Current State of Modern Biotechnological-Based Aeromonas hydrophila Vaccines for Aquaculture: A Systematic Review.

This systematic review describes what "the cutting edge vaccines for Aeromonas hydrophila are". The focus is on types of high tech biotechnological based vaccines, target gene or antigen in developing these vaccines, and challenge model fish species used in vaccines efficacy testing. Vaccines delivery methods, immune response, and their efficacy, adjuvant or carrier systems used, and the overall experimental setup or design of the vaccines under investigation are also described. The search for the original papers published between 2009 and 2018 was conducted in June of 2018, using the PubMed and Google scholar electronic database. Twenty-three (23/4386) studies were included in the final assembly using PRISMA guidelines (Protocol not registered). Recombinant protein vaccines were the highly experimented type of the modern biotechnological based vaccines identified in the selected studies (16/23; 70%). Outer membrane proteins (OMPs) of different ß-barrels were shown to be a potential antigenic entity for A. hydrophila vaccines (57%). Intraperitoneal route with conventional carries or adjuvants was the highly applied delivery system while very few studies used herbal based vaccine adjuvants and nanomaterial as a vaccine carrier. Variation was observed in terms of protection levels in the selected studies. The experimental designs partly contributed to the observed variation. Therefore, recombinant vaccines that use new carrier system technologies and delivered through oral route in feeds would have been of great value for use in the prevention and control of A. hydrophila infections in fish. Despite the usefulness as academic tools to identify what is important in pathogenicity of the etiological agent to the host fish, these vaccines are only economically viable in very high-value animals. Therefore, if vaccination is a good option for A. hydrophila group, then simple autogenous vaccines based on accurate typing and evidence-based definition of the epidemiological unit for their use would be the most viable approach in terms of both efficacy and economic feasibility especially in low and middle-income countries (LMIC).

Phenotypic and molecular detection of Aeromonads infection in farmed Nile tilapia in Southern highland and Northern Tanzania.

Aeromonads disease outbreaks are now becoming a common phenomenon in freshwater farmed fish worldwide. In Tanzania, the aquaculture field is increasingly growing save to sustain food protein demand and strengthen household income. To avoid losses that tilapia fish farmers might account, information on magnitude of infection and characteristics of the aetiological agent is vital. This study aimed to establish the prevalence of aeromonads infection in farmed tilapia and assess pond and fish health management practices. A cross sectional study was carried out between February 2017 and October 2018 and a total of 816 whole fish samples were aseptically collected from 32 ponds in Ruvuma, Mbeya, Iringa and Kilimanjaro regions. During sampling, water quality parameters were taken and questionnaires to assess the knowledge of farmers were also provided. Isolation and identification of bacteria was conducted using conventional biotyping and molecular techniques. A total of 201 (80.4%) of 250 isolates that were conventionally identified were confirmed to be aeromonads by amplification of 820 bp rpoD gene, making the overall prevalence of 24.6% (201, n = 816). Sequencing of rpoD gene and phylogenetic analysis revealed two aeromonads species, Aeromonas hydrophila and Aeromonas veronii. To the best of our knowledge this is the first report to establish the prevalence of aeromonads in apparently healthy farmed tilapia in Southern highlands and Northern zone of Tanzania. In addition it was observed that farmers were lacking proper knowledge and awareness on pond management practices and fish health management. In conclusion, the infection rate of aeromonads in apparently health tilapia coupled with lack of proper knowledge and awareness on pond and fish health management by fish farmers in the study area poses risk of diseases outbreaks in their farms in future. Therefore, it is recommended that the farmers should be trained on basic pond and fish health management and control strategies.

Circulation of Rift Valley Fever Virus Antibody in Cattle during Inter-Epizootic/Epidemic Periods in Selected Regions of Tanzania.

