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  • Transmission of HIV from infants to women who breastfeed them.

    Posted on July 1st, 2012 admin No comments

    This title may surprise some.   In a paper (abstract, below) from a group at CDC I learned yet another HIV/AIDS related acronym.  It’s CBWT, Child-to-Breastfeeding-Woman Transmission.

    There have been several reports over many years of HIV infected infants born to mothers who were HIV uninfected.   These infections were noted as early as the late 1980s in the former Soviet Union, in Libya in 1998, in Kyrgyzstan, Kazakhstan, Romania as well as in Africa.   In every instance except in Africa, there cases were investigated with varying degrees of thoroughness.   The sources of infection were invariably associated with contaminated blood,   either from transfusions, or from procedures in unsafe healthcare settings, where for example sterilization of instruments is inadequate, or injection equipment is reused.

    The infections noted in infants that were investigated occurred as outbreaks and all were determined to be nosocomial.    Although infected infants born to uninfected mothers have been noted in Africa, remarkably, it appears that none have been investigated.

    It will probably remain for a future historian to understand why cases of HIV infection in infants, horizontally rather than vertically transmitted, have yet to be investigated in Africa.

    In those non-African outbreaks that were investigated transmission occurred through unsafe medical care, so what do we know of the safety of health care facilities in Africa ?

    Unfortunately unsafe health care remains a problem in many facilities in high prevalence areas in Africa.

    Taking Kenya as an example, Simon Colley has written in one of my blogs

    “Where does Kenya fit into this picture? As UNAIDS admit, there’s not much data. But there is a document called the Service Provision Assessment which looks at conditions in various kinds of health facility, such as hospitals, clinics and pharmacies.

    A few samples from this document may suffice to illustrate Kenya’s women capacity to prevent HIV transmission through unsafe injections and other healthcare practices: Between 10 and 15% of facilities don’t have adequate supplies of needles, syringes or latex gloves; between 55 and 70% don’t have running water or soap; many don’t have facilities for disposing of contaminated equipment or supplies of disinfectant; less than half have guidelines for infection prevention and less than 10% have guidelines for sterilization.

    Although this document dates from 2004, we don’t know if there has been any change

    There’s little doubt that unsafe health care is still a problem in Kenya and other high HIV prevalence countries. What’s not clear is how big a problem it is. Because, despite admitting that they don’t have the sort of data on unsafe health care that would allow an estimate to be made, UNAIDS and the WHO have failed to investigate or to carry out the research required”

    This is a table taken from the Service Provision Assessment  that speaks for itself.

    .

    As the title of this post indicates, infants infected either vertically or through exposure to contaminated blood are able to transmit HIV to seronegative women who breast feed them.

    Mother to child transmission is the leading cause of HIV infection in infants. Some of these infected infants will be orphans and so place seronegative women who breastfeed them at risk.  Wet-nursing is the complete nursing of another woman’s infant and still occurs as does cross-nursing which is the nursing of another infant by a woman  while still nursing her own child.  Estimates of the prevalence of these practices vary by region and the overall prevalence is not known.

    Worldwide the greatest risk for CBWT is carried by seronegative mothers whose infants become infected through exposure to contaminated blood.  Rates of CBWT were as high as 40-60% among mothers  breastfeeding infants who became infected after birth.

    This report on CBWT highlights the importance of unsafe health care facilities in the transmission of HIV.   Of course HIV is not the only pathogen that can be transmitted in such settings.

    Why so few resources have been devoted to the improvement of health care facilities in developing nations is puzzling.  Could it be that like the provision of clean water and sanitation, improving health care facilities is not something that can generate much profit?

    Perhaps it will be left to HIV activists who have successfully drawn public attention to other neglected issues, to alert funders and policy makers to the dangerous condition of many healthcare facilities in the developing world.

    The benefits of improving infection control in these facilities extend far beyond effects in HIV transmission.

    A group of individuals have been trying to bring attention to this issue for many years and I do recommend looking at the website they have created to directly alert people in Africa to dangers in health care facilities with no or poor infection control procedures.

    (1)

    A Review of Evidence for Transmission of Human Immunodeficiency Virus from Children to Breastfeeding Women and Implications for Prevention.

    Kirsten M Little, Peter Kilmarx, Allan Taylor, Charles Rose, Emilia Rivadeneira. And Steven Nesheim.

    The Pediatric Infectious Disease Journal Publish ahead of print.

    DOI:10.1097/INF.0b013e318261130f

    Abstract

    Background: Child-to-Breastfeeding-Woman Transmission (CBWT) of HIV occurs when an HIV-infected infant transmits the virus to an HIV-uninfected woman through breastfeeding. Transmission likely occurs as a result of breastfeeding contact during a period of epithelial disruption, such as maternal skin fissures and/or infant stomatitis. Despite extensive epidemiologic and phylogenetic evidence, however, CBWT of HIV continues to be overlooked.

