The Hidden Impact of the COVID-19 Pandemic on Routine Childhood Immunization Coverage in Cameroon.

Background: The third round of the global pulse survey demonstrated that the abrupt and rapid progression of the COVID-19 pandemic significantly disrupted childhood immunization in many countries. Although Cameroon has reported over 120,000 COVID-19 cases, the reported national childhood vaccination coverage during the pandemic seems to have increased compared to that during the pre-COVID-19 period. Indeed, the first dose of the diphtheria, tetanus, and pertussis-containing vaccine (DTP-1) coverage increased from 85.4% in 2019 to 87.7% in 2020, and DTP-3 coverage increased from 79.5% in 2019 to 81.2% in 2020. The paucity of literature on the impact of COVID-19 on childhood vaccination in COVID-19 hotspot regions poses a challenge in developing a context-specific immunization recovery plan, hence the need to conduct this study. Methodology: We conducted a cross-sectional study using 2019 (pre-pandemic period) and 2020 (pandemic period) district childhood immunization data from the DHIS-2 database, weighted using completeness for each data entry against regional data completeness in 2020. Based on COVID-19 incidence, two hotspot regions were selected, with all districts (56/56) included in the final analysis. The Chi-square test was used to compare DTP-1 and DTP-3 coverage during the pre-pandemic and pandemic periods. Results: In the two hotspot regions, 8247 children missed DTP-1, and 12,896 children did not receive DTP-3 vaccines in the pandemic period compared to the results from the pre-pandemic period. Indeed, there was a significant drop in DTP-1 and DTP-3 coverage of 0.8% (p = 0.0002) and 3.1% (p = 0.0003), respectively, in the Littoral Region. Moreover, the Centre Region reported a 5.7% (p < 0.0001) and 7.6% (p < 0.0001) drop in DTP-1 and DTP-3 coverage, respectively. Most districts in the hotspot regions reported a decline in childhood immunization access (62.5%) and utilization (71.4%). Indeed, in the Littoral Region, 46% (11/24) and 58% (14/24) of districts experienced decreased vaccination access and utilization, respectively. Meanwhile, 75% (24/32) and 81% (26/32) of districts in the Centre Region experienced a drop in vaccination access and utilization, respectively. Conclusion: This study reported a situation where the national immunization indicators mask the impact of COVID-19 on childhood immunization in heavily hit regions. Therefore, this study presents valuable information for ensuring continuous vaccination service delivery during public health emergencies. The findings could also contribute to developing an immunization recovery plan and informing policy on future pandemic preparedness and response.

Factors Associated with Zero-Dose Childhood Vaccination Status in a Remote Fishing Community in Cameroon: A Cross-Sectional Analytical Study.

Background: Cameroon's suboptimal access to childhood vaccinations poses a significant challenge to achieving the Immunization Agenda 2030 goal-ranking among the top 15 countries with a high proportion of zero-dose (unvaccinated) children worldwide. There are clusters of zero-dose children in pockets of communities that traditionally miss essential healthcare services, including vaccination. The Manoka Health District (MHD) is home to such settlements with consistently low vaccination coverages (DPT-HepB-Hib-1: 19.8% in 2021) and frequent outbreaks of vaccine-preventable diseases (VPD). Therefore, the absence of literature on zero-dose children in this context was a clarion call to characterize zero-dose children in fragile settings to inform policy and intervention design. Methodology: This cross-sectional analytical study involved 278 children, 0-24 months of age, selected from a 2020 door-to-door survey conducted in the two most populous health areas in an archipelago rural district, MHD (Cap-Cameroon and Toube). We used R Statistical Software (v4.1.2; R Core Team 2021) to run a multivariable logistic regression to determine zero-dose associated factors. Results: The survey revealed a zero-dose proportion of 91.7% (255) in MHD. Children who were delivered in health facilities were less likely to be zero-dose than those born at home (AOR: 0.07, 95% CI: 0.02-0.30, p = 0.0003). Compared to children born of Christian mothers, children born to minority non-Christian mothers had higher odds of being zero-dose (AOR: 6.55, 95% CI: 1.04-41.25, p = 0.0453). Children born to fathers who are immigrants were more likely to be zero-dose children than Cameroonians (AOR: 2.60, 95% CI = 0.65-10.35, p = 0.0016). Younger children were likely to be unvaccinated compared to older peers (AOR: 0.90, 95% CI: 0.82-1.00, p = 0.0401). Conclusions: In the spirit of "leaving no child behind," the study highlights the need to develop context-specific approaches that consider minority religious groups, immigrants, and younger children, including newborns, often missed during vaccination campaigns and outreaches.

Pre-conceptional folic acid supplementation: A possible cause for the increasing rates of ankyloglossia.

