Major histocompatibility complex diversity in the endangered Ethiopian wolf (Canis simensis)

The major histocompatibility complex (MHC) influences immune response to infection and vaccination. In most species, MHC genes are highly polymorphic, but few wild canid populations have been investigated. In Ethiopian wolves, we identified four DLA (dog leucocyte antigen)-DRB1, two DLA-DQA1 and five DQB1 alleles. Ethiopian wolves, the world's rarest canids with fewer than 500 animals worldwide, are further endangered and threatened by rabies. Major rabies outbreaks in the Bale Mountains of southern Ethiopia (where over half of the Ethiopian wolf population is located) have killed over 75% of wolves in the affected sub-populations. In 2004, following a rabies outbreak, 77 wolves were vaccinated, and 19 were subsequently recaptured to monitor the effectiveness of the intervention. Pre- and post-vaccination rabies antibody titres were available for 18 animals, and all of the animals sero-converted after vaccination. We compared the haplotype frequencies of this group of 18 with the post-vaccination antibody titre, and showed that one haplotype was associated with a lower response (uncorrected P < 0.03). In general, Ethiopian wolves probably have an adequate amount of MHC variation to ensure the survival of the species. However, we sampled only the largest Ethiopian wolf population in Bale, and did not take the smaller populations further north into consideration.

A systematic review of nutritional rickets in Ethiopia: status and prospects

BACKGROUND

Nutritional rickets contributes to the high burden of illness and death among Ethiopian children below 5 years of age. Lack of adequate information appears to have negatively influenced the impact of prevention and treatment programs.

OBJECTIVES

The objective of this systematic review is to review existing body of knowledge about nutritional rickets in Ethiopia and develop recommendations that will guide development of strategies for effective interventions and research.

METHODS

Published and unpublished information on nutritional rickets in Ethiopia was collected systematically. The information was critically reviewed and discussed in the context of regional and global situation.

RESULTS

The major cause of nutritional rickets in Ethiopian children is lack of exposure to sunshine and/or inadequate intake of vitamin D. Lack of awareness and traditional beliefs are major causes for not exposing infants to sunshine. The disease is associated with poor socioeconomic status, low birth weight, protein-energy malnutrition and common childhood infections. Severe form of rickets is commonly seen at about 18 months of age. Rickets predisposes Ethiopian children to pneumonia. Diagnostic criteria used in most studies include two or more clinical signs and a characteristic radiological or biochemical abnormality. There are critical gaps in our knowledge about the epidemiology, ecology, and potentially effective interventions to prevent and treat rickets in Ethiopian children.

CONCLUSION

Most of the studies on nutritional rickets in Ethiopia have been conducted in hospital settings. There is a need for well designed epidemiological and ecological studies. The biologic basis for the striking association between PEM and active rickets seen in Ethiopia needs to be determined The role of calcium deficiency, the part played by genetic factors, the nature of the association between the duration of breastfeeding and rickets, and the role of complimentary feeds in Ethiopian children need to be explored. Studies are required to determine the amount of sunshine required to prevent rickets in Ethiopian infants. Studies are required to establish criteria for the diagnosis of clinical and sub clinical rickets, particularly in malnourished children. Prevention programs need to be pursued consistently and systematically and treatment options, including the single massive dose of vitamin D, need to be re-evaluated and optimal mode of treatment determined.