Tanzania is one of the sub-Saharan countries that have experienced a number of Rift Valley fever (RVF) outbreaks at intervals of 10-20 years since the first isolation of the virus during the early 1930s. Recent studies have reported serological evidence of inter epizootic/epidemic period circulation of RVF virus (RVFV) in livestock and humans. The aim of this study was to conduct a cross-sectional survey in Tanzania during 2015/16 to further explore the possibility that RVFV was circulating among cattle during the Inter epizootic/epidemic period. A total of 443 cattle samples were collected in Manyara, Dodoma, Singida, and Mbeya regions of Tanzania. The samples were tested for RVFV antibodies using a commercial ELISA kit and a plaque reduction neutralization test. Serum samples were also tested for RVFV viral RNA by an reverse transcription polymerase chain reaction (RT-PCR) assay. An overall RVFV seroprevalence rate of 7.7% (34/443) was detected by ELISA among cattle in all four regions. The Mbeya region cattle had the highest seroprevalence of 26.4% (23/87), followed by Dodoma 5.9% (10/171) and lastly Singida 0.9% (1/101). Of 33 ELISA antibody-positive samples, only 0.2% (1/443) had IgM antibody. Of 36 ELISA antibody-positive and doubtful samples, 32 were positive for neutralizing antibody with titers between 10 and > 10,240. None of the samples were positive for RVFV viral RNA by RT-PCR. The detection of RVFV antibodies in cattle suggested that these animals were involved in an enzootic cycle during the interepidemic period and that the high antibody titers may confer protection of cattle against RVFV.

Safety and immunogenicity of Rift Valley fever MP-12 and arMP-12ΔNSm21/384 vaccine candidates in goats (Capra aegagrus hircus) from Tanzania.

Vaccination of domestic ruminants is considered to be an effective strategy for protecting these animals against Rift Valley fever (RVF), but available vaccines have limitations. Therefore, the aim of this study was to determine the safety and immunogenicity of RVF virus (RVFV) mutagenesis passage 12 (MP-12) and arMP-12ΔNSm21/384 vaccine candidates in goats (Capra aegagrus hircus) in Tanzania. Goats were vaccinated intramuscularly with RVFV MP-12 or arMP-12ΔNSm21/384, and then on Day 87 post-vaccination (PV) all animals were revaccinated using the RVFV MP-12 vaccine candidate. Serum samples were collected from the animals before and after vaccination at various intervals to test for RVFV using a Vero cell culture assay and reverse transcription polymerase chain reaction and for RVFV-neutralising antibody using a plaque reduction neutralisation assay. Serum samples collected before vaccination on Days -14 and 0, and on Days 3, 4 and 5 PV were negative for RVFV and neutralising antibody. All animals remained healthy, and viremia was not detected in any of the animals. Rift Valley fever virus antibody was first detected on Day 5 PV at a 1:10 dilution in five of five animals vaccinated with the MP-12 vaccine and in five of eight animals vaccinated with arMP-12ΔNSm21/384. Titres then increased and were sustained at 1:40 to 1:640 through to Day 87 PV. All animals that were revaccinated on Day 87 PV with MP-12 developed antibody titres ranging from 1:160 to as high as 1:10 240 on Days 14 and 21 PV. Although the antibody titres for goats vaccinated with RVF MP-12 were slightly higher than titres elicited by the arMP-12ΔNSm21/384 vaccine, these findings demonstrated that both vaccines are promising candidates for the prevention of RVF among Tansanian goats.

Serological evidence of inter-epizootic/inter-epidemic circulation of Rift Valley fever virus in domestic cattle in Kyela and Morogoro, Tanzania.

