The epidemiology of foot-and-mouth disease (FMD) in Africa is unique in the sense that six of the seven serotypes of FMD viruses (Southern African Territories [SAT] 1, SAT2, SAT3, A, O, and C), with the exception of Asia-1, have occurred in the last decade. Due to underreporting of FMD, the current strains circulating throughout sub-Saharan Africa are in many cases unknown. For SAT1, SAT2, and serotype A viruses, the genetic diversity is reflected in antigenic variation, and indications are that vaccine strains may be needed for each topotype. This has serious implications for control using vaccines and for choice of strains to include in regional antigen banks. The epidemiology is further complicated by the fact that SAT1, SAT2, and SAT3 viruses are maintained and spread by wildlife, persistently infecting African buffalo in particular. Although the precise mechanism of transmission of FMD from buffalo to cattle is not well understood, it is facilitated by direct contact between these two species. Once cattle are infected they may maintain SAT infections without the further involvement of buffalo. No single strategy for control of FMD in Africa is applicable. Decision on the most effective regional control strategy should focus on an ecosystem approach, identification of primary endemic areas, animal husbandry practices, climate, and animal movement. Within each ecosystem, human behavior could be integrated in disease control planning. Different regions in sub-Saharan Africa are at different developmental stages and are thus facing unique challenges and priorities in terms of veterinary disease control. Many science-based options targeting improved vaccinology, diagnostics, and other control measures have been described. This review therefore aims to emphasize, on one hand, the progress that has been achieved in the development of new technologies, including research towards improved tailored vaccines, appropriate vaccine strain selection, vaccine potency, and diagnostics, and how it relates to the conditions in Africa. On the other hand, we focus on the unique epidemiological, ecological, livestock farming and marketing, socioeconomic, and governance issues that constrain effective FMD control. Any such new technologies should have the availability of safe livestock products for trade as the ultimate goal.

This paper describes the molecular characterization of foot‐and‐mouth disease viruses (FMDV) recovered from outbreaks in Tanzania that occurred between 1967 and 2009. A total of 44 FMDV isolates, containing representatives of serotypes O, A, SAT 1 and SAT 2 from 13 regions of Tanzania, were selected from the FAO World Reference Laboratory for FMD (WRLFMD) virus collection. VP1 nucleotide sequences were determined for RT‐PCR amplicons, and phylogenetic reconstructions were determined by maximum likelihood and neighbour‐joining methods. These analyses showed that Tanzanian type O viruses fell into the EAST AFRICA 2 (EA‐2) topotype, type A viruses fell into the AFRICA topotype (genotype I), type SAT 1 viruses into topotype I and type SAT 2 viruses into topotype IV. Taken together, these findings reveal that serotypes O, A, SAT 1 and SAT 2 that caused FMD outbreaks in Tanzania were genetically related to lineages and topotypes occurring in the East African region. The close genetic relationship of viruses in Tanzania to those from other countries suggests that animal movements can contribute to virus dispersal in sub‐Saharan Africa. This is the first molecular description of viruses circulating in Tanzania and highlights the need for further sampling of representative viruses from the region so as to elucidate the complex epidemiology of FMD in Tanzania and sub‐Saharan Africa.

Zambia has been experiencing low livestock productivity as well as trade restrictions owing to the occurrence of foot and mouth disease (FMD), but little is known about the epidemiology of the disease in these endemic settings. The fundamental questions relate to the spatio-temporal distribution of FMD cases and what determines their occurrence. A retrospective review of FMD cases in Zambia from 1981 to 2012 was conducted using geographical information systems and the SaTScan software package. Information was collected from peer-reviewed journal articles, conference proceedings, laboratory reports, unpublished scientific reports and grey literature. A space–time permutation probability model using a varying time window of one year was used to scan for areas with high infection rates. The spatial scan statistic detected a significant purely spatial cluster around the Mbala–Isoka area between 2009 and 2012, with secondary clusters in Sesheke–Kazungula in 2007 and 2008, the Kafue flats in 2004 and 2005 and Livingstone in 2012. This study provides evidence of the existence of statistically significant FMD clusters and an increase in occurrence in Zambia between 2004 and 2012. The identified clusters agree with areas known to be at high risk of FMD. The FMD virus transmission dynamics and the heterogeneous variability in risk within these locations may need further investigation.

