Tungiasis infection among primary school children in Northeastern Tanzania: prevalence, intensity, clinical aspects and associated factors

Abstract

Objective: To investigate the prevalence, intensity, clinical aspects and factors associated with tungiasis infection among primary school children in Northeastern Tanzania.

Methods: A quantitative school-based cross-sectional study was conducted among 401 primary school children. Participants were assessed through clinical examination to look for embedded Tunga penetrans in their hands, feet, arms and legs. A structured questionnaire was used to enquire about factors associated with tungiasis infection. The data were analysed using descriptive statistics, Chi-squared test and logistic regression, with p<0.05 taken to indicate significance.

Results: The overall prevalence of tungiasis infection was 21.2%. Of the 85 tungiasis-infested children, 54 [63.5%, 95% confidence interval (CI) 53.1-74.1] had mild infection, 25 (29.4%, 95% CI 19.0-39.6) had moderate infection, and six (7.1%, 95% CI 1.2-12.9) had heavy infection. A moderate level of knowledge was significantly associated with high odds of tungiasis infection [adjusted odds ratio (AOR) 3.16, 95% CI 1.50-6.67], while not keeping a dog/cat at home was a protective factor (AOR 0.47, 95% CI 0.25-0.89).

Conclusions: Moderate prevalence of tungiasis infection was observed among primary school children favoured by factors related to the host, parasitic agent and environment. There is a need for a health education programme in schools encouraging use of appropriate footwear (closed shoes), use of locally accessible repellents (coconut oil), fumigation of households, and washing dogs/cats with insecticides.

Keywords: Northeastern Tanzania; Primary school children; Tunga penetrans; Tungiasis infection.

Figure 1

Physiopathology of tungiasis. (A) Pictorial view of Tunga penetrans invading epidermis, with hypertrophic changes in abdominal segments. The oviposition and excretion of faeces continues until the parasite's death. Around the parasite, the epidermal layer shows hypertrophic and hyperkeratotic changes. Hyperaemia and inflammatory changes occur in the dermal layer, where T. penetrans acquires nutrients. (B) The five stages of Fortaleza classification: 1: invasion by the parasite; 2: complete penetration of epidermis and faecal excretion; 3: hyperkeratotic changes of epidermis and hypertrophic changes of abdominal segments; 4: lesion involution after parasite's death; 5: residual skin abrasion. Complications with infection and necrosis are summarized in the last square. (C) Photographs of lesions at different stages of infection, indicated by a number.

Figure 2

t Preventive practices on tungiasis among study participants.