M Jasseh
Medical Research Council, Demographic Surveillance, Department Member
In 1997, The Gambia became the first African country to introduce conjugate Haemophilus influenzae type b (Hib) vaccine with good disease control through to 2010. Culture-based surveillance for invasive bacterial disease in eastern... more
In 1997, The Gambia became the first African country to introduce conjugate Haemophilus influenzae type b (Hib) vaccine with good disease control through to 2010. Culture-based surveillance for invasive bacterial disease in eastern Gambia, specifically the Basse Health and Demographic Surveillance System (BHDSS) area, was conducted from 12 May 2008 and in Fuladu West district from 12 September 2011 until 31 December 2013. In 2011, Hib serology was measured in 5-34-year-olds. In all, 16,735 of 17,932 (93%) eligible patients were investigated. We detected 57 cases of invasive H. influenzae disease; 24 (42%) were type b. No cases of Hib disease were detected in the BHDSS area in 2008-2009; 1 was detected in 2010, 2 in 2011, 4 in 2012 and 7 in 2013. In 2013, the incidence of Hib disease in those aged 2-11 and 2-59 months in the BHDSS area was 88 [95% confidence interval (CI): 29-207] and 22 (95% CI: 9-45) cases per 10 person-years, respectively. In 2013, disease incidence in Fuladu West among those aged 0-59 months was 26 (95% CI: 7-67) cases per 10 person-years. Nine of 24 Hib cases were vaccine failures (2 HIV positive) and 9 were too young to have been vaccinated. The proportion of children aged 5-6 years (n = 223) with anti-Hib IgG ≥1.0 μg/mL was 67%; the antibody nadir was in 9-14-year-olds (n = 58) with 55% above threshold. Hib disease in eastern Gambia has increased in recent years. Surveillance in developing countries should remain alert to detect such changes.
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The age pattern of mortality in sub-Saharan Africa and how it varies across the continent remain poorly understood. The region lacks accurate registration statistics and assumptions about mortality patterns are needed to produce and... more
The age pattern of mortality in sub-Saharan Africa and how it varies across the continent remain poorly understood. The region lacks accurate registration statistics and assumptions about mortality patterns are needed to produce and smooth mortality estimates. These have had to be taken from model life table systems based on non-African data. Birth histories collected in national Demographic and Health Surveys are used to investigate age patterns of mortality in childhood in the sub-national regions of 26 countries of continental Sub-Saharan Africa. The majority of populations display a pattern of higher child relative to infant mortality than in any existing model system, including the Princeton "North" models. This reflects the existence of a "hump" of excess mortality in the late post-neonatal period and second year of life in more than three-quarters of sub-national populations. Age patterns of mortality vary markedly within and between countries, though adja...
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This Perspective describes key considerations for the design and analysis of candidate vaccine trials during public health emergencies.
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To describe the spatial pattern in under-5 mortality rates in the Basse Health and Demographic Surveillance System (BHDSS); and to test for associations between under-5 deaths and biodemographic and socioeconomic risk factors. Using data... more
To describe the spatial pattern in under-5 mortality rates in the Basse Health and Demographic Surveillance System (BHDSS); and to test for associations between under-5 deaths and biodemographic and socioeconomic risk factors. Using data on child survival from 2007-2011 in the BHDSS, we mapped under-5 mortality by km(2) . We tested for spatial clustering of high or low death rates using Kulldorff's spatial scan statistic. Associations between child death and a variety of biodemographic and socioeconomic factors were assessed with Cox proportional hazards models, and deviance residuals from the best-fitting model were tested for spatial clustering. The overall death rate among children under 5 was 0.0195 deaths per child-year. We found two spatial clusters of high death rates and one spatial cluster of low death rates; children in the two high clusters died at a rate of 0.0264 and 0.0292 deaths per child-year, while in the low cluster the rate was 0.0144 deaths per child-year. We...
