Aquatic systems are affected by a variety of anthropogenic activities that decrease water quality through the introduction of organic and inorganic pollutants. To investigate the relationship between fish parasite communities and water quality, metazoan parasites were examined in 140 specimens of the Mozambique tilapia (Oreochromis mossambicus) sampled in three lakes in the Limpopo Province, namely the Luphephe–Nwanedi Dams (regarded as unpolluted), the Flag Boshielo Dam (regarded as moderately polluted) and a return water dam on a mine site (regarded as polluted). The monogenean parasites Cichlidogyrus halli, digenean larval stages of Clinostomum and Diplostomum spp. and a gryporynchid cestode were found in or on O. mossambicus in all the sampled sites. The distribution of monogeneans (Cichlidogyrus sclerosus, Cichlidogyrus dossoui, Cichlidogyrus tilapiae, Scutogyrus longicornis and three Enterogyrus spp.), metacercarial stages of two digeneans (Neascus and Acanthostomum spp.) and nematodes (an unidentified nematode, Contracaecum sp., Paracamallanus cyathopharynx and Procamallanus laevionchus) was limited to the unpolluted and moderately polluted lakes. Larval stages of Diplostomum sp. were present in O. mossambicus collected from the unpolluted and polluted sites. The variability of the calculated infection indices (prevalence, mean abundance and mean intensity) and the parameters of species richness and diversity suggest that the structure of parasite communities are affected by the pollution levels of the water. The unpolluted reference site had the highest species richness and the highest overall parasite abundance values.

Yersinia pestis, the bacterial agent of plague, is primarily a parasite of wild rodents that persists in permanent, discrete enzootic foci throughout the world. The disease is transmitted in humans by bites from fleas of wildlife rodent species. Therefore surveillance is the ultimate public health solution through plague detection in domestic dogs, other carnivores and wild rodents. The investigations of die-offs amongst plague-susceptible colonial rodents are also significant to determine the presence of Y. pestis in a susceptible population. This study details the identification of the plague reservoir in a suspected endemic area of Zambia. The study was undertaken through rodent investigation for the presence of Y. pestis. A total of 105 rodents were sampled routinely and during a suspected plague period. On dissection 4 (3.81%, 95% CI: 1.23−10.0) rodents sampled during an outbreak showed signs of spleen enlargement. The blood, liver, lymph nodes and spleen of each rodent were subjected to culture on 6% sheep blood agar and MaCconkey agar. Colonies obtained were identified as Y. pestis by colony morphologic features, biochemical profiles, mouse inoculation assay and polymerase chain reaction (PCR). The PCR primers used targeted the Y. pestis plasminogen activator gene, chromosomal ferric iron uptake regulation gene and the outer membrane protein B gene. The isolates were also subjected to antibiotic sensitivity tests using the disk diffusion method on Mueller-Hinton agar with sensitivity being observed with ampicillin, amoxicillin, chloramphenicol, gentamycin, streptomycin, tetracycline and trimethoprim-sulfamethoxazole. The findings, identifies a natural reservoir of Y. pestis in Zambia providing the public health officials with a definite host for the control strategy.

Zambia has been experiencing low livestock productivity as well as trade restrictions owing to the occurrence of foot-and-mouth disease (FMD) and contagious bovine pleura pneumonia (CBPP). Foot-and-mouth disease was first recorded in Zambia in 1933 in the Western Province and since then the country has experienced repeated outbreaks. Bearing in mind the pressure that may be existing on the many risk factors for FMD including climate change, there is need to review our knowledge on FMD control. We present the spatial distribution of the FMD outbreaks that have been recorded in Zambia in the last twenty years, and the effect of the vaccinations and movement control that have been applied. We propose further strain characterisation of previous FMD outbreaks, including full sequence of VP1 gene and the 5’UTR site. The data will be geo-coded and populated with risk factor attributes. We also present preliminary findings of the buffalo and cattle probang sampling that was conducted in Lochnivar and Kafue National Park. We further probang sampled 25 buffalo at each interface area in Sioma Ngwezi, Lukusuzi and Lower Zambezi national parks. Villages in close proximity to the buffalo populations as well as those not in close proximity will be multistage cluster sampled for comparison. The data will be geo-coded and populated with risk factor and foot-and-mouth disease virus (FMDV) characterisation attributes. Data collected using a pre-tested structured questionnaire will be geo-coded and populated with identified risk factors and stored in a database and will be spatially modelled to determine their effect on FMD occurrence and control measures. New outbreaks of FMD that may occur will be investigated to find out if there are new strains involved, species affected and predisposing risk factors. The authors conclude that impacts of FMD on livelihoods if appropriate control measures are not put in place are far more devastating especially at community level. Presented with the current poverty levels failure to institute result oriented control measures will exacerbate the already life-threatening situation.

