Infectious bursal disease virus (IBDV) is a bi-segmented RNA virus, which belongs to the genus Avibirnavirus of the family Birnaviridae. Two serotypes, 1 and 2, exist in IBDV. The serotype 1 IBDVs are the causative agents of infectious bursal disease (IBD) in chickens worldwide and lead to immunosuppression in young birds. Genome re-assortment has been speculated to occur and contribute to the emergence of new IBDV strains. However, evidence was lacking until recently when two re-assortant viruses were detected in China. In this study, we determined the complete nucleotide sequence of an IBDV, designated KZC-104, from a confirmed natural IBD outbreak in Lusaka, Zambia in 2004. The genome consisted of 3074 and 2651 nucleotides in the coding regions of segments A and B, respectively. Alignment of both nucleotide and deduced amino acid sequences, and phylogenetic analysis revealed that the genome segment A of KZC-104 was derived from a very virulent strain, whereas its segment B was derived from a classical attenuated strain. On BLAST search, the full-length segments A and B sequences showed 98% closest nucleotide homology to the very virulent strain D6948 and 99.8% closest nucleotide homology to the classical attenuated strain D78, respectively. This is a unique IBDV reassortant strain, which has emerged in nature involving segment B of a live attenuated vaccine. This observation provides direct evidence for the involvement of vaccine strains in the emergence of reassortant IBDV in the field. Taken together, these findings suggest an additional risk of using live IBDV vaccines, which may act as genetic donors for genome re-assortment. Further studies are required to investigate the epidemiology and biological characteristics of reassortant strains so that the appropriate and safe IBDV vaccines can be recommended.

Cysticercosis, caused by Taenia solium eggs, is a zoonotic disease whose consequences can be severe especially in the cerebral localisation (neuorcysticercosis). Indeed, neurocysticercosis is the first cause of epilepsy amongst the infectious etiology group. Following the increase of epilepsy cases in Kinshasa and Bas-Congo, it was important to assess the fraction attributable to neurocysticercosis especially as data on cysticercosis in Democratic Republic Of Congo (DRC) dating from 1970. A joint study between veterinary and human doctors was conducted in the provinces of Bas-Congo and Kinshasa between 2008 and 2010. Blood samples were collected from the general population, patients with epilepsy and pigs. These samples were analysed using ELISA antigen in the laboratory of the Institute of Tropical Medicine in Antwerp. Patients positive to ELISA antigen took the CT scan exam for the confirmation of neurocysticercosis. In the province of Kinshasa, of 530 epileptic patients, 6.3% were identified as neurocysticercosis cases. Out of a total of 498 pigs, 38.9% were positive for cysticercosis. In the province of Bas- Congo, of 943 inhabitants from Malanga village, 21.6% were positive with predominance in males (26.4% versus 17.5%). A total of 145 pigs from 5 villages were examined and 41.2% found positive. We can conclude that cysticercosis in the DRC has been neglected for a long time and cysticercosis could be a real major public health problem. Prospective studies addressing the consequences of cysticercosis in communities are needed in order to prevent epilepsy due to neurocysticercosis.

Malaria is a major health care problem in tropical regions due to the increasing resistance of Plasmodium falciparum against widely available antimalarial drugs. Traditional societies relied on medicinal plants to treat parasitic infections. As a result, drugs like quinine and artemisinin were isolated from herbs and barks (Varughese et al. 2010). Sceletium tortuosum has been used as medicine for social and spiritual purposes by San hunter gatherers and Khoi pastoralists. Sceletium tortuosum is rich in alkaloids, one of the important classes of natural product producing treatment for parasitic infections (Kayser et al. 2002). Laboratory preparation of extracts of fresh S. tortuosum plant material was conducted mimicking traditional methods of preparation using organic solvents. Mesembrine was isolated from a methanol extract using conventional column chromatography. Sixteen extracts and mesembrine were evaluated for antiplasmodium activity using a plasmodium lactate dehydrogenase culture sensitivity assay with chloroquine as reference drug. Of the sixteen extracts, four showed activity against P. falciparum with IC50 ranging between 1.47 µg/mL and 7.32 µg/mL. Extracts prepared from stored material at -20 °C showed no antiplasmodium activity. The four originally active extracts were re-screened six months later, but the antimalarial activity could not be reproduced. To determine discrepancy in biological results, chemical profiling of the extracts was done using high performance liquid chromatography technique. Differences were observed in the profiles of the active extracts when compared to those of stored plant material. The instability of plant constituents observed could be a result of plant storage suggesting that the plant is best used when fresh.

