First isolation of West Nile virus in Zambia from mosquitoes.

Mosquito surveillance studies to identify mosquito-borne flaviviruses have identified West Nile Virus (WNV) for the first time in Zambia. The Zambian WNV isolate from Culex quinquefasciatus mosquitoes collected in the Western Province was closely related genetically to WNV lineage 2 South African strains which have been previously shown to be highly neuroinvasive. These data provide the first evidence of the circulation of WNV in Zambia and suggest there should be an increased awareness of possible associated human and animal diseases in that country.

Co-circulation of multiple genotypes of African swine fever viruses among domestic pigs in Zambia (2013-2015).

During 2013-2015, several and severe outbreaks of African swine fever (ASF) affected domestic pigs in six provinces of Zambia. Genetic characterization of ASF viruses (ASFVs) using standardized genotyping procedures revealed that genotypes I, II and XIV were associated with these outbreaks. Molecular and epidemiological data suggest that genotype II ASFV (Georgia 2007/1-like) detected in Northern Province of Zambia may have been introduced from neighbouring Tanzania. Also, a genotype II virus detected in Eastern Province of Zambia showed a p54 phylogenetic relationship that was inconsistent with that of p72, underscoring the genetic variability of ASFVs. While it appears genotype II viruses detected in Zambia arose from a domestic pig cycle, genotypes I and XIV possibly emerged from a sylvatic cycle. Overall, this study demonstrates the co-circulation of multiple genotypes of ASFVs, involvement of both the sylvatic and domestic pig cycle in ASF outbreaks in Zambia and possible trans-boundary spread of the disease in south-eastern Africa. Indeed, while there is need for regional or international concerted efforts in the control of ASF, understanding pig marketing practices, pig population dynamics, pig housing and rearing systems and community engagement will be important considerations when designing future prevention and control strategies of this disease in Zambia.

Serological Survey of Foot-and-Mouth Disease Virus in Buffaloes (Syncerus caffer) in Zambia.

A study was conducted to determine the serotypes of foot-and-mouth disease viruses (FMDV) circulating in African buffaloes (Syncerus caffer) from selected areas in Zambia. Sera and probang samples were collected between 2011 and 2012 and analysed for presence of antibodies against FMDV while probang samples were used to isolate the FMDV by observing cytopathic effect (CPE). Samples with CPE were further analysed using antigen ELISA. High FMD seroprevalence was observed and antibodies to all the three Southern African Territories (SAT) serotypes were detected in four study areas represented as follows: SAT2 was 72.7 percent; SAT1 was 62.6 percent; and SAT3 was 26.2 percent. Mixed infections accounted for 68.6 percent of those that were tested positive. For probang samples, CPE were observed in three of the samples, while the antigen ELISA results showed positivity and for SAT1 (n = 1) and SAT2 (n = 2). It is concluded that FMDV is highly prevalent in Zambian buffaloes which could play an important role in the epidemiology of the disease. Therefore livestock reared at interface with the game parks should be included in all routine FMDV vaccination programmes.

Challenges and economic implications in the control of foot and mouth disease in sub-saharan Africa: lessons from the zambian experience.

Foot and mouth disease is one of the world's most important livestock diseases for trade. FMD infections are complex in nature and there are many epidemiological factors needing clarification. Key questions relate to the control challenges and economic impact of the disease for resource-poor FMD endemic countries like Zambia. A review of the control challenges and economic impact of FMD outbreaks in Zambia was made. Information was collected from peer-reviewed journals articles, conference proceedings, unpublished scientific reports, and personal communication with scientists and personal field experiences. The challenges of controlling FMD using mainly vaccination and movement control are discussed. Impacts include losses in income of over US$ 1.6 billion from exports of beef and sable antelopes and an annual cost of over US$ 2.7 million on preventive measures. Further impacts included unquantified losses in production and low investment in agriculture resulting in slow economic growth. FMD persistence may be a result of inadequate epidemiological understanding of the disease and ineffectiveness of the control measures that are being applied. The identified gaps may be considered in the annual appraisal of the FMD national control strategy in order to advance on the progressive control pathway.

