Manufacturers increasingly incorporate elements of data analytics, GPS and remote sensing in a race to make farming more precise. A tractor that maps a field, drives itself and precisely calibrates its movements within inches to minimise wasted fuel, fertiliser or seed is already almost standard on the large-scale farms seen in many developed countries. The combination of food demand and rising farmers' expectations has forced agricultural companies to make big advances beyond auto-steer - introduced about 15 years ago - towards remote sensing and cloud-based data collection on the dozens of variables, from soil moisture to nutrient levels, that govern modern farming. Mark Rosegrant, of the International Food Policy Research Institute, estimates that the rigorous adoption of "precision agriculture" technology could increase yield on any given farm by about 10 per cent, compared with average global annual crop yield increases of about 1 per cent.

31 Has human-to-human transmission of the H5N1 avian influenza virus been described?

32 In brucellosis, is it possible to see a brucella agglutination test of more than 1/160 even for years after specific and successful therapy of brucellosis?

33 Please define the terms holoendemic, mesoendemic, and hyperendemic in relation to malaria.

34 You only recommend malarone for malarial prophylaxis when there is a significant chlorquine resistance. Isn't malarone now widely used in travellers going to areas with low resistance.

35 Parenteral vaccination with a killed suspension of Vibrio cholerae is recommended by some - isn't an oral vaccine better?

36 Please suggest possible reasons why Entamoeba histolytica infection associated with bloody diarrhoea is not relieved by treatment with ciprofloxacin and metronidazole 400 mg 2 daily over a 3-week period.

37 Is there a basis for treating patients for filariasis according to the eosinophil count (except for cases of tropical pulmonary eosinophils; TPE)? Filariasis is everywhere in my part of the world; a fluorescent antibody test (FAT) might not be very useful - except when there are very high values.

38 Why do patients who ingest eggs from a tapeworm in contaminated food not develop tapeworms?

39 I have a query about one of the details in the book. You mention that perihepatitis is a feature of gonorrhoeal infection, but other books say that perihepatitis (Fitz-Hugh-Curtis syndrome) is a complication of chlamydial infections. Is there a possibility of perihepatitis in gonorrhoea? Thank you.

40 In the 7th edition of Kumar and Clark Clinical Medicine, you indicate that there is no benefit in treating the male partner of a woman diagnosed with bacterial vaginosis (BV). As many physicians use the 2 g 1 metronidazole dose, is this unwarranted? Does it differ in women experiencing frequent recurrences of infection?