R. Chunge - Academia.edu (original) (raw)
Papers by R. Chunge
East African Medical Journal, Aug 1, 1989
East African medical journal, 1987
East African medical journal, 1988
L'examen de 177 malades consultant a la clinique dentaire de l'Hopital regional de Kiambu... more L'examen de 177 malades consultant a la clinique dentaire de l'Hopital regional de Kiambu au Kenya a revele que 46,3% etaient porteurs de protozoaires dans leur bouche. 5 seulement (2,8%) etaient porteurs de Trichomonas tenas alors que la plupart (94,1%) etaient porteurs d'Entamoeba gingivalis. Trois etaient porteurs des deux. L'âge n'influence pas la prevalence et il existe une association entre la prevalence et la deterioration du parodonte
East African medical journal, 1989
Observation chez une femme chez qui on fait un examen de selles de routine. Mise en evidence d... more Observation chez une femme chez qui on fait un examen de selles de routine. Mise en evidence d'œufs de Dicrocoelium
Head lice are cosmopolitan and endemic. While they are not responsible for the spread of any dise... more Head lice are cosmopolitan and endemic. While they are not responsible for the spread of any disease, they are the cause of considerable social distress. They can infest anybody and do not discriminate between class or cleanliness. Head lice are transmitted primarily by direct contact. The only satisfactory method to clear an infestation is by chemical treatment. The most effective pediculicides to date are those which contain permethrin (Nix) or malathion (Prioderm). Compliance with product instructions eliminates the need for nit removal after treatment. Treatment of inanimate objects and the environment should be discouraged. To obtain effective control of head lice, the whole community needs to be involved. Parents must be encouraged to screen themselves and their children regularly in the home, and to treat themselves only when necessary.
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1986
Of 1270 schoolchildren (651 girls and 619 boys) from 33 urban and rural primary schools in differ... more Of 1270 schoolchildren (651 girls and 619 boys) from 33 urban and rural primary schools in different regions of Kenya who were examined for head lice, 17.1% were infested (8% with living lice or nits. 9.1% with dead nits). The overall difference between infestation rates in urban and rural schools was not significant, bit there was considerable variation in the five different regions selected. Infestation was not sex-related. Infestation rates tended to be higher in older children and in children with longer hair. Negroid children had lower infestation rates than non-Negroid children. The criterion-seems to be-hair type. Prevalence of infestation was higher in private schools because non-Negroid children predominate in these schools. There was no correlation between infestation and the sharing of a towel or comb, but infestation tended to be higher in those who wash less, in those who share their bed. and in those who sleen with roommates. Levels of infestation were low, with most harbouring ody one or two lice.
East African Medical Journal, 2016
We wish to comment on our experience with treatment of Blastocystis spp.,which is an intestinal o... more We wish to comment on our experience with treatment of Blastocystis spp.,which is an intestinal organism frequently identified in human stool specimens. As noted by Tan (1) in a comprehensive review covering all aspects of Blastocystis, it was originally classified as a yeast before being called a protozoan; currently it is placed in the Stramenophile group which is neither protozoan nor fungal. At least nine sub-types of Blastocystis have been identified, several of which are zoonotic; it is therefore recommended by Tan (1) that it should be called Blastocystis spp. rather than Blastocystis hominis in laboratory reports. Blastocystis is cosmopolitan in distribution though it is more prevalent in tropical countries and in environments with poor sanitation. Transmission is likely to be faecal-oral and its life cycle is believed to be similar to that of amoebae. It has several stages, from smooth and granular vacuolar forms to amoeboid and cyst forms, which range in size, shape and arrangement of chromatin material (1). From our observations it is often misdiagnosed in stool reports as amoebic cysts, or ignored altogether. The prevalence of Blastocystis in rural Kenyan communities, where it is frequently found alongside other intestinal parasites, ranges from 17% to 36% (2, 3) but can be higher among targeted groups of children: we obtained rates of 61% (35/57) in a rural childrens' home in 2015 and 53.7% (51/95) in an urban primary school in 2008; it is consistently the commonest parasite identified in stool specimens in our laboratory at the Centre for Tropical and Travel Medicine (CTTM) in Nairobi, Kenya, with monthly frequencies averaging about 35% (Unpublished data, CTTM). As reviewed by Tan (1), the role of Blastocystis as an intestinal pathogen remains controversial, with several studies being inconclusive and others finding a significant association with Irritable Bowel Syndrome (IBS) and a range of other symptoms such as diarrhoea, flatulence and bloating. In Europe and the USA metronidazole and trimethoprim-sulfamethoxazole remain the drugs of choice to treat symptomatic blastocystosis. In Kenya, paromomycin (aminosidine sulphate) has been marketed as an effective anti-amoebic drug ever since successful trials were conducted countrywide in the 1980's (4). It is an aminoglycoside drug manufactured in both