Seroprevalence of Toxoplasma gondii and associated risk factors among pregnant women attending antenatal care in Ilala Municipality, Dar es Salaam, Tanzania

doi:10.21203/rs.3.rs-1534701/v1

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Research Article

Seroprevalence of Toxoplasma gondii and associated risk factors among pregnant women attending antenatal care in Ilala Municipality, Dar es Salaam, Tanzania

https://doi.org/10.21203/rs.3.rs-1534701/v1

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Background

Toxoplasma gondii (T. gondii) infection during pregnancy is associated with a variety of complications to the mother and baby. In Tanzania, there is a paucity of data on exposure T. gondii infection among pregnant women and the associated risk factors. Therefore, this study investigated the seroprevalence of T. gondii and associated factors among pregnant women attending antenatal care in Ilala Municipality, Dar es Salaam.

Methods

A cross-sectional study was carried out among 383 pregnant women attending antenatal health care. A five mL of blood sample was collected from each of the recruited pregnant women, processed to obtain serum, and tested for the presence of IgG and IgM anti-T. gondii specific antibodies. A structured questionnaire was used to gather information on the risk factors predisposing pregnant women to the infection. Data analysis was performed using descriptive statistics and logistic regression.

Results

Of the 383 participants, 104 (27.2%) were positive for antibodies specific to T. gondii; 102 (26.63%) were positive only for IgG, and 2 (0.52%) were positive both for IgM and IgG antibodies. Significantly risk factors for T. gondii infection included: increased maternal age (34-39) years [AOR = 3.714, 95% CI:1.522-9.062), eating unwashed fruits [AOR = 7.385, 95% CI:3.994-13.658,], not washing hand with soap after meat preparation [AOR = 7.525, 95% CI:3.403-16.642], consumption of undercooked meat [AOR = 3.746, 95% CI:1.945-7.217], and consumption of raw vegetable [AOR = 1.986, 95% CI:1.038-3.800].

Conclusions

The seroprevalence of T. gondii infection (27.2%), indicates ongoing transmission hence the need for regular screening during antenatal care and establishment of a control program.

Toxoplasma gondii

pregnant women

seroprevalence

risk factors

Dar es Salaam

Toxoplasmosis is a zoonotic disease caused by an intracellular protozoan called Toxoplasma gondii (T.gondii) (Mgode et al., 2014). Approximately over 60% of the world population has been exposed to T.gondii infection, with seropositivity rates ranging from less than 10% to over 90% in different parts of the world or within regions in the same country (Pappas, Roussos and Falagas, 2009; Van der Colf et al., 2014; Dama, Nováková and Flegr, 2016). Acquisition of T.gondii is through the ingestion of tissue cysts in meat, ingestion of food, water, or soil contaminated with sporulated oocysts, and directly from the cat feces (Murebwayire et al., 2017). Additionally, transfusion of T. gondii unscreened blood and organ transplant permit the dissemination of T.gondii tachyzoites to a large variety of body organs, causing congenital diseases during pregnancy (Robert-gangneux and Dardé, 2012; Abamecha and Awel, 2016; Alvarado et al., 2016).

The majority of healthy individuals with T. gondii infections are asymptomatic. However, immune-compromised individuals, immunosuppressive drugs users, and pregnant women who acquired toxoplasmosis during pregnancy suffer severe infection and high mortality (Musa, 2014; Alvarado et al., 2016). The primary infection during gestation age determines the risk of maternal-fetal transmission, which ranges from (10–24%) in the first trimester to (60–90%) in the third trimester of which the risk of congenital defect become more severe with earlier infections (Doehring et al., 1995; Dunn et al., 1999; Cook et al., 2000; Yohanes et al., 2017). The circulation of T.gondii parasites across the fetal placenta barrier results in miscarriage, preterm delivery, death in utero, neonatal growth retardation, hydrocephalus, cerebral calcification, neurological or ophthalmic disease in the new-born, during childhood or adolescence (Van der Colf et al., 2014; Musa, 2014; Alvarado et al., 2016; Chandrasena et al., 2016; Tilahun et al., 2018; Rouatbi et al., 2019).

The seroprevalence of T. gondii infection ranges from 4–78% among pregnant women in endemic countries (Mwambe et al., 2013; Paul et al., 2018). Variation in prevalence’s depends on local environmental factors, especially on temperature and moisture, kitchen habits, and hygienic standards (Dama, Nováková and Flegr, 2016). Routinely maternal screening through serological tests to monitor acute and latent T. gondii infections during pregnancy reduces the possibility of fetal infections and substantial damages. However, in most of the resource-limited countries, including Tanzania, screening of the T. gondii is not done. Hence, the pregnant women remain undiagnosed (Mwambe et al., 2013; Paul et al., 2018; Teweldemedhin et al., 2019).

