Severe fever with thrombocytopaenia syndrome (SFTS) is an emerging infectious disease discovered in 2010 and has a case fatality as high as 30%. We intended to study the immune protection conferred by SFTS with natural infection. We collected and analysed 4-year follow-up data to study the characteristics of neutralising antibodies against SFTS virus (SFTSV). The 50% plaque reduction neutralisation test was used for the detection of neutralising antibodies against SFTSV. Geometric mean titres (GMTs) and proportions of patients with a protective titre were analysed, and the persistence of protection was predicted. The titre of antibodies declined yearly in the 4-year study period. Approximately 3 months after infection, the GMT was 143 (95% confidence interval (CI): 89–231), and 100% of patients had a protective titre. In the fourth year, the GMT declined to 53 (95% CI: 37–76), and 95% of patients had a protective titre. The titre was higher in females than in males. On average, the protection offered by neutralising antibodies against SFTSV could last as long as 9 years. The durations of protection were different for different initial titres. The characteristics of neutralising antibodies can be used as a reference for the vaccination doses and schedules of forthcoming vaccines.

Orthobunyaviruses, tri-segmented, negative-sense RNA viruses, have long been associated with mild to severe human disease in Africa, but not haemorrhagic fever. However, during a Rift Valley fever outbreak in East Africa in 1997–1998, Ngari virus was isolated from two patients and antibody detected in several others with haemorrhagic fever. The isolates were used to identify Ngari virus as a natural Orthobunyavirus reassortant. Despite their potential to reassort and cause severe human disease, characterization of orthobunyaviruses is hampered by paucity of genetic sequences. Our objective was to obtain complete gene sequences of two Bunyamwera virus and three Ngari virus isolates from recent surveys in Kenya and to determine their phylogenetic positioning within the Bunyamwera serogroup. Newly sequenced Kenyan Bunyamwera virus isolates clustered closest to a Bunyamwera virus isolate from the same locality and a Central African Republic isolate indicating that similar strains may be circulating regionally. Recent Kenyan Ngari isolates were closest to the Ngari isolates associated with the 1997–1998 haemorrhagic fever outbreak. We observed a temporal/geographical relationship among Ngari isolates in all three gene segments suggesting a geographical/temporal association with genetic diversity. These sequences in addition to earlier sequences can be used for future analyses of this neglected but potentially deadly group of viruses.

A peptide library was used to screen for regions containing potential linear B-cell epitope sites in the glycoproteins and nucleoprotein of Crimean-Congo haemorrhagic fever virus (CCHFV) in an enzyme-linked immunosorbent assay (ELISA). The library consisted of 156 peptides, spanning the nucleoprotein and mature GN and GC proteins in a 19-mer with 9-mer overlap format. Using pooled serum samples from convalescent patients to screen the library, six peptides were identified as potential epitope sites. Further testing of these six peptides with individual patient sera identified two of these peptides as probable epitope sites, with peptide G1451–1469 reacting to 13/15 and peptide G1613–1631 to 14/15 human sera. These peptides are situated on the GC protein at amino acid positions 1451–1469 (relative to CCHFV isolate SPU103/97) (TCTGCYACSSGISCKVRIH) and 1613–1631 (FMFGWRILFCFKCCRRTRG). Identified peptides may have application in ELISA for diagnostic or serosurveillance purposes.

Crimean Congo haemorrhagic fever virus (CCHFV) is a bunyavirus with a single-stranded RNA genome consisting of three segments (S, M, L), coding for the nucleocapsid protein, envelope glycoproteins and RNA polymerase, respectively. To date only five complete genome sequences are available from southern African isolates. Complete genome sequences were generated for 10 southern African CCHFV isolates using next-generation sequencing techniques. The maximum-likelihood method was used to generate tree topologies for 15 southern African plus 26 geographically distinct complete sequences from GenBank. M segment reassortment was identified in 10/15 southern African isolates by incongruencies in grouping compared to the S and L segments. These reassortant M segments cluster with isolates from Asia/Middle East, while the S and L segments cluster with strains from South/West Africa. The CCHFV M segment shows a high level of genetic diversity, while the S and L segments appear to co-evolve. The reason for the high frequency of M segment reassortment is not known. It has previously been suggested that M segment reassortment results in a virus with high fitness but a clear role in increased pathogenicity has yet to be shown.

Animal losses due to abortion and malformed offspring during the lambing period 2011/2012 amounted to 50% in ruminants in Europe. A new arthropod-borne virus, called Schmallenberg virus (SBV), was identified as the cause of these losses. Blood samples were obtained from 40 goat flocks and tested for antibodies against SBV by ELISA, with 95% being seropositive. The calculated intra-herd seroprevalence (median 36·7%, min-max 0–93·3%) was smaller than in cattle or sheep flocks. Only 25% of the farmers reported malformations in kids. Statistical analysis revealed a significantly lower risk of goats housed indoors all year-round to be infected by SBV than for goats kept outside day and night. The low intra-herd seroprevalence demonstrates that German goat flocks are still at risk of SBV infection. Therefore, they must be protected during the next lambing seasons by rescheduling the mating period, implementing indoor housing, and continuous treatment with repellents or vaccination.