RESUMO
Approximately 20,745 new cases of cancer were registered annually with 13,199 (64%) deaths in 2020 in Cameroon. Despite the increasing cancer burden, there is a paucity of reliable data that can enhance decision-making for cancer control in Cameroon. This assessment was, therefore, designed to generate data that may enable stakeholders, policymakers and funders to make data-driven decisions on cancer control. We conducted a cross-sectional survey in July 2020, which enabled us to collect data on key cancer variables from six adult cancer treatment centres in Cameroon. The key components of the assessment included case detection, service availability, human resource capacity, cost of chemotherapy and radiotherapy, the safety of chemotherapy sessions, data systems, patient education, palliative care, funding for chemotherapy and chemotherapy stock. Data were compiled and analysed using Microsoft Excel 2016. Data from four of the 6 sites show that 1,636 new cases were recorded representing an annual case detection rate of 11.8%. All the six assessed facilities offered chemotherapy services, 5/6 (83.3%) offered surgery for cancers, while just 1 (16.7%) offered radiotherapy services. In addition, none offered nuclear medicine services for cancer care and treatment. Similarly, none of the facilities had the WHO-recommended number of human resources for optimal cancer care. Overall, there were only 6 medical oncologists, 2 surgical oncologists, 3 radiation oncologists and 14 oncology nurses providing services across the 6 cancer treatment centres. Treatment services are expensive for an average national, with a complete course of chemotherapy followed by radiotherapy costing ~XAF 1,240,000 (~$2,480). None of the survey facilities had a recommended safe biosafety cabinet and clean room for the preparation of chemotherapies, rendering the preparation of chemotherapies suboptimal and hazardous. Data collection tools were manual, relatively available and very different across all the surveyed sites and the interval for data collection and transmission was collectively undefined. Optimal cancer care in adult cancer treatment centres is limited by several health systems and socio-economic factors. The identification of these barriers has enabled the formulation of action-oriented interventions, leveraging on the recently adopted national strategy for the prevention and control of cancers in the country.
RESUMO
A possible role in RNA replication for interactions between conserved complementary (cyclization) sequences in the 5'- and 3'-terminal regions of Flavivirus RNA was previously suggested but never tested in vivo. Using the M-fold program for RNA secondary-structure predictions, we examined for the first time the base-pairing interactions between the covalently linked 5' genomic region (first ~160 nucleotides) and the 3' untranslated region (last ~115 nucleotides) for a range of mosquito-borne Flavivirus species. Base-pairing occurred as predicted for the previously proposed conserved cyclization sequences. In order to obtain experimental evidence of the predicted interactions, the putative cyclization sequences (5' or 3') in the replicon RNA of the mosquito-borne Kunjin virus were mutated either separately, to destroy base-pairing, or simultaneously, to restore the complementarity. None of the RNAs with separate mutations in only the 5' or only the 3' cyclization sequences was able to replicate after transfection into BHK cells, while replicon RNA with simultaneous compensatory mutations in both cyclization sequences was replication competent. This was detected by immunofluorescence for expression of the major nonstructural protein NS3 and by Northern blot analysis for amplification and accumulation of replicon RNA. We then used the M-fold program to analyze RNA secondary structure of the covalently linked 5'- and 3'-terminal regions of three tick-borne virus species and identified a previously undescribed additional pair of conserved complementary sequences in locations similar to those of the mosquito-borne species. They base-paired with DeltaG values of approximately -20 kcal, equivalent or greater in stability than those calculated for the originally proposed cyclization sequences. The results show that the base-pairing between 5' and 3' complementary sequences, rather than the nucleotide sequence per se, is essential for the replication of mosquito-borne Kunjin virus RNA and that more than one pair of cyclization sequences might be involved in the replication of the tick-borne Flavivirus species.