In Tanzania, the seroprevalence of T. gondii infection and associated risk factors have not fully been established among pregnant women, and there is no intervention in place as it is for other conditions. Also, their level of knowledge on T. gondii infection effects on the fetus, transmission, and preventions is not known. Therefore, this study aimed to determine the seroprevalence of T. gondii and associated factors among pregnant women attending antenatal care in Ilala Municipality, Dar es Salaam. The findings will provide basic information on the current burden of the disease and associated risk factors that might be used to develop appropriate control interventions for the prevention and treatment of toxoplasmosis in pregnant women.

Ethical consideration

Ethical clearance was obtained from the Institutional Review Board (IRB) of the Muhimbili University of Health and Allied Sciences (IRB#: MUHAS-REC-07-2020-390). Permission was obtained from the Ilala municipality administrative authorities in all respective study sites before beginning the study. Signed informed consent was obtained from each study participant before blood collection, and the collected information was kept confidential.

Study design and settings

A quantitative facility-based cross-sectional study was conducted in August 2020 to determine the seroprevalence of Toxoplasma gondii and associated risk factors among pregnant women attending public antenatal clinics in Ilala municipality. Ilala municipal council is the regional headquarter for the Dar es Salaam Region (Figure 1). The Ilala municipal is lies between the longitudes of 39° and 40° east and latitude of 60° and 70° south of the equator, having an area of 1,393 km² (Municipal Profile-Ilala Municipal Council, 2021). The municipal council has approximately a population of 1,220,611 whereby males are 595,928 and females are 624,683 (NBS, 2012). The Ilala municipal has a total of 36 wards with 2 public health centers and 24 public dispensaries (Municipal Profile-Ilala Municipal Council, 2021). Ilala municipal was selected because it’s among the endemic area for Toxoplasmosis with the highest population of women.

Study population

The study population was the pregnant women attending public antenatal clinics in the Ilala municipality. Only the pregnant women who agreed and signed informed consent were enrolled in this study.

Sample size determination and sampling procedures

The minimum sample size for seroprevalence determination was estimated using the formula for a cross-sectional survey: n = Z² P (100-P)/ε², whereby; n=minimum sample size required, Z= standard normal deviate of 1.96 on using a 95% confidence interval, p= expected true proportion of taken from the previous study done in Dar es salaam, Tanzania (35%) (Doehring et al., 1995), and ε = margin of error (5%). Through computation with the above formula, a minimum sample size of 349 was obtained. Considering 5% of the sample size for non-response rate and the design effect of 1.5 (Umulisa, 2012). Therefore, the total sample obtained was 549 pregnant women.

A multi-stage sampling technique was applied to enroll the 549 pregnant women in this study. In the 1^st stage, one health center and four dispensaries were selected by simple random sampling technique. In the second stage, a probability proportional to size (PPS) was applied to obtain the sample for recruitment in each facility selected. For the PPS sampling, the preceding month's attendance for ANC services in the selected facilities was extracted from the registries of each facility and summed up. Then the attendance for the preceding month of each facility was divided by the facilities sum attendances and multiplied by the overall sample size (n) to obtain the sample to recruited per selected facility. In the selected facilities, recruitment of pregnant women attending ANC services was done according to daily catchment, where the daily catchment was less than the expected daily eligible recruitment; consecutive pregnant women were recruited until sample for the facility was achieved. Where daily catchment exceeded the expected daily recruitment, systematic sampling was used to recruit until completion of the sample size for the facility. In a month, a total of 118, 75, 72, 58, and 60 pregnant women from Chanika health center, Buyuni, Kinyerezi, Kitunda, and Tabata A dispensaries, respectively accepted to be enrolled in the study by signing the informed consent.

Data collection tool

The structured questionnaire adapted and modified from Mwambe et al., 2013; Paul et al., 2018; Teweldemedhin et al., 2019 were used to collect the required information. The questionnaire had four sections; section A was used to collect information on socio-demographic characteristics such as age, marital status, occupation, level of education, gravidity, trimester of pregnancy, section B collected information on the risk exposures to T. gondii infection such as cat ownership, history of contact with cats, history of consumption of undercooked meat, eating unwashed fruits, drinking of raw milk and unboiled water and domestic/household gardening to T.gondii infection, and section C focused on awareness and knowledge about toxoplasmosis causes, mode of transmission, symptoms, effects, and preventive measures. All participants (383) were asked awareness questions. However, in the knowledge section, only forty participants who were aware of toxoplasmosis were interviewed.

