Research Articles

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A research article reports the results of original research, assesses its contribution to the body of knowledge in a given area, and is published in a peer-reviewed scholarly journal. The faculty publications through published and on-going articles/researches are captured in this community

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    A longitudinal study of malaria infection, morbidity and antibody titres in infants of a rural community in Ghana.
    (Transactions of the Royal Society of Tropical Medicine and Hygiene, 1995) Akanmori, B.D.; Afari, E.A.; Sakatoku, H.; Nkrumah, F.K.
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    Malaria infection, morbidity and transmission in two ecological zones Southern Ghana
    (1995-05) Afari, E.A.; Appawu, M.; Dunyo, S.; Baffoe-Wilmot, A.; Nkrumah, F.K.
    A one year survey was conducted in 1992 to compare malaria infection, morbidity and transmission patterns between a coastal savannah community (Prampram) and a community (Dodowa) in the forest zone in southern Ghana. The study population of 6682 at Prampram and 6558 at Dodowa were followed up in their homes once every two weeks and all episodes of clinical malaria recorded. Blood films for microscopy were prepared from 600 participants randomly selected in each community in April and in August representing dry and wet seasons respectively. Mosquitoes biting humans between 1800 hrs and 0600 hrs, as well as indoor and outdoor resting mosquitoes were collected weekly. All mosquitoes collected were classified into species and examined for sporozoites by dissection and ELISA. The incidence rate of clinical malaria was higher in Dodowa (106.6/1000 pop.) than in Prampram (68.5/1000 pop.) It was highest in < 10 year age groups in both communities. It was also higher in the wet season than in the dry season. The prevalence of patent parasitaemia at Prampram and Dodowa in April in the dry season. The prevalence of patent parasitaemia at Prampram and Dodowa in April 1992 was 19.8% (117/590) and 42.2% (253/599) respectively. The corresponding figures for August were 26.6%(160/602)at Prampram and 51.3% (309/602) at Dodowa. Plasmodium falciparum infection contributed 78-85% of the parasitaemia in April and 93-99% in August. The average man-biting rate for Anopheles gambiae s.l was higher at Prampram than at Dodowa (1.54 vs 0.79 bites/man/night) but the average sporozoite rate was higher at Dodowa than at Prampram (2% vs 0.7%). The peak of biting density at Prampram occurred in June whilst that of Dodowa occurred in November.
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    Antibody response to 17D yellow fever vaccine in Ghanaian infants
    (2001) Osei-Kwasi, M.; Dunyo, S.K.; Koram, K.A.; Afari, E.A.; Odoom, J.K.; Nkrumah, F.K.
    To assess the seroresponses to yellow fever vaccination at 6 and 9 months of age; assess any possible adverse effects of immunization with the 17D yellow fever vaccine in infants, particularly at 6 months of age. METHODS: Four hundred and twenty infants who had completed BCG, OPV and DPT immunizations were randomized to receive yellow fever immunization at either 6 or 9 months. A single dose of 0.5 ml of the reconstituted vaccine was administered to each infant by subcutaneous injection. To determine the yellow fever antibody levels of the infants, each donated 1 ml whole blood prior to immunization and 3 months post-immunization. Each serum sample was titred on Vero cells against the vaccine virus. FINDINGS: The most common adverse reactions reported were fever, cough, diarrhoea and mild reactions at the inoculation site. The incidences of adverse reactions were not statistically different in both groups. None of the pre-immunization sera in both age groups had detectable yellow fever antibodies. Infants immunized at 6 months recorded seroconversion of 98.6% and those immunized at 9 months recorded 98% seroconversion. The GMT of their antibodies were 158.5 and 129.8, respectively. CONCLUSIONS: The results indicate that seroresponses to yellow fever immunization at 6 and 9 months as determined by seroconversion and GMTs of antibodies are similar. The findings of good seroresponses at 6 months without significant adverse effects would suggest that the 17D yellow fever vaccine could be recommended for use in children at 6 months in outbreak situations or in high risk endemic areas.
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    Randomized, controlled trial of trivalent oral poliovirus vaccine (sabin) starting at birth in Ghana
    (1995) Osei-Kwasi, M.; Afari, E.A.; Mimura, K.; Obeng-Ansah, I.; Ampofo, W.K.; Nkrumah, F.K.