BACKGROUND: There is an increasing awareness to ankyloglossia (tongue-tie) in infants, with marked increase in its report in the medical literature. Some reports indicate increase in prevalence. Whether the increase ankyloglossia rate is a real phenomenon or merely reflects increased awareness and reports has to be determined. One explanation for the increasing ankyloglossia rates is the growing trend of breast feeding initiation, often impaired by ankyloglossia, which brings it to medical attention. We propose an alternative hypothetical explanation based on increasing utilization of periconceptional folic acid supplementation for the prevention of neural tube defects (NTDs). Inadequate folic acid supply during organogenesis impairs cell division, and the mid-line structures are at the highest risk. We postulated that higher folic acid supply during organogenesis might enhance tissue synthesis with tighter closure of mid-line structures including the lingual frenulum, resulting in ankyloglossia. METHODS: To assess this hypothesis, we undertook an observational case control study comparing folic acid utilization before pregnancy in mothers of infants with and without ankyloglossia. Infants with ankyloglossia (n = 85) were compared to a control group without ankyloglossia (n = 140). RESULTS: There was a slight, insignificant elevated frequency of reported utilization of folic acid ("any intake") among mothers of infants with ankyloglossia compared with controls (74.1% and 66.4%, respectively). This difference was slightly higher, yet insignificant when folic acid intake "in most days" was considered (65.9% and 53.6%, respectively, OR = 1.67, 95%CI = 0.93-3.05, P = 0.07). In contrast, the reported intake of pre-conceptional folic acid "on a regular basis" was significantly higher among mothers of infants with ankyloglossia compared with controls (54.1% and 25.7%, respectively, OR = 3.41, 95%CI = 1.85-6.27, p < 0.0001). INTERPRETATION: The reported association between higher frequency of regular pre-conceptional folic acid intake and ankyloglossia, supports the hypothesis for this association. More studies are required to test this hypothesis.

Pertussis in infants under one year old: risk markers and vaccination status--a case-control study.

BACKGROUND: Pertussis is a contagious bacterial disease causing substantial health burden. Pertussis-related morbidity and mortality are highest in young infants. We investigated risk markers for pertussis and vaccination status in infants. METHODS: Reported pertussis cases under one year old during 1998-2011 in the Jerusalem district were matched to controls by birthdate and residence. Data sources included epidemiological investigations, health records and vaccination records (number and dates of DTP\DTaP doses scheduled at 2, 4, 6 months). Vaccine effectiveness was calculated by number of vaccine doses stratified by age group. Timeliness of vaccine doses was also evaluated. RESULTS: The study population included 1268 infants under 1 year: 317 pertussis cases and 951 age-matched controls (mean age 3.95±3, median 2.9 months). Low birthweight (<2500g, 12.3% in cases vs. 6.3% in controls) and high birth order (4th and above) were found to be independent risk markers. Male gender and low socio-economic status were more frequent among cases. Some 40% of the cases (127/317) were hospitalized, most of them (111/127, 87.4%) were under 4 months (mean age 2.42±2.05, median 1.8 months). The distribution of the number of pertussis vaccine doses 0, 1, 2 and 3 differed considerably being 42.2%, 32.7%, 15.6%, 9.5% vs. 13.7%, 41.9%, 22.9%, 21.5% among cases and controls (≥2m), respectively. The overall vaccine effectiveness found was 72.9%, 76.1% and 84.4%, for the 1st, 2nd and 3rd doses of a pertussis vaccine. The infant's age at the first dose of pertussis vaccine was recorded with follow-up until age 18 months. Delay was more common among cases with a lower proportion vaccinated-78.9% at 18 months vs. 99% in controls. CONCLUSIONS: Specific risk markers for pertussis in young infants were identified. Reported pertussis cases over age 2 months were significantly more likely to be unvaccinated and have delayed vaccinations. The vaccine effectiveness increased with the number of vaccine doses.

Congenital toxoplasmosis--prenatal aspects of Toxoplasma gondii infection.

Toxoplasma gondii (T. gondii) is the cause of toxoplasmosis. Primary infection in an immunocompetent person is usually asymptomatic. Serological surveys demonstrate that world-wide exposure to T. gondii is high (30% in US and 50-80% in Europe). Vertical transmission from a recently infected pregnant woman to her fetus may lead to congenital toxoplasmosis. The risk of such transmission increases as primary maternal infection occurs later in pregnancy. However, consequences for the fetus are more severe with transmission closer to conception. The timing of maternal primary infection is, therefore, critically linked to the clinical manifestations of the infection. Fetal infection may result in natural abortion. Often, no apparent symptoms are observed at birth and complications develop only later in life. The laboratory methods of assessing fetal risk of T. gondii infection are serology and direct tests. Screening programs for women at childbearing age or of the newborn, as well as education of the public regarding infection prevention, proved to be cost-effective and reduce the rate of infection. The impact of antiparasytic therapy on vertical transmission from mother to fetus is still controversial. However, specific therapy is recommended to be initiated as soon as infection is diagnosed.