HIV-positive caregivers in the US often feed infants pre-chewed food, a possible mode of HIV transmission

Premastication of food for infants is a common practice among HIV-infected caregivers, US investigators report in the online edition of the Journal of Acquired Immune Deficiency Syndromes. Overall, a third of HIV-positive mothers and other HIV-infected care providers gave food which they had pre-chewed to infants.

“This is the first epidemiological investigation to assess the risk of HIV infection from receiving premasticated food or to characterize the details of premastication…in HIV-affected families across several pediatric HIV clinical care sites in the US, including Puerto Rico,” write the authors. “Conducting the study in multiple sites allowed us to more broadly assess the child feeding practices in diverse geographical and cultural settings.”

Three cases of HIV transmission to infants via premastication have been reported in the US. Therefore, to prevent possible transmission of the virus, HIV-positive caregivers in the US are recommended not to feed their infants pre-chewed food.

However, the prevalence of premastication among HIV-positive caregivers in industrialised countries has received little attention.

Therefore investigators from the US Centers for Disease Control (CDC) designed a case-controlled study to assess the risk of HIV transmission presented by premastication. They also conducted a cross-sectional investigation involving the caregivers of HIV-exposed children to assess the prevalence of premastication.

A total of eleven HIV-infected infants and 35 HIV-exposed but uninfected infants were included in the case-controlled study. All received care in late 2009 at paediatric HIV clinics in the US. The mothers were interviewed about their demographics, premastication habits, oral health, breastfeeding behaviours and other possible modes of HIV transmission to their infants.

Almost all the participants were African American. The median age of the infants at the time of interview was between 75 and 90 months.

A total of 27% of HIV-infected children were fed premasticated food compared to 20% of the controls. However, this difference lacked significance. The investigators believe this is because of the study’s small sample size.

An oral health condition that could involve the contamination of pre-chewed food to blood was present in 18% of the caregivers of the HIV-infected children and 6% of controls. However, HIV-infected infants were no more likely than HIV-negative children (27% vs. 34%) to have an oral condition that could facilitate the transmission of HIV via premasticated food.

None of the case patients or the controls was breastfed. Nor were there any cases of sexual abuse in the HIV-infected children.

The cross-sectional study involved 155 HIV-positive caregivers who were recruited at nine HIV clinics in the US and Puerto Rico in late 2009 and early 2010. All their infants were aged six months and over. The majority of the caregivers were the biological mothers of the infants in their care (80%). Most were African American (68%) and 21% were Hispanic or Latino.

A total of 31% of infants were fed premasticated food either from the primary caregiver of someone else. Premastication was more common among younger than older caregivers (under 19 years = 44% vs. over 40 years = 13%).

Premasticated food was provided to infants as young as one month and as old as 36 months.

The caregivers who reported feeding pre-chewed food to infants were asked about the frequency of this behaviour. Thirty-nine percent reported that it occurred one to three times a week and 37% said that it occurred over four times each week.

Meat was the food most commonly premasticated (80%), followed by fruits (39%), vegetables (37%) and sweets (30%).

Reasons for feeding pre-chewed food to infants included “child wanted some of the caregiver’s food” (64%); “caregiver did not want the child to choke” (62%); “pre-chewing is done in my family” (31%). Only 4% reported pre-mastication because they did not have appropriate baby food.

“Premastication was a common practice among caregivers of HIV-exposed infants in the cross-sectional study,” comment the investigators. “Therefore premasticaiton…presents a risk of HIV transmission to children in their care.”

The investigators acknowledge that the findings of their research are limited by the small size of the samples. They therefore call for further research “to determine the relative contribution of…HIV transmission risks associated with premastication versus breastfeeding and other modes of transmission.”

They conclude, “public health officials should continue to educate caregivers and healthcare providers about the risk of disease transmission, including HIV infection, via premastication.”