Derivation and Internal Validation of a Novel Risk Assessment Tool to Identify Infants and Young Children at Risk for Post-Discharge Mortality in Dar es Salaam, Tanzania and Monrovia, Liberia.

OBJECTIVE: To derive and validate internally a novel risk assessment tool to identify young children at risk for all-cause mortality ≤60 days of discharge from hospitals in sub-Saharan Africa. STUDY DESIGN: We performed a prospective observational cohort study of children aged 1-59 months discharged from Muhimbili National Hospital in Dar es Salaam, Tanzania and John F. Kennedy Medical Center in Monrovia, Liberia (2019-2022). Caregivers received telephone calls up to 60 days after discharge to ascertain participant vital status. We collected socioeconomic, demographic, clinical, and anthropometric data during hospitalization. Candidate variables with P < .20 in bivariate analyses were included in a multivariable logistic regression model with best subset selection to identify risk factors for the outcome. We internally validated our tool using bootstrapping with 500 repetitions. RESULTS: There were 1933 young children enrolled in the study. The median (IQR) age was 11 (4, 23) months and 58.7% were males. In total, 67 (3.5%) died during follow-up. Ten variables contributed to our tool (total possible score 82). Cancer (aOR 10.6, 95% CI 2.58, 34.6), pedal edema (aOR 6.94, 95% CI 1.69, 22.6), and leaving against medical advice (aOR 6.46, 95% CI 2.46, 15.3) were most predictive of post-discharge mortality. Our risk assessment tool demonstrated good discriminatory value (optimism corrected area under the receiver operating characteristic curve 0.77), high precision, and sufficient calibration. CONCLUSIONS: After validation, this tool may be used to identify young children at risk for post-discharge mortality to direct resources for follow-up of high-risk children.

Discovery and validation of biomarkers to guide clinical management of pneumonia in African children.

BACKGROUND: Pneumonia is the leading cause of death in children globally. Clinical algorithms remain suboptimal for distinguishing severe pneumonia from other causes of respiratory distress such as malaria or distinguishing bacterial pneumonia and pneumonia from others causes, such as viruses. Molecular tools could improve diagnosis and management. METHODS: We conducted a mass spectrometry-based proteomic study to identify and validate markers of severity in 390 Gambian children with pneumonia (n = 204) and age-, sex-, and neighborhood-matched controls (n = 186). Independent validation was conducted in 293 Kenyan children with respiratory distress (238 with pneumonia, 41 with Plasmodium falciparum malaria, and 14 with both). Predictive value was estimated by the area under the receiver operating characteristic curve (AUC). RESULTS: Lipocalin 2 (Lpc-2) was the best protein biomarker of severe pneumonia (AUC, 0.71 [95% confidence interval, .64-.79]) and highly predictive of bacteremia (78% [64%-92%]), pneumococcal bacteremia (84% [71%-98%]), and "probable bacterial etiology" (91% [84%-98%]). These results were validated in Kenyan children with severe malaria and respiratory distress who also met the World Health Organization definition of pneumonia. The combination of Lpc-2 and haptoglobin distinguished bacterial versus malaria origin of respiratory distress with high sensitivity and specificity in Gambian children (AUC, 99% [95% confidence interval, 99%-100%]) and Kenyan children (82% [74%-91%]). CONCLUSIONS: Lpc-2 and haptoglobin can help discriminate the etiology of clinically defined pneumonia and could be used to improve clinical management. These biomarkers should be further evaluated in prospective clinical studies.

Etiology of severe childhood pneumonia in the Gambia, West Africa, determined by conventional and molecular microbiological analyses of lung and pleural aspirate samples.

Molecular analyses of lung aspirates from Gambian children with severe pneumonia detected pathogens more frequently than did culture and showed a predominance of bacteria, principally Streptococcus pneumoniae, >75% being of serotypes covered by current pneumococcal conjugate vaccines. Multiple pathogens were detected frequently, notably Haemophilus influenzae (mostly nontypeable) together with S. pneumoniae.

