Analysis of Haemophilus species in patients with respiratory tract infections in Yaoundé, Cameroon.

OBJECTIVES: To identifyHaemophilus species and characterize antimicrobial susceptibility of isolates from patients with respiratory tract infections (RTIs) in Cameroon. METHODS: Isolates (n = 95) were from patients with RTIs obtained from two Hospitals in Yaoundé, Cameroon. Isolates were identified by biochemical assay, PCR-based method, MALDI-TOF and whole genome sequencing. Antibiotic minimum inhibitory concentrations were determined by E-test. RESULTS: H. influenzae was the most prevalent species varying from 76.8% to 84.2% according to different methods. The isolates were mainly nontypable (n = 70, 96%). Three isolates of H. influenzae were capsulated (b, e and f). The isolates were genetically diverse and 40 unique sequence types were identified including 11 new ones. Resistance to ampicillin was observed among 55.3% (52/94) and 9% (14/52) produced TEM-1 ß-lactamase. PBP3 mutations occurred in 57.7% of ampicillin resistant isolates (30/52). Eleven isolates were chloramphenicol resistant with 80% producing chloramphenicol acetyltransferase (8/10). Four Haemophilus isolates were rifampicin resistant with two mutations in rpoB gene. Five isolates were ciprofloxacin resistant and harbored mutations in the quinolone resistance determining regions of gyrA and parC genes. CONCLUSION: H. influenzae isolates are highly diverse and show high levels of antibiotic resistance. H. influenzae serotype b is still circulating in the post-vaccination era.

HBV immunization and vaccine coverage among hospitalized children in Cameroon, Central African Republic and Senegal: a cross-sectional study.

BACKGROUND: Hepatitis B is a major health concern in Africa. The vaccine against hepatitis B virus (HBV) was introduced into the Expanded Programme on Immunization (EPI) of Cameroon and Senegal in 2005, and of CAR (Central African Republic) in 2008. A cross-sectional study was conducted to assess HBV immunization coverage following the vaccine's introduction into the EPI and factors associated with having been vaccinated. METHODS: All hospitalized children, regardless of the reasons for their hospitalization, between 3 months and 6 years of age, for whom a blood test was scheduled during their stay and whose condition allowed for an additional 2 mL blood sample to be taken, and who provided the parent's written consent were included. All children anti-HBs- and anti-HBc + were tested for HBsAg. Vaccination coverage was assessed in three different ways: immunization card, maternal recall and serologic anti-HBs profile. RESULTS: 1783 children were enrolled between April 2009 and May 2010. An immunization card was only available for 24 % of the children. The median age was 21 months. Overall HBV immunization coverage based on immunization cards was 99 %, 49 % and 100 % in Cameroon, CAR and Senegal, respectively (p < 0,001). The immunization rate based on maternal recall was 91 %, 17 % and 88 % in Cameroon, CAR and Senegal, respectively (p < 0,001). According to serology (anti-HBs titer ≥ 10 mUI/mL and anti-HBc-), the coverage rate was 68 %, 13 % and 46 % in Cameroon, CAR and Senegal, respectively (p < 0,001). In Senegal and Cameroon, factors associated with having been vaccinated were: mother's higher education (OR = 2.2; 95 % CI [1.5-3.2]), no malnutrition (OR = 1.6; 95 % CI [1.1-2.2]), access to flushing toilets (OR = 1.6; 95 % CI [1.1-2.3]), and < 24 months old (OR = 2.1; 95 % CI [1.3-3.4] between 12 and 23 months and OR = 2.7; 95 % CI [1.6-4.4] < 12 months). The prevalence of HBV-infected children (HBsAg+) were 0.7 %, 5.1 %, and 0.2 % in Cameroon, CAR and Senegal, respectively (p < 0.001). CONCLUSIONS: Assessing immunization coverage based on immunization cards, maternal recall or administrative data could be usefully reinforced by epidemiological data combined with immunological profiles. Serology-based studies should be implemented regularly in African countries, as recommended by the WHO. Malnutrition, lack of maternal education and poverty are factors associated with vaccine non-compliance. The countries' vaccination programs should actively address these problems.

Drug resistance among drug-naive and first-line antiretroviral treatment-failing children in Cameroon.

BACKGROUND: Scale-up to antiretroviral therapy (ART) requires surveillance for HIV drug resistance. With the goal of attaining 100% pediatric ART coverage in Cameroon, strategies to limit the spread of HIV resistance among children are very important. METHODS: From June 2009 through February 2011, 92 HIV-1-infected children (41 ART-naive, 51 failing first-line ART) living in Yaoundé, Cameroon, were enrolled; HIV-1 Prot-RT genotypic resistance testing (GRT) was performed using an inhouse assay. Among 40 children failing first-line ART, treatment response was evaluated at weeks 24 and 48 after treatment was changed, based on GRT results. RESULTS: The mean age was 72 months both for children who were drug-naive and those failing ART (range: 3-144 and 12-144, respectively), with a mean viremia of 5.59 log and 4.71 log RNA copies/mL, a median CD4 of 17% (588 cells/µL) and 23% (719 cells/µL), respectively. Median time-to-treatment failure was 610 days. A prevalence of 4.9% and 90% drug resistance was observed, respectively, among children who were drug-naive and those failing first-line ART, with circulating recombinant form CRF02_AG as the most prevalent clade (58.6% and 62%, respectively). After a change to GRT-based treatment, more than 90% of children had viremia <3 log RNA copies/mL at week 24 and confirmed at week 48, with 70% achieving undetectable viremia, although without correlation to immune response; 97.5% had switched to lopinavir/ritonavir-containing regimens. CONCLUSION: HIV-1 drug resistance was low among ART-naive children and very high among those failing first-line ART. Treatment change based on GRT was successful for most children, with lopinavir/ritonavir regimens being very promising for second-line use.