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International travel is increasing and a significant number of travellers will develop a febrile illness during or shortly after their return from the tropics. The differential diagnosis is broad and a systematic approach to the management of these patients is required in order to establish the diagnosis and to initiate prompt and effective treatment. Fever may be due to infectious agents found only in tropical countries, or due to infections unrelated to travel and found worldwide. Important infections that should be considered in all returning travellers include malaria, dengue, enteric fever, rickettsial infections, and HIV seroconversion. Other diagnoses will be considered after a detailed history including countries visited with dates, activities undertaken and symptoms. At a minimum, all travellers from countries where there is malaria transmission should be tested repeatedly for malaria as well as having several sets of blood cultures taken. Many tropical infections are diagnosed serologically at specialist reference laboratories. Specialist advice on the investigation and management of returning travellers should be sought from infectious diseases physicians and microbiologists. Patients with malaria or enteric fever may deteriorate rapidly and travellers should be advised to seek prompt medical attention if they become unwell after travel to the tropics. This review will focus on some of the more important imported infections, diagnostic clues from the history, examination and investigations, and important considerations in their management.

Up to one-third of dairy calves are born after dystocia and this is a major cause of calf mortality. This study investigated the neonatal physiology, survival, health and subsequent growth of dairy calves following dystocia and is the first longitudinal study to analyse multiple effects and to look beyond the perinatal period. A total of 455 live born Holstein calves (N: No assistance, n=360; FN: Farmer assistance but normally presented calf, n=82; FM: Farmer assistance of malpresented calf, n=13) were followed from birth to first service (heifers) or until leaving the farm (bulls). Compared to N calves, FN and FM animals had higher salivary cortisol concentrations at day 1 (P0.001) and FN calves had lower passive immune transfer (P=0.03). Dystocia had no biologically significant impact on rectal temperature throughout the first 4 days (P0.05). During the first 60 days, FM calves had a higher proportion of days with non-routine health treatments (P0.05) and, by the time of weaning, mortality in FN and FM heifers was higher than in N calves (2.8×; P0.01). However, in surviving calves, growth to first service was not affected by dystocia category (P0.05). Calves which survive dystocia experience lower passive immunity transfer, higher mortality and higher indicators of physiological stress. Such calves have poorer welfare in the neonatal period and possibly beyond. Strategies need to be implemented to improve the subsequent health and welfare of such calves and to lower the incidence of dystocia.

Publisher Summary This chapter discusses methyl ethers of D -galactose. The 2,3,4,6-tetramethyl- D -galactopyranos is obtained by the full methylation of the methyl α- or β- D -galactopyranosides, followed by acid hydrolysis of the products. Selective trimethylation at positions 3, 4, and 6 has been accomplished by starting with the 1,2-isopropylidene- D -galactopyranose. The supposed 1,3-anhydro- D -galactopyranoset, the structure of which is assigned from the fact that it is not oxidized by periodate, would have supplied a starting material for 2,4,6-trimethyl- D -galactose, but subsequent investigation as shown that its full methylation and the subsequent hydrolysis of the product yields 2,3,5-trimethyl- D -galactose , proving that this galactosan is actually l,6-anhydro-α-D-galactofuranose. Sugar is obtained in crystalline form by methylation of methyl 3,4-isopropylidene-β- D -galactopyranosid 6-nitrate, followed by stepwise removal of the substituent radicals. The synthesis of the sugar presented certain technical problems. While the obvious starting material is either of the methyl 4,6-benzylidene- D -galactopyranosides it is quite clear that neither carboxylic nor sulphonic nor nitric esters could be used for temporary masking of hydroxyls 2 and 3.