Is the absolute requirement for informed consent before HIV testing a barrier to public health? A case report and management challenges.

Clinicians in sub-Saharan Africa are faced with a major challenge of parental refusal to test their children for HIV. We present a case of a nine-month-old child with a clinical presentation suggestive of HIV infection whose mother persistently declined HIV testing of the child or herself. The case illustrates the difficulties faced by the clinicians caring for the child in an isolated location in West Africa. While not eliminating these difficulties, an opt-out approach to paediatric HIV testing in sub-Saharan Africa may increase the proportion of children who access treatment when they need it, particularly when this is backed by the development of more effective national and regional clinical and legislative frameworks for HIV testing in children.

Morbidity and unplanned healthcare encounters after hospital discharge among young children in Dar es Salaam, Tanzania and Monrovia, Liberia.

BACKGROUND: Researchers and healthcare providers have paid little attention to morbidity and unplanned healthcare encounters for children following hospital discharge in low- and middle-income countries. Our objective was to compare symptoms and unplanned healthcare encounters among children aged <5 years who survived with those who died within 60 days of hospital discharge through follow-up phone calls. METHODS: We conducted a secondary analysis of a prospective observational cohort of children aged <5 years discharged from neonatal and paediatric wards of two national referral hospitals in Dar es Salaam, Tanzania and Monrovia, Liberia. Caregivers of enrolled participants received phone calls 7, 14, 30, 45, and 60 days after hospital discharge to record symptoms, unplanned healthcare encounters, and vital status. We used logistic regression to determine the association between reported symptoms and unplanned healthcare encounters with 60-day post-discharge mortality. RESULTS: A total of 4243 participants were enrolled and had 60-day vital status available; 138 (3.3%) died. For every additional symptom ever reported following discharge, there was a 35% greater likelihood of post-discharge mortality (adjusted odds ratio [aOR] 1.35, 95% confidence interval [CI] 1.10 to 1.66; p=0.004). The greatest survival difference was noted for children who had difficulty breathing (2.1% among those who survived vs 36.0% among those who died, p<0.001). Caregivers who took their child home from the hospital against medical advice during the initial hospitalisation had over eight times greater odds of post-discharge mortality (aOR 8.06, 95% CI 3.87 to 16.3; p<0.001) and those who were readmitted to a hospital had 3.42 greater odds (95% CI 1.55 to 8.47; p=0.004) of post-discharge mortality than those who did not seek care when adjusting for site, sociodemographic factors, and clinical variables. CONCLUSION: Surveillance for symptoms and repeated admissions following hospital discharge by healthcare providers is crucial to identify children at risk for post-discharge mortality.

Identifying neonates at risk for post-discharge mortality in Dar es Salaam, Tanzania, and Monrovia, Liberia: Derivation and internal validation of a novel risk assessment tool.

INTRODUCTION: The immediate period after hospital discharge carries a large burden of childhood mortality in sub-Saharan Africa. Our objective was to derive and internally validate a risk assessment tool to identify neonates discharged from the neonatal ward at risk for 60-day post-discharge mortality. METHODS: We conducted a prospective observational cohort study of neonates discharged from Muhimbili National Hospital in Dar es Salaam, Tanzania, and John F Kennedy Medical Centre in Monrovia, Liberia. Research staff called caregivers to ascertain vital status up to 60 days after discharge. We conducted multivariable logistic regression analyses with best subset selection to identify socioeconomic, demographic, clinical, and anthropometric factors associated with post-discharge mortality. We used adjusted log coefficients to assign points to each variable and internally validated our tool with bootstrap validation with 500 repetitions. RESULTS: There were 2344 neonates discharged and 2310 (98.5%) had post-discharge outcomes available. The median (IQR) age at discharge was 8 (4, 15) days; 1238 (53.6%) were male. In total, 71 (3.1%) died during follow-up (26.8% within 7 days of discharge). Leaving against medical advice (adjusted OR [aOR] 5.62, 95% CI 2.40 to 12.10) and diagnosis of meconium aspiration (aOR 6.98, 95% CI 1.69 to 21.70) conferred the greatest risk for post-discharge mortality. The risk assessment tool included nine variables (total possible score=63) and had an optimism corrected area under the receiver operating characteristic curve of 0.77 (95% CI 0.75 to 0.80). A score of ≥6 was most optimal (sensitivity 68.3% [95% CI 64.8% to 71.5%], specificity 72.1% [95% CI 71.5% to 72.7%]). CONCLUSIONS: A small number of factors predicted all-cause, 60-day mortality after discharge from neonatal wards in Tanzania and Liberia. After external validation, this risk assessment tool may facilitate clinical decision making for eligibility for discharge and the direction of resources to follow-up high risk neonates.

