Myth or truth: investigation of the jumping ability of Tunga penetrans (Siphonaptera: Tungidae)

Female sand fleas (Tunga penetrans Linnaeus, 1758, Siphonaptera: Tungidae) cause a severe parasitic skin disease known as tungiasis. T. penetrans is a small flea, measuring less than 1 mm in length. The females of this species burrow into the skin of human and animal hosts and mostly affect the feet. This has led to the anecdotal assumption that T. penetrans, unlike its relatives in the Siphonaptera family, would have a limited jumping ability potentially not reaching higher body parts. However, there is no data supporting this. This study evaluated the jumping capabilities of T. penetrans for height and distance using sticky tapes. The vertical jump of the female T. penetrans ranged from 4.5 to 100 mm with a mean of 40 mm whereas the vertical jump of the male T. penetrans ranged from 1.2 to 138 mm with a mean of 46 mm. The horizontal jump of the female T. penetrans ranged from 18 to 138 mm with a mean of 64 mm and that of the male ranged from 9 to 251 mm with a mean of 80 mm. Based on the literature, fleas of various species have been described as jumping vertically 50-100 times their size and horizontally 5-100 times their size. In this respect, sand fleas appear to have equal expert jumping abilities to their relatives. Their aggregation on people's feet is not likely a result of their poor jumping ability but might be an adaptation to the host's behavior which would require further investigations.

Scabies in Resource-Poor Communities in Nasarawa State, Nigeria: Epidemiology, Clinical Features and Factors Associated with Infestation

Epidemiology and clinical features of scabies remain largely unknown in Nigeria’s rural communities. To fill this gap, we performed a cross-sectional study in three rural communities in north central Nigeria. A total of 500 individuals were included and examined for scabies infestation; a questionnaire was applied to collect socio-demographic and behavioral data. Scabies was diagnosed in 325 (65.0%) participants. Excoriations (68.6%), vesicles (61.8%), and papules (58.8%) were common skin lesions. Itching was the most common symptom (77.5%); 64% complained of sleep disturbances. Lymphadenopathy was identified in 48.3%. Lesions were most commonly encountered on the abdomen (35.5%), inguinal area (19.1%), and interdigital spaces (14.2%). Poverty-related variables, such as illiteracy (OR: 7.15; 95% CI: 3.71–13.95), low household income (7.25; 1.19–88.59), absence of a solid floor inside house (12.17; 2.83–52.34), and overcrowding (1.98; 1.08–2.81) were significantly associated with infestation. Individual behavior, such as sharing of beds/pillows (2.11; 1.42–3.14) and sharing of clothes (2.51; 1.57–3.99), was also highly significantly associated with scabies. Regular bathing habits (0.37; 0.24–0.56) and regular use of bathing soap (0.36; 0.21–0.53) were protective factors. Scabies is extremely common in the communities under study and is associated with considerable morbidity. The disease is intrinsically linked with extreme poverty.