Blood collection and serological analysis

Following completion of the structured interview schedule at antenatal clinics, trained laboratory technologists aseptically collected 5ml of venous blood from each study participant using a sterile vacutainer tube and dispensed it into a sterile tube. Collected samples were uniquely labeled with code numbers and then transported from collection sites to Muhimbili National Hospital (MNH) for examination. The collected blood samples were centrifuged at 3000 rpm for 10 minutes to obtain serum samples. Then the serums samples were examined for anti-T. gondii immunoglobulin M and G using the Abbot Architect analyzer. The architect Toxo IgG and IgM analyzer had sensitivity of 97.5% and 89.9%, respectively and specificity of 99.1% and 99.8%, respectively (23,24). The internal quality control and respondents immunoglobulin results were interpreted as per manufacture instruction as IgG with < 1.6, 1.6-3, and ≥ 3 considered as non-reactive (negative), gray zone, and reactive (positive) antibody results respectively, while with IgM <0.50,0.50-1 and ≥ 1 were regarded as non-reactive (negative), gray zone and reactive (positive) antibody respectively (Teweldemedhin et al., 2019). The labeled aliquots of examined serum samples were stored in the freezer at -20^oC or colder at MNH.

Data analysis

The obtained results were entered and analyzed using the Statistical Package for Social Sciences (SPSS) version 22.0 software produced by IBM Corporation, Armonk, NY, USA. Descriptive statistics were used to summarize and describe the variables in the frequency tables with their proportions. Pearson's chi-square test was used to compare proportions and to assess the association between a T. gondii seroprevalence and independent variables. Knowledge was assessed using five questions, each answer was given a mark of one for a correct, zero for the incorrect, and then the total score for each participant was calculated. Subsequently, the mean score was calculated, aiding in the classification of the levels of knowledge. The obtained mean score was 2.3. Hence, a score > 2 was classified as a high level of knowledge and a score ≤ 2 as a low level of knowledge. Univariate logistic regression was used to identify the variables for multivariable logistic regression. All independent variables with a p-value < 0.25 in the univariate analysis were subjected to the multivariable analysis to adjust potential confounders. The p-values < 0.05 were considered statistically significant.

Socio-demographic characteristics of the study participants

A total of 383 participants were recruited, with a response rate of 69.76%. Of the 383 pregnant women recruited, more than half (55.1%) were aged < 27 years and had primary education (56.7%). The majority of the pregnant women were married (88.8%), with less than half (40.2%) in the second trimester (Table 1).

Table 1: Socio-demographic information of pregnant women participated in the study (n=383)

Socio-demographics	Categories	Respondents (n)	Percentage (%)
Age (years)	≤ 27	211	55.1
	28-33	119	31.1
	34-39	44	11.5
	≥ 40	9	2.3
Marital status	Single	36	9.4
	Divorced/separated	7	1.8
	Married	340	88.8
Occupational	Student	4	1.0
	Housewife	152	39.7
	Peasant	27	7.0
	Businesswomen	188	49.1
	Employed	12	3.1
Education level	None	14	3.7
	Primary school	217	56.7
	Secondary and above	152	39.7
Gravidity	Primigravid	91	23.8
	Multigravid	292	76.2
Trimester of pregnancy	First trimester	80	20.9
	Second trimester	154	40.2
	Third trimester	149	38.9
Health facilities	Chanika health center	117	30.5
	Buyuni dispensary	73	19.1
	Kinyerezi dispensary	75	19.6
	Tabata A dispensary	60	15.7
	Kitunda dispensary	58	15.1

Seroprevalence of T. gondii infection among pregnant women

The overall prevalence of T. gondii infection among pregnant women was 104(27.2%), with 102 (26.6%) positive for T. gondii specific IgG while 2 (0.52%) tested positive for both T. gondii specific IgG and IgM antibodies (Figure 2).

Influence of socio-demographic characteristics on T. gondii infection

The prevalence of T. gondii was higher among the pregnant women in the first trimester (31.3), aged 34 -39 years (45.5%), married (27.6%), businesswomen (28.7%), multigravid (28.4%). Also, there was a statistically significant association between the age groups of the pregnant women and the prevalence of T. gondii infection (p=0.007) (Table 2).