tablet and syrup formulations. It has been the drug of choice for all symptomatic cases of intestinal amoebiasis and other protozoa for over 20 years in our outpatient clinic at CTTM, during which time it became apparent that it was also effective in eliminating Blastocystis, either alone or occurring with other protozoa. The treatment regimen for intestinal protozoa and blastocystosis is paromomycin at a dose of 500mg BD for 5 days for adults above 50kg (4). These observations are consistent with our findings from a study in 2008, in which we initiated a comparative treatment trial of anti-protozoal drugs, including paromomycin, among a group of 95 schoolchildren aged 3 to 12 years in a relatively low socioeconomic environment within Nairobi. The study did not end conclusively due to poor follow-up and the results were therefore not published. However, we were able to extract specific records for 51 children aged 6 to 12 years infected with Blastocystis, either in mixed infections or alone, of whom 24 received treatment with paromomycin at a dose of 125mg or 250mg BD below and above 25kg respectively for 5 days. All stools before and after treatment were examined microscopically
East African medical journal, 1985
East African medical journal, 1985
The subject of helminths in Kenya has been reviewed from over 100 published papers and almost 50 ... more The subject of helminths in Kenya has been reviewed from over 100 published papers and almost 50 Annual Medical Reports dating from 1900 to 1983. From the earliest reports available intestinal helminths are mentioned as being a major cause of morbidity in Kenya. The most important intestinal helminths in Kenya are Necator americanus (hookworm) Ascaris lumbricoides (roundworm) and Taenia saginata (beef tapeworm). Hookworm has long been recognized as a cause of nutritional deficiency. It has chiefly been associated with anemia especially in combination with schistosomiasis. Treatment of hookworm often effectively reduces anemia. Historically it has been difficult to treat because of drug side effects. Modern treatments combine drugs. There have been no hookworm control programs since combined environmental/treatment interventions in the 1920s. Roundworm is estimated to effect 25% of the Kenyan population. It is related to standards of hygiene and has caused considerable morbidity and some child mortality and influences nutritional status. It is responsive to drug treatment and prevalence reduction programs are cost-effective but reinfection is a problem. The beef tapeworm does not greatly vary in prevalence between regions in Kenya but appears to be more prevalent in animal husbandry regions. It is an affector of nutrition in cattle and humans making eradication a complicated proposition. Other types of parasitic infection are discussed. Diagnostic technics for all types of intestinal parasites are varied. It has been established that these helminths are prevalent in all regions of Kenya and that they are generally as prevalent today as they were 60 or more years ago despite various limited attempts at control. Their distribution tends to differ in varying degrees from 1 region to another. The apparent variations of roundworm and beef tapeworm are not significant whereas the prevalence of hoodworm is significantly higher in the coastal reions than elsewhere in Kenya.
East African medical journal, 1989
Cryptosporidiosis has come to recent prominence as a cause of diarrhoea throughout the world in b... more Cryptosporidiosis has come to recent prominence as a cause of diarrhoea throughout the world in both adults and children, producing either an acute self-limiting diarrhoea or a protracted chronic diarrhoea which can be fatal in immunosuppressed patients. This study was therefore conducted to assess the prevalence of the infection among children less than five years of age in a rural community in Kiambu District, Kenya. 1420 diarrhoea specimens from children less than five years which were processed for bacteriology and parasitology were also examined for Cryptosporidium oocysts, using the modified Ziehl-Neelsen (ZN) acid-fast stain, 3.8% of all the diarrhoea samples were positive for oocysts. 320 non-diarrhoeic stools from children in the same age group were also examined and were all negative for Cryptosporidium oocysts. The results of this study would imply that infection with Cryptosporidium is associated with acute childhood diarrhoea in Kenya.
East African medical journal, 1989
One thousand four hundred and twenty diarrhoea specimens from 846 children aged 0 to 60 months we... more One thousand four hundred and twenty diarrhoea specimens from 846 children aged 0 to 60 months were collected and analysed for bacteria, parasites and rotavirus over a 16 month period, from June 1985 to September 1986 inclusive. The study was conducted in 4 villages situated in Kiambu District, Kenya. All the specimens were analysed for rotavirus and parasites, including Cryptosporidium. The majority of the specimens were analysed for enteropathogenic Escherichia coli (EPEC), Shigella, Salmonella, Campylobacter and Aeromonas. Only 387 specimens were analysed for enterotoxigenic E. coli (ETEC). However, of this proportion analysed for ETEC, 33% were positive. A total of 344 specimens were negative for any organisms while a further 140 were only positive for parasites which have been implicated as being pathogenic, including Ascaris lumbricoides, Hymenolepis nana, Trichomonas hominis and Blastocysts hominis were considered to be at least potentially pathogenic and capable of causing d...