The effectiveness of conjugate Haemophilus influenzae type B vaccine in The Gambia 14 years after introduction.

BACKGROUND: The Gambia was the first country in Africa to introduce conjugate Haemophilus influenzae type b (Hib) vaccine, which, as in other developing countries but unlike industrialized countries, is delivered as a 3-dose primary series with no booster. This study assessed its effectiveness 14 years after introduction. METHODS: Using methods standardized during >20 years in the study site, clinical and microbiological surveillance for invasive Hib disease (primarily meningitis) in the Western Region of The Gambia from 2007 to 2010 was complemented with studies of Hib carriage in children aged 1 to <2 years, Hib antibody levels in children aged <5 years, and Hib vaccine coverage and timing in children aged 1 to <2 years. RESULTS: The incidence of Hib meningitis remained low (averaging 1.3 per 100 000 children aged <5 years annually), as did the Hib oropharyngeal carriage rate (0.9%). Hib antibody levels were protective in >99% of those surveyed, albeit with lower titers in older children; and coverage of conjugate Hib vaccination was high (91% having 3 doses at 1-2 years of age) using a schedule that was delivered at median ages of 2.6 months, 4.3 months, and 6 months for the first, second, and third doses, respectively. CONCLUSIONS: Conjugate Hib vaccine was delivered on time in a 3-dose primary series without booster to a high proportion of eligible children and this was associated with effective disease control up to 14 years after introduction. It is important that surveillance continues in this first African country to introduce the vaccine to determine if effective control persists or if a booster dose becomes necessary as has been the case in industrialized countries.

Serotype analysis of Streptococcus pneumoniae in lung and nasopharyngeal aspirates from children in the Gambia by MassTag PCR.

Streptococcus pneumoniae strains comprise >90 serotypes. Here we describe establishment of a MassTag PCR assay designed to serotype S. pneumoniae and demonstrate its utility in tests using 31 paired lung aspirate and nasopharyngeal aspirate samples from children with pneumonia in the Gambia. Serotypes 1, 5, and 14 in were implicated in 90% of lung infections. With 5 exceptions, serotypes found in lung aspirates were also found in nasopharyngeal aspirates.

Incidence of Haemophilus influenzae type b disease in The Gambia 14 years after introduction of routine Haemophilus influenzae type b conjugate vaccine immunization.

OBJECTIVE: Haemophilus influenzae type b (Hib) conjugate vaccine was first introduced in Africa in The Gambia in 1997 as a primary 3-dose course in infancy with no booster, and was followed by the disappearance of invasive Hib disease by 2002. A cluster of cases detected non-systematically in post-infant children in 2005-2006 raised the question of the need for a booster dose. The objective of this study was to determine the incidence of invasive Hib disease in Gambian children 14 years after the introduction of Hib conjugate vaccine. STUDY DESIGN: This hospital-based clinical and microbiological Hib disease surveillance in 3 hospitals in the western region of The Gambia was undertaken between October 2007 and December 2010 applying the same methods used in a previous Hib vaccine effectiveness study in 1997-2002. RESULTS: The annual incidences of Hib meningitis and all invasive Hib disease in children aged <5 years remained below 5 cases per 100,000 children during 2008-2010. The median age of patients with any invasive Hib disease was 5 months. CONCLUSION: Hib conjugate vaccination as a primary 3-dose course in The Gambia remains highly effective in controlling invasive Hib disease, and current data do not support the introduction of a booster dose.

