Neglected tropical diseases of Namibia: Unsolved mysteries

Noden, Bruce H.; Colf, Berta E. van der

doi:10.1016/j.actatropica.2012.09.007

Cited by 21 publications

(33 citation statements)

References 85 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the study did not differentiate between rickettsial species, spotted fever rickettsiae are normally transmitted by ticks or fleas, of which eight potential vector species have been recorded in Namibia [11]. Rickettsia felis , a spotted fever group rickettsiae transmitted by cat or rat fleas [57], remains to be identified south of Angola, Zambia and Mozambique.…”

Section: Discussionmentioning

confidence: 81%

“…The 7–10% seroprevalence of R. typhi among cats in similar climates of Zimbabwe and South Africa indicates that climate may not significantly limit the epidemiology [59]. The observed north-south regional trend observed may not be important, either, as Wessels et al [36] observed a low agglutination response in 59% of patients in the northern Kavango region, indicating possible exposure to typhus group rickettsiae [11]. Compared with other countries in Southern Africa, the relatively high prevalence among Namibian blood donors demonstrates a need for further follow up on this important pathogenic group.…”

Section: Discussionmentioning

confidence: 91%

“…At least 15 zoonotic pathogens capable of causing febrile illness have been historically reported in Namibia’s 13 administrative regions [11]. Pathogenic bacteria, notably C. burnetii , Bartonella henselae , as well as, spotted fever and typhus group rickettsiae were highlighted as potentially posing the greatest risk to animal and human health [11]. These zoonotic bacteria have been increasingly noted throughout sub-Saharan Africa, and there is a need to specifically focus on their epidemiology [12]–[14].…”

Section: Introductionmentioning

confidence: 99%

“…Coxiella burnetii , the causative agent of Q fever, is potentially transmissible via blood transfusion [15], [16] or even by ticks [11]. Reported to affect pregnant woman, Coxiella burnetii can cause foetal loss and affect intrauterine growth of the foetus [13].…”

Section: Introductionmentioning

confidence: 99%

“…However, virtually nothing is known about their presence in Namibia [11]. A single small serosurvey in northern Namibia in the mid-1980s reported a 2% seroprevelence for C. burnetii and evaluated the presence of rickettsiae, but the diagnostics used were not conclusive [36].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Exposure and Risk Factors to Coxiella burnetii, Spotted Fever Group and Typhus Group Rickettsiae, and Bartonella henselae among Volunteer Blood Donors in Namibia

et al. 2014

Self Cite

View full text Add to dashboard Cite

BackgroundThe role of pathogen-mediated febrile illness in sub-Saharan Africa is receiving more attention, especially in Southern Africa where four countries (including Namibia) are actively working to eliminate malaria. With a high concentration of livestock and high rates of companion animal ownership, the influence of zoonotic bacterial diseases as causes of febrile illness in Namibia remains unknown.Methodology/Principal FindingsThe aim of the study was to evaluate exposure to Coxiella burnetii, spotted fever and typhus group rickettsiae, and Bartonella henselae using IFA and ELISA (IgG) in serum collected from 319 volunteer blood donors identified by the Blood Transfusion Service of Namibia (NAMBTS). Serum samples were linked to a basic questionnaire to identify possible risk factors. The majority of the participants (64.8%) had extensive exposure to rural areas or farms. Results indicated a C. burnetii prevalence of 26.1% (screening titre 1∶16), and prevalence rates of 11.9% and 14.9% (screening titre 1∶100) for spotted fever group and typhus group rickettsiae, respectively. There was a significant spatial association between C. burnetii exposure and place of residence in southern Namibia (P<0.021). Donors with occupations involving animals (P>0.012), especially cattle (P>0.006), were also significantly associated with C. burnetii exposure. Males were significantly more likely than females to have been exposed to spotted fever (P<0.013) and typhus (P<0.011) group rickettsiae. Three (2.9%) samples were positive for B. henselae possibly indicating low levels of exposure to a pathogen never reported in Namibia.Conclusions/SignificanceThese results indicate that Namibians are exposed to pathogenic fever-causing bacteria, most of which have flea or tick vectors/reservoirs. The epidemiology of febrile illnesses in Namibia needs further evaluation in order to develop comprehensive local diagnostic and treatment algorithms.

show abstract

Section: Discussionmentioning

confidence: 81%

Section: Discussionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Exposure and Risk Factors to Coxiella burnetii, Spotted Fever Group and Typhus Group Rickettsiae, and Bartonella henselae among Volunteer Blood Donors in Namibia

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

Evaluation of Moringa oleifera seed lectin in traps for the capture of Aedes aegypti eggs and adults under semi-field conditions

et al. 2014

View full text Add to dashboard Cite

The water-soluble lectin isolated from Moringa oleifera seeds (WSMoL) is a larvicidal, ovicidal, and oviposition-stimulating agent against Aedes aegypti under laboratory conditions. This study investigated the effect of WSMoL in traps for the capture of A. aegypti eggs and adult females under semi-field conditions and determined whether gravid females could detect WSMoL by an olfactory response. WSMoL was isolated according to a previously described procedure using chitin chromatography. The bioassays were performed in large cages (12.5 m(3)). Two traps for collection of eggs (ovitrap) or adult mosquitoes (MosquiTRAP(TM)) were placed in a cage. One was filled with WSMoL (0.1 mg/mL) and the other with tap water (negative control). An infusion of Panicum maximum leaves was used as a positive control. Forty gravid females were then released in each cage. After 2 (for oviposition) or 3 h (for female capture), the traps were removed, and the number of eggs or females was counted. An olfactometry assay was performed to investigate whether the effect of WSMoL on gravid females was linked to an olfactory response. WSMoL showed an oviposition-stimulating effect (65 ± 14%) that was similar (p < 0.05) to that promoted by the P. maximum infusion (67 ± 11%). The efficiency of MosquiTRAP(TM) in capturing gravid females was not increased by WSMoL. The olfactometry assay indicated that the response of females to WSMoL did not involve the stimulation of olfactory sensilla. WSMoL effectively captured eggs when used in ovitraps under semi-field conditions; this property, together with the ovicidal and larvicidal activities of this lectin, makes it an interesting candidate for A. aegypti control.

show abstract