Table 2: Influence of socio-demographic characteristics on T. gondii infection (n=383)

Variable	Categories	Examined (n=383)	Sero status (%)	p –value
Age group	≤ 27	211	45(21.3)	0.007*
	28-33	119	37(31.1)
	34-39	44	20(45.5)
	≥ 40	9	2(22.2)
Marital status	Single	36	9(25.0)	0.700
	Divorced/separated	7	1(14.3)
	Married	340	94(27.6)
Occupational	Student	4	1(25.0)	0.669
	Housewife	152	42(27.6)
	Peasant	27	4(14.8)
	Businesswomen	188	54(28.7)
	Employed	12	3(25)
Education level	None	14	4(28.6)	0.659
	Primary school	217	55(25.3)
	Secondary and above	152	45(29.6)
Gravidity	Primigravid	91	21(23.1)	0.317
	Multigravid	292	83(28.4)
Trimester	First trimester	80	25(31.3)	0.651
	Second trimester	154	40(26.0)
	Third trimester	149	39(29.2)
Health facilities	Chanika health center	117	30 (25.6)	0.759
	Buyuni dispensary	73	17 (23.3)
	Kinyerezi dispensary	75	24 (32.0)
	Tabata A dispensary	60	18 (30.0)
	Kitunda dispensary	58	15 (25.9)

*Statistically significant (p < 0.05)

The risk factors for the T. gondii infection among the pregnant women

More than a quarter of the pregnant women (26%) own domestic cats and of which two-third (66.7%) had a history of cat contact. Also, a majority (71.2%) reported eating unwashed fruits, eating raw vegetables (75%), and undercooked meat (78.8%). The prevalence of T. gondii infection was statistically significantly associated with owning the cat (p < 0.000), eating unwashed fruits (p < 0.000), handwashing practice before meat preparation (p < 0.000) and after household gardening (p < 0.000), and history of consuming undercooked meat (p < 0.000), and raw vegetables (p < 0.000) (Table 3).

Table 03: The risk factors for the T. gondii infection among the pregnant women in Ilala municipality of Dar es Salaam (n=383)

Variable	Examined	Percentage	Sero status	p-value
Own domestic cats
Yes	59	15.4	27(26.0)	0.000*
No	324	84.6	77(74.0)
History of cat contact
Yes	32	54.2	18(66.7)	0.078
No	27	45.8	9(33.3)
Eat unwashed fruits
Yes	125	32.6	74(71.2)	0.000*
No	258	67.4	30(28.8)
Wash hands after meat preparation
Yes	177	46.2	12(11.5)	0.000*
No	206	53.8	92(88.5)
Wash hands after household gardening
Yes	173	45.2	29(27.9)	0.000*
No	210	54.8	75(72.1)
Source of drinking water
Tape water	176	46.0	48(46.2)	0.387
Well water	202	52.7	56(53.8)
Mineral bottled water	05	1.3	0(0.0)
Boil drinking water
Yes	109	28.5	33(31.7)	0.386
No	274	71.5	71(63.3)
Drinking raw milk
Yes	110	28.7	35(33.7)	0.193
No	273	71.3	69(66.3)
History of consuming undercooked meat
Yes	194	50.7	82(78.8)	0.000*
No	189	49.3	22(21.2)
History of consuming raw vegetable
Yes	217	56.7	78(75.0)	0.000*
No	166	43.3	26(25)
Awareness
Yes	40	10.4	11(10.6)	0.959
No	343	89.6	93(89.4)
Level of Knowledge
High	23	57.5	6(5.8)	0.714
Low	17	42.5	98(94.2)

* Statistically significant (p < 0.05)

Awareness of toxoplasmosis among the study participants

Out of 383 pregnant women surveyed, less than a quarter (10.4%) had heard of toxoplasmosis, while the rest had never heard of toxoplasmosis. Of 40 study participants who were aware, nearly two third (65.0%) heard of toxoplasmosis on the social media (WhatsApp, Facebook and Instagram) (Table 4).

Table 4: Awareness of toxoplasmosis among the study participants (n=383)

Variable	n (%)
Heard of toxoplasmosis
Yes	40(10.4)
No	343(89.6)
Source of the information
Course of study	07(17.5)
Social media (WhatsApp, Facebook, Instagram)	16(40)
Hospital/Health clinics	11(27.5)
News media (Television, radio, magazine)	04(10)
All sources mentioned	02(5)

Influence of socio-demographic characteristics on the awareness of toxoplasmosis among the study participants

Pregnant women with secondary and above education were more aware of toxoplasmosis compared to pregnant women with primary education and none. There was a statistically significant association between awareness and the level of education (p < 0.000) (Table 5).

