Factors Associated with Leishmania Asymptomatic Infection: Results from a Cross-Sectional Survey in Highland Northern Ethiopia

Background

In northern Ethiopia the prevalence of visceral leishmaniasis is steadily rising posing an increasing public health concern. In order to develop effective control strategies on the transmission of the disease it is important to generate knowledge on the epidemiological determinants of the infection.

Methodology/Principal Findings

We conducted a cross-sectional survey on children 4–15 years of age using a multi staged stratified cluster sampling on high incidence sub-districts of Amhara regional state, Ethiopia. The survey included a socio-demographic, health and dietary questionnaire, and anthropometric measurements. We performed rK39-ICT and DAT serological tests in order to detect anti-Leishmania antibodies and carried out Leishmanin Skin Test (LST) using L.major antigen. Logistic regression models were used. Of the 565 children surveyed 56 children were positive to infection (9.9%). The individual variables that showed a positive association with infection were increasing age, being male and sleeping outside [adjusted odds ratios (95% CI): 1.15 (1.03, 1.29), 2.56 (1.19, 5.48) and 2.21 (1.03, 4.71) respectively] and in relation to the household: past history of VL in the family, living in a straw roofed house and if the family owned sheep [adjusted OR (95% CI): 2.92 (1.25, 6.81), 2.71 (1.21, 6.07) and 4.16 (1.41, 12.31) respectively].

Conclusions/Significance

A behavioural pattern like sleeping outside is determinant in the transmission of the infection in this area. Protective measures should be implemented against this identified risk activity. Results also suggest a geographical clustering and a household focalization of the infection. The behaviour of the vector in the area needs to be clarified in order to establish the role of domestic animals and house materials in the transmission of the infection.     

Inner structural organization of the distal humerus in Paranthropus and Homo

The taxonomic attribution of isolated hominin distal humeri has been a matter of uncertainty and disagreement notwithstanding their relative abundance in the fossil record. Four taxonomically-based morphotypes, respectively representing P. boisei, P. robustus, non-erectus early Homo and H. erectus, have been identified based on the cross-sectional outer shape variation of an assemblage of Plio-Pleistocene eastern and southern African specimens (Lague, 2015). However, the existence of possible differences between Paranthropus and Homo in the inner structural organisation at this skeletal site remains unexplored. We used noninvasive imaging techniques to tentatively characterize the endostructural organization of five early Pleistocene distal humeri from South Africa (TM 1517g, SK 24600, SKX 10924, SKX 34805) and Ethiopia (Gombore IB), which have been variably attributed to Paranthropus or Homo. While the investigated specimens reveal diverse degrees of inner preservation related to their taphonomic and diagenetic history, in all but SK 24600 from Swartkrans we could comparatively assess some geometric properties at the most distal cross-sectional level (%CA, I_x/I_y, I_max/I_min) and quantify cortical bone thickness topographic variation across the preserved shaft portions by means of a 2-3D Relative Cortical Thickness index. Whenever possible, we also provided details about the site-specific organization of the cancellous network and measured the same parameters in a comparative sample of twelve adult extant humans. For most features, our results indicate two main patterns: the first includes the specimens TM 1517g, SKX 10924 and SKX 34805, while the second endostructural morphotype sets apart the robust Homo aff. erectus Gombore IB specimen from Melka Kunture, which more closely resembles the condition displayed by our comparative human sample. Notably, marked differences in the amount and pattern of proximodistal cortical bone distribution have been detected between Gombore IB and SKX 34805 from Swartkrans. Given its discordant outer and inner signatures, we conclude that the taxonomic status of SKX 34805 deserves further investigations.     

Knowledge,Attitudes and Practices Related to Visceral Leishmaniasis in Rural Communities of Amhara State: A Longitudinal Study in Northwest Ethiopia

Background

In the northwest of Ethiopia, at the South Gondar region, there was a visceral leishmaniasis (VL) outbreak in 2005, making the disease a public health concern for the regional health authorities ever since. The knowledge on how the population perceives the disease is essential in order to propose successful control strategies.