BACKGROUND: Tanzania is among the Rift Valley fever (RVF) epizootic/endemic countries in sub Saharan Africa, where RVF disease outbreaks occur within a range of 3 to 17-year intervals. Detection of Rift Valley fever virus (RVFV) antibodies in animals in regions with no previous history of outbreaks raises the question of whether the disease is overlooked due to lack-of effective surveillance systems, or if there are strains of RVFV with low pathogenicity. Furthermore, which vertebrate hosts are involved in the inter-epidemic and inter-epizootic maintenance of RVFV? In our study region, the Kyela and Morogoro districts in Tanzania, no previous RVF outbreaks have been reported. METHODOLOGY: The study was conducted from June 2014 to October 2015 in the Kyela and Morogoro districts, Tanzania. Samples (n = 356) were retrieved from both the local breed of zebu cattle (Bos indicus) and Bos indicus/Bos Taurus cross breed. RVFV antibodies were analyzed by two enzyme-linked immunosorbent assay (ELISA) approaches. Initially, samples were analyzed by a RVFV multi-species competition ELISA (cELISA), which detected both RVFV IgG and IgM antibodies. All serum samples that were positive with the cELISA method were specifically analysed for the presence of RVFV IgM antibodies to trace recent infection. A plaque reduction neutralization assay (PRNT80) was performed to determine presence of RVFV neutralizing antibodies in all cELISA positive samples. FINDINGS: Overall RVFV seroprevalence rate in cattle by cELISA in both districts was 29.2% (104 of 356) with seroprevalence rates of 33% (47/147) in the Kyela district and 27% (57/209) in the Morogoro district. In total, 8.4% (30/356) of all cattle sampled had RVFV IgM antibodies, indicating current disease transmission. When segregated by districts, the IgM antibody seroprevalence was 2.0% (3/147) and 12.9% (27/209) in Kyela and Morogoro districts respectively. When the 104 cELISA positive samples were analyzed by PRNT80 to confirm that RVFV-specific antibodies were present, the majority (89%, 93/104) had RVFV neutralising antibodies. CONCLUSION: The results provided evidence of widespread prevalence of RVFV antibody among cattle during an inter-epizootic/inter-epidemic period in Tanzania in regions with no previous history of outbreaks. There is a need for further investigations of RVFV maintenance and transmission in vertebrates and vectors during the long inter-epizootic/inter-epidemic periods.

The impact of anthelmintic drugs on weight gain of smallholder goats in subtropical regions.

Helminth infections are recognised as a major impediment to the productivity of goats in smallholder production systems. We used a multilevel framework to estimate the impact that administration of locally available anthelminthic drugs can have on the weight gains of goats in smallholder settings in India and Tanzania. We recruited 234 goats from 92 households from Odisha state in India and 253 goats from 15 households from Dodoma region in Tanzania. The goats were non-pregnant adult females, and from each household a minimum of two goats were recruited wherever possible. Each goat was randomly assigned to treatment with a locally available anthelminthic drug, or non-treatment. Each animal was tagged, weighed and had its body condition score (BCS) assessed. Animals were followed up after 28 and 56 days and re-weighed. To account for the local variations in exposure to helminths and for variations between households and herds, the data were analysed in a multilevel mixed model with herd in village as nested random effects. Over the 56 days of study, the non-treated goats in India had gained a mean of 30.64 g per day (a daily gain of 0.23% baseline body weight) and in Tanzania 66.01 g per day (0.33% baseline body weight). From the mixed model, the treated goats in India gained a mean of 25.22 g per day more than non-treated goats, this is significantly greater than the weight gain in non-treated goats (p < 0.001). In Tanzania treated goats gained a mean of 9.878 g per day more than non-treated goats, which is also significantly greater than non-treated goats (p = 0.007). Furthermore, in India and Tanzania, goats with a lighter weight at the baseline survey gained greater amounts of weight. In both studies the BCS of the treated goats improved by a greater amount than the non-treated goats. In this study we have demonstrated that in certain settings, the administration of anthelminthic drugs has a clear beneficial impact on goat weight.

A novel rapid direct haemagglutination-inhibition assay for measurements of humoral immune response against non-haemagglutinating Fowlpox virus strains in vaccinated chickens.

