Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts

The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9 % to 16.9 % in rodents and 0.26% to 10.75 % in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and neighbouring countries

Home ranges, sex ratio and recruitment of the multimammate rat (Mastomys natalensis) in semi-arid areas in Tanzania

Investigation of home ranges, sex ratio and recruitment of the multimammate rat (Mastomys natalensis) in semi-arid areas of Tanzania was conducted in maize and fallow fields using the capture-mark-release (CMR) technique. The aim of this study was to generate useful data for the management of M. natalensis. The relative home range size of M. natalensis was significantly higher during the wet [544 m2±25 standard error (SE)] than during the dry (447 m2 ±18 SE) season, in males (521 m2 ±23 SE) than in females (450 m2 ±17 SE) and in adults (576 m2 ±34 SE) than in juveniles (459 m2 ±16 SE). However, there were no significant differences between habitats. Sex ratio was not significantly different (p=0.44) between habitats. Recruitment was significantly higher (p=0.000) in maize fields (mean=0.43) than in fallow land (mean=0.32) and differed significantly over time (p=0.0001) with the highest recruitment recorded from April to July and the lowest from October to December. Management strategies should focus on managing rodents inhabiting maize fields using methods that affect their recruitment in order to reduce the population increase of M. natalensi

Local <i>Leptospira</i> serovars recommended for use in microscopic agglutination test (MAT) in eastern and central African region.

<p>* Infecting <i>Leptospira</i> serovars detected in MAT using known local serovars and two unknown pig isolates.</p><p>Local <i>Leptospira</i> serovars recommended for use in microscopic agglutination test (MAT) in eastern and central African region.</p

Proportion of prevalence of <i>Leptospira</i> serovars in humans, animals and fish.

<p>Proportion of prevalence of <i>Leptospira</i> serovars in humans, animals and fish.</p

Occurrence, distribution and seroprevalence of local and reference <i>Leptospira</i> serovars in blood collected from humans, domestic and wild mammals and fish in Tanzania (titres ≥ 1:20).

<p>* Leptospirosis prevalence in rodents from study site located 30 km away from <i>Leptospira</i> isolation sites in Tanzania; NA-untested</p><p>Occurrence, distribution and seroprevalence of local and reference <i>Leptospira</i> serovars in blood collected from humans, domestic and wild mammals and fish in Tanzania (titres ≥ 1:20).</p

<i>Leptospira</i> isolation rate in different animal species in Tanzania.

<p><i>Leptospira</i> isolation rate in different animal species in Tanzania.</p

<i>Leptospira</i> isolation in various animal hosts in Tanzania.

<p><i>Cricetomys</i> sp. and shrews (<i>Crocidura</i> sp.) yielded significantly more isolates that other animal species.</p

<i>Leptospira</i> serovars and animal species from which they were isolated in Tanzania.

<p><i>Leptospira</i> serovars and animal species from which they were isolated in Tanzania.</p

Microscopic agglutination titres of isolate RM4 and RM7 reaction with monoclonal antibodies for serogroup Grippotyphosa.

<p>Microscopic agglutination titres of isolate RM4 and RM7 reaction with monoclonal antibodies for serogroup Grippotyphosa.</p

<i>Leptospira</i> isolates RM4 and RM7 agglutination with monoclonal antibodies for serogroup Grippotyphosa.

<p>11 of 13 monoclonal antibodies reacted with these isolates.</p