4 health care centers, 48 major mosquito breeding sites, 10 borehole wells, 7 shopping areas, major roads, streams, the shore of Lake Victoria, and other geographic features of interest associated with a longitudinal study of malaria in 15 villages in western Kenya. 70 sq. km were mapped, including 42.0 km of roads, 54.3 km of streams, and 15.0 km of lake shore. Location data were entered into a geographic information system for map production and linkage with various databases for spatial analyses. Spatial analyses using parasitologic and entomologic data are presented as examples. Less than $25,000 was spent upon this project, of which $15,000 was for hardware and software.

Children and medicines: self-treatment of common illnesses among Luo schoolchildren in western Kenya.

In a rural area of western Kenya, primary schoolchildren's health seeking behaviour in response to common illnesses was investigated. 57 primary schoolchildren (age 11-17 years, median 13 years) were interviewed weekly about their health status and health seeking activities for 30 weeks. The children each experienced on average 25 illness episodes during this period. Most episodes could be categorised into 4 groups: 'cold', 'headache', 'abdominal complaints' and 'injuries'. One fifth (21%) of the illness episodes were serious enough to keep the children from school. In 28% of them, an adult was consulted, while 72% were not reported to an adult caretaker. Of the episodes without adult involvement, 81% remained untreated, while 19% were treated by the children themselves with either herbal or Western medicines. Of all the medicines taken by the children, two thirds were provided or facilitated by adults (assisted treatment) and one third taken by the children themselves without adult involvement (self-treatment). Among boys, the proportion of illnesses, which were self-treated increased with age from 12% in the youngest age group (< 13 years) to 34% in the oldest (> 14 years). In girls, the proportion of illnesses which were self-treated was consistently lower than among boys and remained constant around 9% for all age groups. The proportion of Western pharmaceuticals used for self-treatment increased with age from 44% in the youngest age group to 63% in the oldest (average 52% Western pharmaceuticals). Again, there were differences between boys and girls: among the youngest age group, boys were twice as likely to use pharmaceuticals than girls (62 versus 32% of the self-treatments, respectively) and in the oldest age group they were nearly three times more likely (75 versus 25%, respectively). These differences in self-treatment practices and choice of medicines between girls and boys may reflect the higher income potential of boys, who can earn money by fishing. Pharmaceuticals were generally preferred for the treatment of headache and fevers, or colds, while herbal remedies were the preferred choice for the treatment of abdominal complaints and wounds. The most commonly used pharmaceuticals were antimalarials (mainly chloroquine), painkillers and antipyretics (mainly aspirin and paracetamol), which were stocked in most small shops in the village at low prices and readily sold to children. Throughout primary school age Kenyan children are growing into a pluralistic medical practice, integrating Western pharmaceuticals into the local herbal medical system, and gradually become autonomous agents in their health care.

Medicinal plants used by Luo mothers and children in Bondo district, Kenya.

In a follow-up to studies of school-children's medical knowledge among the rural Luo of western Kenya, seven mothers were asked for their knowledge of plant medicine, and the 91 plant remedies mentioned by them were collected, 74 of these remedies were identified as 69 different species (in 13 cases, the material did not allow identification of the species, in two cases, only the family could be identified, and in two, not even this was possible). The results of this survey and some comments on Luo illness concepts are presented below and briefly discussed in relation to the earlier work on school-children and to another survey of Luo plant medicine in the same district. The article concludes that the consensual core of Luo plant medicine is known by ordinary mothers and their children as well as by recognised healers. It is a shared resource, that is used by women, mainly in the care for their children, and it is not an expert domain of knowledge, as is often, in studies of herbal or 'traditional' medicine are studied. The medicinal plants, upon which many mothers as well as healers agree should be examined further pharmacologically in order to assess their efficacy against the common infectious and parasitic diseases found in this area of western Kenya.

Intestinal helminth infections in pregnant women attending antenatal clinic at kitale district hospital, kenya.

Intestinal helminth infections during pregnancy are associated with adverse outcomes including low birth weight and prenatal mortality. The infections are a major public health problem in developing countries. A hospital based survey was undertaken for six months to determine the infection prevalence, intensity, and risk factors. The study involved expectant women attending antenatal clinic. Stool samples were screened microscopically for helminth ova using Kato Katz technique. Information on risk factors was collected using semistructured questionnaire and analyzed using SPSS. Epidemiological data was analysed using descriptive statistics and multivariate analysis. The overall prevalence of infection was 21 (13.8%). Ascariasis was the most prevalent 10 (6.5%), hookworm infection was 6 (3.9%), and trichuriasis was 2 (1.3%). Pregnant women aged below 29 years (OR = 3.63, CI = 0.87-11.75) and those with primary level of education (OR = 3.21, CI = 0.88-11.75) were at a higher risk of infection compared to those aged ≥ 29 years with secondary level of education. Hand washing was significantly associated with reduced likelihood of infection (OR = 0.18, 95% CI = 0.06-0.57). It was concluded that intestinal helminth infections were prevalent among pregnant women. We recommended that all expectant women visiting antenatal clinics be screened for intestinal helminth infections and positive cases be advised to seek treatment.