Fowlpox (FP) is a serious disease in chickens caused by Fowlpox virus (FPV). One method currently used to control FPV is vaccination followed by confirmation that antibody titres are protective using the indirect haemagglutination assay (IHA). The direct haemagglutination inhibition (HI) assay is not done because most FPV strains do not agglutinate chicken red blood cells (RBCs). A novel FPV strain TPV-1 which agglutinates chicken RBCs was discovered recently and enabled a direct HI assay to be conducted using homologous sera. This study is therefore aimed at assessing the direct HI assay using a recently discovered novel haemagglutinating FPV strain TPV-1 in chickens vaccinated with a commercial vaccine containing a non-haemagglutinating FPV.Chicks vaccinated with FPV at 1 day-old had antibody geometric mean titres (GMT) of log2 3.7 at 7 days after vaccination and log2 8.0 at 28 days after vaccination when tested in the direct HI. Chickens vaccinated at 6 weeks-old had antibody geometric mean titres (GMT) of log2 5.0 at 7 days after vaccination and log2 8.4 at 28 days after vaccination when tested in the direct HI. The GMT recorded 28 days after vaccination was slightly higher in chickens vaccinated at 6-week-old than in chicks vaccinated at one-day-old. However, this difference was not significant (P > 0.05). All vaccinated chickens showed "takes". No antibody response to FPV and "takes" were detected in unvaccinated chickens (GMT < 1). There was a slightly higher GMT in chickens of all ages throughout the observation period when the standard assay, the passive (indirect) haemagglutination was used (Overall GMT reached log2 9.3 ±.0.3 on day 28). However, the difference between the two assays was not significant (P > 0.05). CONCLUSION: These findings indicate that a simple and rapid direct HI assay using the FPV TPV-1 strain as antigen may be used to measure antibody levels in chickens vaccinated with non-haemagglutinating strains of FPV, and that the titres are comparable to those obtained by indirect IHA.

Abattoir surveillance demonstrates contagious bovine pleuropneumonia is widespread in Tanzania.

A study was conducted to investigate the presence of contagious bovine pleuropneumonia (CBPP) in the slaughter facilities in 10 regions of Tanzania that reported pathological lesions suggestive of CBPP during meat inspection. The aim was to ascertain if slaughter facilities can be used to monitor the occurrence and spread of CBPP in the country. The study involved a questionnaire survey, clinical examination of animals for CBPP symptoms prior to slaughter and postmortem examination of the respiratory system in slaughtered cattle. A total of 12 slaughterhouses and 31 animal markets were involved in the study. A total of 2736 cattle were slaughtered comprising 1978 and 758 in slaughterhouses and animal markets, respectively. Of the total slaughtered stock, 351 of 2736 (12.8 %) had lesions suggestive of CBPP and of these, 236 (8.6 %) were from slaughterhouses and 115 (4.2 %) from animal markets. Acute CBPP cases were observed in 192 of the 236 (81.4 %) and 71 of the 115 (61.7 %) of the animals inspected in the slaughterhouses and markets, respectively. Chronic cases were encountered in 24 (10.2 %) of the animals slaughtered in the slaughterhouses and 19 (16.5 %) at animal markets. This work has confirmed that targeted monitoring for CBPP lesions through meat inspection can be a useful tool for CBPP surveillance in endemic countries like Tanzania.

Investigation of foot-and-mouth disease outbreaks in the Mbala and Kazungula districts of Zambia.