East African medical journal, 1991
A cross-sectional survey of intestinal parasitic infection in a rural community, Nderu, in Kiambu... more 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 ...
East African medical journal, 1992
Stool specimen results from children with diarrhoea and without diarrhoea, in a rural village com... more 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.
East African medical journal, 1992
Two hundred diarrhoea specimens collected during January to February 1988, from rural children ag... more Two hundred diarrhoea specimens collected during January to February 1988, from rural children aged 0 to 60 months in Kakamega District were examined for bacteria, parasites and rotavirus. The results were compared with a sample of 184 diarrhoea specimens matched for month of collection, taken from data collected in the same manner from children in Kiambu District. The mean ages of children in the 2 samples did not differ significantly. There were significant differences in the prevalence of specific potential pathogens isolated in the 2 areas. Notably, A. lumbricoides and rotavirus were more common in Kakamega, while G. lamblia, Entamoeba histolytica, Trichomonas hominis, Cryptosporidium sp., Hymenolepis nana and EPEC were more common in Kiambu. There was no difference with respect to prevalence of Campylobacter sp. or Blastocystis hominis. Factors which were probably important in determining aetiological differences included climate, water sources, animal contact and crowding. The...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1986
Statistics in Medicine, 1990
The simultaneous estimation of infection rate, cure rate and detectability of parasitic infection... more The simultaneous estimation of infection rate, cure rate and detectability of parasitic infections is considered. A new method for this estimation based on a simple statistical model assuming constant transition rates between parasite states is proposed. Repeated observations on the infection status of the same individuals is required for this method. A maximum likelihood approach is used for parameter estimation and the calculation of standard errors of the estimates. The method is illustrated by a longitudinal study of the presence of Giardia lamblia infection in Kenyan children.
Acta Tropica, 1991
84 young children from a rural community, Nderu, in Kenya, were each followed for up to 10 months... more 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.
East African Medical Journal, Aug 1, 1989
East African medical journal, 1987
East African medical journal, 1988
L'examen de 177 malades consultant a la clinique dentaire de l'Hopital regional de Kiambu... more L'examen de 177 malades consultant a la clinique dentaire de l'Hopital regional de Kiambu au Kenya a revele que 46,3% etaient porteurs de protozoaires dans leur bouche. 5 seulement (2,8%) etaient porteurs de Trichomonas tenas alors que la plupart (94,1%) etaient porteurs d'Entamoeba gingivalis. Trois etaient porteurs des deux. L'âge n'influence pas la prevalence et il existe une association entre la prevalence et la deterioration du parodonte
East African medical journal, 1989
Observation chez une femme chez qui on fait un examen de selles de routine. Mise en evidence d... more Observation chez une femme chez qui on fait un examen de selles de routine. Mise en evidence d'œufs de Dicrocoelium
Head lice are cosmopolitan and endemic. While they are not responsible for the spread of any dise... more Head lice are cosmopolitan and endemic. While they are not responsible for the spread of any disease, they are the cause of considerable social distress. They can infest anybody and do not discriminate between class or cleanliness. Head lice are transmitted primarily by direct contact. The only satisfactory method to clear an infestation is by chemical treatment. The most effective pediculicides to date are those which contain permethrin (Nix) or malathion (Prioderm). Compliance with product instructions eliminates the need for nit removal after treatment. Treatment of inanimate objects and the environment should be discouraged. To obtain effective control of head lice, the whole community needs to be involved. Parents must be encouraged to screen themselves and their children regularly in the home, and to treat themselves only when necessary.
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1986
Of 1270 schoolchildren (651 girls and 619 boys) from 33 urban and rural primary schools in differ... more Of 1270 schoolchildren (651 girls and 619 boys) from 33 urban and rural primary schools in different regions of Kenya who were examined for head lice, 17.1% were infested (8% with living lice or nits. 9.1% with dead nits). The overall difference between infestation rates in urban and rural schools was not significant, bit there was considerable variation in the five different regions selected. Infestation was not sex-related. Infestation rates tended to be higher in older children and in children with longer hair. Negroid children had lower infestation rates than non-Negroid children. The criterion-seems to be-hair type. Prevalence of infestation was higher in private schools because non-Negroid children predominate in these schools. There was no correlation between infestation and the sharing of a towel or comb, but infestation tended to be higher in those who wash less, in those who share their bed. and in those who sleen with roommates. Levels of infestation were low, with most harbouring ody one or two lice.