Research Interests: Demography, Death, Adolescent, Humans, Female, and 15 moreMale, Infant, Gambia, Ethnic Groups, Newborn Infant, Adult, Infant Mortality, Public health systems and services research, Risk Factors, Child mortality, Proportional Hazards Models, Infant Death, Child preschool, Family Characteristics, and Cause of death
Studies in Africa investigating health-seeking behaviour by interviewing tuberculosis patients have revealed patient knowledge issues and significant delays to diagnosis. We aimed to study health-seeking behaviour and experience of those... more
Studies in Africa investigating health-seeking behaviour by interviewing tuberculosis patients have revealed patient knowledge issues and significant delays to diagnosis. We aimed to study health-seeking behaviour and experience of those with cough in The Gambia and to identify whether they had tuberculosis. During a round of a population under 3-monthly demographic surveillance, we identified people >10 years old who had been coughing > or = 3 weeks. A questionnaire was administered concerning demographic data, cough, knowledge, health seeking, and experience at health facilities. Case finding utilised sputum smear and chest X-ray. 122/29,871 coughing individuals were identified. Of 115 interviewed, 93 (81%) had sought treatment; 76 (81.7%) from the health system. Those that visited an alternative health provider first were significantly older than those who visited the health system first (p = 0.03). The median time to seek treatment was 2 weeks (range 0-106). 54 (58.1%) mad...
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Background Malaria is a leading cause of death in children below five years of age in sub-Saharan Africa. All-cause and malaria-specific mortality rates for children under-five years old in a mesoendemic malaria area (The Gambia) were... more
Background Malaria is a leading cause of death in children below five years of age in sub-Saharan Africa. All-cause and malaria-specific mortality rates for children under-five years old in a mesoendemic malaria area (The Gambia) were compared with those from a hyper/holoendemic area (Burkina Faso). Methods Information on observed person-years (PY), deaths and cause of death was extracted from online search, using key words: "Africa, The Gambia, Burkina Faso, malaria, Plasmodium falciparum, mortality, child survival, morbidity". Missing person-years were estimated and all-cause and malaria-specific mortality were calculated as rates per 1,000 PY. Studies were classified as longitudinal/clinical studies or surveys/censuses. Linear regression was used to investigate mortality trends. Results Overall, 39 and 18 longitudinal/clinical studies plus 10 and 15 surveys and censuses were identified for The Gambia and Burkina Faso respectively (1960–2004). Model-based estimates for u...
Research Interests: Demography, Algorithms, Medical Microbiology, Malaria, Economic Development, and 15 moreMedicine, Humans, Burkina Faso, Health Services, Infant, Disease Control, Gambia, Clinical Study, Linear Regression, Child mortality, Mortality rate, Child preschool, Cause of death, Malaria Falciparum, and disease transmission
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Research Interests: Organizational Culture, Leadership, Global Health, Developing Countries, Context, and 13 moreHealth Policy, Health Systems, Staff Development, Humans, People, Male, Public Policy and Administration, The Gambia, Gambia, Health Policy and Planning, Public Administration and Policy, Public health systems and services research, and Delivery of Health Care
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Research Interests: Demography, Africa, Malaria, Adolescent, Humans, and 13 moreChild, Female, Asia, Male, Infant, Data Collection, Aged, Middle Aged, Autopsy, Adult, Child preschool, Cause of death, and Population surveillance
To describe how, through a DSS in a rural area of The Gambia, it has been possible to measure substantial reductions in child mortality rates and how we investigated whether the decline paralleled the registered fall in malaria incidence... more
To describe how, through a DSS in a rural area of The Gambia, it has been possible to measure substantial reductions in child mortality rates and how we investigated whether the decline paralleled the registered fall in malaria incidence in the country. Demographic surveillance data spanning 19.5 years (1 April 1989-30 September 2008) from 42 villages around the town of Farafenni, The Gambia, were used to estimate childhood mortality rates for neonatal, infant, child (1-4 years) and under-5 age groups. Data were presented in five a priori defined time periods, and annual rates per 1000 live births were derived from Kaplan-Meier survival probabilities. From 1989-1992 to 2004-2008, under-5 mortality declined by 56% (95% CI: 48-63%), from 165 (95% CI: 151-181) per 1000 live births to 74 (95% CI: 65-84) per 1000 live births. In 1- to 4-year-olds, mortality during the period 2004-2008 was 69% (95% CI: 60-76%) less than in 1989-1992. The corresponding mortality decline in infants was 39% (95% CI: 23-52%); in neonates, it was 38% (95% CI: 13-66%). The derived annual under-5 mortality rates declined from 159 per 1000 live births in 1990 to 45 per 1000 live births in 2008, thus implying an attainment of MDG4 seven years in advance of the target year of 2015. Achieving MDG4 is possible in poor, rural areas of Africa through widespread deployment of relatively simple measures that improve child survival, such as immunisation and effective malaria control.