Rift Valley fever virus (RVFV) is an acute, zoonotic viral disease caused by a Phlebovirus, which belongs to the Bunyaviridae family. Among livestock, outbreaks of the disease are economically devastating. They are often characterised by large, sweeping abortion storms and have significant mortality in adult livestock. The aim of the current study was to investigate RVFV infection in the Kigoma region, which is nestled under the hills of the western arm of the Great Rift Valley on the edge of Lake Tanganyika, Tanzania. A region-wide serosurvey was conducted on non-vaccinated small ruminants (sheep and goats, n = 411). Sera samples were tested for the presence of anti-RVFV antibodies and viral antigen, using commercial enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction, respectively. The overall past infections were detected in 22 of the 411 animals, 5.4% (Confidence Interval (CI) 95% = 3.5% – 8.1%). The Kigoma rural area recorded the higher seroprevalence of 12.0% (CI 95% = 7.3% – 18.3%; p < 0.0001), followed by Kibondo at 2.3% (CI 95% = 0.5% – 6.5%; p > 0.05) and the Kasulu district at 0.8% (CI 95% = 0.0% – 4.2%; p > 0.05). The prevalence was 12.5% and 4.7% for sheep and goats, respectively. Reverse transcriptase polymerase chain reaction results indicated that only eight samples were found to be positive (n = 63). This study has confirmed, for the first time, the presence of the RVFV in the Kigoma region four years after the 2007 epizootic in Tanzania. The study further suggests that the virus activity exists during the inter-epizootic period, even in regions with no history of RVFV.

Rift Valley fever (RVF), a mosquito-borne transboundary zoonosis, was first confirmed in Rwanda’s livestock in 2012 and since then sporadic cases have been reported almost every year. In 2018, the country experienced its first large outbreak, which was followed by a second one in 2022. To determine the circulating virus lineages and their ancestral origin, two genome sequences from the 2018 outbreak, and thirty-six, forty-one, and thirty-eight sequences of small (S), medium (M), and large (L) genome segments, respectively, from the 2022 outbreak were generated. All of the samples from the 2022 outbreak were collected from slaughterhouses. Both maximum likelihood and Bayesian-based phylogenetic analyses were performed. The findings showed that RVF viruses belonging to a single lineage, C, were circulating during the two outbreaks, and shared a recent common ancestor with RVF viruses isolated in Uganda between 2016 and 2019, and were also linked to the 2006/2007 largest East Africa RVF outbreak reported in Kenya, Tanzania, and Somalia. Alongside the wild-type viruses, genetic evidence of the RVFV Clone 13 vaccine strain was found in slaughterhouse animals, demonstrating a possible occupational risk of exposure with unknown outcome for people working in meat-related industry. These results provide additional evidence of the ongoing wide spread of RVFV lineage C in Africa and emphasize the need for an effective national and international One Health-based collaborative approach in responding to RVF emergencies.

Susceptibility of DT40 cells to pathogenic field strains of infectious bursal disease virus (IBDV) including very virulent and classical virulent strains were studied. After the first and second passage of the virus in DT40 cells, IBDV-specific antigen was readily detected in DT40 cells inoculated with the pathogenic field strain infected bursal homogenates. Nucleotide sequence analysis in the VP2 hypervariable domain, which is critical for the virulence of IBDV, revealed no common amino acid substitutions among the pathogenic IBDVs in accordance with the propagation in DT40 cells. These results indicate that DT40 cells are a useful tool for rapid isolation of pathogenic field strains and successive in vitro analysis of IBDV.