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An outbreak of dengue and high densities of Aedes aegypti were reported in 2014 in northern Mozambique, suggesting an increased risk for other arboviruses such as chikungunya virus (CHIKV) in this region. The aim of this study was to investigate the occurrence of CHIKV during an outbreak of dengue virus (DENV) in Pemba city in northern Mozambique in 2014. Febrile patients (n = 146) seeking medical attention at the Pemba Provincial Hospital between March and April 2014 were enrolled in this study. Blood samples from each participant were tested for chikungunya and DENV RNA, IgM and IgG antibodies using PCR and ELISA, respectively. The median age of the patients was 26 years (interquartile range: 20–34 years), and 52.7% (77/146) were female. We found that 7.0% (8/114) of the patients were positive for CHIKV IgM and 31.5% (46/146) presented with CHIKV IgG antibodies. DENV IgM and IgG antibodies were detected in 38.3% (46/120) and 28.2% (33/117) of the patients, respectively. This study is the first investigation regarding the occurrence of CHIKV in the north of Mozambique over the last 60 years and our data suggest that Mozambicans had been silently exposed to the virus in this part of the country, indicating that not only DENV but also CHIKV is an arbovirus to consider in febrile patients seeking medical attention in northern Mozambique. [ABSTRACT FROM AUTHOR]

Abstract: In Africa and the Arabian Peninsula, outbreaks of Rift Valley fever (RVF) are characterized by abortions in gestating animals and high mortality rates among domestic ruminants. An immunization program using a formalin-inactivated vaccine was initiated in Mozambique in 2002 to control RVF in cattle. In this intervention, the vaccine must be transported for more than a week within the country before it can be administered to the animals, and it is practically impossible to maintain low storage temperatures during that time. Here, we evaluated the influence of transportation conditions on the efficacy of the vaccine. Sixty-three previously unvaccinated and RVF virus seronegative cattle were divided into four groups, which were given vaccine that had been stored for 1 week at 4°C (n =9, group A), at 25°C (n =8, group B), or alternating between 4 and 25°C (n =8, group C), or under the temperature conditions ordinarily occurring during transportation within Mozambique (n =38, group D). The antibody responses induced were monitored for 6–9 months and in some animals up to 21 months. Two immunizations (3 weeks apart) with the formalin-inactivated vaccine induced a long-lasting neutralizing antibody response that was still detectable up to 21 months later. The antibody titers in the animals did not differ significantly between the temperature-assigned vaccine groups A, B, and C, whereas they were significantly higher in group D. These results show that the formalin-inactivated RVF virus vaccine is stable, and, importantly, it is not adversely affected by the variation in temperature that ordinarily occurs during transport within Mozambique. [Copyright &y& Elsevier]

The article presents a pilot study which examined the epidemiology of chikungunya virus (CHIKV), dengue virus (DENV), hantavirus, Rift Valley fever virus (RVFV), and West Nile virus (WNV) in Mozambique in 2012-2013. The study was approved by the National Bioethics Committee in Mozambique and by the Regional Ethical Review Board at Karolinska Institutet in Stockholm, Sweden. Based on the results, persons living in the area are frequently exposed to vectorborne viruses.

A letter to the editor is presented in response to the article on antibodies against Rift Valley fever virus (RVFV) in cattle in Mozambique.

Background: Arboviruses represent the most rapidly spreading mosquito-borne viruses worldwide. In Mozambique, arboviroses have been heavily neglected and for this reason they are never considered in the differential diagnosis of acute febrile illness. A recent dengue outbreak was reported in Pemba, situated in northern Mozambique in 2014, and during the outbreak more than half of dengue suspected cases had their dengue results negative, suggesting other causes of fever of unknown origin. The aim of the study was to investigate the circulation of dengue (DENV), chikungunya (CHIKV), west nile virus (WNV) and rift valley fever (RVF) in febrile and non febrile patients in Pemba, during the outbreak of dengue in 2014. Methods & Materials: A total of 398 individuals were identified, of which, 300 were non febrile and 98 were dengue suspected cases (febrile) attending the outpatient appointment visit at Pemba Provincial Hospital, between March and April 2014 were enrolled in this study. Blood samples were collected from each participant and initially tested for dengue using IgM anti-dengue commercial ELISA and by real time PCR. All dengue negative samples were then tested for chikungunya, RVFV, WNV using the PCR and indirect immunofluorescence assay (IFA) for IgG detection. Results: Of the 398 participants 37.7% (37/98) were DENV positive using PCR and all were negative for CHIKV, RVF andWNVwhen tested by PCR.Amongfebrile patients, IgG antibodies against CHIKV were detected in 27.5% (27/98) of febrile participants by IFA, 10.2% (10/98) were dual positive for IgG anti-DENV and IgG anti-CHIKV and 3.06% (3/98) were positive for IgG anti-RVF. The percentage of positive results for IgG antibodies against DENV, CHIKV, RVFV among non febrile participants were 26% (78/300), 45.3% (136/300) and 1% (3/300), respectively. No sample was positive for IgG anti- WNV antibody among non febrile patients. Conclusion: Our data provide evidence that DENV, CHIKV and RVF co-circulate in northern Mozambique, suggesting that not only DENV but CHIKV and RVFV, should be considered in the differential diagnosis of acute febrile syndrome in northern Mozambique. [ABSTRACT FROM AUTHOR]