Prevalence of prolonged otitis media with effusion among 2 to 3 years old Cameroonian children in the era of 13-valent pneumococcal conjugate vaccines

Objectives: There is data scarcity on the overall effects of pneumococcal conjugate vaccines (PCVs) on otitis media (OM) in low- and middle-income countries. The impact of the 13-valent PCV (PCV13) program on OM was evaluated in Cameroon where infant vaccination was implemented in July 2011 using a 3-dose primary series at 6, 10 and 14 weeks of age. Methods: Through community-based surveillance, we used a retrospective cohort study design to assess OM prevalence among PCV13-vaccinated children aged 24 to 36 months in 2015. This was compared with a 2013 age-matched cohort of PCV13-unvaccinated children. OM was diagnosed by clinical inspection for chronic suppurative OM (CSOM) and tympanometry for OM with effusion (OME). CSOM was defined as draining of the middle ear with duration of more than 2 weeks and prolonged OME was defined as a flat ‘type B’ tympanogram. PCV13-vaccinated and PCV13-unvaccinated cohorts were compared by calculating prevalence odds ratios for OM and baseline characteristics. Results: Altogether, 111 OM cases were identified; 42/433 (9.7%) in the PCV13-unvaccinated in 2013 and 69/413 (16.7%) in the PCV13-vaccinated cohort in 2015. In the 2013 baseline survey, 3/433 (0.7%) children were identified with unilateral CSOM compared to 9/413 (2.2%) in the PCV13-vaccinated cohort in 2015. Bilateral prolonged OME was diagnosed in 7/433 (1.6%) PCV13-unvaccinated children and in 12/413 (2.9%) in PCV13-vaccinated children. Proportions of children with unilateral prolonged OME were 31/433 (7.2%) in the PCV13-unvaccinated group compared with 48/413 (11.6%) in the PCV13-vaccinated group. Multivariate logistic regression analysis showed evidence that PCV13-vaccinated children in 2015 had 40% less risk of contracting OM compared to PCV13-unvaccinated children in 2013 (adjusted prevalence odds ratios = 0.60 [95% confidence interval: 0.38 to 0.94], P = 0.025). Additionally, attributable proportion estimates show that, 58% of OM infections among the PCV13-vaccinated group would still have occurred despite PCV13 vaccination. Conclusion: Our findings provide significant evidence on the effect of PCV13 in decreasing OM or OME among children in this age group. It also supports justification for government's continuation of PCV13 immunization program in the absence of GAVI's funding. Further research is needed to assess the long-term impact of the PCV13 program on in OM Cameroon.Peer reviewe

Assessing the causes of under-five mortality and proportion associated with pneumococcal diseases in Cameroon. A case-finding retrospective observational study: 2006-2012

<div><p>Background</p><p>Vital registration data outlining causes of deaths (CoD) are important for a sustainable health system, targeted interventions and other relevant policies. There is data paucity on vital registration systems in developing countries. We assessed the leading causes and proportions of under-five deaths, and particularly those related to pneumococcal infections in Yaoundé, Cameroon, using hospital registration data.</p><p>Methods</p><p>A retrospective case-finding observational study design was used to access and identify data on 817 death cases in children under-five years of age recorded in health facilities in Yaoundé, within the period January 1, 2006 and December 31, 2012. Patients’ files were randomly selected and needed information including demographic data, date of admission, clinical and laboratory diagnosis, principal and/or underlying causes of death were abstracted into structured case report forms. The International Classification of Diseases and Clinical Modifications 10^th revision (ICD-10-CM) codes (ICD10Data.com 2017 edition) were used to classify the different CoD, retrospectively. Ascertainment of CoD was based on medical report and estimates were done using the Kaplan-Meier procedure and descriptive statistics.</p><p>Results</p><p>Of the 817 death records assessed, malaria was the leading CoD and was responsible for 17.5% of cases. Meningitis was the second largest CoD with 11.0%; followed by sepsis (10.0%), <i>Streptococcus pneumoniae</i> infections (8.3%), malnutrition (8.3%), gastro-enteritis / diarrhoea (6.2%), anaemia (6.1%) and HIV (3.5%), respectively.</p><p>Conclusion</p><p>The main CoD in this population are either treatable or vaccine-preventable; a trend consistent with previous reports across developing countries. Besides, the health effects from non-communicable infections should not be neglected. Therefore, scaling-up measures to reduce causes of under-five deaths will demand sustainable efforts to enhance both treatment and disease prevention strategies, to avoid a decline in the progress towards reducing under-five deaths by 2/3 from the 1990 baseline.</p></div

Seroprevalence of rubella virus antibodies among pregnant women in the Center and South-West regions of Cameroon.

