Yellow fever control in Cameroon: Where are we now and where are we going?

<p>Abstract</p> <p>Background</p> <p>Cameroon is one of 12 African countries that bear most of the global burden of yellow fever. In 2002 the country developed a five-year strategic plan for yellow fever control, which included strategies for prevention as well as rapid detection and response to outbreaks when they occur. We have used data collected by the national Expanded Programme on Immunisation to assess the progress made and challenges faced during the first four years of implementing the plan.</p> <p>Methods</p> <p>In January 2003, case-based surveillance of suspected yellow fever cases was instituted in the whole country. A year later, yellow fever immunisation at nine months of age (the same age as routine measles immunisation) was introduced. Supplementary immunisation activities (SIAs), both preventive and in response to outbreaks, also formed an integral part of the yellow fever control plan. Each level of the national health system makes a synthesis of its activities and sends this to the next higher level at defined regular intervals; monthly for routine data and daily for SIAs.</p> <p>Results</p> <p>From 2004 to 2006 the national routine yellow fever vaccination coverage rose from 58.7% to 72.2%. In addition, the country achieved parity between yellow fever and measles vaccination coverage in 2005 and has since maintained this performance level. The number of suspected yellow fever cases in the country increased from 156 in 2003 to 859 in 2006, and the proportion of districts that reported at least one suspected yellow fever case per year increased from 31.4% to 68.2%, respectively. Blood specimens were collected from all suspected cases (within 14 days of onset of symptoms) and tested at a central laboratory for yellow fever IgM antibodies; leading to confirmation of yellow fever outbreaks in the health districts of Bafia, Méri and Ntui in 2003, Ngaoundéré Rural in 2004, Yoko in 2005 and Messamena in 2006. Owing to constraints in rapidly mobilising the necessary resources, reactive SIAs were only conducted in Bafia and Méri several months after confirmation of the outbreak. In both districts, a total of 60,083 people (representing 88.2% of the 68,103 targeted) were vaccinated. Owing to the same constraints, SIAs were not conducted promptly in response to the outbreaks in Ntui, Ngaoundéré Rural, Yoko and Messamena. However, these four and two other health districts at high risk of yellow fever outbreaks (i.e. Maroua Urban and Ngaoundéré Urban) conducted preventive SIAs in November 2006, vaccinating a total of 752,195 people (92.8% of target population). In both the reactive and preventive SIAs, the mean wastage rates for vaccines and injection material were less than 5% and there was no report of a serious adverse event following immunisation.</p> <p>Conclusion</p> <p>Amidst other competing health priorities, over the past four years Cameroon has successfully planned and implemented evidence-based strategies for preventing yellow fever outbreaks and for detecting and responding to the outbreaks when they occur. In order to sustain these initial successes, the country will have to attain and sustain high routine vaccination coverage in each successive birth cohort in every district. This would require fostering and sustaining high-level political commitment, improving the planning and monitoring of immunisation services at all levels, adequate community mobilisation, and efficient coordination of current and future immunisation partners.</p

Individual and Contextual Factors Associated with Low Childhood Immunisation Coverage in Sub-Saharan Africa: A Multilevel Analysis

Background: In 2010, more than six million children in sub-Saharan Africa did not receive the full series of three doses of the diphtheria-tetanus-pertussis vaccine by one year of age. An evidence-based approach to addressing this burden of un-immunised children requires accurate knowledge of the underlying factors. We therefore developed and tested a model of childhood immunisation that includes individual, community and country-level characteristics. Method and Findings: We conducted multilevel logistic regression analysis of Demographic and Health Survey data for 27,094 children aged 12–23 months, nested within 8,546 communities from 24 countries in sub-Saharan Africa. According to the intra-country and intra-community correlation coefficient implied by the estimated intercept component variance, 21% and 32% of the variance in unimmunised children were attributable to country- and community-level factors respectively. Children born to mothers (OR 1.35, 95%CI 1.18 to 1.53) and fathers (OR 1.13, 95%CI 1.12 to 1.40) with no formal education were more likely to be unimmunised than those born to parents with secondary or higher education. Children from the poorest households were 36% more likely to be unimmunised than counterparts from the richest households. Maternal access to media significantly reduced the odds of children being unimmunised (OR 0.94, 95%CI 0.94 to 0.99). Mothers with health seeking behaviours were less likely to have unimmunised children (OR 0.56, 95%CI 0.54 to 0.58). However, children from urban areas (OR 1.12, 95% CI 1.01 to 1.23), communities with high illiteracy rates (OR 1.13, 95% CI 1.05 to 1.23), and countries with high fertility rates (OR 4.43, 95% CI 1.04 to 18.92) were more likely to be unimmunised. Conclusion: We found that individual and contextual factors were associated with childhood immunisation, suggesting that public health programmes designed to improve coverage of childhood immunisation should address people, and the communities and societies in which they live

