The Dynamics of Severe Anaemia and Malaria Parasitemia in Young Children during the High (Malaria) Transmission Season in Northern Ghana

Location          :Eastern and northern parts of the Kassena-Nankana district

Coordinator    :Francis Anto

Investigators  :Joseph Flanagan and Francis Anto

Collaboration   :Navrongo Health Research centre, Ghana
                       Noguchi Memorial Institute for Medical Research, Ghana
                       Naval Medical Research Center, USA

Funding             :US NAVY

Period Covered:August - December 2001

Size                    :1, 000 children 6-24 month of age

 BACKGROUND           OBJECTIVES          METHODOLOGY          RESULTS

BACKGROUND

In 1996-1997 a study of the attack rate of malaria was done in adults and children in the KND.  In the child cohort the subjects were treated if they developed patent parasitemia, regardless of symptomatology.  That study showed an overall incidence density (in outcomes per person-year) of 4.71 infections/person-yr in the dry season and 6.95 infections/person-year in the wet season for any malaria parasitemia.  For parasitemia with fever it was 1.46 and 1.72, for parasitemia with anemia of Hgb <8 it was 1.72 in each season.  This study also found that during the period 1996-1997, 98-99% of all parasitemias were due to P. falciparum.

OBJECTIVES

The main objective was to study the pattern of anemia and malaria over a four month period in children 6-20 months of age who live in the KND.

• To study the pattern of anemia over a four month period in children 6-20 months of age in the Kassena-Nankana district.

• To establish the incidence rate of new cases of confirmed symptomatic malaria during the high transmission season in children 6-20 months of age

• To determine if the administration of quinine and fansidar to clear blood stage infection changes the incidence of confirmed symptomatic malaria in children 6-20 months of age

• To determine if the administration of a curative regimen of quinine and fansidar alters the pattern of anemia in this population. To evaluate the effect of the simultaneous administration of rotavirus vaccine with polio vaccine versus polio vaccine alone on the sero-conversion to polio viruses types 1 and 3.

To evaluate the immunogenicity of vaccine when given in the wet season versus the dry season.

METHODOLOGY

Five hundred 6-20 month-old, generally healthy residents of the KND were recruited. Half of them were given a curative regimen of quinine and Fansidar to eliminate all erythrocytic stages of malaria parasites. The children were monitored over a period of 16 weeks with once weekly visits by field workers and by routine malaria smears made every four weeks. Non-routine slides were made at any time of malaria-like illness and if parasites were observed the child was brought to NWMH for evaluation and treatment.  Another 500 children, though identified at the start of recruitment were contacted only at the end of the 16 weeks and evaluated.  This group “community control” served as a group for assessing the impact of the follow-up on the wellbeing of the enrolled children.

INCLUSION CRITERIA

1.            Males and females age 6-20 

2.            Willingness of parent or guardian to sign a consent form 

3.            Willingness of parent or guardian to refrain from administering anti-malarial drugs to the child on his or her personal initiative during the study without first consulting the study physicians.

The expectation of continuous residency in the surveyed district for four months at the time of enrollment.

EXCLUSION CRITERIA

1.            Significant preexisting acute or chronic disease at the time of enrollment.

2.            Previous history of allergy or significant intolerance to study drugs.

3.            Inability of the child's parent or guardian to comprehend and signify informed consent.

4.            Expected movement out of the study area or other possible unavailability during 16 week study surveillance period.

Unwillingness to refrain from self-medication, without consultation of one of the study physicians.

RESULTS

At enrolment, 70.5% of the children were parasitemic . The range of parasitemia was 40-175,200/mL. Hb range 5.8-12.3 g/dl.           7% severely anaemic (Hb<6.0g/dl). At the end of the study, the mean days to first symptomatic parasitemia for the treated group was found to be significantly longer (P=0.0001) than the group that did not receive malaria treatment at the start of the study. The mean Hb at 1^st symptomatic parasitemia was much higher (P=0.0002) in the treatment group than in the untreated group