The theme of World TB Day is to Unite to end TB: leave no one behind. The communities affected by TB are also ones where tropical diseases like onchocerciasis and malaria are endemic. A successful strategy to control one disease should ideally be “united” with all basic primary health care interventions, thereby truly leaving no one behind.
While the causative agents differ between TB and tropical diseases such as malaria, lymphatic filariasis and Dengue, control of these diseases shares a common goal – “an urgent need to develop new vaccines for HIV/AIDS, malaria, and tuberculosis, as well as for respiratory syncytial virus and those chronic and debilitating (mostly parasitic) infections known as neglected tropical diseases (NTDs).” In addition to prevention, there is also need for integrated “treatment pipelines directed at NTDs, Malaria, tuberculosis (TB), and human immunodeficiency virus (HIV)/AIDS,” according to Asada.
There is also a need for integrated primary health care (PHC) programming. In the Journal of Infectious Diseases. Simon reports on linkages showing that, “Recent research suggests that NTDs can affect HIV and AIDS, tuberculosis (TB), and malaria disease progression. A combination of immunological, epidemiological, and clinical factors can contribute to these interactions and add to a worsening prognosis for people affected by HIV/AIDS, TB, and malaria.”
The possibility of integrating directly observed treatment (DOT) for TB treatment into community health worker (CHW)/PHC programs that addressed malaria treatment and onchocerciasis control was tested by the Tropical Disease Research Program (TDR) some years ago. CHWs in a few of the study sites were able to successfully include DOT for TB in their community duties, but in other sites community and health worker fears about stigma inhibited action.
TB, malaria and NTDs are among the conditions referred to as the infectious diseases of poverty. We will not eliminate poverty by tackling these diseases one-by-one. A “United” and integrated approach from national to community level is needed.
Typical of our big disease mindset, most donor agencies think of HIV-Tuberculosis coinfection when addressing a connection among the three Global Fund diseases. Take as an example a recent News Flash from the Global Fund: “In a major step toward addressing the growing number of people affected by co-infection with tuberculosis and HIV, the Global Fund is improving the way it approaches treatment programs in countries with high rates of each disease. Millions of people infected with both TB and HIV could benefit from better services.”
The possible neglect of TB and malaria interactions might be understood by the fact that HIV and TB have much wider areas of endemicity than malaria. On the other hand both HIV and TB are disproportionately represented in malaria endemic Africa. At present the main connection between malaria and TB is the fact that they must share out of the same ‘envelope’ when new Global Fund support is distributed through the new funding mechanism to countries, a process that some see as moving more toward donor control and AID effectiveness and away from human rights.
Today the Stop-TB Partnership and related organizations are observing World TB day by noting that at least one-third of newly infected people will not get appropriate treatment. Poor access to or inadequate and inappropriate treatment plagues all three diseases, especially where health systems are weak. We need an integrated approach to strengthen systems and improve care.
In the meantime, researchers have maintained interest in possible interactions between TB and malaria. For example Ann-Kristin Mueller and colleagues have published a study entitled, “An Experimental Model to Study Tuberculosis-Malaria Coinfection upon Natural Transmission of Mycobacterium tuberculosis and Plasmodium berghei,” using a mouse model. A slide presentation on their work is also seen at the website. As Mueller notes, “Concurrent infections most likely modulate the respective immune response to each single pathogen and may thereby affect pathogenesis and disease outcome. Coinfected patients may also respond differentially to anti-infective interventions.”
Mueller puts is mildly when she says that TB-malaria coinfection “has not been studied in detail.” We might need to step back in time over 2900 years where according to Lalremruata and colleagues, “the notion that the agricultural boom and dense crowding occurred in this region (southwest of modern Cairo), especially under the Ptolemies, highly increased the probability for the manifestation and spread of tuberculosis. Here we extend back-wards to ca. 800 BC new evidence for malaria tropica and human tuberculosis co-occurrence in ancient Lower Egypt.”
In a 2013 review on “Co-infection of tuberculosis and parasitic diseases in humans,” Xin-Xu Li and Xiao-Nong Zhou found only two direct reports of malaria and TB co-infection, one a case report from 1945 and the other on host response in malaria and depression of defense against tuberculosis from 1999.
Finally a review of hospital records from 2007 in Luanda, Angola found that Malaria was diagnosed during admission and hospital stay in 37.5% of TB patients. Clearly the time has come to take coinfection seriously as both a research and service delivery topic.