Conservation implications of avian malaria exposure for African penguins during rehabilitation

Abstract

The African penguin (Spheniscus demersus) is the only penguin species that breeds on the African continent and it is currently classified as endangered. Its conservation is assisted by the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) which is a seabird rehabilitation facility based at the Rietvlei Wetland Reserve in Tableview, Cape Town. Despite the success of SANCCOB in rehabilitating diseased, injured or oiled penguins, significant mortalities have occurred at the facility as a result of avian malaria. Avian malaria can be contracted during rehabilitation during which penguins are inadvertently exposed to additional threats. An enzyme-linked immunosorbent assay (ELISA) was used to assess the anti-Plasmodium antibody levels of penguins to avian malaria on entry into the SANCCOB facility from 2001 to 2004 and during their rehabilitation process. Using blood smear data, avian malaria prevalence and malaria-related deaths were also monitored from 2002 to 2013. Significant increases in anti-Plasmodium antibody levels after admission were found during summer months. New infection and not parasite recrudescence was concluded to be the cause of this increase. This source was confirmed by a dramatic drop in penguin mortalities upon exclusion of mosquito vectors in 2008. Mortalities did not depend on the birds’ abilities to produce an anti-Plasmodium antibody response and oiling had no influence on immunity or prevalence of avian malaria infections. This study highlights the importance of mosquito vector control to control pathogen exposure in wild bird rehabilitation centres.

Occurrence and diversity of avian haemosporidia in Afrotropical landbirds

“…In South Africa, research on avian haemosporidia has mostly focused on sea birds, which experience high infection rates as well as a huge diversity of avian haemosporidia (Okanga et al, 2014). A study at the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) found that African Penguins ( Spheniscus demersus ) presented for rehabilitation at the centre were highly susceptible to infection and usually acquired infection during rehabilitation (Botes et al, 2017). Strict vector control measures resulted in the decline of new malaria infections in these endangered birds.…”

The Effects of Critical Care Nutrition on Weight Gain in African Penguin (Spheniscus demersus) Chicks

“…Penguins participating in this study were housed with other rehabilitating penguins in pens according to their age groups and surrounded by insect protective nets. 11,27 Floors, pools, and feeding equipment were cleaned daily with F10 products (Health and Hygiene Ltd, Stormill, Randburg, South Africa). Over a period of 2 weeks all of the birds were fed whole fish and 10 of the animals received supportive feeding with EmerAid Piscivore (treatment group) and 11 animals (control group) were fed the hand-made fish formula; all birds were weighed daily before feeding.…”

Phylogenetic diversity, host specificity and geographic distribution of avian malaria in Africa.

“…In many other bird species, most individuals will have limited or no clinical signs, although clinical signs such as anaemia, necrosis of infected tissue, reduced reproductive success, reduced lifespan or a combination of these effects may impact some individuals (Asghar et al, 2015;Atkinson et al, 2008;Delhaye et al, 2018;Ishtiaq and Barve, 2018;Kilpatrick et al, 2006;Knowles et al, 2010;Valkiūnas, 2005). Healthy birds may be able to immunologically suppress the parasitaemia of these haemosporidians, resulting in chronic low levels of parasitaemia or a full recovery and immunity to further infection (Atkinson et al, 2008;Atkinson and Van Riper III, 1991;Botes et al, 2017;Rivero and Gandon, 2018;Valkiūnas, 2005).…”