Table 5: Influence of socio-demographic characteristics on the awareness of toxoplasmosis among the study participants (n=383)

Variable	Category	Examined	Awareness status (%)	p-value
Age	≤ 27	211	23(6.0)	0.344
	28-33	119	15(3.9)
	34-39	44	2(0.5)
	≥ 40	9	0(0.0)
Marital status	Single	36	4(1.0)	0.657
	Divorced/separated	7	0(0.0)
	Married	340	36(9.4)
Occupation	Student	4	1(0.3)	0.092
	Housewife	152	13(3.4)
	Peasant	27	0(0.0)
	Businesswomen	188	23(6.0)
	Employed	12	3(0.8)
Educational level	None	14	0(0.0)	0.000*
	Primary school	217	11(2.9)
	Secondary and above	152	29(7.6)
Gravidity	Primigravid	91	12(3.1)	0.327
	Multigravid	292	28(7.3)
Trimester	First trimester	80	13(3.4)	0.144
	Second trimester	154	15(3.9)
	Third trimester	149	12(3.1)

* Statistically significant (p < 0.05)

Knowledge on the toxoplasmosis among the pregnant women

Nearly half (47.5%) of the pregnant women did not know the cause of toxoplasmosis. However, almost two-third (65%) knew the correct mode of toxoplasmosis transmission. Almost two-thirds (65%) of the pregnant women reported miscarriage as the complication of toxoplasmosis in pregnant women, and more than one-third (37.5%) correctly reported avoiding contact with cats as the preventive measure of acquiring toxoplasmosis (Table 6). Of the 40 participants, 17(42.5) had a low level of knowledge on toxoplasmosis, while the rest 23 (57.5%) had a high level of knowledge (Figure 3).

Table 6: Knowledge on cause, transmission and symptom, effects and preventive measures of toxoplasmosis (n=40)

Variable	Categories	Respondent n (%)
Causes	Worms	2(5.0)
	Plasmodium	7(17.5)
	Toxoplasma	9(22.5)
	Amoeba	3(7.5)
	I don't know	19(47.5)
Mode of transmission	Contact with infected person	3 (7.5)
	Drinking treated water	3 (7.5)
	Eating raw/undercooked meat	26(65.0)
	Eating food poison	1(2.5)
	Sexual intercourse	2(5.0)
	I don't know	5(12.5)
Symptom	Swollen glands	14(35.0)
	Diarrhoea	3(7.5)
	Legs swelling	6(15.0)
	Nausea	4(10.0)
	I don't know	13(32.5)
Effects	Blindness	1(2.5)
	Eclampsia	1(2.5)
	Anaemia	0(0.0)
	Gestational diabetes	3(7.5)
	Miscarriage	26(65.0)
	I don’t know	9(22.5)
Preventive measures	Avoid eating meat and fruits	6(15.0)
	Avoid contact with cats	15(37.5)
	Avoid hands shaking	4(10.0)
	Avoid drinking untreated water	2(5.0)
	Abstain from sexual intercourse	2(5.0)
	I don't know	11(27.5)

Influence of socio-demographic factors on the levels of the knowledge among the study participants

A high level of knowledge was observed among the women aged 28-33 years, while a low level of knowledge was high among women aged 34-39 years compared to the rest of the age groups. There was a statistically significant association between the age of the participants and the level of education (p = 0.008). A high level of knowledge was observed among the primigravid pregnant women (66.7%) compared to multigravid and pregnant women in the first trimester (61.5%) compared to other trimesters. However, the differences were not statistically significant (Table 7).

Table 7: Influence of socio-demographic factors on the levels of the knowledge among the study participants (n=40)

Variable	Category	Low level (%)	High level (%)	p-value
Age (years)	27	13(56.5)	10(43.5)	0.008*
	28-33	2(13.3)	13(86.7)
	34-39	2(100)	-
	≥ 40	-	-
Marital status	Single	3(75.0)	1(25.0)	0.166
	Divorced/separated	-	-
	Married	14(38.9)	22(61.1)
Occupation	Student	-	1(100.0)	0.934
	Housewife	5(38.5)	8(61.5)
	Peasant	-	-
	Businesswomen	11(47.8)	12(52.2)
	Employed	1(33.3)	2(66.7)
Educational level	None	-	-	0.096
	Primary school	7(63.6)	4(36.4)
	Secondary and above	10(34.5)	19(65.5)
Gravidity	Primigravid	4(33.3)	8(66.7)	0.341
	Multigravid	13(46.4)	15(53.6)
Trimester	First trimester	5(38.5)	8(61.5)	0.849
	Second trimester	6(40)	9(60)
	Third trimester	6(50)	6(50)

* Statistically significant (p < 0.05)

