Toxoplasmainfection and milk consumption: Meta-analysis of assumptions and evidences

Abstract

Toxoplasmosis is the most widespread infection worldwide. It occurs within congenital contamination, organ transplant or immune system depression. Primary infection is mainly foodborne with the ingestion of raw or undercooked meat, unwashed fruit-vegetables, unhygienic water or contaminated milk. Gaps in current knowledge about the risk assessment of Toxoplasma gondii by milk consumption are noted. Contradictory data are observed within risk assessment of milk consumption and toxoplasmosis occurrence. While some papers reported positive correlations between drinking milk and infection transmission to human, other studies stated nonsignificant influence of milk or milk products consumption. New debate about the detection of the parasite in the milk matrix from different hosts raised interrogations. To figure out the real contribution and the potential correlations of milkborne way in toxoplasmic infection, meta-analysis approach was investigated. Overall analysis showed heterogeneous responses and led to state that statistically dairy matrix (other than milk), Bovidae products, agricultural population and countries in Africa, Europe and Southeast Asia are not linked to milkborne toxoplasmosis. The most involved factors are Capridae products, immune-depressed population and North America, Middle East, and Latin territories. The current work advanced those parameters that could affect the public health and should be envisioned in further epidemiological analysis.

Toxoplasma gondii in naturally infected goats: Monitoring of specific IgG levels in serum and milk during lactation and parasitic DNA detection in milk

“…T. gondii DNA was detected by molecular tools in goat milk samples with prevalence ranging from 1 to 32.5% (Spišák et al, 2010;Mancianti et al, 2013;Bezerra et al, 2015;da Silva et al, 2015). Several studies, meta-analysed by Boughattas (2017), have determined the consumption of raw milk, especially of goat origin, as a risk factor enhancing the risk of T. gondii infection. However, the real effectiveness of this transmission route for humans is yet to be defined.…”

Artisan fresh cheese from raw cow's milk as a possible route of transmission in a toxoplasmosis outbreak, in Brazil

“…However, cattle seem to be more resistant to infection, having a low prevalence and lower ability to form tissue cysts (Dubey & Thulliez, ). Regarding the transmission by tachyzoites in cow's milk cheese, previous experimental and epidemiological studies are not evident; however, previous cross‐sectional studies have detected the presence of the T. gondii DNA in cow's milk (Boughattas, , ; Dubey, ; Dubey & Thulliez, ). In this context and considering the epidemiological investigation data and the laboratory results of the samples, the suspicion is based on the contamination of the milk after milking, probably by the addition of water in the cheese‐making process, or even by contact with contaminated surfaces.…”

“…Pregnant women are an important risk group since vertical transmission can trigger foetal pathologies or abortion (Tenter et al, ). The main clinical signs observed in outbreaks of the disease are as follows: fever, lymphadenomegaly, headache, ocular symptoms and myalgia (Boughattas, ; Hill & Dubey, ).…”

Strategy for systematic review of observational studies and meta-analysis modelling of risk factors for sporadic foodborne diseases

“…Although meta-analyses of risk factors of foodborne pathogens are not new; they have been conducted for one pathogen at a time, for a selection of risk factors, and with specific inclusion criteria (Belluco et al, 2017;Boughattas, 2017;Bouzid et al, 2018;Domingues et al, 2012a,b;Kintz et al, 2017;Wei et al, 2016). Our proposal has taken a step forward, by formulating, as far as possible, a general approach that could be employed for all pathogens, yet conservative enough to keep most of the information provided in the primary studies.…”