Malaria and helminth interactions in humans: an epidemiological viewpoint.

In the tropics, helminths are among the most common chronic infections of humans and Plasmodium infections the most deadly. As these two groups of parasites have similar geographical distributions, co-infection is commonplace. It has increasingly been speculated that helminth infections may alter susceptibility to clinical malaria, and there is now increasing interest in investigating the consequences of co-infection, with studies yielding contrasting results. The immunological interactions between helminths and malarial parasites are unclear, although several hypotheses have been proposed. This review provides an epidemiological overview of the possible interactions between helminths and malarial parasites, in relation to geographical distributions and disease patterns, and provides a critical discussion of the results of the epidemiological studies that have so far been conducted to investigate the possible associations. Future studies that might be considered, in order to address the gaps in knowledge, are also considered.

The use of ultrasound to study the prevalence of hydatid cysts in the right lung and liver of sheep and goats in Turkana, Kenya.

Ultrasound examination of the liver and right lung was performed in 260 sheep and 320 goats from the Turkana district of Kenya. Hydatid cysts were visualized in 9.2% of the sheep and 2.5% of the goats. Of the animals positive on ultrasound, 87.5% received post-mortem examinations. Eighteen (6.9%) sheep and 5 (1.5%) goats were positive for hydatid cysts on ultrasound and post-mortem examination. False-positives were a result of Taenia hydatigena cysticerci present in the liver in all but 1 case. Positive predictive value of ultrasound for diagnosis of hydatidosis in sheep and goats was 82.1%.