Foot-and-mouth disease (FMD) is an acute, highly contagious viral infection of domestic and wild cloven-hoofed animals. It is known to be endemic in Zambia, with periodic outbreaks occurring in different geographical areas of the country. This study was conducted to investigate the presence of FMD virus (FMDV) in reported FMD-suspected cases in cattle from the Kazungula and Mbala districts of Zambia. Sixty epithelial tissues or oesophageal-pharyngeal (OP) scrapings (probang samples) were collected from Mbala (n = 51) and Kazungula (n = 9) and examined for FMDV. The FMDV viral RNA and serotypes were examined by realtime reverse transcription polymerase chain reaction (qRT-PCR) and antigen Enzyme- linked immunosorbent assay (ELISA), respectively. Twenty-two samples (36.7%) were positive for the FMDV genome by qRT-PCR with Cycle threshold (Ct) values ranging from 13 to 31. The FMDV-positive samples from epithelial tissues showed relatively higher Ct values compared to those obtained from OP scrapings, irrespective of geographical location. Forty percent (40%; n = 4) of epithelial tissues from Mbala were serotyped into SAT 2 serotype by antigen ELISA. Kazungula samples were serotyped into SAT 1. These findings indicated that Mbala and Kazungula districts had FMD outbreaks in 2012 that were ascribed to at least FMDV serotype SAT 2 and SAT 1 field strains. Furthermore, regular interaction between buffalos from the Mosi-o Tunya Park and domestic animals from surrounding areas could contribute to the occurrence of regular FMD outbreaks in Kazungula, whilst the uncontrolled animal movements across borders between Mbala and Nsumbawanga could be responsible for disease outbreaks in Mbala. In-depth molecular biological studies, including sequencing and phylogeny of the viruses, should be conducted to elucidate the complex epidemiology of FMD in Zambia, thereby providing valuable information needed for the rational control strategy of FMD in Zambia and neighbouring countries.

Molecular survey for foot-and-mouth disease virus in livestock in Tanzania, 2008-2013.

Phylogeography data are of paramount importance in studying the molecular epidemiology dynamics of foot-and-mouth disease virus (FMDV). In this study, epithelial samples and oesophageal-pharyngeal fluids were collected from 361 convalescent animals (cattle and buffaloes) in the field throughout Tanzania between 2009 and 2013. The single plex real-time RT-PCR (qRT-PCR) assay for rapid and accurate diagnosis of FMDV employing the Callahan 3DF-2, 3DF-R primers and Callahan 3DP-1 probe were used. Preparation of the samples was performed according to the OIE manual, with a Kenya O serotype obtained from the attenuated vaccine serving as a positive control and samples collected from healthy animals serving as true negatives. The results indicated that 53.49% of samples (n = 176) were positive for FMDV genome by qRT-PCR, with Ct values ranging from 14 to 32. In addition, molecular typing of the FMDV genome positive samples using serotype specific primers revealed the existence of several serotypes: serotype South Africa Territory 1 (SAT1) (34.25%, n = 60), serotype A (68.92%, n = 98), serotype O (59.20%, n = 98) and SAT2 (54.54%, n = 96). The virus protein 1 sequences analysis for 35 samples was performed and the collective results indicated: 54.28% serotype O, 25.71% serotype A, 14.28% serotype SAT1 and 2.85% serotype SAT2. Therefore in this study, both the phylogenetic trees and spatial distribution of serotypes elucidated the phylodynamics of multiple FMDV field strains in Tanzania and neighbouring countries.

Rapid, sensitive and effective diagnostic tools for foot-and-mouth disease virus in Africa.

Speed is paramount in the diagnosis of highly infectious diseases, such as foot-and-mouth disease (FMD), as well as for emerging diseases; however, simplicity is required if a test is to be deployed in the field. Recent developments in molecular biology have enabled the specific detection of FMD virus (FMDV) by reverse-transcription loop-mediated isothermal amplification (RT-LAMP), real-time reverse-transcription polymerase chain reaction (RT-qPCR) and sequencing. RT-LAMP enables amplification of the FMDV RNA-dependent RNA polymerase 3D(pol) gene at 63 °C (in the presence of a primer mixture and both reverse transcriptase and Bst DNA polymerase) for 1 h, whilst RT-qPCR amplifies the same gene in approximately 2 h 30 min. In this study, we compared the sensitivity and effectiveness of RT-LAMP against RT-qPCR for the detection of the FMDV 3D(pol) gene in 179 oesophageal-pharyngeal scraping samples (collected by probang) obtained from clinically healthy cattle and buffalo in Malawi, Mozambique and Tanzania in 2010. The FMDV detection rate was higher with RT-LAMP (30.2%; n = 54) than with RT-qPCR (17.3%; n = 31). All samples positive by RT-qPCR (Cq ≤ 32.0) were also positive for the RT-LAMP assay; and both assays proved to be highly specific for the FMDV target sequence. In addition, the VP1 sequences of 10 viruses isolated from positive samples corresponded to the respective FMDV serotypes and genotypes. Our findings indicate that the performance of RT-LAMP is superior to RT-qPCR. Accordingly, we consider this test to have great potential with regard to the specific detection and surveillance of infectious diseases of humans and animals in resource-compromised developing countries.