Research Interests: Developing Countries, Population Dynamics, Medicine, Planning, Population, and 15 moreHumans, Measurement, Infant, Census, Incidence, Gambia, Infant Mortality, Perinatal mortality, Child mortality, Poisson Distribution, Proportional Hazards Models, Population Statistics, Child preschool, Cause of death, and Population surveillance
Between 1980 and 2000 total fertility in Kenya fell by about 40 per cent, from some eight births per woman to around five. During the same period, fertility in Uganda declined by less than 10 per cent. An analysis of the proximate... more
Between 1980 and 2000 total fertility in Kenya fell by about 40 per cent, from some eight births per woman to around five. During the same period, fertility in Uganda declined by less than 10 per cent. An analysis of the proximate determinants shows that the difference was due primarily to greater contraceptive use in Kenya, though in Uganda there was also a reduction in pathological sterility. The Demographic and Health Surveys show that women in Kenya wanted fewer children than those in Uganda, but that in Uganda there was also a greater unmet need for contraception. We suggest that these differences may be attributed, in part at least, first, to the divergent paths of economic development followed by the two countries after Independence; and, second, to the Kenya Government's active promotion of family planning through the health services, which the Uganda Government did not promote until 1995.
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Research Interests: Child health, Malaria, Medicine, Seasonality, Humans, and 15 moreChild, Female, Male, Infant, Randomised Controlled Trial, Randomized Trial, Pyrimethamine, Antimalarials, PLoS Med, Health Workers, Intermittent Preventive Treatment, Amodiaquine, Child preschool, Medical and Health Sciences, and Drug combinations
Background Screening doors, windows and eaves of houses should reduce house entry by eusynanthropic insects, including the common African house mosquito Culex pipiens quinquefasciatus and other culicines. In the pre-intervention year of a... more
Background Screening doors, windows and eaves of houses should reduce house entry by eusynanthropic insects, including the common African house mosquito Culex pipiens quinquefasciatus and other culicines. In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against mosquito house entry, a multi-factorial risk factor analysis study was used to identify factors influencing house entry by culicines of nuisance biting and medical importance. These factors were house location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound. Results 40,407 culicines were caught; the dominant species were Culex thalassius, Cx. pipiens s.l., Mansonia africanus, M. uniformis and Aedes aegypti. There were four times more Cx. pipiens s.l. in Farafenni town (geometric mean/trap/night = 8.1, 95% confidence intervals, CIs = 7.2–9.1) than in surrounding villages (2....
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Background In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify... more
Background In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify factors that influence mosquito house entry. Methods Mosquitoes were sampled using CDC light traps in 976 houses, each on one night, in Farafenni town and surrounding villages during the malaria-transmission season in The Gambia. Catches from individual houses were both (a) left unadjusted and (b) adjusted relative to the number of mosquitoes caught in four sentinel houses that were operated nightly throughout the period, to allow for night-to-night variation. Houses were characterized by location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound. Results 106,536 mosquitoes were caught, of which 55% were Anopheles gambiae sensu lato, the major malaria vectors in the regio...
Research Interests: Geography, Medical Microbiology, Malaria, Housing, Medicine, and 15 moreAnimals, Performance Model, Population Density, Risk factors, Gambia, Anopheles gambiae, Mosquito Control, Randomized Controlled Trial, Intervention study, Risk Factors, Confidence Interval, Insect Vectors, Geometric mean, Domestic animal, and Model performance
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Research Interests: Medical Microbiology, Biology, Medicine, Emerging Infectious Diseases, Disease Outbreaks, and 15 moreHumans, Female, Male, Infant, Incidence, Risk factors, Gambia, Clinical Sciences, Meningococcal disease, Meningitis, Public health systems and services research, Odds ratio, Risk Factors, Case Control Studies, and Child preschool
M= SB+ C+ R 19 xm matrix M of age-specific mortality rates is a weighted combination of age-varying components S (19 xn), with weights B (nx m), plus a constant vector C (19 x 1), and possibly a vector of age-specific residuals R (19 x... more
M= SB+ C+ R 19 xm matrix M of age-specific mortality rates is a weighted combination of age-varying components S (19 xn), with weights B (nx m), plus a constant vector C (19 x 1), and possibly a vector of age-specific residuals R (19 x 1).(19 is the number of standard ...