Rabies status in Zambia for the period 1985-2004.

Rabies has been present in Zambia since the early years of the 20th century. It is a significant public health problem in Zambia. Domestic dogs accounted for 69.7% (1348/1935) of the samples received for rabies diagnosis for the period 1985-2004. Of the 1069 positive cases confirmed by the fluorescent antibody test, 747 (69.9%) were from domestic dogs, 139 (13.0%) from cattle and 98 (9.2%) from humans. Wildlife samples accounted for 4.5% (87/1935) of the samples tested with the jackal (Canis adustus) being the predominant species. Cases of rabies were highest in Lusaka Province followed by the Copperbelt, Southern and Central Provinces. The monthly distribution of canine rabies showed an average of 2.93 (95% CI 2.59-3.29) dog positive cases per month. The study confirms that rabies is endemic in Zambia and that the domestic dog is the principal maintenance host. The epidemiology and control measures currently used in Zambia are herein discussed highlighting their limitations and successes. Based on the findings obtained from this study we advocate for strengthening the delivery of public health services and that steps must taken to reduce the incidence of rabies in Zambia.

Anthrax in animals and humans in Mongolia.

Anthrax is endemic throughout Mongolia, except in the semi-desert and desert areas of the south. The prevalence of anthrax in Mongolia had drastically decreased since the 1950s due to the use of anthrax antiserum and vaccines, but the privatisation of the animal husbandry sector and changes in the structures of the veterinary and medical delivery systems in Mongolia over the last decade have resulted in challenges for disease control. Animal and human anthrax has become an increasing problem since the mid-1990s. Human cutaneous anthrax is common in Mongolia as a result of exposure to infected animals. In this paper, the authors identify potential causes forthe increase of anthrax in Mongolia. The current prevention efforts may not be adequate. Anthrax surveillance and control must be intensified, particularly in areas of high prevalence.

The prevalence of bovine herpesvirus-1 in traditional cattle in Southern Province, Zambia.

A study was conducted to determine the prevalence of bovine herpesvirus-1 (BHV-1), which causes infectious bovine rhinotracheitis, in cattle destined for market in Southern Province, Zambia. A total of 116 nasal secretion samples were tested using the direct fluorescent antibody test, while blood samples from the same cattle were examined by a commercial enzyme-linked immunosorbent assay kit. The prevalence of the BHV-1 antigens in cattle was 23.28% (27/116), while the mean prevalence of the BHV-1 antibodies was 48.28% (56/116). This study showed that cattle in transit to markets could easily spread the virus, which was reactivated by the stress of trekking for long distances under unfavourable conditions, to the other cattle with which they came into contact. Thus, these transit cattle posed a serious threat to other bovines. Systems of cattle trading where cattle must be transported a long wayto market should be reviewed by the authorities to minimise the conditions that may exacerbate the spread of infection.

Short report: prevalence of antibodies against spotted fever, murine typhus, and Q fever rickettsiae in humans living in Zambia.

The causative agents of rickettsial diseases (Rickettsia conorii, R. typhi, and Coxiella burnetii) have been reported throughout the African continent. However, there have been no reports on epidemiologic surveys of these infections in Zambia. This study was designed to clarify the prevalence of three rickettsioses in 377 humans in Zambia. The seroprevalence of antibodies against R. conorii, R. typhi, and C. burnetii was 16.7%, 5.0%, and 8.2%, respectively. The rates of antibody positivity against R. conorii and C. burnetii were higher in the eastern (23.1% and 11.8%) and western (16.8% and 7.4%) areas of Zambia than in the northern (3.0% and 3.0%) area of this country. There was little difference among the three areas in the distribution of antibodies against R. typhi. Since cattle breeding is more extensive in the western and eastern areas than in the northern area, it is thought that cattle-breeding areas are foci of R. conorii and C. burnetii infections in Zambia.

Distribution of Rift Valley fever among cattle in Zambia.