Methodology/Principal findings

Two surveys on VL knowledge, attitudes and practices were conducted at the beginning (May 2009) and at the end (February 2011) of a VL longitudinal study carried out in rural communities of Libo Kemkem and Fogera, two districts of the Amhara Regional State. Results showed that VL global knowledge was very low in the area, and that it improved substantially in the period studied. Specifically, from 2009 to 2011, the frequency of proper knowledge regarding VL signs and symptoms increased from 47% to 71% (p<0.0001), knowledge of VL causes increased from 8% to 25% (p<0.0001), and knowledge on VL protection measures from 16% to 55% (p<0.0001). Moreover, the improvement observed in VL knowledge was more marked among the families with no previous history of VL case. Finally, in 2011 more than 90% of the households owned at least an impregnated bed net and had been sprayed, and attitudes towards these and other protective measures were very positive (over 94% acceptance for all of them).

Conclusions/Significance

In 2009 the level of knowledge regarding VL was very low among the rural population of this area, although it improved substantially in the study period, probably due to the contribution of many actors in the area. VL patients and relatives should be appropriately informed and trained as they may act as successful health community agents. VL risk behavioural patterns are subject to change as attitudes towards protective measures were very positive overall.     

Leishmania aethiopica: strain identification and characterization of superoxide dismutase-B genes

This study was performed to characterize the genes that code for superoxide dismutase (SOD) in Leishmania aethiopica. It involved three main steps: specimen collection and parasite isolation, species identification, and molecular characterization of the SOD genes. Out of 20 skin slit specimens cultured and processed from suspected cutaneous leishmaniasis patients enrolled in the study, five (25%) were found to be positive for motile promastigotes. Isoenzyme electrophoresis and PCR-RFLP results confirmed that the isolates were L. aethiopica. Superoxide dismutase-B (SODB) genes were identified from L. aethiopica for the first time. Iron superoxide dismutase-B genes amplified from promastigotes of L. aethiopica (LaeFeSODB) were similar in size to the SODB genes of other Leishmania species. Nucleotide sequences of LaeFeSODB1 showed 95.4, 93.5, and 97.3% identity with L. donovani SODB1 (LdFeSODB1) L. major SODB1 (LmFeSODB1) and L. tropica SODB1 (LtrFeSODB1), respectively. Similarly, LaeFeSODB2 showed 95.9 and 94.1 and 97.6% identity with LdFeSODB2 and LmFeSODB2 and LtrFeSODB2, respectively. On the other hand, predicted amino acid sequence comparison indicated that LaeFeSODB1 had 91.3, 89.8, and 93.9% identity with LdFeSODB1, LmFeSODB1, and LtrFeSODB1, respectively. The difference in nucleic acid sequence of LaeFeSODB from that of LmFeSODB and LtrFeSODB can be utilized to develop specific molecular methods that help differentiate these species in places where there is an overlap in the distribution of these species. In addition, the data provide information about the situation of L. aethiopica with respect to SODB genes.     

Effect of a formulation of Bacillus firmus on root-knot nematode Meloidogyne incognita infestation and the growth of tomato plants in the greenhouse and nursery

Bacillus firmus, commercial WP formulation (BioNem) was evaluated against the root-knot nematode Meloidogyne incognita in a laboratory, greenhouse and under field conditions on tomato plants. In the laboratory tests, an aqueous suspension of BioNem at 0.5%, 1%, 1.5% and 2% concentration reduced egg hatching from 98% to 100%, 24-days after treatment. Treatment of second-stage juveniles with 2.5% and 3% concentration of BioNem, caused 100% inhibition of mobility, 24 h after treatment. In the green house trials, BioNem applied at 8 g/pot (1200 cc soil) planted with a tomato seedlings reduced gall formation by 91%, final nematode populations by 76% and the number of eggs by 45%. Consequently, plant height and biomass was increased by 71% and 50%, respectively, compared to the untreated control, 50-days after treatment application. Application of BioNem at 16 g/pot was phytotoxic to plants. In the field trails, BioNem applied at 200 and 400 kg ha⁻¹ was effective in reducing the number of galls (75-84%), and increased shoot height (29-31%) and weight (20-24%) over the untreated control, 45-days after treatment. Our results indicate that B. firmus is a promising microorganism for the biological control of M. incognita in tomato pots.     