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Research Interests: Epidemiology, Accessibility, Data Analysis, Health Care, Developing Countries, and 15 moreHealth, Humans, Age, Distance, Female, Care, Gambia, Access to Health Care, Child mortality, Case Control Study, Confidence Interval, Case Control Studies, Child preschool, Health Services Accessibility, and Interviews as topic
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Research Interests: Focus Groups, Tropical Medicine, Housing, Insecticides, Humans, and 15 moreChild, Animals, Temperature, Anemia, Gambia, VECTOR, Mosquito Control, Questionnaires, Plasmodium falciparum, The American, Nino, Rural Population, Malaria Falciparum, Medical and Health Sciences, and Residence Characteristics
Women continue to die in unacceptably large numbers around the world as a result of pregnancy, particularly in sub-Saharan Africa and Asia. Part of the problem is a lack of accurate, population-based information characterising the issues... more
Women continue to die in unacceptably large numbers around the world as a result of pregnancy, particularly in sub-Saharan Africa and Asia. Part of the problem is a lack of accurate, population-based information characterising the issues and informing solutions. Population surveillance sites, such as those operated within the INDEPTH Network, have the potential to contribute to bridging the information gaps. To describe patterns of pregnancy-related mortality at INDEPTH Network Health and Demographic Surveillance System sites in sub-Saharan Africa and southeast Asia in terms of maternal mortality ratio (MMR) and cause-specific mortality rates. Data on individual deaths among women of reproductive age (WRA) (15-49) resident in INDEPTH sites were collated into a standardised database using the INDEPTH 2013 population standard, the WHO 2012 verbal autopsy (VA) standard, and the InterVA model for assigning cause of death. These analyses are based on reports from 14 INDEPTH sites, coveri...
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This article reports levels, trends, and age patterns of adult mortality in 23 sub-Saharan Africa countries, based on the sibling histories and orphanhood data collected by the countries’ Demographic and Health Surveys. Adult mortality... more
This article reports levels, trends, and age patterns of adult mortality in 23 sub-Saharan Africa countries, based on the sibling histories and orphanhood data collected by the countries’ Demographic and Health Surveys. Adult mortality has risen sharply since HIV became prevalent, but the size and speed of the mortality increase varies greatly among countries. Excess mortality is concentrated among women aged 25–39 and among men aged 30–44. These data suggest that the increase in the number of men who die each year has exceeded somewhat the increase for women. It is time for a systematic attempt to reconcile the demographic and epidemiological evidence concerning AIDS in Africa.
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Research Interests: Clinical Trial, Malaria, Tropical Medicine, Drug interactions, Public Health, and 18 moreGene expression, Multidisciplinary, Inflammatory Immune Response, Humans, Charcoal, Mice, Female, Animals, Male, PLoS one, Middle Aged, Adult, Activated Charcoal, Survival Rate, Antimalarials, Cerebral Malaria, Overall Survival, and Plasmodium berghei
Background In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify... more
Background In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify factors that influence mosquito house entry. Methods Mosquitoes were sampled using CDC light traps in 976 houses, each on one night, in Farafenni town and surrounding villages during the malaria-transmission season in The Gambia. Catches from individual houses were both (a) left unadjusted and (b) adjusted relative to the number of mosquitoes caught in four sentinel houses that were operated nightly throughout the period, to allow for night-to-night variation. Houses were characterized by location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound. Results 106,536 mosquitoes were caught, of which 55% were Anopheles gambiae sensu lato, the major malaria vectors in the region. There were seven fold higher numbers of An. gambiae s.l. in the villages (geometric mean per trap night = 43.7, 95% confidence intervals, CIs = 39.5–48.4) than in Farafenni town (6.3, 5.7–7.2) and significant variation between residential blocks (p Conclusion This study demonstrates that the risk of malaria transmission is greatest in rural areas, where large numbers of people sleep in houses made of mud blocks, where the eaves are open, horses are not tethered nearby and where churai is not burnt at night. These factors need to be considered in the design and analysis of intervention studies designed to reduce malaria transmission in The Gambia and other parts of sub-Saharan Africa.