One-health approaches have started being applied to health systems in some countries in controlling infectious diseases in order to reduce the burden of disease in humans, livestock and wild animals collaboratively. However, one wonders whether the problem of lingering and emerging zoonoses is more affected by health policies, low application of one-health approaches, or other factors. As part of efforts to answer this question, the Southern African Centre for Infectious Disease Surveillance (SACIDS) smart partnership of human health, animal health and socio-economic experts published, in April 2011, a conceptual framework to support One Health research for policy on emerging zoonoses. The main objective of this paper was to identify which factors really affect the burden of disease and how the burden could affect socio-economic well-being. Amongst other issues, the review of literature shows that the occurrence of infectious diseases in humans and animals is driven by many factors, the most important ones being the causative agents (viruses, bacteria, parasites, etc.) and the mediator conditions (social, cultural, economic or climatic) which facilitate the infection to occur and hold. Literature also shows that in many countries there is little collaboration between medical and veterinary services despite the shared underlying science and the increasing infectious disease threat. In view of these findings, a research to inform health policy must walk on two legs: a natural sciences leg and a social sciences one.

Relatively high prevalence of HIV and AIDS and food insecurity in Rufiji District whilst the linkage between the two problems was not known was the basis of this study. Data were collected amongst 225 households between November 2005 and October 2006 through participatory rural appraisal (PRA), household income and expenditure survey (HIES) and structured interviews. Binary logistic regression was used for analysis in which case the dependent variable was food security in terms of food insecure (0) and food secure (1) based on kilocalories consumed per adult equivalent per day. The independent variables included having been affected by HIV and AIDS in terms of not affected (0) and affected (1). The results reveal that the odds for households affected by HIV and AIDS to be food secure were 0.705 times as high as the odds for households not affected by HIV and AIDS to be food secure. This means that households affected by HIV and AIDS were less likely to be food secure as opposed to those not affected by HIV and AIDS. The B statistic for having been affected by HIV and AIDS was negative (B = -0.350) meaning that being affected by HIV and AIDS had negative impact on food security. However, the Wald statistic which shows the magnitude of impact was small (0.251) and not significant (p = 0.617). This shows that HIV and AIDS had little impact on food security. Based on these findings, it is concluded that although being affected by HIV and AIDS has negative impact on food security, it does not automatically make households food insecure, especially in a short run, and that some non-HIV and AIDS factors like high dependency ratio and low ability to buy food have bigger negative impact than that of HIV and AIDS on food security. On the basis of the conclusion, it is recommended that efforts to improve food security amongst households affected by HIV and AIDS should consider both HIV and AIDS and non-HIV and AIDS factors.