Rubella infection in early pregnancy can lead to miscarriages, fetal death, or birth of an infant with congenital rubella syndrome (CRS). In Cameroon, like in many developing countries, rubella surveillance is not well-established. The aim of this study was to determine the prevalence of rubella virus specific antibodies among pregnant Cameroonians. We conducted a cross-sectional study for rubella infection among pregnant women attending antenatal clinics in the Center and South-West regions of Cameroon. Demographic data and blood were collected and tested for rubella specific antibodies (IgG and IgM), and for the IgM positive cases, IgG avidity and real time PCR was done. From December 2015 to July 2017, 522 serum samples were collected and tested from pregnant women. The seroprevalence of rubella specific IgG was 94.4%, presumably due to immunity induced by wild-type rubella virus. The seroprevalence of rubella specific IgM was 5.0%, possibly indicating rubella infection. However, IgG avidity testing of the IgM positive cases detected high avidity IgGs, ranging from 52.37% to 87.70%, indicating past rubella infection. 5.6% (29/522) of the participants had negative results for IgG to rubella virus, indicating susceptibility to rubella infection. None of the participants had received a rubella containing vaccine (RCV), but 51% (266/522) of the pregnant women lived in a house with a child with records of at least one dose of RCV. Rubella virus RNA was not detected in the urine of any IgM positive case. Findings from this study show that rubella infection is significant in Cameroon. Some pregnant women are still susceptible to rubella infection. For a better management of rubella infection in pregnancy in Cameroon, consideration should be taken to investigate for IgG-avidity test in cases with positive rubella IgM result to distinguish between recent from past rubella infection

Impact of 13-valent pneumococcal conjugate vaccine on laboratory-confirmed pneumococcal meningitis and purulent meningitis among children <5 years in Cameroon, 2011–2018

Background The 13-valent pneumococcal conjugate vaccine (PCV13) entered Cameroon’s childhood national immunization programme (NIP) in July 2011 under a 3-dose schedule (6, 10, 14 weeks of age) without any catch-up. We described the impact of PCV13 onserotype distribution among pneumococcal meningitis cases over time. Methods We used laboratory-based sentinel surveillance data to identify meningitis cases among 2-to 59-month-old children with clinically-suspected bacterial meningitis (CSBM) admitted to hospitals in Yaoundé (August 2011-December 2018). Purulent meningitis cases had a cerebrospinal fluid (CSF) white blood cell (WBC) count 20 per mm3. Pneumococcal meningitis cases had S. pneumoniae identified from CSF, with serotyping by polymerase chain reaction. Years 2011-2014 were described as early PCV13 era (EPE) and years 2015-2018 as late PCV13 era (LPE) impact periods. Results Among children hospitalized with CSBM who had a lumbar puncture obtained, there was no significant change from the EPE versus the LPE in the percentage identified with purulent meningitis: 7.5% (112/1486) versus 9.4% (154/1645), p = 0.0846. The percentage of pneumococcal meningitis cases due to PCV13 vaccine-serotype (VST) decreased from 62.0% (31/50) during the EPE to 35.8% (19/53) in the LPE, p = 0.0081. The most frequent pneumococcal meningitis VSTs during the EPE were 6A/6B (30%) and 5 (6%), and during the LPE were 14 (13.2%), 3 (7.6%), 4 (5.6%) and 18C (5.6%). Conclusion Four to seven years after PCV13 introduction, the proportion of pneumococcal meningitis due to vaccine serotypes has declined, mainly due to reductions of serotypes 6A/6B, 1, 19A, and 23F; nevertheless, PCV13 VSTs remain common. Because the analyzed surveillance system was not consistent or population based, we could not estimate incidence or overall impact; this emphasizes the need for improved surveillance to document further the utility of PCV13 immunization in Cameroon.publishedVersionPeer reviewe