    To evaluate the efficacy of the schedule currently recommended for immunization with trivalent oral poliovirus vaccine (TOPV) (i.e., at birth, 6 weeks, 10 weeks, and 14 weeks after birth), we randomly assigned 452 infants into test (231 infants) and control (221 infants) groups. The test group received TOPV as currently recommended, and the dose at birth was omitted for the control group. At 10, 14, and 18 weeks of age, the levels of poliovirus neutralizing antibodies as well as seroconversion rates were consistently higher for the test group than for the control group. The final seroconversion rates against poliovirus types 1, 2, and 3 were 83.5%, 91% and 83%, respectively, for the test group and 75%, 83.2%, and 79.1%, respectively, for the control group. The TOPV immunization schedule starting at birth therefore produced better results. Seroconversion rates as well as antibody levels were highest in infants with low maternal antibodies
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    Comparison of AIK-C measles vaccine in infants at 6 months with schwarz vaccine at 9 months: A randomized controlled trial in Ghana
    (1998) Nkrumah, F.K.; Osei-Kwasi, M.; Dunyo, S.K.; Koram, K.A.; Afari, E.A.
    In a randomized controlled trial in a measles endemic area, standard-dose (4.0 log10pfu) AIK-C measles vaccine administered at 6 months of age was compared to standard-dose Schwarz vaccine (3.7log10pfu) given at 9 months. Seroconversion rates at 3 and 6 months after immunization in the two groups were comparable and similar. The geometric mean titres achieved were, however, significantly higher in the Schwarz group (P < 0.05). No immediate serious side-effects were observed with either vaccine. We conclude that standard-dose AIK-C measles vaccine can be recommended for measles immunization in children below 9 months of age, especially in highly endemic and high-risk areas in developing countries. PIP: The seroresponse of standard-dose heat-stable AIK-C measles vaccine administered to infants at 6 months of age was compared to that of standard-dose Schwarz vaccine administered at 9 months of age in a measles-endemic area in West Africa. The study was conducted in Asamankese, the capital town of Ghana's East Akim District. Infants 24-27 weeks of age who had been attending the Asamankese maternal-child health clinic regularly and had received all the required immunizations were enrolled and randomly assigned to receive the AIK-C (n = 184) or the Schwarz (n = 193) vaccine. No severe adverse reactions were reported during the 10-day follow-up period in either vaccine group. In the AIK-C group, 96.9% of infants who were seronegative at preimmunization and 79.4% of those with preexisting antibodies had seroconverted by 3 months after immunization; at 6 months after immunization, these rates were 97.3% and 100%, respectively. In the Schwarz group, 98.2% of infants seronegative at immunization and 100% of those with preexisting antibodies seroconverted by 3 months after immunization; at 6 months, these rates were 99.1% and 80%, respectively. Although the geometric mean titres achieved were significantly higher in the Schwarz vaccine group, these titres were above the protective level of 200 mIU in the AIK-C group. Administration of measles vaccine at a younger age may be more easily incorporated into current Expanded Program on Immunization schedules.
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    Pertussis immunization with acellular vaccines in Ghanaian children
    (1995-06) Hori, H.; Afari, E.A.; Akanmori, B.D.; Kamiya, Y.; Sakatoku, H.; Nkrumah, F.K.; Fukai, K.
    In the present study, the persistence of antibodies to pertussis antigens was assessed in 51 Ghanaian children immunized with one of two acellular vaccines and one whole cell vaccine in early infancy. The effect of a booster dose 1 year after primary immunization was also examined. Antibody titres to pertussis toxin (PT) and filamentous haemagglutinin (FHA) were measured 1 month and 1 year after primary immunization and 1 month after the booster dose. Although geometric titres (GMTs) to FHA were significantly higher in the two types of acellular vaccinees in the whole cell vaccinees 1 month after primary immunization, GMTs to FHA and PT after 1 year were not significantly different in the three groups. Geometric mean titres to PT and FHA following the booster dose were significantly higher in the acellular vaccinees than in the whole cell vaccinees. Seropositivity rates to PT and FHA in the acellular vaccinees, which were more than 93.3% 1 month after primary immunization, ranged from 50.0 to 77.8% after 1 year. In conclusion, the acellular vaccines did not produce higher antibody levels than the whole cell vaccine 1 year after primary immunization. The booster dose was essential to maintaining sufficient seropositivity to pertussis antigens.
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    A randomized controlled trial of two acellular pertussis-diphtheria-tetanus vaccines in primary immunization in Ghana: Antibody responses and adverse reactions
    (1994) Hori, H.; Afari, E.A.; Akanmori, B.D.; Kamiya, Y.; Sakatoku, H.; Nkrumah, F.K.; Fukai, K.
    Two acellular pertussis vaccines combined with diphtheria and tetanus toxoids (APDT vaccines) were compared with a whole cell PDT (WCPDT) vaccine in primary immunization in Ghana. One is a liquid vaccine which is used for general immunization in Japan and the other is a freeze-dried vaccine newly developed as a heat-stable vaccine. Eighty-nine infants were recruited in the study. Sixty-eight who completed three doses of the immunization were assessed for immunological responses. Twenty-one dropped out because of sickness or moving from the study area. A total of 242 vaccinations in 89 infants were followed up for adverse reactions. Geometric mean titres (GMTs) to filamentous haemagglutinin in the two APDT vaccinees were significantly higher than in the WCPDT recipients. GMTs to pertussis toxin, diphtheria and tetanus toxoids were not significantly different among the three groups. Seropositive rates to pertussis antigens, tetanus and diphtheria toxoids were 94.4 to 100% in the two APDT vaccines. Systemic reactions within 7 days of inoculation were similarly low in the three groups, but significantly fewer infants had local reactions after either of the two APDT vaccines than after the WCPDT vaccine.