In the present study, 1,421 cattle in 32 herds within nine districts, which are important cattle-producing centers in the nine provinces of Zambia, were tested for Rift Valley fever by the indirect immunofluorescence assay. One hundred and forty-seven cattle (10.5%) in 28 herds (88.9%) in the nine districts tested were positive for Rift Valley fever implying a country-wide distribution. In districts associated with flood plains and/or "dambos" (low lying areas of perpetual flooding), high herd and individual positive rates (100% and > 10%, respectively) were found, suggesting a significance of these features in the distribution of the disease.

Detection of viral genome in non-neural tissues of cattle experimentally infected with bovine herpesvirus 1.

To obtain further information on the latent infection with bovine herpesvirus 1 (BHV-1) in the natural host, we examined the nasal secretions and various tissues of experimentally infected calves using virus isolation, polymerase chain reaction (PCR), and immuno-PCR/antigen (Immuno-PCR/Ag) assays. In the nasal secretions, viral DNA was detected in samples with virus isolation titers of 10(4.3) TCID50 or more by PCR. On the same samples, Immuno-PCR/Ag remained positive up to day 19 p.i. the last day of test. BHV-1 DNA was detected from the following tissues in all the calves at day 22 p.i.: trigeminal ganglia, ovaries, lungs, nasal and tracheal mucosae, spleen, prescapular and precrural lymph nodes, and peripheral blood leukocytes (PBL), but not skeletal muscles. Virus was not recovered from any of these tissues. The present findings suggest a possible role of leukocytes in BHV-1 latent infection.

Bovine clostridial infections in Zambia (1985-1994).

Retrospective surveillance study of clostridial infections of cattle in Zambia, for the period 1985 to 1994, showed that out of the 318 cases observed, 62.8% and 24.2% were from Western and Southern provinces, respectively. Of the 6 clostridia species identified, Clostridium septicum (38.1%) followed by C. chauvoei (36.2%) and C. perfringens (13.2%) were dominant. Although the highest incidence for clostridial infections was in 1989 (75 cases) and 1990 (77 cases), the number of C. perfringens cases seemed to increase. More cases were found in the dry season until the onset of the rains, that is, the period August to December.

Viral diseases of livestock in Zambia.

This review is to provide information on viral diseases of livestock in Zambia. The distribution of the diseases as well as the control measures and limited research that has been done, are described. Foot and mouth disease (FMD) causes serious economic losses in the cattle industry. So far five serotypes (SAT1, SAT2, SAT3, O and At of FMD virus have been isolated in Zambia. Other notifiable viral diseases are rabies, Rift Valley fever, Lumpy skin disease, African horse sickness, bluetongue, African swine fever, Newcastle disease, Marek's disease, fowlpox and infectious bursal disease. Based on the reports of clinical and/or serological diagnoses, these are widespread in the country, although their precise incidence rates are not known. With the establishment of a veterinary school equipped with modern diagnostic facilities and the increasing number of qualified veterinary personnel, this review would stimulate surveillance study on the viral diseases for the ultimate goal of achieving effective disease control measures.

African swine fever in Zambia: potential financial and production consequences for the commercial sector.

The first officially recorded outbreak of African swine fever (ASF) in Zambia was in Eastern province in 1965. The disease now covers almost the whole province and is endemic in the indigenous breeds. In 1989, an outbreak of ASF occurred on a commercial property in central Zambia for the first time and was eradicated by depopulation. In order to examine the justification of the drastic control measures and the continued ban on the export of pigs and their products, the impact of the outbreak on the affected property as well as the potential consequences on the commercial pig sector in the district was assessed in the present study. The affected property lost 421,238 Zambian Kwacha (ZK) (USf439,965) as a result of the outbreak and control measures. However, the cost to the district could have been at least ZK14,917,500 (US$1,415,323) if the measures had not been effected. Furthermore, not taking such measures would have increased the risk to the entire commercial pig sector along the line of rail in urban centers.

Development of immuno-PCR for diagnosis of bovine herpesvirus 1 infection.

A highly sensitive immuno-PCR method specific for the detection of antigens of and antibodies to bovine herpesvirus 1 was established. This assay attained a high sensitivity of up to 10(7.0) times higher than that of enzyme-linked immunosorbent assay (ELISA) or PCR for antigen detection and 10(5.0) times higher than that of ELISA for antibody detection.