    Objective: This paper summarizes the available evidence for CBWT from nosocomial outbreaks, during which nosocomially HIV-infected infants transmitted the virus to their mothers through breastfeeding. This paper also explores the CBWT risk associated with HIV-infected orphans and their female caretakers, and the lack of guidance regarding CBWT prevention in infant feeding recommendations.

    Methods: We searched online databases including PubMed and ScienceDirect for English language articles published from January 1975 to January 2011 using the search terms “HIV”, “perinatal”, “child-to-mother”, and “breastfeeding”. The citations from all selected articles were reviewed for additional studies.

    Results: We identified five studies documenting cases of CBWT. Two studies contained data on the number of HIV-infected women, as well as the proportion breastfeeding. Rates of CBWT ranged from 40 – 60% among women reporting breastfeeding after their infants were infected.

    Conclusions: Poor infection control practices, especially in areas of high HIV prevalence, have resulted in pediatric HIV infections and put breastfeeding women at risk for CBWT. Current infant feeding guidelines and HIV prevention messages do not address CBWT, and fail to provide strategies to help women reduce their risk of acquiring HIV during breastfeeding.

  • AIDS Origins.

    Posted on September 30th, 2010 admin No comments

    Unsafe medical practices in equatorial Africa fifty to eighty years ago probably helped to set in motion an epidemic of hepatitis C infection.

    Two articles in the current issue of Clinical Infectious Diseases show that injections for the treatment and prevention of endemic diseases highly prevalent in parts of the Central African Republic and Cameroon were probably responsible for the spread of the hepatitis C virus and of human T lymphotropic virus 1 (HTLV-1).

    Human African Trypanosomiasis more familiarly known as sleeping sickness is spread by the bite of the tsetse fly and is almost invariably fatal if untreated.  It is a horrible disease.  This video will give some idea of its impact1.

    Sleeping sickness was highly prevalent in south-eastern regions of the Central African Republic.

    It was treated with intramuscular injections of pentamidine after about 1946 until 1950.  Before 1946, subcutaneous or intravenous injections of another drug, orsanine, had been used.  If there was central nervous system involvement treatment consisted of 12 weekly intravenous injections of yet another drug,  tryparsamide.   Injections of pentamidine were also used at a population level to prevent infection.   Intramuscular injections were given twice a year between 1947 and 1953.

    In Cameroon, the risk of acquiring hepatitis C was associated with the intravenous administration of quinine to treat malaria.   Other possibilities for transmission 50-80 years ago include intravenous injections to treat syphilis or yaws, and   blood transfusions.

    Re-usable equipment was all that was available at that time.  Disposable needles and syringes had not yet been introduced.   Much less information would have then been available about how easily infectious agents can be transferred by contaminated injection equipment.

    The relevance to HIV is that the rural areas in the south east of the Central African Republic and the southern Cameroon are close to the sites where SIVcpx has been isolated from chimpanzees.   This virus is believed to be the precursor of HIV-1.

    The HIV-1 and HIV-2 epidemics originated from cross species jumps from two different non-human primates.  Attempts have been made, in the case of HIV-1, to pinpoint in time when the fateful transfer occurred, as if it were a unique event, rather than something that has probably happened countless times.  Cross species transmission of some viruses may in fact be quite efficient.  Simian foamy virus (SFV) causes absolutely  no ill effects in humans, but about 25% of people reporting a monkey bite or scratch in Cameroon  have evidence of SFV infection.

    Man and other primates have been living in proximity in Africa for millennia, so cross species transfer of viruses will have been frequent.

    The “why now” question about the HIV epidemic is not about when the species jump occurred, but about when conditions were such that widespread human to human infection became likely enough to start an epidemic.    It’s just not plausible that two unique events, the jump of HIV-1 and HIV-2, each from two different primate species occurred in the same time frame.

    Conditions that enabled the widespread transmission of HIV between humans probably resulted from a multiplicity of factors coming together at the same time.  But part of the puzzle may be explained by unsafe medical practices 50 to 80 years ago in regions of Africa where SIVcpz has been found.   What may have been fateful was not a unique monkey to human transmission but that something that happens repeatedly    was occurring at a particular time and place where further spread between humans was facilitated to a greater or lesser extent by unsafe medical practices.