Serosurveillance of foot-and-mouth disease virus in selected livestock-wildlife interface areas of Tanzania.

Foot-and-mouth disease (FMD) is caused by a virus of the genus Aphthorvirus of the family Picornaviridae. There is great scientific need for determining the transmission dynamics of FMD virus (FMDV) by drawing more attention to the livestock-wildlife interface areas. A variety of literature suggests that buffalo could serve as reservoir of FMDV in wildlife and cattle. However, many FMDV research studies conducted on experimentally infected cattle as carriers and groups of animal highly susceptible to FMDV (i.e. bovine calves) have shown lower chances of transmission of the virus between carriers and the susceptible groups. These findings underscore the importance of continued research on the role played by carrier animals on FMDV transmission dynamics under natural conditions. The aim of this research study was to determine FMDV infection status among buffalo and cattle herds in selected livestock-wildlife interface areas. The sampled areas included Mikumi, Mkomazi and Ruaha national parks, where a total of 330 buffalo and bovine sera samples were collected. Laboratory analysis of the samples was done through the NSP ELISA technique using the PrioCHECK® FMDV NS Kit for detection of antibodies directed against 3ABC non-structural proteins and confirming natural infections. Results showed that 76.3% of tested sera samples were positive for FMDV. However, serotyping of NSP ELISA seroreactors with LPBE is yet to be done. This information is important for further epidemiological studies towards developing effective FMD control strategies.

Existence of variant strains Fowlpox virus integrated with Reticuloendotheliosis virus in its genome in field isolates in Tanzania.

Fowlpox virus (FPV) is one example of poultry viruses which undergoes recombination with Reticuloendotheliosis virus (REV). Trepidation had been raised, and it was well established on augmented pathogenicity of the FPV upon integration of the full intact REV. In this study, we therefore intended at assessing the integration of REV into FPV genome of the field isolates obtained in samples collected from different regions of Tanzania. DNA extraction of 85 samples (scabs) was performed, and FPV-specific PCR was done by the amplification of the highly conserved P4b gene. Evaluation of FPV-REV recombination was done to FPV-specific PCR positively identified samples by amplifying the env gene and REV long terminal repeats (5' LTR). A 578-bp PCR product was amplified from 43 samples. We are reporting for the first time in Tanzania the existence of variant stains of FPV integrated with REV in its genome as 65 % of FPV identified isolates were having full intact REV integration, 21 % had partial FPV-REV env gene integration and 5 % had partial 5' LTR integration. Despite of the fact that FPV-REV integrated stains prevailed, FPV-REV-free isolates (9 %) also existed. In view of the fact that full intact REV integration is connected with increased pathogenicity of FPV, its existence in the FPV genome of most field isolates could have played a role in increased endemic, sporadic and recurring outbreaks in selected areas in Tanzania.

Challenges and prospects for the control of foot-and-mouth disease: an African perspective.

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.

Development of a One Health National Capacity in Africa : the Southern African Centre for Infectious Disease Surveillance (SACIDS) One Health Virtual Centre Model.