East African Medical Journal, 2016
We wish to comment on our experience with treatment of Blastocystis spp.,which is an intestinal o... more We wish to comment on our experience with treatment of Blastocystis spp.,which is an intestinal organism frequently identified in human stool specimens. As noted by Tan (1) in a comprehensive review covering all aspects of Blastocystis, it was originally classified as a yeast before being called a protozoan; currently it is placed in the Stramenophile group which is neither protozoan nor fungal. At least nine sub-types of Blastocystis have been identified, several of which are zoonotic; it is therefore recommended by Tan (1) that it should be called Blastocystis spp. rather than Blastocystis hominis in laboratory reports. Blastocystis is cosmopolitan in distribution though it is more prevalent in tropical countries and in environments with poor sanitation. Transmission is likely to be faecal-oral and its life cycle is believed to be similar to that of amoebae. It has several stages, from smooth and granular vacuolar forms to amoeboid and cyst forms, which range in size, shape and arrangement of chromatin material (1). From our observations it is often misdiagnosed in stool reports as amoebic cysts, or ignored altogether. The prevalence of Blastocystis in rural Kenyan communities, where it is frequently found alongside other intestinal parasites, ranges from 17% to 36% (2, 3) but can be higher among targeted groups of children: we obtained rates of 61% (35/57) in a rural childrens' home in 2015 and 53.7% (51/95) in an urban primary school in 2008; it is consistently the commonest parasite identified in stool specimens in our laboratory at the Centre for Tropical and Travel Medicine (CTTM) in Nairobi, Kenya, with monthly frequencies averaging about 35% (Unpublished data, CTTM). As reviewed by Tan (1), the role of Blastocystis as an intestinal pathogen remains controversial, with several studies being inconclusive and others finding a significant association with Irritable Bowel Syndrome (IBS) and a range of other symptoms such as diarrhoea, flatulence and bloating. In Europe and the USA metronidazole and trimethoprim-sulfamethoxazole remain the drugs of choice to treat symptomatic blastocystosis. In Kenya, paromomycin (aminosidine sulphate) has been marketed as an effective anti-amoebic drug ever since successful trials were conducted countrywide in the 1980's (4). It is an aminoglycoside drug manufactured in both tablet and syrup formulations. It has been the drug of choice for all symptomatic cases of intestinal amoebiasis and other protozoa for over 20 years in our outpatient clinic at CTTM, during which time it became apparent that it was also effective in eliminating Blastocystis, either alone or occurring with other protozoa. The treatment regimen for intestinal protozoa and blastocystosis is paromomycin at a dose of 500mg BD for 5 days for adults above 50kg (4). These observations are consistent with our findings from a study in 2008, in which we initiated a comparative treatment trial of anti-protozoal drugs, including paromomycin, among a group of 95 schoolchildren aged 3 to 12 years in a relatively low socioeconomic environment within Nairobi. The study did not end conclusively due to poor follow-up and the results were therefore not published. However, we were able to extract specific records for 51 children aged 6 to 12 years infected with Blastocystis, either in mixed infections or alone, of whom 24 received treatment with paromomycin at a dose of 125mg or 250mg BD below and above 25kg respectively for 5 days. All stools before and after treatment were examined microscopically
East African medical journal, 1985
East African medical journal, 1985
The subject of helminths in Kenya has been reviewed from over 100 published papers and almost 50 ... more The subject of helminths in Kenya has been reviewed from over 100 published papers and almost 50 Annual Medical Reports dating from 1900 to 1983. From the earliest reports available intestinal helminths are mentioned as being a major cause of morbidity in Kenya. The most important intestinal helminths in Kenya are Necator americanus (hookworm) Ascaris lumbricoides (roundworm) and Taenia saginata (beef tapeworm). Hookworm has long been recognized as a cause of nutritional deficiency. It has chiefly been associated with anemia especially in combination with schistosomiasis. Treatment of hookworm often effectively reduces anemia. Historically it has been difficult to treat because of drug side effects. Modern treatments combine drugs. There have been no hookworm control programs since combined environmental/treatment interventions in the 1920s. Roundworm is estimated to effect 25% of the Kenyan population. It is related to standards of hygiene and has caused considerable morbidity and some child mortality and influences nutritional status. It is responsive to drug treatment and prevalence reduction programs are cost-effective but reinfection is a problem. The beef tapeworm does not greatly vary in prevalence between regions in Kenya but appears to be more prevalent in animal husbandry regions. It is an affector of nutrition in cattle and humans making eradication a complicated proposition. Other types of parasitic infection are discussed. Diagnostic technics for all types of intestinal parasites are varied. It has been established that these helminths are prevalent in all regions of Kenya and that they are generally as prevalent today as they were 60 or more years ago despite various limited attempts at control. Their distribution tends to differ in varying degrees from 1 region to another. The apparent variations of roundworm and beef tapeworm are not significant whereas the prevalence of hoodworm is significantly higher in the coastal reions than elsewhere in Kenya.