Predictive value of clinician impression for readmission and postdischarge mortality among neonates and young children in Dar es Salaam, Tanzania and Monrovia, Liberia.

BACKGROUND: There are no validated clinical decision aids to identify neonates and young children at risk of hospital readmission or postdischarge mortality in sub-Saharan Africa, leaving the decision to discharge a child to a clinician's impression. Our objective was to determine the precision of clinician impression to identify neonates and young children at risk for readmission and postdischarge mortality. METHODS: We conducted a survey study nested in a prospective observational cohort of neonates and children aged 1-59 months followed 60 days after hospital discharge from Muhimbili National Hospital in Dar es Salaam, Tanzania or John F. Kennedy Medical Center in Monrovia, Liberia. Clinicians who discharged each enrolled patient were surveyed to determine their perceived probability of the patient's risk of 60-day hospital readmission or postdischarge mortality. We calculated the area under the precision-recall curve (AUPRC) to determine the precision of clinician impression for both outcomes. RESULTS: Of 4247 discharged patients, 3896 (91.7%) had available clinician surveys and 3847 (98.7%) had 60-day outcomes available: 187 (4.8%) were readmitted and 120 (3.1%) died within 60 days of hospital discharge. Clinician impression had poor precision in identifying neonates and young children at risk of hospital readmission (AUPRC: 0.06, 95% CI: 0.04 to 0.08) and postdischarge mortality (AUPRC: 0.05, 95% CI: 0.03 to 0.08). Patients for whom clinicians attributed inability to pay for future medical treatment as the reason for risk for unplanned hospital readmission had 4.76 times the odds hospital readmission (95% CI: 1.31 to 17.25, p=0.02). CONCLUSIONS: Given the poor precision of clinician impression alone to identify neonates and young children at risk of hospital readmission and postdischarge mortality, validated clinical decision aids are needed to aid in the identification of young children at risk for these outcomes.

A Prospective, observational cohort study to identify neonates and children at risk of postdischarge mortality in Dar es Salaam, Tanzania and Monrovia, Liberia: the PPDM study protocol.

INTRODUCTION: Over half of the 5 million annual deaths among children aged 0-59 months occur in sub-Saharan Africa. The period immediately after hospitalisation is a vulnerable time in the life of a child in sub-Saharan Africa as postdischarge mortality rates are as high as 1%-18%. Identification of neonates and children who are at highest risk for postdischarge mortality may allow for the direction of interventions to target patients at highest risk. METHODS AND ANALYSIS: The Predicting Post-Discharge Mortality study is a prospective, observational study being conducted at Muhimbili National Hospital (Dar es Salaam, Tanzania) and John F. Kennedy Medical Center (Monrovia, Liberia). The aim is to derive and validate two, age population specific, clinical prediction rules for the identification of neonates (n=2000) and children aged 1-59 months (n=2000) at risk for all-cause mortality within 60 days of discharge from the neonatal intensive care unit or paediatric ward. Caregivers of participants will receive phone calls 7, 14, 30, 45 and 60 days after discharge to assess vital status. Candidate predictor variables will include demographic, anthropometric and clinical factors. Elastic net regression will be used to derive the clinical prediction rules. Bootstrapped selection with repetitions will be used for internal validation. Planned secondary analyses include the external validation of existing clinical prediction models, determination of clinicians' ability to identify neonates and children at risk of postdischarge mortality at discharge, analysis of factors associated with hospital readmission and unplanned clinic visits and description of health-seeking behaviours in the postdischarge period. ETHICS AND DISSEMINATION: This study received ethical clearance from the Tanzania National Institute of Medical Research, Muhimbili University of Health and Allied Sciences, the John F. Kennedy Medical Center Institutional Review Board, and the Boston Children's Hospital Institutional Review Board. Findings will be disseminated at scientific conferences and as peer-reviewed publications.