Cross-Sectional Study of Malnutrition and Associated Factors among School Aged Children in Rural and Urban Settings of Fogera and Libo Kemkem Districts,Ethiopia

Introduction

Little information is available on malnutrition-related factors among school-aged children ≥5 years in Ethiopia. This study describes the prevalence of stunting and thinness and their related factors in Libo Kemkem and Fogera, Amhara Regional State and assesses differences between urban and rural areas.

Methods

In this cross-sectional study, anthropometrics and individual and household characteristics data were collected from 886 children. Height-for-age z-score for stunting and body-mass-index-for-age z-score for thinness were computed. Dietary data were collected through a 24-hour recall. Bivariate and backward stepwise multivariable statistical methods were employed to assess malnutrition-associated factors in rural and urban communities.

Results

The prevalence of stunting among school-aged children was 42.7% in rural areas and 29.2% in urban areas, while the corresponding figures for thinness were 21.6% and 20.8%. Age differences were significant in both strata. In the rural setting, fever in the previous 2 weeks (OR: 1.62; 95% CI: 1.23–2.32), consumption of food from animal sources (OR: 0.51; 95% CI: 0.29–0.91) and consumption of the family''s own cattle products (OR: 0.50; 95% CI: 0.27–0.93), among others factors were significantly associated with stunting, while in the urban setting, only age (OR: 4.62; 95% CI: 2.09–10.21) and years of schooling of the person in charge of food preparation were significant (OR: 0.88; 95% CI: 0.79–0.97). Thinness was statistically associated with number of children living in the house (OR: 1.28; 95% CI: 1.03–1.60) and family rice cultivation (OR: 0.64; 95% CI: 0.41–0.99) in the rural setting, and with consumption of food from animal sources (OR: 0.26; 95% CI: 0.10–0.67) and literacy of head of household (OR: 0.24; 95% CI: 0.09–0.65) in the urban setting.

Conclusion

The prevalence of stunting was significantly higher in rural areas, whereas no significant differences were observed for thinness. Various factors were associated with one or both types of malnutrition, and varied by type of setting. To effectively tackle malnutrition, nutritional programs should be oriented to local needs.     

Micronutrient Deficiencies and Related Factors in School-Aged Children in Ethiopia: A Cross-Sectional Study in Libo Kemkem and Fogera Districts,Amhara Regional State

Introduction

The present study describes the distribution of selected micronutrients and anaemia among school-aged children living in Libo Kemkem and Fogera (Amhara State, Ethiopia), assessing differences by socio-demographic characteristics, health status and dietary habits.

Methods

A cross-sectional survey was carried out during May–December 2009. Socio-demographic characteristics, health status and dietary habits were collected. Biomarkers were determined for 764 children. Bivariate and multivariable statistical methods were employed to assess micronutrient deficiencies (MD), anaemia, and their association with different factors.

Results

More than two thirds of the school-aged children (79.5%) had at least one MD and 40.5% had two or more coexisting micronutrient deficiencies. The most prevalent deficiencies were of zinc (12.5%), folate (13.9%), vit A (29.3%) and vit D (49%). Anaemia occurred in 30.9% of the children. Children living in rural areas were more likely to have vit D insufficiency [OR: 5.9 (3.7–9.5)] but less likely to have folate deficiency [OR: 0.2 (0.1–0.4)] and anaemia [OR: 0.58 (0.35–0.97)]. Splenomegaly was positively associated with folate deficiency and anaemia [OR: 2.77 (1.19–6.48) and 4.91 (2.47–9.75)]. Meat and fish consumption were inversely correlated with zinc and ferritin deficiencies [OR: 0.2 (0.1–0.8) and 0.2 (0.1–0.9)], while oil consumption showed a negative association with anaemia and deficiencies of folate and vitamin A [0.58 (0.3–0.9), OR: 0.5 (0.3–0.9) and 0.6 (0.4–0.9)]. Serum ferritin levels were inversely correlated to the presence of anaemia (p<0.005).

Conclusion

There is a high prevalence of vitamin A deficiency and vitamin D insufficiency and a moderate prevalence of zinc and folate deficiencies in school-aged children in this area. The inverse association of anaemia and serum ferritin levels may be due to the presence of infectious diseases in the area. To effectively tackle malnutrition, strategies should target not only isolated micronutrient supplementation but also diet diversification.     