Cystic echinococcosis (CE) is caused by the tapeworm, Echinococcus granulosus. The tapeworms resides in the small intestines of canids and the lifecycle involves both intermediate and definitive hosts. Humans are accidental intermediate hosts. Cystic echinococcosis is an economically important infection constituting a threat to public health, and is considered an emerging disease around the world. There are at least 10 Echinococcus strain types (G1 – G10), each exhibiting diversity of morphology, development and host range. The epidemiology of CE is poorly understood in South Africa. A retrospective data analysis of the National Health Laboratory Service (NHLS) laboratory information system on echinococcosis serology, microscopy and histopathology results in eight provinces (excluding KwaZula-Natal) showed an overall positivity rate in submitted diagnostic samples of 17.0% (1056/6211), with the Eastern Cape (30.4%), North West (19.0%) and Northern Cape (18.0%) provinces showing highest rates. The data showed considerable variability between provinces. The review also showed that most proven cases were negative on serology, implying that the actual number of patients could be underestimated. To our knowledge, no data exist about the prevalent strains of E. granulosus and this prospective study will attempt to fill that gap. The aim is to genotype strains causing the disease in South Africa. Two different polymerase chain reaction (PCR) methods will be used to respectively target the 12S rRNA and nad 1 genes. To date, three samples have been genotyped as G1, G5 and G6; suggesting diversity of strains prevalent in the country, but more data is needed for a clearer picture.

In this study we examined the anti-tick properties of the essential oil of Tagetes minuta L. (Asteraceae: Asterales) against Hyalomma rufipes ticks. We obtained the essential oil of T. minuta by hydro-distillation of a combination of fresh flowers, leaves and soft stems, and analysed these by using gas chromatography (GC) and gas chromatography-linked mass spectrometry (GC-MS). The oil had a high percentage of monoterpenes and the major compounds identified were cis-ocimene (28.5%), beta-ocimene (16.83%) and 3-methyl-2-(2-methyl-2-butenyl)-furan (11.94%). Hyalomma rufipes adults displayed a significant (P < 0.05) dose repellent response to the essential oil of T. minuta. Probit analysis indicated a repellent EC50 of T. minuta essential oil for male ticks to be 0.072 mL/mL (CI 0.053 mL/mL to 0.086 mL/mL) and 0.070 mL/mL (CI 0.052 mL/mL to 0.084 mL/mL) for female ticks. There were no significant differences in repellent responses between male and female ticks. The oil also significantly (P < 0.05) delayed moulting of 60% of H. rufipes engorged nymphs. These results suggest that T. minuta may be a potential source of anti-tick agents.

Foot-and-mouth disease (FMD) is endemic in Tanzania. Since the first reports in 1954, FMD has caused significant economic losses in the country due to mortality and morbidity of livestock and costs associated with controlling the disease. The aim of this study was to review the serotype and genetic relationships of the FMD virus (FMDV) recovered from outbreaks in Tanzania, and compare them with viruses detected from elsewhere in the sub-Saharan region. At the World Reference Laboratory for foot-and-mouth disease (WRLFMD), a total of 106 FMD viruses have been isolated from samples collected between 1967 and 2009 from northern, southern, eastern and central parts of Tanzania. The presence of FMDV was determined by laboratory methods such as VI, CF, antigen ELISA and RT-PCR. Phylogenies of VP1 sequences were determined by the Neighbour-joining method. Foot-and-mouth disease virus SAT1 was the most frequent serotype (46.2%; n = 49) isolated in Tanzania followed by O (26.4%; n = 27), A (14.1%; n = 15) and SAT 2 (11.3%; n = 13). Genotyping showed that type O viruses fell into either the EAST AFRICA 1 (EA-1) or EA-2 topotypes, type A’s into the AFRICA topotype (genotype I), type SAT 1’s into topotype I and type SAT 2’s into topotype IV. This study reveals that serotypes A, O, SAT1 and SAT2 cause FMD outbreaks in Tanzania. Recent samples from outbreaks in 2008, 2009 and 2010 have been typed as serotypes A, O, SAT1 and SAT2. Phylogenetic analysis of FMDV isolates from Tanzania showed that they are genetically related to lineages and topotypes from West and East Africa. In Tanzania, lack of comprehensive animal movement records and inconsistent vaccination programs make it difficult to determine the exact source of FMD outbreaks or to trace the transmission of the disease over time. Therefore, further collection and analysis of samples from domestic and wild animals, together with improved local epidemiological investigation of FMD outbreaks is required to elucidate the complex epidemiology of FMD in the sub-Saharan region.

A foresight vision for infectious diseases in Africa