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K Tetteh

Publications and source records attributed to K Tetteh.

4 recordsLinked to original sources

Index of potential contamination: Schistosoma haematobium infections in school children in the Ashanti Region of Ghana.

BACKGROUND: Children are acknowledged as the most vulnerable group to urinary schistosomiasis. OBJECTIVE: To determine the age group(s) of school children considered as the major contributor(s) to the spread of the disease. DESIGN: Observational/Prospective (concurrent) studies. SETTING: Barekuma, Aninkroma and Hiawo Besease, riparian communities in the Ashanti Region of Ghana. SUBJECTS: Hundred children each were randomly selected from Barekuma and Hiawo Besease basic schools with population age profiles between 4 and 18 years. They were then categorised into 4-6, 7-9, 10-12, 13-15 and 16-18 years, respectively. However, at Aninkroma, the entire school population of 119 pupils, aged between 4 and 15 years were used. They were similarly grouped into 4-6, 7-9, 10-12 and 13-15 years, respectively. Urine filtration method was used for isolation and enumeration of S. haematobium eggs from the subjects. The subjects were monitored through repetition of the experiment at fortnightly intervals over four weeks. MAIN OUTCOME MEASURES: Corrected relative Index of Potential Contamination (IPC) expressed as percentage after calculating the crude IPC. RESULTS: The age groups with the highest relative IPCs at Barekuma, Aninkroma and Hiawo Besease were 7-9, 10-12 and 13-15 years, registering 35.6%, 53.9% and 57.7%, respectively. The age group 4-6 years consistently had the lowest IPC in all the communities. CONCLUSION: The age groups 7-9,10-12 and 13-15 years were considered to be the major transmitters of the disease in the communities.

Adolescent↗

Frequent and persistent, asymptomatic Plasmodium falciparum infections in African infants, characterized by multilocus genotyping.

To determine the duration and complexity of naturally acquired Plasmodium falciparum infections in small children, a longitudinal cohort study of 143 newborns was conducted in coastal Ghana. On average, children experienced 2 episodes of infection in their first 2 years of life, the median duration of an asymptomatic infection was <4 weeks, and estimates of the mean number of parasite genotypes per infection were 1.15-2.28. Nevertheless, 40% of the children experienced infections lasting </=12 weeks, and both the duration and complexity of infections increased with age. The longest period of continual infection was 64 weeks, and the maximum persistence of a single parasite genotype was 40 weeks. Thus, malaria infections in infants <5 months old tend to be asymptomatic and rapidly cleared; persistent asymptomatic parasitemia is more common in children >5 months old. The ability of very young children to clear or control malaria infections indicates the presence of effective innate or immune antiparasite mechanisms.

Age Factors↗

Lack of association between maternal antibody and protection of African infants from malaria infection.

Maternally derived antibodies are believed to protect infants against infection, but there is little direct evidence for a protective role of passively acquired antibodies against malaria. A longitudinal study of malaria infection in 143 infants was conducted in a region of southern Ghana where Plasmodium falciparum is endemic. Infants born in the high-transmission season were less likely to become infected in the first 20 weeks of life than children born in the low-transmission season. Plasma, obtained at birth, was tested for immunoglobulin G (IgG) and IgG subclasses to P. falciparum schizonts and recombinant circumsporozoite antigen, MSP-1(19), MSP-2, AMA-1, and Pf155 (also called ring-infected erythrocyte surface antigen). Antibody levels at birth were not associated with resistance to malaria infection. On the contrary, antibodies at birth were positively associated with infection, indicating that high levels of maternally derived antibodies represent a marker for intensity of exposure to malaria infection in infants. However, all five children who experienced high-density infections (>100 parasites/microl of blood) were seronegative for MSP-1(19) at the time of infection.

Adolescent↗