Knowledge and practices relating to malaria in a semi-urban area of Cameroon: choices and sources of antimalarials, self-treatment and resistance

Introduction: Malaria is a major public health problem in Sub-Saharan Africa where it kills a child under the age of five every 30 seconds. In Cameroon, malaria accounts for 40-45% of medical consultations, 57% of hospitalization days and 40% of mortality among children below 5 years. Community knowledge and practices can enhance the fight against this disease. The aim of the study was to make a local analysis of the people&rsquo;s knowledge and practices relating to the choice and source of antimalarials, self-medication, malaria dosage and resistance in order to establish behavioural baseline and epidemiological determinants and their implications for malaria control. Methods: The design was a community-based cross-sectional study in a semi-urban setting. The survey consisted of 253 volunteer participants (from among 350 contacted) from different socio-demographic backgrounds to whom structured questionnaires were administered. The respondent&rsquo;s consent was sought and gained and subjects who could not read or write or understand English language were communicated to in the local language. The questionnaire was administered by trained interviewers according to the schedule of the respondent. The data was analysed using SPSS. Results: Antimalarials commonly cited for malaria treatment were chloroquine (26.1%) and nivaquine (14.6%) and analgesics: panadol (23%) and paracetamol (12.3%) including native drugs (6.3%). 141(55.7%) (95% confidence interval (CI): 49.6&ndash;61.8%) participants practiced self-medication of malaria. 26.1% participants knew the correct adult malarial dosage for chloroquine or nivaquine. 125(40.4%) (95% CI: 34.4-46.7%) participants got their antimalarials from health centers, 27(10.6%) from shops, 24(9.5%) from hawkers, 23(9.1%) from the open market and 16 (6.3%) from herbalists. 66 (26.1%) (95% CI: 20.7-31.5%) participants knew the correct adult dosage for chloroquine or nivaquine treatment of malaria. 85(33.6%) (95% CI: 27.8&ndash;36.6%) participants had correct knowledge of malarial resistance. Of the 85 (33.6%) participants who had correct knowledge of antimalarial drug resistance, 52(20.6%) ascribed antimalarial drug resistance to continuous fever for a long time during treatment, 15 (5.9%) to serious fever during treatment and 18 (7.1%) when chloroquine does not stop fever. 23(27.1%) participants with correct knowledge of malarial resistance were in the 31-35 age group bracket compared with other age groups (P=0.1). There was a significant difference in correct knowledge of malarial resistance and participant&rsquo;s profession (p=0.0). Conclusion: Malaria self-medication is common in Ndu but knowledge of antimalarial drug resistance is poor. Improvement in the self-treatment of malaria could be attained by providing clear information on choices of drugs for malaria treatment. Proper health information on the rational use of ant-malarial drugs must be provided in an appropriate manner to all groups of people in the society including village health workers, women associations, churches, school children, &ldquo;Mngwah&rdquo; opinion leaders, herbalists, health workers and chemists. Self-medication should be improved upon by giving correct information on the dosage of malaria treatment on radio, television, posters and newspapers because banning it will push many people to use it in hiding.Key words: Malaria, knowledge, practices, antimalarials, choices, sources, self-medication, resistance, Cameroo

The acceptability of three vaccine injections given to infants during a single clinic visit in South Africa

BACKGROUND: The Expanded Programme on Immunisation (EPI) has increased the number of antigens and injections administered at one visit. There are concerns that more injections at a single immunisation visit could decrease vaccination coverage. We assessed the acceptability and acceptance of three vaccine injections at a single immunisation visit by caregivers and vaccinators in South Africa. METHODS: A mixed methods exploratory study of caregivers and vaccinators at clinics in two provinces of South Africa was conducted. Quantitative and qualitative data were collected using questionnaires as well as observations of the administration of three-injection vaccination sessions. RESULTS: The sample comprised 229 caregivers and 98 vaccinators. Caregivers were satisfied with the vaccinators’ care (97 %) and their infants receiving immunisation injections (93 %). However, many caregivers, (86 %) also felt that three or more injections were excessive at one visit. Caregivers had limited knowledge of actual vaccines provided, and reasons for three injections. Although vaccinators recognised the importance of informing caregivers about vaccination, they only did this sometimes. Overall, acceptance of three injections was high, with 97 % of caregivers expressing willingness to bring their infant for three injections again in future visits despite concerns about the pain and discomfort that the infant experienced. Many (55 %) vaccinators expressed concern about giving three injections in one immunisation visit. However, in 122 (95 %) observed three-injection vaccination sessions, the vaccinators administered all required vaccinations for that visit. The remaining seven vaccinations were not completed because of vaccine stock-outs. CONCLUSIONS: We found high acceptance by caregivers and vaccinators of three injections. Caregivers’ poor understanding of reasons for three injections resulted from limited information sharing by vaccinators for caregivers. Acceptability of three injections may be improved through enhanced vaccinator-caregiver communication, and improved management of infants’ pain. Vaccinator training should include evidence-informed ways of communicating with caregivers and reducing injection pain. Strategies to improve acceptance and acceptability of three injections should be rigorously evaluated as part of EPI’s expansion in resource-limited countries.IS