    In previous posts about the pathogenesis of HIV disease I have frequently pointed out the relevance of some endemic infections in Africa to HIV disease.   Some of these infections, by contributing to immune activation will enhance HIV replication, and it seems reasonable that infectivity will increase because of greater viral loads.   So this is yet an additional factor favouring the spread of HIV.  The regions of the Central African Republic and Cameroon mentioned above carry a particularly heavy burden of endemic infections associated with immune activation.

    Are unsafe medical practices a thing of the past?

    Do we no longer need to be concerned that they may contribute to the spread of HIV infection?

    Simon Collery works in development in Kenya.  He is in a position to address the issue of the safety of medical practices from the field.

    The following was written by Simon Collery:

    I have been studying the spread and decline of HIV through Kenya for seven years, using any relevant material I can find, whether it be medical, scientific, economic, geographical or administrative. Part of the picture I have of the epidemic in Kenya is drawn from this research.

    Another part of the picture derives from living and working in Kenya, and also some time in Tanzania and Uganda, for three years, talking with people, observing, writing, discussing and reasoning.

    My tentative conclusions are that, despite being extremely poor, having a very high disease burden, low levels of education, terrible healthcare, crumbling infrastructure, long periods of food insecurity and many other adverse conditions, Kenyans are much like people from other countries.  That may not sound like a very profound conclusion until you compare it to assumptions that are frequently made that Africans have a great deal of sex much of it being unsafe.

    On the other hand when it comes to health care facilities Kenyans are exposed to conditions that are vastly different to those experienced by people living in the developed world.

    Let’s look at Kenya in more detail. Overall prevalence of HIV infection is about 7%, but in North Eastern Province it’s less than 1%, about a third of the level found in Washington DC. But in the poorest province, the one with the highest rates of poverty, the lowest levels of education, the least access to health services and some of the highest rates of ‘unsafe’ sexual behaviour, you also find the lowest prevalence of HIV.

    In contrast, the highest rates of HIV are found among one tribe, the Luo, many of whom depend on the fast declining fishing industry around Lake Victoria. Prevalence there is 20% or higher, closer to rates found in the highest prevalence countries in the world, such as Swaziland or Lesotho.

    Many aspects of sexual behaviour in the Luo area are similar to what you’d find in other areas, in Kenya and elsewhere.

    HIV is not just about sex. Therefore, reducing HIV transmission should consist of more than education to reduce sexual transmission.

    When it comes to non-sexual transmission of HIV, such as transmission through unsafe injections, UNAIDS does not say very much, merely referring to their statement that 70 -90% of transmissions result from heterosexual sex.

    How did they work out that HIV transmission from unsafe injections in Kenya probably only contribute between 0.6 and 2% of infections? The question is pertinent considering the same report that includes this table, admits that there is very little information available on injection safety and that it is difficult to get baselines.

    The World Health Organization gives a slightly different story . They estimate that, worldwide, up to 40% of injections are unsafe, because needles and syringes are reused without sterilization. In some countries this figure can be as high as 70%. They also estimate that about 70% of injections are unnecessary or the drug could be administered orally. These phenomena give rise to over one third of hepatitis B and C infections and between 2% and 9% of HIV infections.

    Where does Kenya fit into this picture? As UNAIDS admit, there’s not much data. But there is a document called the Service Provision Assessment which looks at conditions in various kinds of health facility, such as hospitals, clinics and pharmacies.

    A few samples from this document may suffice to illustrate Kenya’s capacity to prevent HIV transmission through unsafe injections and other healthcare practices: Between 10 and 15% of facilities don’t have adequate supplies of needles, syringes or latex gloves; between 55 and 70% don’t have running water or soap; many don’t have facilities for disposing of contaminated equipment or supplies of disinfectant; less than half have guidelines for infection prevention and less than 10% have guidelines for sterilization.

    Although this document dates from 2004, we don’t know if there has been any change.

    Here is part of a table from the report:

    There’s little doubt that unsafe health care is still a problem in Kenya and other high HIV prevalence countries. What’s not clear is how big a problem it is. Because, despite admitting that they don’t have the sort of data on unsafe health care that would allow an estimate to be made, UNAIDS and the WHO have failed to investigate or to carry out the research required.

    While sexual transmission may be the predominant mode of HIV transmission, non-sexual transmission is significant and neglected.  What is inescapable is that, if we truly care about the health of populations, the conditions of health care facilities in many parts of the world are completely unacceptable, as shown in the WHO report above.  These conditions pose a danger of acquiring not only HIV, but of many other infectious diseases.

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    1:  This video was made in the Democratic Republic of Congo where in some regions the prevalence of trypanosomiasis exceeds that of HIV.  Although HIV replication can be enhanced by many endemic infections In Africa, trypanosomiasis may be one that could exert an inhibitory effect.

    This was also posted to my POZ blog site.