Where there is no local author: a network bibliometric analysis of authorship parasitism among research conducted in sub-Saharan Africa.

INTRODUCTION: Authorship parasitism (ie, no authors affiliated with the country in which the study took place) occurs frequently in research conducted in low-income and middle-income countries, despite published recommendations defining authorship criteria. The objective was to compare characteristics of articles exhibiting authorship parasitism in sub-Saharan Africa to articles with author representation from sub-Saharan African countries. METHODS: A bibliometric review of articles indexed in PubMed published from January 2014 through December 2018 reporting research conducted in sub-Saharan Africa was performed. Author affiliations were assigned to countries based on regular expression algorithms. Choropleth maps and network diagrams were created to determine where authorship parasitism occurred, and multivariable logistic regression was used to determine associated factors. RESULTS: Of 32 061 articles, 14.8% (n=4754) demonstrated authorship parasitism, which was most common among studies from Somalia (n=175/233, 75.1%) and Sao Tome and Principe (n=20/28, 71.4%). Authors affiliated with USA and UK institutions were most commonly involved in articles exhibiting authorship parasitism. Authorship parasitism was more common in articles: published in North American journals (adjusted OR (aOR) 1.26, 95% CI 1.07 to 1.50) than in sub-Saharan African journals, reporting work from multiple sub-Saharan African countries (aOR 8.41, 95% CI 7.30 to 9.68) compared with work from upper-middle income sub-Saharan African countries, with <5 authors (aOR 14.46, 95% CI 12.81 to 16.35) than >10 authors, and was less common in articles published in French (aOR 0.60, 95% CI 0.41 to 0.85) than English. CONCLUSIONS: Authorship parasitism was common in articles reporting research conducted in sub-Saharan Africa. There were reliable predictors of authorship parasitism. Investigators and institutions in high-income countries, as well as funding agencies and journals should promote research from sub-Saharan Africa, including its publication, in a collaborative and equitable manner.

Impact of the introduction of pneumococcal conjugate vaccination on invasive pneumococcal disease and pneumonia in The Gambia: 10 years of population-based surveillance.

BACKGROUND: The Gambia introduced seven-valent pneumococcal conjugate vaccine (PCV7) in August 2009, followed by PCV13 in May, 2011, using a schedule of three primary doses without a booster dose or catch-up immunisation. We aimed to assess the long-term impact of PCV on disease incidence. METHODS: We did 10 years of population-based surveillance for invasive pneumococcal disease (IPD) and WHO defined radiological pneumonia with consolidation in rural Gambia. The surveillance population included all Basse Health and Demographic Surveillance System residents aged 2 months or older. Nurses screened all outpatients and inpatients at all health facilities using standardised criteria for referral. Clinicians then applied criteria for patient investigation. We defined IPD as a compatible illness with isolation of Streptococcus pneumoniae from a normally sterile site (cerebrospinal fluid, blood, or pleural fluid). We compared disease incidence between baseline (May 12, 2008-May 11, 2010) and post-vaccine years (2016-2017), in children aged 2 months to 14 years, adjusting for changes in case ascertainment over time. FINDINGS: We identified 22 728 patients for investigation and detected 342 cases of IPD and 2623 cases of radiological pneumonia. Among children aged 2-59 months, IPD incidence declined from 184 cases per 100 000 person-years to 38 cases per 100 000 person-years, an 80% reduction (95% CI 69-87). Non-pneumococcal bacteraemia incidence did not change significantly over time (incidence rate ratio 0·88; 95% CI, 0·64-1·21). We detected zero cases of vaccine-type IPD in the 2-11 month age group in 2016-17. Incidence of radiological pneumonia decreased by 33% (95% CI 24-40), from 10·5 to 7·0 per 1000 person-years in the 2-59 month age group, while pneumonia hospitalisations declined by 27% (95% CI 22-31). In the 5-14 year age group, IPD incidence declined by 69% (95% CI -28 to 91) and radiological pneumonia by 27% (95% CI -5 to 49). INTERPRETATION: Routine introduction of PCV13 substantially reduced the incidence of childhood IPD and pneumonia in rural Gambia, including elimination of vaccine-type IPD in infants. Other low-income countries can expect substantial impact from the introduction of PCV13 using a schedule of three primary doses. FUNDING: Gavi, The Vaccine Alliance; Bill & Melinda Gates Foundation; UK Medical Research Council; Pfizer Ltd.