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    Impact of primary health care on child morbidity and mortality in rural Ghana: The Gomoa experience
    (Central African Journal of Medicine, 1995-05) Afari, E.A.; Nkrumah, F.K.; Nakana, T.; Sakatoku, H.; Hori, H.; Binka, F.
    The impact of a combination of PHC intervention activities on child survival, growth, morbidity and mortality was assessed in three selected rural communities (Gomoa Fetteh, Gomoa Onyadze/Otsew Jukwa and Gomoa Mprumem) in the Central Region of Ghana from 1987 to 1990. EPI, provision of basic essential drugs and supplies for the treatment of common childhood diseases, treatment of the sick child, growth monitoring, health education, provision of antenatal services, family planning, training and supervision of Community Health Workers, disease surveillance and special studies were the major PHC strategies used to improve the health of the child and the pregnant woman in the three communities. These activities in their totality have had significant impact on morbidity and mortality in children under five and on maternal mortality in children under five and on maternal mortality over the study period 1987 to 1990. Although malaria, acute respiratory infections and diarrhoea diseases continue to be major causes of childhood morbidity, deaths due to these diseases have dramatically declined. Measles and other vaccine preventable diseases no longer contribute significantly to childhood morbidity and mortality. Infant and under five mortality have been reduced from 114.6/1000 and 155.6/1000 live births to 40.8/1000 and 61.2/1000 live births respectively. The crude birth rates however, remain almost the same over the five year period (43 to 48/1000 pop.) but crude death rates have declined (11 to 12.4/1000 pop.).(ABSTRACT TRUNCATED AT 250 WORDS)
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    Health centre versus home presumptive diagnosis of malaria in southern Ghana: Implications for home-based care policy.
    (2000) Dunyo, S.K.; Afari, E.A.; Koram, K.A.; Ahorlu, C.K.; Abubakar, I.; Nkrumah, F.K.
    A study was conducted in 1997 to compare the accuracy of presumptive diagnosis of malaria in children aged 1-9 years performed by caretakers of the children to that of health centre staff in 2 ecological zones in southern Ghana. Similar symptoms were reported in the children at home and at the health centre. In the home setting, symptoms were reported the same day that they occurred, 77.6% of the children with a report of fever were febrile (axillary temperature ≥ 37.5°C)and 64.7% of the reports of malaria were parasitologically confirmed. In the health centre, the median duration of symptoms before a child was seen was 3 days (range 1-14 days), 58.5% of the children with a report of fever were febrile and 62.6% of the clinically diagnosed cases were parasitologically confirmed. In the 2 settings almost all the infections were due to Plasmodium falciparum. Parasite density was 3 times higher in the health centre cases compared to the home-diagnosed cases. Early and appropriate treatment of malaria detected in children by caretakers may prevent complications that arise as a result of persistence of symptoms and attainment of high parasitaemic levels.
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    Malaria-related beliefs and behaviour in southern Ghana: Implications for treatment, prevention and control.
    (Tropical Medicine and International Health, 2(5), 488-499., 1997) Ahorlu, C.K.; Dunyo, S.K.; Afari, E.A.; Koram, K.A.; Nkrumah, F.K.
    A research infrastructure was established in two ecological zones in southern Ghana to study the variables of malaria transmission and provide information to support the country's Malaria Action Plan (MAP) launched in 1992. Residents' beliefs and practices about causes, recognition, treatment and prevention of malaria were explored in two ecological zones in southern Ghana using epidemiological and social research methods. In both communities females constituted more than 80% of caretakers of children 1-9 years and the illiteracy rate was high. Fever and malaria, which are locally called Asra or Atridi, were found to represent the same thing and are used interchangebly. Caretakers were well informed about the major symptoms of malaria, which correspond to the current clinical case definition of malaria. Knowledge about malaria transmission us, however, shrouded in many misconceptions. Though the human dwellings in the study communities conferred no real protection against mosquitoes, bednet usage was low while residents combatted the nuisance of mosquitoes with insecticide sprays, burning of coils and herbs, which they largely considered as temporary measures. Home treatment of malaria combining herbs and over-the-counter drugs and inadequate doses of chloroquine was widespread. There is a need for a strong educational component to be incorporated into the MAP to correct misconceptions about malaria transmission, appropriate treatment and protection of households. Malaria control policies should recognize the role of home treatment and drug shops in the management of malaria and incorporate them into existing control strategies.