Among the many challenges to health, infectious diseases stand out for their ability to have a profound impact on humans and animals. The recent years have witnessed an increasing number of novel infectious diseases. The numerous examples of infections which originated from animals suggest that the zoonotic pool is an important and potentially rich source of emerging diseases. Since emergence and re-emergence of pathogens, and particularly zoonotic agents, occur at unpredictable rates in animal and human populations, infectious diseases will constitute a significant challenge for the public health and animal health communities in the twenty-first century. The African continent suffers from one of the highest burdens of infectious diseases of humans and animals in the world but has the least capacity for their detection, identification and monitoring. Lessons learnt from recent zoonotic epidemics in Africa and elsewhere clearly indicate the need for coordinated research, interdisciplinary centres, response systems and infrastructures, integrated surveillance systems and workforce development strategies. More and stronger partnerships across national and international sectors (human health, animal health, environment) and disciplines (natural and social sciences) involving public, academic and private organisations and institutions will be required to meet the present and future challenges of infectious diseases. In order to strengthen the efficiency of early warning systems, monitoring trends and disease prediction and timely outbreak interventions for the benefit of the national and international community, it is essential that each nation improves its own capacity in disease recognition and laboratory competence. The SACIDS, a One Health African initiative linking southern African academic and research institutions in smart partnership with centres of science excellence in industrialised countries as well as international research centres, strives to strengthen Africa's capacity to detect, identify and monitor infectious diseases of humans and animals, to better manage health and socio-economic risks posed by them, and to improve research capacity in investigating the biologic, socio-economic, ecologic and anthropogenic factors responsible for emergence and re-emergence of infectious diseases.

Treponema pallidum infection in the wild baboons of East Africa: distribution and genetic characterization of the strains responsible.

It has been known for decades that wild baboons are naturally infected with Treponema pallidum, the bacterium that causes the diseases syphilis (subsp. pallidum), yaws (subsp. pertenue), and bejel (subsp. endemicum) in humans. Recently, a form of T. pallidum infection associated with severe genital lesions has been described in wild baboons at Lake Manyara National Park in Tanzania. In this study, we investigated ten additional sites in Tanzania and Kenya using a combination of macroscopic observation and serology, in order to determine whether the infection was present in each area. In addition, we obtained genetic sequence data from six polymorphic regions using T. pallidum strains collected from baboons at two different Tanzanian sites. We report that lesions consistent with T. pallidum infection were present at four of the five Tanzanian sites examined, and serology was used to confirm treponemal infection at three of these. By contrast, no signs of treponemal infection were observed at the six Kenyan sites, and serology indicated T. pallidum was present at only one of them. A survey of sexually mature baboons at Lake Manyara National Park in 2006 carried out as part of this study indicated that roughly ten percent displayed T. pallidum-associated lesions severe enough to cause major structural damage to the genitalia. Finally, we found that T. pallidum strains from Lake Manyara National Park and Serengeti National Park were genetically distinct, and a phylogeny suggested that baboon strains may have diverged prior to the clade containing human strains. We conclude that T. pallidum infection associated with genital lesions appears to be common in the wild baboons of the regions studied in Tanzania. Further study is needed to elucidate the infection's transmission mode, its associated morbidity and mortality, and the relationship between baboon and human strains.

Towards one health disease surveillance: the Southern African Centre for Infectious Disease Surveillance approach.

Africa has the highest burden of infectious diseases in the world and yet the least capacity for its risk management. It has therefore become increasingly important to search for 'fit-for- purpose' approaches to infectious disease surveillance and thereby targeted disease control. The fact that the majority of human infectious diseases are originally of animal origin means we have to consider One Health (OH) approaches which require inter-sectoral collaboration for custom-made infectious disease surveillance in the endemic settings of Africa. A baseline survey was conducted to assess the current status and performance of human and animal health surveillance systems and subsequently a strategy towards OH surveillance system was developed. The strategy focused on assessing the combination of participatory epidemiological approaches and the deployment of mobile technologies to enhance the effectiveness of disease alerts and surveillance at the point of occurrence, which often lies in remote areas. We selected three study sites, namely the Ngorongoro, Kagera River basin and Zambezi River basin ecosystems. We have piloted and introduced the next-generation Android mobile phones running the EpiCollect application developed by Imperial College to aid geo-spatial and clinical data capture and transmission of this data from the field to the remote Information Technology (IT) servers at the research hubs for storage, analysis, feedback and reporting. We expect that the combination of participatory epidemiology and technology will significantly improve OH disease surveillance in southern Africa.