Zinc as an adjunct therapy in the management of severe pneumonia among Gambian children: randomized controlled trial.

BACKGROUND: The benefit of zinc as an adjunct therapy for severe pneumonia is not established. We assessed the benefit of adjunct zinc therapy for severe pneumonia in children and determined whether the study children were zinc deficient. METHODS: This was a randomized, parallel group, double-blind, placebo-controlled trial with an allocation ratio of 1:1 conducted in children with severe pneumonia to evaluate the efficacy of daily zinc as an adjunct treatment in preventing 'treatment failure' (presence of any sign of severe pneumonia) on day-5 and day-10 and in reducing the time to resolution of signs of severe pneumonia. Six hundred and four children 2-59 months of age presenting with severe pneumonia at six urban and rural health care facilities in The Gambia were individually randomised to receive placebo (n = 301) or zinc (n = 303) for seven days. To determine if the study children were zinc deficient, supplementation was continued in a randomly selected subgroup of 121 children from each arm for six months post-enrolment, and height-gain, nutritional status, plasma zinc concentrations, and immune competence were compared. RESULTS: Percentage of treatment failure were similar in placebo and zinc arms both on day 5 (14.0% vs 14.1%) and day 10 (5.2% vs 5.9%). The time to recovery from lower chest wall indrawing and sternal retraction was longer in the placebo compared to zinc arm (24.4 vs 23.0 hours; P = 0.011 and 18.7 vs 11.0 hours; P = 0.006 respectively). The time to resolution for all respiratory symptoms of severity was not significantly different between placebo and zinc arms (42.3 vs 30.9 hours respectively; P = 0.242). In the six months follow-up sub-group, there was no significant difference in height gain, height-for-age and weight-for-height Z-scores, mid upper arm circumference, plasma zinc concentrations, and anergy at six months post-enrolment. CONCLUSIONS: In this population, zinc given as an adjunct treatment for severe pneumonia showed no benefit in treatment failure rates, or clinically important benefit in time to recovery from respiratory symptoms and showed marginal benefit in rapidity of resolution of some signs of severity. This finding does not support routine use of zinc as an adjunct treatment in severe pneumonia in generally zinc replete children. TRIAL REGISTRATION: ISRCTN33548493.

Impact of the introduction of pneumococcal conjugate vaccination on pneumonia in The Gambia: population-based surveillance and case-control studies.