HIV Infection Is Associated with a Lower Incidence of Constriction in Presumed Tuberculous Pericarditis: A Prospective Observational Study

The original publication is available at http:/www.plosone.orgBackground: Pericardial constriction is a serious complication of tuberculous pericardial effusion that occurs in up to a quarter of patients despite anti-tuberculosis chemotheraphy. The impact of human immunodeficiency virus (HIV) infection on the incidence of constrictive pericarditis following tuberculous pericardial effusion is unknown. Methods and Results: We conducted a prospective observational study to determine the association between HIV infection and the incidence of constrictive pericarditis among 185 patients (median age 33 years) with suspected tuberculous pericardial effusion. These patients were recruited consecutively between March and October 2004 on commencement of anti-tuberculosis treatment, from 15 hospitals in Cameroon, Nigeria and South Africa. Surviving patients (N = 119) were assessed for clinical evidence of constrictive pericarditis at 3 and 6 months of follow-up. Clinical features of HIV infection were present in 42 (35.2%) of the 119 patients at enrolment into the study.66 of the 119 (56.9%) patients consented to HIV testing at enrolment. During the 6 months of follow-up, a clinical diagnosis of constrictive pericarditis was made in 13 of the 119 patients (10.9%, 95% confidence interval [CI] 5.9-18%). Patients with clinical features of HIV infection appear less likely to develop constriction than those without (4.8% versus 14.3%; P = 0.08). None of the 33 HIV seropositive patients developed constriction, but 8 (24.2%, 95%CI 11.1-42.3%)of the 33 HIV seronegative patients did (P = 0.005). In a multivariate logistic regression model adjusting simultaneously for several baseline characteristics, only clinical signs of HIV infection were significantly associated with a lower risk of constriction (odd ratio 0.14, 95% CI 0.02-0.87, P = 0.035). Conclusions: These data suggest that HIV infection is associated with a lower incidence of pericardial constriction in patients with presumed tuberculous pericarditis. © 2008 Ntsekhe et al.This study was funded, in part, through research grants from the University of Cape Town, the Medical Scholarships for South African Blacks (MESAB), the Medical Research Council of South Africa, the National Research Foundation of South Africa.Publishers' versio

Dealing with substantial heterogeneity in Cochrane reviews. Cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Dealing with heterogeneity in meta-analyses is often tricky, and there is only limited advice for authors on what to do. We investigated how authors addressed different degrees of heterogeneity, in particular whether they used a fixed effect model, which assumes that all the included studies are estimating the same true effect, or a random effects model where this is not assumed.</p> <p>Methods</p> <p>We sampled randomly 60 Cochrane reviews from 2008, which presented a result in its first meta-analysis with substantial heterogeneity (I²greater than 50%, i.e. more than 50% of the variation is due to heterogeneity rather than chance). We extracted information on choice of statistical model, how the authors had handled the heterogeneity, and assessed the methodological quality of the reviews in relation to this.</p> <p>Results</p> <p>The distribution of heterogeneity was rather uniform in the whole I²interval, 50-100%. A fixed effect model was used in 33 reviews (55%), but there was no correlation between I²and choice of model (P = 0.79). We considered that 20 reviews (33%), 16 of which had used a fixed effect model, had major problems. The most common problems were: use of a fixed effect model and lack of rationale for choice of that model, lack of comment on even severe heterogeneity and of reservations and explanations of its likely causes. The problematic reviews had significantly fewer included trials than other reviews (4.3 vs. 8.0, P = 0.024). The problems became less pronounced with time, as those reviews that were most recently updated more often used a random effects model.</p> <p>Conclusion</p> <p>One-third of Cochrane reviews with substantial heterogeneity had major problems in relation to their handling of heterogeneity. More attention is needed to this issue, as the problems we identified can be essential for the conclusions of the reviews.</p

The African Vaccine-Preventable Diseases Network: a vaccine advocacy initiative

Achieving high and equitable childhood immunisation coverage in Africa will not only protect children from disability and premature death, it will also boost productivity, reduce poverty and support the economic growth of the continent. Thus, Africa needs innovative and sustainable vaccine advocacy initiatives. One such initiative is the African Vaccine-Preventable Diseases Network, formed in 2009. This association of immunisation practitioners, vaccinologists, paediatricians, and infectious disease experts provides a platform to advocate for the introduction of newly available vaccines (e.g. 10-valent and 13-valent pneumococcal conjugate and rotavirus vaccines) into the Expanded Programme on Immunisation (EPI) as well as increased and equitable coverage for established EPI vaccines.Key words: Vaccine preventable diseases, vaccine, network, Africa, awareness, child healt