Arboviruses are a major public health problem worldwide and are predominantly present in intertropical areas. Chikungunya, dengue and zika viruses have been implicated in recent epidemics in Asia, America and Africa. In Cameroon, data on these viruses are fragmentary. The purpose of this study was to determine the frequency of detection of these three viruses in febrile patients in Douala, Cameroon. A cross-sectional and descriptive study was conducted from March to April 2017 at the New-Bell District Hospital in Douala. Blood samples were collected from febrile patients and tested for malaria infections using Rapid Diagnostic test. Plasma harvested was later analyzed for the presence of chikungunya, dengue and zika viruses by a Trioplex real-time RT-PCR at Centre Pasteur of Cameroon. A total of 114 participants were included, of which 63.2% were females, reflecting a sex ratio (female/male) of 1.7. The median age was 26 years, range [0.25–81]. Eight (7%) of the 114 participants were infected with Dengue virus (DENV) among which 5 were identified as serotype 1. No cases of infection by either Zika virus or Chikungunya virus were detected. Three cases of dengue-malaria co-infection (13%) were recorded. No association was found between socio-demographic factors and dengue infection. The phylogenetic analysis of the partial envelope E gene showed that all the five DENV serotype 1 samples belonged to subtype V, similarly to strains from West African countries, particularly those from Nigeria, Senegal and Côte d’Ivoire. This study showed the circulation of DENV serotype 1 in febrile patients and raises the alarm for the establishment of a sustained surveillance system to detect cases and prevent potential outbreaks in Cameroon. The existence of dengue-malaria co-infections suggests that surveillance of arboviruses should not be limited to febrile, non-malarial cases.

Background: On May 2017, a case of dengue serotype 1 was detected and confirmed through routine surveillance in a traveler returning from Kribi, a seaside town of Southern Cameroon. This study aimed at confirming the circulation of dengue virus (DENV) in Southern Cameroon. Methods: A cross sectional study was carried out in Londji near Kribi from June 21–25, 2017, by a joint team of Centre Pasteur of Cameroon and the Department of Diseases, Epidemics and Pandemics Control. Blood samples of consented participants were collected and tested for anti-D ENV IgM using an IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA), and for the detection of Zika, dengue, or chikungunya viruses using Trioplex real-time reverse transcription-polymerase chain reaction (RT-PCR). DENV RNA-positive samples were serotyped using an end-point nested RT-PCR. Results: Ninety-one participants were enrolled, 50.55% (46/91) of them males. The mean age of the population was 30.71 years (±18.89). In total, 14.28% (13/91) of the participants had DENV infection (3 anti-DENV IgM positive and 10 DENV serotype 1 RT-PCR positive). Conclusion: The detection of DENV serotype 1 in an autochthonous population during this survey is a confirmation that the seaside city of Kribi is a risk area for contracting dengue infection in Cameroon.

Chikungunya viruses containing the A226V mutation detected retrospectively in Cameroon form a new geographical subclade,

Rubella is an acute and contagious viral infection whose gravidity resides in infection during pregnancy, which can result in miscarriage, fetal death, stillbirth, or infants with congenital malformations. This study aimed to describe the genome of rubella viruses (RUBVs) circulating in Cameroon. Throat swabs were collected from health districts as part of the measles surveillance program from 2010 to 2016 and sent to the Centre Pasteur of Cameroon. Samples were amplified by genotyping reverse transcription polymerase chain reaction (RT‐PCR) in the search of two overlapping fragments of the gene that encodes the E1 envelope glycoprotein of RUBV. PCR products were sequenced and phylogenetic analysis was performed with MEGA 6 software. Overall, 9 of 43 samples (20.93%) were successfully amplified and sequenced but only eight sequences could be exploited for phylogenetic analysis with respect to the required fragment length of 739 nucleotides. Analysis of viral sequences from Cameroon with other epidemiologically relevant sequences from around the world showed that all RUBVs belonged to lineage L1 of genotype 1G. Cameroon sequences clustered with viruses from West Africa including Nigeria, Ivory Coast, and Ghana with a percentage similarity of 95.4% to 99.2%. This study will enable an update on the molecular epidemiology of RUBV in Cameroon and help in monitoring circulating RUBV for a better implementation of elimination strategies.