East African medical journal, 1989
Cryptosporidiosis has come to recent prominence as a cause of diarrhoea throughout the world in b... more Cryptosporidiosis has come to recent prominence as a cause of diarrhoea throughout the world in both adults and children, producing either an acute self-limiting diarrhoea or a protracted chronic diarrhoea which can be fatal in immunosuppressed patients. This study was therefore conducted to assess the prevalence of the infection among children less than five years of age in a rural community in Kiambu District, Kenya. 1420 diarrhoea specimens from children less than five years which were processed for bacteriology and parasitology were also examined for Cryptosporidium oocysts, using the modified Ziehl-Neelsen (ZN) acid-fast stain, 3.8% of all the diarrhoea samples were positive for oocysts. 320 non-diarrhoeic stools from children in the same age group were also examined and were all negative for Cryptosporidium oocysts. The results of this study would imply that infection with Cryptosporidium is associated with acute childhood diarrhoea in Kenya.
East African medical journal, 1989
One thousand four hundred and twenty diarrhoea specimens from 846 children aged 0 to 60 months we... more One thousand four hundred and twenty diarrhoea specimens from 846 children aged 0 to 60 months were collected and analysed for bacteria, parasites and rotavirus over a 16 month period, from June 1985 to September 1986 inclusive. The study was conducted in 4 villages situated in Kiambu District, Kenya. All the specimens were analysed for rotavirus and parasites, including Cryptosporidium. The majority of the specimens were analysed for enteropathogenic Escherichia coli (EPEC), Shigella, Salmonella, Campylobacter and Aeromonas. Only 387 specimens were analysed for enterotoxigenic E. coli (ETEC). However, of this proportion analysed for ETEC, 33% were positive. A total of 344 specimens were negative for any organisms while a further 140 were only positive for parasites which have been implicated as being pathogenic, including Ascaris lumbricoides, Hymenolepis nana, Trichomonas hominis and Blastocysts hominis were considered to be at least potentially pathogenic and capable of causing d...
East African medical journal, 1991
A cross-sectional survey of intestinal parasitic infection in a rural community, Nderu, in Kiambu... more 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 ...
East African medical journal, 1992
Stool specimen results from children with diarrhoea and without diarrhoea, in a rural village com... more 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.
East African medical journal, 1992
Two hundred diarrhoea specimens collected during January to February 1988, from rural children ag... more Two hundred diarrhoea specimens collected during January to February 1988, from rural children aged 0 to 60 months in Kakamega District were examined for bacteria, parasites and rotavirus. The results were compared with a sample of 184 diarrhoea specimens matched for month of collection, taken from data collected in the same manner from children in Kiambu District. The mean ages of children in the 2 samples did not differ significantly. There were significant differences in the prevalence of specific potential pathogens isolated in the 2 areas. Notably, A. lumbricoides and rotavirus were more common in Kakamega, while G. lamblia, Entamoeba histolytica, Trichomonas hominis, Cryptosporidium sp., Hymenolepis nana and EPEC were more common in Kiambu. There was no difference with respect to prevalence of Campylobacter sp. or Blastocystis hominis. Factors which were probably important in determining aetiological differences included climate, water sources, animal contact and crowding. The...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1986
Statistics in Medicine, 1990
The simultaneous estimation of infection rate, cure rate and detectability of parasitic infection... more The simultaneous estimation of infection rate, cure rate and detectability of parasitic infections is considered. A new method for this estimation based on a simple statistical model assuming constant transition rates between parasite states is proposed. Repeated observations on the infection status of the same individuals is required for this method. A maximum likelihood approach is used for parameter estimation and the calculation of standard errors of the estimates. The method is illustrated by a longitudinal study of the presence of Giardia lamblia infection in Kenyan children.
Acta Tropica, 1991
84 young children from a rural community, Nderu, in Kenya, were each followed for up to 10 months... more 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.