Haute prévalence des anti-corps Anti-D chez les femmes en âge d’avoir des enfants au Centre Pasteur du Cameroun

We conducted a cross sectional retrospective study to determine anti-D and D-negative phenotype rates among Cameroonian women of reproductive age (15 – 44 years), in order to evaluate the importance of D alloimmunization. Analysis of the haematology laboratory records from January 2006 to December 2007 harvested 225 results for red blood cell alloantibody screening and 2460 D phenotypes. Anti-D rate was found to be high at 4% and not linked to women’s parity. Three hundred and fifty two (14.3%) women were found to be D-negative. Anti-D rates significantly decreased with age from 18.8% among teenagers (15-19) to 7.8% among older women (35-44) (p = 0.001). The number of women submitted to both irregular antibody screening and type D phenotype determination was not strong enough (50) to analyse the link between anti-D rate and antigen D distribution in our study (Afr J Reprod Health 2009; 13[3]:47-52).Nous avons mené une étude retrospective et transversale pour déterminer les anti-D et les taux de phénotype D-négatif chez les femmes en âge d’avoir de reproduction (15 - 44 ans) à l’aide des laboratories du Centre Pasteur du Cameroun afin d’évaluer l’importance de l’alloimmunisation-D. L’analyse des documents du laboratoire d’hématologie de janvier 2006 au décembre 2007 ont produit 255 résultats pour le dépistage de l’alloanticorps du globule rouge et 2460 phénotypes-D. Quatre vingt-six pourcent (40/50) des femmes ont subi les deux dépistages de l’anticorps irrégulier et le phénotype-D était D-négatif. Le taux de l’anti-D s’est montré élevé à 4% et resté le même à tous les âges, ce qui indique qu’il n’y avait pas assez de mesures de prévention par rapport à l’alloimmunisation-D. Le test chez 352 femmes (14,3%) était D-négatif. Le test de la Dnégativité ont diminué de façon significative avec l’âge. Allant de 18,8% chez les adolescents (15-19) jusqu’à 7,8% chez les femmes plus âgées (33-44) (p= 0,001) (Afr J Reprod Health 2009; 13[3]:47-52)

Whole-cell pertussis vaccine induces low antibody levels in human immunodeficiency virus-infected children living in sub-Saharan Africa.

International audienceThe WHO recommendations for the immunization of children infected with human immunodeficiency virus (HIV) differ slightly from the guidelines for uninfected children. The introduction of antiretroviral therapy for HIV-infected infants should considerably prolong their life expectancy. The question of the response to the whole-cell pertussis (wP) vaccine should now be addressed, particularly in countries in which pertussis remains endemic. To evaluate the persistence of antibodies to the wP vaccine in HIV-infected and uninfected children who had previously received this vaccine in routine clinical practice, we conducted a cross-sectional study of children aged 18 to 36 months, born to HIV-infected mothers and living in Cameroon or the Central African Republic. We tested blood samples for antibodies to the wP vaccine and for antibodies to diphtheria and tetanus toxoids (D and T, respectively) in the context of the use of a combined DTwP vaccine. We enrolled 50 HIV-infected children and 78 uninfected, HIV-exposed children in the study. A lower proportion of HIV-infected children than uninfected children had antibodies against the antigens tested for all valences of the DTwP vaccine. Agglutinin levels were substantially lower in HIV-infected than in HIV-exposed but uninfected children (30.0% versus 55.1%, respectively; P = 0.005). We also observed a high risk of low antibody levels in response to the DTwP vaccine in HIV-infected children with severe immunodeficiency (CD4 T-cell level, <25%). The concentrations of antibodies induced by the DTwP vaccine were lower in HIV-infected children than in uninfected children. This study supports the need for a booster dose of the DTwP vaccine in order to maintain high antibody levels in HIV-infected children

Achieving a high cure rate with direct-acting antivirals for chronic Hepatitis C virus infection in Cameroon: a multi-clinic demonstration project

