A young adult with leptospirosis associated acute inflammatory demyelinating polyneuropathy

Leptospirosis is a zoonotic disease that commonly affects the liver and kidney. It can rarely affect the neurological system with aseptic meningitis being the commonest neurological presentation. We present the case of a patient with leptospirosis complicated by acute inflammatory demyelinating polyneuropathy.

Contribution

To our knowledge, this is the first reported case of acute inflammatory demyelinating polyneuropathy as a complication of leptospirosis in South Africa.

A study of leptospirosis in South African horses and associated risk factors

Most leptospiral infections in horses are asymptomatic; however, acute disease manifestations as well as reproductive failure and recurrent uveitis have been reported. In South Africa, the epidemiology of the disease in horses is not well documented. A serosurvey to determine what serovars were present in horses from Gauteng, KwaZulu-Natal and Western Cape Provinces and to get an estimate of the seroprevalence of leptospirosis was carried out from January 2013 until April 2014 with the assistance of four large equine hospitals located in these provinces. Furthermore, associations between potential risk factors and both seropositive horses to the predominant serovar Bratislava and to Leptospira spp. were statistically evaluated using univariate analysis and multivariable logistic regression models. A total of 663 horse sera were collected and tested against a panel of 24 leptospiral serovars using the microscopic agglutination test. The most predominant serovars in Gauteng were Bratislava [32%, 95% CI: 29-35%]; Djasiman [10.4%, 95% CI: 8-12%] and Arborea [8.9%, 95% CI: 7-11%], in the Western Cape Province, Bratislava [27.35%, 95% CI: 23-32]; Djasiman [15.4%, 95% CI: 12-19%] and Arborea [14.5%, 95% CI: 11-18%] and in KwaZulu-Natal, Bratislava [39.4%, 95% CI: 34-44%]; Arborea [9.6%, 95% CI: 7-13%]; and Tarassovi [7.7%, 95% CI: 5-10%] respectively. Twenty one serovars representing 17 serogroups were detected with serovar Bratislava being the most serodominant. The apparent prevalence to one or more serovars of Leptospira spp. at a serum dilution of 1:100 in Gauteng, KwaZulu-Natal and Western Cape Provinces were 49%; 37% and 32% respectively. The true prevalence was calculated for each province taking into account the clustering effect during the sampling and was found to be between 24 and 74% in Gauteng; 26-39% in the Western Cape and 20-54% in KwaZulu-Natal. Nooitgedacht (South African horse breed) horses were found to be at greater risk of being seropositive to both serovar Bratislava (OR=5.08) and Leptospira spp. (OR=6.3). Similarly, horses residing on properties with forestry in the vicinity were found to be at greater risk of being seropositive to both serovar Bratislava (OR=9.3) and Leptospira spp. (OR=5.2). This study has shown that a high proportion of horses in South Africa are exposed to a wide range of serovars, inferring a complex epidemiology. It also describes for the first time new serovars of Leptospira in South African horses that have not previously been reported.

Leptospirosis in Sub-Saharan Africa: a systematic review

BACKGROUND

Leptospirosis is an emerging zoonotic infection worldwide, possibly due to climate change and demographic shifts. It is regarded as endemic in Sub-Saharan Africa; however, for most countries scarce epidemiological data, if any, exist. The primary objectives were to describe the prevalence of leptospirosis in countries in Sub-Saharan Africa, and to develop options for prevention and control in the future.

METHODS

A systematic review was conducted to determine the prevalence of leptospirosis in Sub-Saharan Africa; the PRISMA guidelines were followed. Medline/PubMed, Embase, The Cochrane Library, Web of Science, BIOSIS Previews, the African Index Medicus, AJOL, and Google Scholar were searched.

RESULTS

Information about the prevalence and incidence of leptospirosis in humans is available, but remains scarce for many countries. Data are unavailable or outdated for many countries, particularly those in Central Africa. Most data are available from animals, probably due to the economic losses caused by leptospirosis in livestock. In humans, leptospirosis is an important cause of febrile illness in Sub-Saharan Africa. It concerns numerous serogroups, harboured by many different animal carriers.

DISCUSSION

A wide variety of data was identified. Prevalence rates vary throughout the continent and more research, especially in humans, is needed to reliably gauge the extent of the problem. Preventive measures need to be reconsidered to control outbreaks in the future.

Leptospira interrogans at the human-wildlife interface in northern Botswana: a newly identified public health threat

Leptospirosis is the most widespread zoonosis in the world. In northern Botswana, humans live in close proximity to a diversity of wildlife and peridomestic rodents and may be exposed to a variety of zoonotic pathogens. Little is known regarding the occurrence and epidemiology of L. interrogans in Africa despite the recognized global importance of this zoonotic disease and the threat it poses to public health. In Botswana, banded mongooses (Mungos mungo) live in close proximity to humans across protected and unprotected landscapes and may be a useful sentinel species for assessing the occurrence of zoonotic organisms, such as L. interrogans. We utilized PCR to screen banded mongoose kidneys for leptospiral DNA and identified 41.5% prevalence of renal carriage of L. interrogans (exact binomial 95% CI 27.7-56.7%, n = 41). Renal carriage was also detected in one Selous' mongoose (Paracynictis selousi). This is the first published confirmation of carriage of L. interrogans in either species. This is also the first report of L. interrogans occurrence in northern Botswana and the only report of this organism in a wildlife host in the country. Pathogenic Leptospira are usually transmitted indirectly to humans through soil or water contaminated with infected urine. Other avenues, such as direct contact between humans and wildlife, as well as consumption of mongooses and other wildlife as bushmeat, may pose additional exposure risk and must be considered in public health management of this newly identified zoonotic disease threat. There is a critical need to characterize host species involvement and pathogen transmission dynamics, including human-wildlife interactions that may increase human exposure potential and infection risk. We recommend that public health strategy be modified to include sensitization of medical practitioners to the presence of L. interrogans in the region, the potential for human infection, and implementation of clinical screening. This study illustrates the need for increased focus on neglected zoonotic diseases as they present an important threat to public health.