Factors associated with T. gondii seropositivity among the study participants

The results of bivariate logistic regression analysis show that maternal age, presence of a domestic cat at home, eating unwashed fruits, not washing hands with soap after meat preparation, not washing hands with soap after household gardening, consumption raw/undercooked meat, and consumption of raw/undercooked vegetable were significantly associated with T. gondii infection. However, upon adjusting for the confounders, the result of multivariate logistic regression analysis showed that age of 34-39 years (p = 0.004), eating unwashed fruits (p < 0.001), not washing hands with soap after meat preparation (p < 0.001), consumption of raw/undercooked meat (p < 0.001), and consumption of raw vegetable (p < 0.038) were the statistically significant risk factors of T. gondii infection (Table 8).

Table 8: Bivariate and multivariate logistic regression of associated factors with T. gondii seropositivity among pregnant women (n=383)

Variable	Sero status	Univariate		Multivariate
Variable	Sero status	COR (95% CI)	p-value	AOR (95% CI)	p-value
Age
≤ 27	45(21.3)	1		1
28-33	37(31.1)	1.66(1.00-2.77)	0.050	1.86(0.94-3.67)	0.074
34-39	20(45.5)	3.07(1.56-6.06)	0.001*	3.71(1.52-9.06)	0.004*
≥ 40	2(22.2)	1.05(0.21-5.25)	0.949	0.67(0.09-4.94)	0.697
Marital status
Single	9(25.0)	1
Divorced/separated	1(14.3)	0.50(0.05-4.73)	0.546
Married	94(27.6)	1.15(0.52-2.53)	0.735
Occupation
Student	1(25.0)	1
Housewife	42(27.6)	1.15(0.12-11.32)	0.908
Peasant	4(14.8)	0.52(0. 04-6.34)	0.610
Businesswomen	54(28.7)	1.21 (0. 12-11.88)	0.871
Employed	3(25)	1.00 (0.07-13.64)	1.000
Educational level
None	4(28.6)	1
Primary school	55(25.3)	0.85 (0.23-2.82)	0.789
Secondary and above	45(29.6)	1.05 (0.31-3.53)	0.935
Gravidity
Primigravid	21(23.1)	1
Multigravid	83(28.4)	1.32(0.76-2.29)	0.318
Trimester
First trimester	25(31.3)	1
Second trimester	40(26.0)	0.77(0.426-1.40)	0.393
Third trimester	39(29.2)	0.78(0.423-1.42)	0.415
Presence of domestic cat
Yes	27(26.0)	2.71(1.53-4.80)	0.001*	1.90(0.89-4.08)	0.098
No	77(74.0)	1		1
History of cat contact
Yes	18(66.7)	2.57(0.89-7.44)	0.081
No	9(33.3)	1
Eat unwashed fruits
Yes	74(71.2)	11.03(6.55-18.58)	0.000*	7.39(4.00-13.66)	0.000*
No	30(28.8)	1		1
Wash hands after meat preparation
Yes	12(11.5)	1		1
No	92(88.5)	11.10(5.81-21.20)	0.000*	7.53(3.40-16.64)	<0.001*
Wash hands after household gardening
Yes	29(27.9)	1		1
No	75(72.1)	2.80(1.69-4.50)	0.000*	0.90(0.46-1.80)	0.765
Source of drinking water
Tape water	48(46.2)	1
Well water	56(53.8)	1.02(0.65-1.61)	0.922
Mineral bottled water	0(0.0)	0.00(0)	0.999
Boil drinking water
Yes	33(31.7)	1.24(0.76-2.03)	0.387
No	71(63.3)	1
Drinking raw milk
Yes	35(33.7)	1.38(0.85-2.24)	0.194	0.98(0.51-1.90)	0.947
No	69(66.3)	1		1
History of consuming undercooked meat
Yes	82(78.8)	5.60(3.30-9.42)	0.000*	3.75(1.95-7.23)	<0.001*
No	22(21.2)	1		1
History of consuming raw vegetable
Yes	78(75.0)	3.02(1.90-4.99)	0.000*	1.99(1.04-3.80)	0.038*
No	26(25)	1		1
Awareness
Yes	11(27.5)	1.02(0.49-2.12)	0.959
No	29(72.5)	1
Level of knowledge
High	23(57.5)	0.51(0.13-2.07)	0.346
Low	17(42.5)	1

AOR= Adjusted Odds Ratio, COR= Crude Odds Ratio, CI= Confidence interval 1=Reference, *statistically significant (p < 0.05)