BACKGROUND: Pneumococcal conjugate vaccines (PCVs) are used in many low-income countries but their impact on the incidence of pneumonia is unclear. The Gambia introduced PCV7 in August, 2009, and PCV13 in May, 2011. We aimed to measure the impact of the introduction of these vaccines on pneumonia incidence. METHODS: We did population-based surveillance and case-control studies. The primary endpoint was WHO-defined radiological pneumonia with pulmonary consolidation. Population-based surveillance was for suspected pneumonia in children aged 2-59 months (minimum age 3 months in the case-control study) between May 12, 2008, and Dec 31, 2015. Surveillance for the impact study was limited to the Basse Health and Demographic Surveillance System (BHDSS), whereas surveillance for the case-control study included both the BHDSS and Fuladu West Health and Demographic Surveillance System. Nurses screened all outpatients and inpatients at all health facilities in the surveillance area using standardised criteria for referral to clinicians in Basse and Bansang. These clinicians recorded clinical findings and applied standardised criteria to identify patients with suspected pneumonia. We compared the incidence of pneumonia during the baseline period (May 12, 2008, to May 11, 2010) and the PCV13 period (Jan 1, 2014, to Dec 31, 2015). We also investigated the effectiveness of PCV13 using case-control methods between Sept 12, 2011, and Sept 31, 2014. Controls were aged 90 days or older, and were eligible to have received at least one dose of PCV13; cases had the same eligibility criteria with the addition of having WHO-defined radiological pneumonia. FINDINGS: We investigated 18 833 children with clinical pneumonia and identified 2156 cases of radiological pneumonia. Among children aged 2-11 months, the incidence of radiological pneumonia fell from 21·0 cases per 1000 person-years in the baseline period to 16·2 cases per 1000 person-years (23% decline, 95% CI 7-36) in 2014-15. In the 12-23 month age group, radiological pneumonia decreased from 15·3 to 10·9 cases per 1000 person-years (29% decline, 12-42). In children aged 2-4 years, incidence fell from 5·2 to 4·1 cases per 1000 person-years (22% decline, 1-39). Incidence of all clinical pneumonia increased by 4% (-1 to 8), but hospitalised cases declined by 8% (3-13). Pneumococcal pneumonia declined from 2·9 to 1·2 cases per 1000 person-years (58% decline, 22-77) in children aged 2-11 months and from 2·6 to 0·7 cases per 1000 person-years (75% decline, 47-88) in children aged 12-23 months. Hypoxic pneumonia fell from 13·1 to 5·7 cases per 1000 person-years (57% decline, 42-67) in children aged 2-11 months and from 6·8 to 1·9 cases per 1000 person-years (72% decline, 58-82) in children aged 12-23 months. In the case-control study, the best estimate of the effectiveness of three doses of PCV13 against radiological pneumonia was an adjusted odds ratio of 0·57 (0·30-1·08) in children aged 3-11 months and vaccine effectiveness increased with greater numbers of doses (p=0·026). The analysis in children aged 12 months and older was underpowered because there were few unvaccinated cases and controls. INTERPRETATION: The introduction of PCV in The Gambia was associated with a moderate impact on the incidence of radiological pneumonia, a small reduction in cases of hospitalised pneumonia, and substantial reductions of pneumococcal and hypoxic pneumonia in young children. Low-income countries that introduce PCV13 with reasonable coverage can expect modest reductions in hospitalised cases of pneumonia and a marked impact on the incidence of severe childhood pneumonia. FUNDING: GAVI's Pneumococcal vaccines Accelerated Development and Introduction Plan, Bill & Melinda Gates Foundation, and UK Medical Research Council.

Effect of the introduction of pneumococcal conjugate vaccination on invasive pneumococcal disease in The Gambia: a population-based surveillance study.

BACKGROUND: Little information is available about the effect of pneumococcal conjugate vaccines (PCVs) in low-income countries. We measured the effect of these vaccines on invasive pneumococcal disease in The Gambia where the 7-valent vaccine (PCV7) was introduced in August, 2009, followed by the 13-valent vaccine (PCV13) in May, 2011. METHODS: We conducted population-based surveillance for invasive pneumococcal disease in individuals aged 2 months and older who were residents of the Basse Health and Demographic Surveillance System (BHDSS) in the Upper River Region, The Gambia, using standardised criteria to identify and investigate patients. Surveillance was done between May, 2008, and December, 2014. We compared the incidence of invasive pneumococcal disease between baseline (May 12, 2008-May 11, 2010) and after the introduction of PCV13 (Jan 1, 2013-Dec 31, 2014), adjusting for changes in case ascertainment over time. FINDINGS: We investigated 14 650 patients, in whom we identified 320 cases of invasive pneumococcal disease. Compared with baseline, after the introduction of the PCV programme, the incidence of invasive pneumococcal disease decreased by 55% (95% CI 30-71) in the 2-23 months age group, from 253 to 113 per 100 000 population. This decrease was due to an 82% (95% CI 64-91) reduction in serotypes covered by the PCV13 vaccine. In the 2-4 years age group, the incidence of invasive pneumococcal disease decreased by 56% (95% CI 25-75), from 113 to 49 cases per 100 000, with a 68% (95% CI 39-83) reduction in PCV13 serotypes. The incidence of non-PCV13 serotypes in children aged 2-59 months increased by 47% (-21 to 275) from 28 to 41 per 100 000, with a broad range of serotypes. The incidence of non-pneumococcal bacteraemia varied little over time. INTERPRETATION: The Gambian PCV programme reduced the incidence of invasive pneumococcal disease in children aged 2-59 months by around 55%. Further surveillance is needed to ascertain the maximum effect of the vaccine in the 2-4 years and older age groups, and to monitor serotype replacement. Low-income and middle-income countries that introduce PCV13 can expect substantial reductions in invasive pneumococcal disease. FUNDING: GAVI's Pneumococcal vaccines Accelerated Development and Introduction Plan (PneumoADIP), Bill & Melinda Gates Foundation, and the UK Medical Research Council.

