Quantification of Infection with Schistosoma haematobium in Relation to Epidemiology and Selective Population Chemotherapy. I. Minimal Number of Daily Egg Counts in Urine Necessary to Establish Intensity of Infection

AbstractIn epidemiological surveys for urinary schistosomiasis caused by Schistosoma haematobium in communities around Agulu Lake, Anambra State, Nigeria, between 1990 and 1992, the infection was found to be endemic in the area, especially in three towns: Nri, Agulu, and Adazi Nnukwu. The prevalence rates varied between these communities and with the year. Inter-town prevalence rates ranged from 5.96% to 54.00%. Intravillage prevalence rates ranged between 5.50% to 96.43%. Prevalence rates were highest in villages very close to Agulu lake. There was no significant difference in prevalence between the schools. Host age, but not sex, was found to play a significant role in prevalence and intensity of infection. There was also a strong correlation between visible haematuria and egg count per 10 ml urine, but eggs could be isolated in urine samples of different shades of coloration. Analysis of incidence of infection in these communities shows that Schistosoma haematobium incidence is high in Nri (55.17%) and low at Adazi Nnukwu (5.26%). Both Bulinus globosus and B. truncatus were found in the lake and both shed mammalian bifid schistosome cercariae.

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The influence of transmission season on parasitological cure rates and intensity of infection after praziquantel treatment of Schistosoma haematobium-infected schoolchildren in Mozambique

Parasitology ◽

10.1017/s0031182009006210 ◽

2009 ◽

Vol 136 (13) ◽

pp. 1771-1779 ◽

Cited By ~ 23

Author(s):

G. AUGUSTO ◽

P. MAGNUSSEN ◽

T. K. KRISTENSEN ◽

C. C. APPLETON ◽

B. J. VENNERVALD

Keyword(s):

Schistosoma Haematobium ◽

Geometric Mean ◽

Intensity Of Infection ◽

Transmission Season ◽

Low Transmission ◽

Seasonal Transmission ◽

Transmission Pattern ◽

Control Programmes ◽

Cure Rates ◽

The Impact

SUMMARYSchistosoma haematobium is refractory to praziquantel (PZQ) during the prepatent period of infection. A hypothesis based on this observation is that in areas where S. haematobium transmission is seasonal, the outcome of chemotherapy depends on the timing of the treatment relative to the annual transmission pattern. To examine this hypothesis, a study was carried out in southern Mozambique. Following demonstration of seasonal transmission, PZQ was administered separately to two cohorts of S. haematobium-infected schoolchildren in (1) the high and (2) the low transmission seasons and followed up after two months when levels of infection and intensities were measured. The prevalence of infection decreased from 54·2% and 51·7% in cohorts 1 and 2 to 30·3% and 1·8%, respectively. The geometric mean intensity of infection decreased from 23·3 eggs/10 ml of urine at baseline to 15·6 eggs/10 ml of urine in cohort 1 (treated during high transmission season), and from 23·5 eggs/10 ml urine to 7·3 eggs/10 ml of urine in cohort 2 (treated during low transmission season). The observed cure rates in cohorts 1 and 2 were 69·7% and 98·2%, respectively. Differences in infection between the cohorts in terms of cure rate and level of infection two months post-treatment were statistically significant and indicate that in areas with a seasonal transmission pattern, the effect of PZQ can be enhanced if treatment takes place during the low transmission season. We conclude that appropriately timed PZQ administration will increase the impact of schistosomiasis control programmes.

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Long-term suppression of adult bladder morbidity and severe hydronephrosis following selective population chemotherapy for Schistosoma haematobium.

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.1999.61.476 ◽

1999 ◽

Vol 61 (3) ◽

pp. 476-481 ◽

Cited By ~ 18

Author(s):

A K Subramanian ◽

P Mungai ◽

J H Ouma ◽

P Magak ◽

C H King ◽

...