Objectives: Highly effective direct-acting antivirals (DAAs) for Hepatitis C treatment are largely inaccessible in sub-Saharan Africa. Data on treatment feasibility and outcomes in clinical settings are limited. We assessed the feasibility of achieving a high (≥90%) cure rate with DAAs in six gastroenterology clinics in Cameroon. Methods: Patients with chronic Hepatitis C virus (HCV) infection were treated for 12 or 24 weeks with ledipasvir/sofosbuvir, ledipasvir/sofosbuvir/ribavirin or sofosbuvir/ribavirin, depending on the stage of liver disease and HCV genotype. The cure rate was defined as the proportion of patients with a sustained virological response 12 weeks after treatment completion (SVR12) among all treatment completers. Results: We identified 190 HCV RNA positive patients between September-2017 and August-2018, 161 (84.7%) of whom started treatment. 105 (65.2%) were female, median age was 61.3 years [IQR = 55.9–66.9] and 11 (6.8%) were HIV-positive. Median plasma HCV RNA was 6.0 log10IU/mL [IQR = 5.6–6.4]. HCV genotypes identified were 1 (34.8%), 2 (13.7%), 4 (50.9%), 1 and 4 (0.6%); 46 (28.6%) strains of 160 single-genotype infections were non-subtypeable. Of 158 treatment completers, 152 (96.2%, 95%CI = 91.9–98.6%) achieved SVR12. Six patients did not achieve SVR12: five carried HCV with NS5A resistance mutations and one with NS5B resistance mutations. Three patients died before and two after treatment completion. The most common adverse events were asthenia (12.0%), headache (11.4%) and dizziness (18.9%). Conclusion: High cure rates of Hepatitis C with DAAs are achievable in clinical settings of Cameroon. However, the accessibility and provision of HCV screening, diagnosis, treatment, monitoring and care should be addressed for large-scale implementation

HIV-infected children living in Central Africa have low persistence of antibodies to vaccines used in the Expanded Program on Immunization.

International audienceBACKGROUND: The Expanded Program on Immunization (EPI) is the most cost-effective measures to control vaccine-preventable diseases. Currently, the EPI schedule is similar for HIV-infected children; the introduction of antiretroviral therapy (ART) should considerably prolong their life expectancy. METHODS AND PRINCIPAL FINDINGS: To evaluate the persistence of antibodies to the EPI vaccines in HIV-infected and HIV-exposed uninfected children who previously received these vaccines in routine clinical practice, we conducted a cross-sectional study of children, aged 18 to 36 months, born to HIV-infected mothers and living in Central Africa. We tested blood samples for antibodies to the combined diphtheria, tetanus, and whole-cell pertussis (DTwP), the measles and the oral polio (OPV) vaccines. We enrolled 51 HIV-infected children of whom 33 were receiving ART, and 78 HIV-uninfected children born to HIV-infected women. A lower proportion of HIV-infected children than uninfected children had antibodies to the tested antigens with the exception of the OPV types 1 and 2. This difference was substantial for the measles vaccine (20% of the HIV-infected children and 56% of the HIV-exposed uninfected children, p<0.0001). We observed a high risk of low antibody levels for all EPI vaccines, except OPV types 1 and 2, in HIV-infected children with severe immunodeficiency (CD4(+) T cells <25%). CONCLUSIONS AND SIGNIFICANCE: Children were examined at a time when their antibody concentrations to EPI vaccines would have still not undergone significant decay. However, we showed that the antibody concentrations were lowered in HIV-infected children. Moreover, antibody concentration after a single dose of the measles vaccine was substantially lower than expected, particularly low in HIV-infected children with low CD4(+) T cell counts. This study supports the need for a second dose of the measles vaccine and for a booster dose of the DTwP and OPV vaccines to maintain the antibody concentrations in HIV-infected and HIV-exposed uninfected children

Low antibody concentrations or titers to the EPI antigens in relation to the percentage of CD4⁺ T cells.

*<p>Odds ratio</p>†<p>Confidence interval</p

Logistic regression analysis of various characteristics of children in relation to low antibody concentrations or titers to EPI vaccines (HIV-exposed uninfected children as reference group).

†<p>Adjusted Odds Ratio</p>‡<p>Confidence interval</p

Association between measles antibody concentration and children's characteristics.

*<p>Odds ratio of low measles antibody response</p>†<p>Confidence interval</p>‡<p>Chi square test, Fisher exact test or chi square test for trend as appropriate</p>§<p>Median age</p>||<p>Mid upper arm circumference</p>¶<p>Mean globular volume</p