In the current study, the overall T. gondii infection rate was 27.2% among the surveyed pregnant women, thus indicating the ongoing transmission in the studied area. The overall seroprevalence was lower than 35%, 30.9%, and 44.6% reported in Dar es Salaam, Mwanza, and Kilimanjaro in Tanzania, respectively (Doehring et al., 1995; Mwambe et al., 2013; Paul et al., 2018). This might be due to differences in food consumption habits, occupation status, age group, sanitary conditions, and urban setting (Murebwayire et al., 2017). The findings showed the majority of surveyed seropositive pregnant women had chronic infection suggesting for either past infection or acquired immunity thus cannot infect their fetus unless they are immune suppressed (Bamba et al., 2017). Less than one percent of the seropositive respondents (0.52%) were positive for IgG and IgM. This observation is in agreement with the findings reported in Ethiopia (Yohanes et al., 2017) but was low compared to that reported in northern Tanzania and Brazil (Gontijo, Vinaud and Castro, 2015; Paul et al., 2018). Availability of the IgM antibodies during pregnancy predicts the presence of acute T. gondii infection that poses a potential risk of maternal-fetal transmission (Yohanes et al., 2017).

The pregnant women aged 34–39 years were three times higher at risk of T. gondii compared to the age group < 27 years. It can be interpreted that one of the three pregnant women above 34–39 years has T. gondii antibodies. Similar to the findings in Mwanza-Tanzania, and Ethiopia (Mwambe et al., 2013; Teweldemedhin et al., 2019). This association does not mean that older age is a risk factor predisposing to T. gondii infection but might be explained that as the age increases, the chances of being exposed is high, and anti-toxoplasma antibodies may retain at a constant level in serum for years. Thus, call for special attention to the screen for anti-toxoplasma antibodies to all older pregnant women attending antenatal services.

The cat is the only definitive host producing feces that contain million of oocysts within a short time and play a critical role in transmitting T. gondii (Musa, 2014; Murebwayire et al., 2017; Yohanes et al., 2017). Though the history of owning a cat increases the risk for toxoplasmosis, this study showed no significant association between cat ownership and T. gondii infection. Fewer cats decrease the risk of transmission to the environment and livestock as well hence reducing the seroprevalence of toxoplasmosis in the local population. This was contrary to other studies reported in Burkina Faso, Egypt and Ethiopia reported a significant association between of presence of cats at home and history of cat contact to T gondii infection (Bamba et al., 2017; Hassanain, Shaapan and Hassanain, 2018; Teweldemedhin et al., 2019).

Eating undercooked meat had been inconsistently reported as a potential risk factor for contracting T. gondii infection in many parts of Africa (Abdelraouf and Eldeek, 2017; Murebwayire et al., 2017; Hassanain, Shaapan and Hassanain, 2018). Pregnant women with habits of eating undercooked meat had 3.7 times increased odds of T. gondii infection compared with their counterparts. This could be explained by the fact that pregnant women in the study area consume barbeque from animals and birds, which is an important food that might contain tachyzoites. This finding is in agreement with studies conducted elsewhere (Alvarado et al., 2016; Abdelraouf and Eldeek, 2017; Bamba et al., 2017; Murebwayire et al., 2017).

An association was found between the consumption of raw vegetables and T. gondii infection, with more than three-quarters of pregnant women (75%) consuming raw vegetables/salads being infected. This is because the raw vegetable (salads) might contain T.gondii oocysts that remain infective for 12 to 24 months under favorable conditions (Achaw et al., 2019). However, our observation was contrary to the finding reported from other studies (Retmanasari et al., 2017; Hassanain, Shaapan and Hassanain, 2018; Achaw et al., 2019). The variation of the current results with others might be due to eating habits and food preparation practices among the studied populations.

Thoroughly washing of fruits before eating is one of the important preventive measures for toxoplasmosis. About one-third (32.6%) of pregnant women were eating unwashed fruits. Pregnant women eating unwashed fruits had 7.3 times increased risk of contracting with T. gondii infection compared to their counterparts. Similar to the findings from Ethiopia (Alvarado-esquivel, Estrada-martínez and Liesenfeld, 2011; Tegegne et al., 2016; Achaw et al., 2019; Teweldemedhin et al., 2019). Also, more than half of the surveyed pregnant women do not wash their hands with soap following raw meat preparation and household gardening to prevent them from contracting with T.gondii infection. The findings show that not washing hands with soap following meat preparation increases 7.5 times more risk of being infected with T. gondii parasites. The cysts from infected meat might be ingested during hand-to-mouth contact following contact with raw/undercooked meat. This is in line with findings from India (Retmanasari et al., 2017).