One Health - ‘joining the dots’

An initial census of layer farms in Khartoum State, Sudan, was carried out in late 2007 and early 2008 and found that there were 252 layer farms with a total population of 2 221 800 birds. This paper reports the findings of the census. Based on this information, a structured questionnaire survey of 92 farms was then conducted in the state in April 2008 to collect data on antibiotic usage, demographic data and public health awareness. Ninety-eight per cent of participating farms comprised open-sided houses. It was found that 49% of the farms surveyed were on antibiotic treatment when the survey was conducted, whilst 59% of the farms had used antibiotics within the last 3 months. The study found that farmers and producers had a lack of knowledge about antimicrobial residues, their withdrawal periods and the risk posed by the consumption of these residues. The study also concluded that traditional farming systems in Sudan relied heavily on antimicrobial medication to control disease and almost half of the farms surveyed were treating their flocks with antimicrobials. In addition to this, there was a lack of disease control programmes which probably resulted in a massive use of antibiotics to control endemic diseases. This was further compounded by the absence of governmental supervision and control on the use of drugs.

Over the past few decades a large number of new and emerging infectious diseases have been recognised in humans, partly because of improved diagnostic technologies and increased awareness and also, partly because of dynamic ecological changes between human hosts and their exposure to animals and the environment (Coker et al. 2011). Some 177 new pathogenic organisms have been recognised to be ‘emerging’, that is, have newly arisen or been newly introduced into human populations; almost three quarters of these, 130 (73%), have come from zoonotic origins (Cascio et al. 2011; Cutler, Fooks & Van Der Poel 2010; Taylor, Latham & Woolhouse 2001; Woolhouse & Gowtage-Sequeria 2005). One of the most prevalent and important human infectious disease is influenza, a disease responsible globally for a quarter million deaths annually. In the USA alone the toll from influenza is estimated at 36 000 deaths and 226 000 hospitalisations, and it ranks as the most important cause of vaccine preventable mortality in that country (CDC 2010). The epidemiological behaviour of human influenza clearly defines it as an emerging infectious disease and the recent understanding of its zoonotic origins has contributed much to the understanding of its behaviour in humans (Fauci 2006).

The work in the papers and abstracts was supported by Wellcome Trust Grant WT087546MA to the Southern African Centre for Infectious Disease Surveillance (http://www.sacids.org) and its collaborating UK partner institutions, namely the London School of Hygiene and Tropical Medicine (http://www.lshtm.ac.uk), the Royal Veterinary College (http://www.rvc.ac.uk) and the London International Development Centre (http://www.lidc.org.uk). The work presented by Esron Karimuribo et al. was supported by Rockefeller Foundation.

Brucellosis is an endemic disease in Zimbabwe caused by the genus <em>Brucella</em>. <em>Brucella</em> seroprevalence was recently reported to be high in the wildlife-livestock interface in the Chiredzi district and the neighbouring Gonarezhou National Park (GNP) in Zimbabwe, and higher amongst communal cattle with an abortion history and access to grazing in GNP than amongst communal cattle with no abortion history or access to grazing in GNP. The aim of this study was to investigate <em>Brucella</em> species in brucellosis seropositive cattle in the Chiredzi district with access to GNP using isolation and identification. Isolation of<em> Brucella </em>species from whole blood (<em>n</em> = 18) and milk samples (<em>n</em> = 10) from seropositive animals with an abortion history was based on the rose Bengal test (RBT) and enzyme-linked immunoassays (enzyme- linked immunosorbent assay [ELISA]; indirect ELISA and complement ELISA), using microbiology and polymerase chain reaction (PCR) methods. <em>Brucella abortus</em> was cultured and identified from blood and milk collected from seropositive cows in both communal areas. The<em> Brucella</em>-specific 16-23S intergenic spacer (ITS) PCR and multiplex AMOS-PCR assays verified the identification of the cultures. Our results confirmed that <em>B. abortus</em> is present in cattle on communal farms in the Chiredzi district in Zimbabwe and might cause cattle abortions. The need for implementing control measures and raising public awareness on zoonotic transmission of brucellosis are recommended.

The first collection of unengorged and fully engorged larvae of Nuttalliella sp. (N. namaqua?) from the murid rodents Micaelamys namaquensis, Aethomys chrysophilus and Acomys spinosissimus in Limpopo Province and from M. namaquensis in the Northern Cape Province, South Africa, is documented. A total of nine larvae were collected from two M. namaquensis in the Soutpansberg mountain range in the Limpopo Province during April 2009. During the last week of September 2011, 221 larvae were collected from rodents at the same locality and 10 of 48 M. namaquensis, 6 of 12 Ae. chrysophilus and 3 of 14 Ac. spinosissimus were infested. One of the M. namaquensis harboured 53 larvae. Five larvae were collected from two M. namaquensis in the Northern Cape Province. Total genomic DNA was extracted from two larvae and a region of the 18S rRNA gene was sequenced for these. BLASTn searches revealed similarity between these specimens and the Nuttalliella sequences published on GenBank.