Rabies post-exposure prophylaxis at a clinic in Fajara, The Gambia.

BACKGROUND: The Gambia is a popular holiday destination that is classified as a high-risk area for rabies exposure by the WHO. METHODS: This was a retrospective study of 49 subjects with rabies exposure attending The Medical Research Council Clinical Service, The Gambia, for treatment. Their demographics, details of exposure and treatment delivery were evaluated. RESULTS: An estimated 16% (8/49) of all exposures were likely to be from rabid animals. Moreover, 24% (12/49) of patients were tourists, none of whom had received pre-exposure prophylaxis. CONCLUSION: Rabies exposure is a serious risk for Gambians and visitors. Tourists should be advised about pre-exposure prophylaxis and risk reduction of rabies exposure.

Highly accurate diagnosis of pleural tuberculosis by immunological analysis of the pleural effusion.

Pleural TB is notoriously difficult to diagnose due to its paucibacillary nature yet it is the most common cause of pleural effusions in TB endemic countries such as The Gambia. We identified both cellular and soluble biomarkers in the pleural fluid that allowed highly accurate diagnosis of pleural TB compared to peripheral blood markers. Multi-plex cytokine analysis on unstimulated pleural fluid showed that IP-10 resulted in a positive likelihood ratio (LR) of 9.6 versus 2.8 for IFN-γ; a combination of IP-10, IL-6 and IL-10 resulted in an AUC of 0.96 and positive LR of 10. A striking finding was the significantly higher proportion of PPD-specific IFN-γ+TNF-α+ cell population (PPD-IGTA) in the pleural fluid compared to peripheral blood of TB subjects. Presence of this pleural PPD-IGTA population resulted in 95% correct classification of pleural TB disease with a sensitivity of 95% and specificity of 100%. These data suggest that analysis of the site of infection provides superior diagnostic accuracy compared to peripheral blood for pleural TB, likely due to the sequestration of effector cells at this acute stage of disease.

The exposure of infants and children to carbon monoxide from biomass fuels in The Gambia: a measurement and modeling study.

Smoke from biomass fuels is a risk factor for pneumonia, the leading cause of child death worldwide. Although particulate matter (PM) is the metric of choice for studying the health effects of biomass smoke, measuring children's PM exposure is difficult. Carbon monoxide (CO), which is easier to measure, can be used as a proxy for PM exposure. We measured the exposure of children ≤ 5 years of age in The Gambia to CO using small, passive, color stain diffusion tubes. We conducted multiple CO measurements on a subset of children to measure day-to-day exposure variability. Usual CO exposure was modeled using a mixed effects model, which also included individual and household level exposure predictors. Mean measured CO exposure for 1181 children (n=2263 measurements) was 1.04 ± 1.46 p.p.m., indicating that the Gambian children in this study on average have a relatively low CO exposure. However, 25% of children had exposures of 1.3 p.p.m. or higher. CO exposure was higher during the rainy months (1.33 ± 1.62 p.p.m.). Burning insect coils, using charcoal, and measurement done in the rainy season were associated with higher exposure. A parsimonious model with fuel, season, and other PM sources as covariates explained 39% of between-child variation in exposure and helped remove within-child variability.