Regarding awareness on toxoplasmosis, the present study shown that the large majority (89.6%) of the pregnant women were unaware that there is a disease called toxoplasmosis i.e. they never heard, read or saw any information regarding toxoplasmosis. This is due to a lack of health education about the disease when attending antenatal care. Social media was reported as one of the leading sources of toxoplasmosis, and there was a significant association between awareness and the level of education, whereby respondents with secondary and above education were more aware compared to their counterparts. Individual with secondary school and above education acquires a good ability to explore toxoplasmosis knowledge from different sources such as socio media. This finding is in agreement with other authors reported in Malaysia and Brazil (de Moura et al., 2013; Yan, Loganathan and Nimir, 2018).

In the current study, more than half (57.5%) of pregnant women aware of toxoplasmosis had high knowledge. However, close to two-thirds (62.5%) of them did not know the preventive measures. In this study, pregnant women had a high level of knowledge compared to the reports from Nigeria, in which none of the pregnant women was knowledgeable (Dairo, Ogunjimi and Ayinmode, 2018). However, the level of knowledge of the surveyed population was not associated with T. gondii infections. This disagrees with the findings from Cameroon, which reported a high prevalence (68.25%) of the disease among knowledgeable pregnant women compared to none knowledgeable (32.24%) (Retmanasari et al., 2017).

Study limitations

The study had the following limitations, the inability to follow up on the trend regarding IgG antibody titers for at least two months to confirm congenital toxoplasmosis. The use of serological diagnosis without molecular technique could have underestimated the prevalence of T. gondii. In addition, obtaining retrospective information from the participants could be subjected to recall bias.

The current study showed a seroprevalence of T. gondii infection among pregnant women in Ilala Municipality in Dar es Salaam was 27.2%. The main risk factors for transmission in the study area were increasing maternal age, eating unwashed fruits, lack of handwashing following meat preparation, consumption of undercooked meat, and consumption of raw vegetables. Therefore, we recommend regular screening of toxoplasmosis among pregnant women attending antenatal care. Provision of health education to pregnant women attending antenatal care enhances awareness and knowledge on toxoplasmosis preventive measures. In addition, the burden of maternal and congenital toxoplasmosis should be established using avidity tests and molecular techniques to advise policymakers on the need to establish toxoplasmosis control programs.

IgG

Immunoglobulin G

IgM

Immunoglobulin M.

MNH

Muhimbili National Hospital.

MUHAS

Muhimbili University of Health and Allied Sciences.

PPS

Probability Proportional to Size

Ethical approval and consent to participate

This study received ethical clearance from the Muhimbili University of Health and Allied Sciences Institutional Review Board with the approval number IRB#: MUHAS-REC-07-2020-390. Signed informed consent was obtained from each study participant before blood collection, and the collected information was kept confidential.

Consent for publication

No identifying personal or clinical details of the participants are presented that compromise anonymity.

Availability of data and materials

The data sets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Competing interest

The authors declare that they have no competing interests.

Funding

The authors disclosed receipt of the following financial support for the research; the Liverpool John Moores University Global Challenge Research Fund Internal Grants Scheme and the Ministry of Health, Community Development, Gender, Elderly and Children (MoHCDEC) (Tanzania).

Authors’ contributions

ML and DT designed the study, ML and EB collected the data, ML, VM, and EB did data analysis, interpretation of the findings, and manuscript drafting, DT revised the manuscript. All authors have read and approved the final version of the manuscript.

Acknowledgments

We would like to thank staff members of sample collection sites for their cooperation during data collection. We are grateful to Muhimbili National Hospital staff for their cooperation during laboratory work. We also acknowledge the study participants for their willingness to participate.

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Seroprevalence of Toxoplasma gondii and associated risk factors among pregnant women attending antenatal care in Ilala Municipality, Dar es Salaam, Tanzania

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Abstract

Figures

Background

Methods

Ethical consideration

Study design and settings

Study population

Sample size determination and sampling procedures

Data collection tool

Blood collection and serological analysis

Data analysis

Results

Socio-demographic characteristics of the study participants

Seroprevalence of T. gondii infection among pregnant women

Influence of socio-demographic characteristics on T. gondii infection

The risk factors for the T. gondii infection among the pregnant women

Awareness of toxoplasmosis among the study participants

Influence of socio-demographic characteristics on the awareness of toxoplasmosis among the study participants

Knowledge on the toxoplasmosis among the pregnant women

Factors associated with T. gondii seropositivity among the study participants

Discussion

Study limitations

Conclusions

Abbreviations

Declarations

References

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