Urban Onsite Sanitation Upgrades and Synanthropic Flies in Maputo, Mozambique: Effects on Enteric Pathogen Infection Risks.
Environ Sci Technol
; 57(1): 549-560, 2023 01 10.
Article
em En
| MEDLINE
| ID: mdl-36516327
ABSTRACT
Synanthropic filth flies transport enteric pathogens from feces to food, which upon consumption poses an infection risk. We evaluated the effect of an onsite sanitation interventionâincluding fly control measuresâin Maputo, Mozambique, on the risk of infection from consuming fly-contaminated food. After enumerating flies at intervention and control sites, we cultured fecal indicator bacteria, quantified gene copies for 22 enteric pathogens via reverse transcription quantitative polymerase chain reaction (RT-qPCR), and developed quantitative microbial risk assessment (QMRA) models to estimate annual risks of infection attributable to fly-contaminated foods. We found that the intervention reduced fly counts at latrine entrances by 69% (aRR = 0.31, [0.13, 0.75]) but not at food preparation areas (aRR = 0.92, [0.33, 2.6]). Half of (23/46) of individual flies were positive for culturable Escherichia coli, and we detected ≥1 pathogen gene from 45% (79/176) of flies, including enteropathogenic E. coli (37/176), adenovirus (25/176), Giardia spp. (13/176), and Trichuris trichiura (12/176). We detected ≥1 pathogen gene from half the flies caught in control (54%, 30/56) and intervention compounds (50%, 17/34) at baseline, which decreased 12 months post-intervention to 43% (23/53) at control compounds and 27% (9/33) for intervention compounds. These data indicate flies as a potentially important mechanical vector for enteric pathogen transmission in this setting. The intervention may have reduced the risk of fly-mediated enteric infection for some pathogens, but infrequent detection resulted in wide confidence intervals; we observed no apparent difference in infection risk between groups in a pooled estimate of all pathogens assessed (aRR = 0.84, [0.61, 1.2]). The infection risks posed by flies suggest that the design of sanitation systems and service delivery should include fly control measures to prevent enteric pathogen transmission.
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Base de dados:
MEDLINE
Assunto principal:
Saneamento
/
Dípteros
Tipo de estudo:
Etiology_studies
/
Risk_factors_studies
Limite:
Animals
País/Região como assunto:
Africa
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Estados Unidos