Keyword(s):

Schistosoma Haematobium ◽

Selective Population

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Schistosoma haematobium infections in preschool children from two rural communities in Ijebu East, south-western Nigeria

Journal of Helminthology ◽

10.1017/s0022149x11000459 ◽

2011 ◽

Vol 86 (3) ◽

pp. 323-328 ◽

Cited By ~ 11

Author(s):

U.F. Ekpo ◽

O.M. Alabi ◽

A.S. Oluwole ◽

S.O. Sam-Wobo

Keyword(s):

Preschool Children ◽

Rural Communities ◽

Schistosoma Haematobium ◽

Stream Water ◽

Older Children ◽

Intensity Of Infection ◽

Focus Group Discussions ◽

Group Discussions ◽

Water Contact ◽

Interview Guide

AbstractThere is an urgent need for information on schistosomiasis in preschool children, who are often excluded in mass treatment programmes. The prevalence and intensity of Schistosoma haematobium infection were determined in preschool children aged ≤ 6 years in two rural communities in Ijebu East, south-western Nigeria. Two urine samples each were collected from 83 preschool children from the two communities, tested for microhaematuria using reagent strips and then processed and examined with a microscope for S. haematobium eggs. Focus group discussions on perceptions of the disease and water contact practices were held in the communities with their guardians, caregivers and preschool children, using an interview guide. The prevalence of S. haematobium in the two communities was 14 (16.9%), with no significant differences (P = 0.661) in infection rate between boys (18.4%) and girls (14.7%). Both prevalence and intensity of infection did not increase significantly with age in both Korede and Obada community. However, there were significant differences in prevalence of infection between the two communities (P = 0.035). There was no association (P = 0.750) between intensity in boys (0.176 eggs/10 ml urine) and girls (0.110 eggs/10 ml urine). Focal group discussions with guardians and caregivers revealed that preschool children acquired infection early in their lives through exposure to infected stream water by their mothers, while the older children visit the stream for playing, bathing and swimming. It has therefore become imperative for preschool children to be included in the planning of schistosomiasis intervention programmes as a means of reducing transmission.

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Prevalence and Intensity of Urinary Schistosomiasis among Residence: A Case Study in River Benue, Adamawa State, North Eastern Nigeria

Asian Journal of Research in Zoology ◽

10.9734/ajriz/2019/v2i230065 ◽

2019 ◽

pp. 1-10

Author(s):

R. S. Naphtali ◽

J. S. Ngwamah

Keyword(s):

Schistosoma Haematobium ◽

Cross Sectional Study ◽

Intensity Of Infection ◽

Chi Square ◽

Cross Sectional ◽

Urinary Schistosomiasis ◽

Vulnerable Communities ◽

Significant Difference ◽

North Eastern

Background: In Nigeria, an infection caused by Schistosoma haematobium has been known to be endemic especially among residents along Rivers, and it is responsible for considerable public health problems. Aims: This study aimed at assessing the prevalence and intensity of infection among the vulnerable communities. Study Design: A cross-sectional study involving 1,404 participants within age bracket 5-55 years old and above, in ten communities across five Local Government Areas along River Benue in Adamawa State, was conducted. Urine samples were collected from randomly selected study subjects and were examined using centrifugation and sedimentation techniques. The intensity of infection was ascertained as eggs/10mls of urine and values expressed as Mean ± SD. Data on demography were obtained by structured questionnaires. The simple percentage was used and Chi-square as well to ascertain the associations between prevalence and other parameters. P<0.05 was considered as significant. Results and Discussion: The overall prevalence and intensity of infection were 23.2% and 513±0.05 eggs/10 ml of urine respectively. Kabawa had the highest infection rate and intensity with 12.4% and 80±0.02 respectively. The lowest was recorded in Kangle (12.3% and 24±0.82 eggs/10 ml), with a significant association between parasite intensity and community (p<0.05). Gender-related prevalence and intensity revealed that males (25.5% and 289±4.66 eggs/10 ml) were more affected than the females (20.8% and 206±4.49 eggs/10 ml). Participants within age bracket 5-14 years old had the highest prevalence (36.6%) and intensity (142±0.005 eggs/10 ml), while the lowest was recorded among age group 45-54 years old with 9.0% and 42±0.040 eggs/10 ml. Prevalence and intensity of infection was highest among Subjects fetching water from River/Streams (31.8%, 46±0.080 egg/10 ml of urine), whereas the least were observed among borehole fetchers (13.8% and 241±0.302 egg/10 ml of urine). Occupational related prevalence and intensity were highest among Fishers with 35.0% and 188±0.012 egg/10 ml of urine. Chemotherapy and Health Education should be advocated across the study area. Conclusion: This study has established that Schistosoma haematobium infection is prevalent among the residents living along the River Benue in Adamawa State, Nigeria. Although infection was more among the males than the females, there was no significant difference, but there were significant differences in prevalence and intensity with age, the source of drinking water, and occupation.

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