Plausible explanations include late presentation associated with absence of Leptospira in blood, and pre-treatment with antimicrobial drugs prior to admission. A wide range of oral antibiotics is available over the counter in Thailand, and self-medication prior to hospital presentation is common. The quantification of Leptospira in blood during this study was a useful exercise, since this can provide critical baseline information during the development of point of care antigen detection tests. The finding that the bacterial count was higher in patients who were culture positive compared with those who were culture negative was intuitive. Our data on the window of PCR or culture positivity after the onset of symptoms suggest that these tests only have clinical utility within the first week of clinical manifestations, as reported previously. We observed that the period over which PCR was positive after the start of symptoms was longer than that for culture. A small number of patients were positive by culture but negative by PCR. However, the difficulty and expense of culture combined with the prolonged delay before culture becomes positive means that culture results will not influence individual patient care. The basis for a negative PCR result but positive culture remains unexplained, but possible explanations include a very low count in the initial sample associated with a stochastic effect in which the organism was present in the aliquot taken for culture but not for PCR. Fat content data were collected for 5 colonies whereas head width for only the four colonies collected in 2009. Logistic regression was used to examine how the probability of foraging changed with increased fat content and body size. Finally, we used a regression to examine whether fat content predicted foraging effort for one colony. Our results support the hypothesis that division of labor can be organized by nutritional status, and that fat storage may be a conserved means of organizing foraging behavior even in a species where all individuals are capable of mating and reproducing. Even when all individuals are capable of reproducing, nutritional variation may sort individuals into distinct groups and physiological cues conserved from solitary insects may reinforce specialization. Studies of the molecular basis of foraging and reproduction in social insects generally suggest that division of labor is derived from conserved pathways present in solitary ancestors. Pou5f1, a POU and homeobox transcription factor, is essential for maintaining the pluripotential phenotype. It is expressed in pluripotent cells of morula, cells of the inner cell mass, epiblasts, and primordial germ cells. In female PGCs, Pou5f1 is repressed by the onset of meiotic prophase I and is reexpressed after birth, coinciding with the growth phase of oocytes. In male embryos, Pou5f1 expression persists in germ cells throughout fetal development.