Factors associated with utilization of long term family planning methods among women of reproductive age attending Bahir Dar health facilities,Northwest Ethiopia

Objective

This health institution based cross section study was designed to determine factors associated with utilization of long term family planning methods among women reproductive age attending Bahir Dar health facilities.

Result

A total of 406 women were interviewed in this study. The mean age (standard deviation) of the study participants was 26.96?±?6.31. About 99% of the study participants were consisted from Amhara ethnic group and 60.6% of them urban dwellers. In this study about 90.9% of the study participants had information about LTFP methods and 26.4% of them utilizing the methods. Factors like; knowledge of the women towards LTFP, spousal discussion on FP and occupation of the women affects LTFP utilization (6 times, 3 times and 4 times, respectively) when compared with their counter parts. In addition monthly income of the household was also associated to LTFP methods. In this study less percentage (26.4%) of women’s utilizing LTFP methods that were significantly associated with the knowledge of women on LTFP, spousal discussion on FP, occupation of the women and monthly income of the household. As result continuous health education will be recommended.

     

Bovine Tuberculosis at the Wildlife-Livestock-Human Interface in Hamer Woreda,South Omo,Southern Ethiopia

Bovine tuberculosis (BTB) is endemic in cattle in the Ethiopian Highlands but no studies have been done so far in pastoralists in South Omo. This study assessed the prevalence of bovine tuberculosis (BTB) at an intensive interface of livestock, wildlife and pastoralists in Hamer Woreda (South Omo), Ethiopia. A cross-sectional survey including a comparative intradermal skin testing (CIDT) was conducted in 499 zebu cattle and 186 goats in 12 settlements. Sputum samples from 26 symptomatic livestock owners were cultured for TB. Fifty-one wildlife samples from 13 different species were also collected in the same area and tested with serological (lateral flow assay) and bacteriological (culture of lymph nodes) techniques. Individual BTB prevalence in cattle was 0.8% (CI: 0.3%–2%) with the >4 mm cut-off and 3.4% (CI: 2.1%–5.4%) with the >2 mm cut-off. Herd prevalence was 33.3% and 83% when using the >4 and the >2 mm cut-off respectively. There was no correlation between age, sex, body condition and positive reactors upon univariate analysis. None of the goats were reactors for BTB. Acid fast bacilli (AFB) were detected in 50% of the wildlife cultures, 79.2% of which were identified as Mycobacterium terrae complex. No M. bovis was detected. Twenty-seven percent of tested wildlife were sero-positive. Four sputum cultures (15.4%) yielded AFB positive colonies among which one was M. tuberculosis and 3 non-tuberculous mycobacteria (NTM). The prevalence of M. avium-complex (MAC) was 4.2% in wildlife, 2.5% in cattle and 0.5% in goats. In conclusion, individual BTB prevalence was low, but herd prevalence high in cattle and BTB was not detected in goats, wildlife and humans despite an intensive contact interface. On the contrary, NTMs were highly prevalent and some Mycobacterium spp were more prevalent in specific species. The role of NTMs in livestock and co-infection with BTB need further research.     

Leishmania aethiopica: development of specific and sensitive PCR diagnostic test

PCR has proved useful for rapid diagnosis and typing of Leishmania. Lack of specificity to discriminate between species and/or sensitivity to detect from clinical samples has always been an issue. Previously developed primers either require PCR–RFLP analysis for Leishmania aethiopica discrimination or lack sensitivity to detect L. aethiopica from clinical samples. Here we report the development and validation of L. aethiopica specific PCR primers (V5F/V10R) based on cysteine protease B (cpb), a multicopy and polymorphic gene of Leishmania. V5F/V10R primers differentiate L. aethiopica from Leishmania tropica, Leishmania major, Leishmania donovani and Leishmania infantum by direct PCR. In addition, they are sensitive enough to detect L. aethiopica from biopsy samples. The primers can be very useful for epidemiological studies, species typing and diagnosis of L. aethiopica directly from clinical samples. Implementation of these primers in routine L. aethiopica diagnosis can improve detection rate, save time, money and labor required for culturing Leishmania.