Plants extracts from Cameroon pharmacopeia strongly inhibit the Chikungunya virus infection by targeting entry and replication steps.

ETHNOPHARMACOLOGICAL RELEVANCE: Cameroon is one of the sub-Saharan African countries affected by Chikungunya virus (CHIKV). With the absence of approved treatment, this disease represents globally a major public health concern. Several plants are traditionally used in Cameroon for the treatment of virus induced fever and arthralgia. But to date there is no study that validate the efficacy of these plants for the treatment of Chikungunya virus infection. AIM OF THE STUDY: This study aims to explore the inhition effect, mechanism of action of plant extracts against Chikungunya virus. MATERIAL AND METHODS: An ethnobotanical survey conducted in some regions of Cameroon, led to the identification of nine medicinal plants used in traditional medicine for the healing of fever-related diseases and arthritis. Crude hydro-ethanolic extracts of each plant were prepared by maceration and their effects against CHIKV infection were investigated. CHIKV S27 strain was used to infection in Vero cell line. The antiviral activities were determined by plaque assay and/or RT-PCR targeting E1 envelope gene of CHIKV. Dose-response studies of the active plants were also determined by flow cytometry and Western blot. RESULTS: Four extracts, Entada africana Guill et Pers. (E4), Entandrophragma cylindricum Sprague (EI), Khaya grandifoliola C. D.C. Sapindales (E2) and Macaranga hurifolia Beille (E6) showed antiviral activity with the half-maximal inhibitory concentration of 8.29; 8.14; 12.81 and 26.89 µg/mL respectively. All extracts were nontoxic up to the concentration of 100 µg/µL. Entandrophragma cylindricum Sprague (EI), Khaya grandifoliola C. D.C. Sapindales (E2), and Entada africana Guill et Pers. (E4) showed strong inhibition on the entry step of viral infection. At the same time, only Entandrophragma cylindricum Sprague (EI) inhibited the viral titer significantly in replication and intercellular assembly steps. Four plant extracts namely Entandrophragma cylindricum Sprague (EI), Macaranga hurifolia Beille (E6), Phragmentera capitata (Sprengel) Balle (E12), and Detarium microcarpum (E13) were effective against egression step. CONCLUSIONS: Together, the results of this study showed anti-chikungunya activities of Entandrophragma cylindricum Sprague (EI) and Macaranga hurifolia Beille (E6), with therapeutics perspectives and can be promising sources of the development of anti-CHIKV molecule in future.

Program on immunization and cold chain monitoring: the status in eight health districts in Cameroon.

BACKGROUND: Cold chain monitoring is a precondition to ensure immunization quality, efficacy and safety. In Cameroon, the Expanded Program on Immunization (EPI) has National Standard Operating Procedure (SOP) that describes the vaccines, the cold chain system and equipment, its use and recommended procedures to control and monitor the temperatures and the cold chain. This study was conducted to assess the status of cold chain in eight health districts in Cameroon. FINDINGS: The study was carried out in eight health districts out of fifty with poor immunization coverage rate. Data were collected using a validated form by observation and consultation of related documents. District Health Services (DHS) and four Integrated. Health Centers (IHC) randomly selected were targeted per health district. Forty health facilities were included. Twenty eight (70.0%) had at least one functional refrigerator for EPI activities. The power supply was reported to be permanent in 7 (20.6%) out of 34. (85.0%) health facilities with access to power supply. The temperature monitoring chart was pasted on 27 (96.4%) of the cold chain equipment. On 16 (59.3%) of these charts, the temperature was recorded twice daily as recommended. Seven (25.9%) of 27 refrigerators assessed had temperature out of the recommended range of 2 to 8°C. Almost 23.30% of health centers did not received any supervision on cold chain monitoring during a vaccination campaign. CONCLUSION: This study documents failure of the cold chain maintenance and questions the efficacy and safety of vaccines administered during EPI activities in Cameroun. These findings indicate that appropriate actions are needed to ensure monitoring of EPI cold chain in the country.