Letter to the editor
To Deworm or not to Deworm: that is the question M. Townsend Cooper, Jr. Director of Medical Ministries, Anglican Diocese of Peru
I am writing to comment on your article in the March issue (Pathogens in Global Health Volume 107 Issue No.2) titled ‘Factors associated with parasitic infection amongst street children in orphanages across Lima, Peru’ by Bailey, et al. I am a pediatrician working for the Anglican Church in health programs that span the entire city of Lima. I was thrilled to see an article that addresses actual data of parasite frequency among marginalized populations in Lima. There is quite a bit of data regarding parasite incidence in general in Peru, but as evidenced by the references of the article, there has been a relative paucity of zonal data for the city of Lima. When present, this data seems to vary significantly, as in this article, the cited 2006 article (Iannaconne, et al, 2006), and an article by the same author in 2007 (Iannaconne, et al, 2007), a situation that calls for further investigation and definition of the problem. The data from the March study almost exactly matches our internal data gathered from regions as geographically disparate as San Juan de Miraflores in the southern cone of the city and Ventanilla in the northern cone of the city. The important point regarding this variation is that the different data indicate different answers to an important question: Should we initiate and/or support standardized programs to combat intestinal helminthes in the Lima metropolitan area? The World Health Organization recommendations on this point are clear, with 20% incidence as the accepted threshold for single dose treatment with albendazole for T. Trichura, A. duodenolae/N. Americanus, and A. lumbriciodes (Preventative Chemotherapy in Human Helminthiasis, WHO 2006). There are then different frequencies recommended based on the levels above this threshold. The numbers for the country of Peru as a whole meet the WHO threshold, but most of the data from Lima does not. Among numerous NGOs and even many government clinics, ‘deworming’ programs are the accepted policy, normally using a single treatment albendazole, 400 mg. A question that is alarmingly missing from such practice is - What are we treating when we do this? The answer seems to be: not much.
ß W. S. Maney & Son Ltd 2013 DOI 10.1179/2047772413Z.000000000156
As noted in the study, the most frequent pathogenic organism is G. Lamblia. While a longer course of albendazole has shown to be effective for G. Lamblia, a single dose treatment is ineffective, and it is unlikely that blanket treatment for this pathogenic protozoan would be effective anyway due to the high rate of re-infection in the absence of other extensive interventions. It was disappointing in the discussion section that the intestinal helminthes were not further subcategorized into intestinal nematodes and intestinal cestodes. The treatment for the two is fundamentally different. The nematodes respond to treatment with standard albendazole, but the cestodes (specifically H. nana in this case) are treated with praziquantel, a relatively expensive medicine that is used in mass deworming for schistosomiasis and in treatment of other parasitic disease. Thus, the total ‘intestinal helminth’ figure listed was deceptively high for assessing the need for implementing a deworming program. The susceptible helminthes for an albendazole program (nematodes) were only at about 8%. As stated, the threshold for standard deworming for these pathogens sits at 20% according to the World Health Organization. Anywhere below this number, individual treatment is the standard. While Peru’s numbers in general may be above the WHO standard, these are numbers that also include the mountains, and more importantly, the jungle, where the soil transmitted nematode rate would be much higher. The city of Lima represents a much different incidence and deserves very different consideration when instituting treatment protocols. What are the downsides of indiscriminate use of albendazole, a relatively safe medicine? The obvious possible drawbacks include adverse reactions (admittedly low with this medicine) and resource wastage. However, there is a more subtle problem as well. If we are focused on the wrong pathogen (i.e. the wrong problem), then both the medical community and the individual patients and families risk not focusing on the correct problems, which are many.
Pathogens and Global Health
2013
VOL .
107
NO .
6
281
In the interest of reasonable resource utilization for marginalized populations, it is imperative to further define the pathogenic problems for the microcommunities of Lima. I applaud the authors for their contribution to the discussion, and I look forward to further scientific inquiry into optimal approaches for treatment and resource allocation.
References: 1 Bailey, C., Lopez, S., Camero, A., Taiquiri, C., Arhuay, Y., & Moore, D. (2013). Factors associated with parasitic infection
282
Pathogens and Global Health
2013
VOL .
107
NO .
6
amongst street children in orphanages across Lima, Peru. Pathogens in Global Health, 107 (2), 52–57 2 Iannaconne, J., & Alvarin˜o, L. (2007). Helmintos intestinales en escolares de Chorrillos y Pachacamac, Lima, Peru´. Biologist (Lima), 5 (1), 27–34 3 Iannaconne, J., Benites, M. J., & Chirinos, L. (2006). Prevalencia de infeccio´n por para´sitos intestinales en escolares de primaria de Santiago de Surco, Lima, Peru´. Parasitologı´a´ Latinoamericana. 2006; 1–2 (61), 54– 62. 4 World Health Organization. (2006). Preventive Chemotherapy in human helminthiasis : coordinated use of antihelminthic drugs in control interventions : a manual for health professionals and programme managers. Geneva, Switzerland.
To Deworm or not to Deworm: that is the question M. Townsend Cooper, Jr. Director of Medical Ministries, Anglican Diocese of Peru
I am writing to comment on your article in the March issue (Pathogens in Global Health Volume 107 Issue No.2) titled ‘Factors associated with parasitic infection amongst street children in orphanages across Lima, Peru’ by Bailey, et al. I am a pediatrician working for the Anglican Church in health programs that span the entire city of Lima. I was thrilled to see an article that addresses actual data of parasite frequency among marginalized populations in Lima. There is quite a bit of data regarding parasite incidence in general in Peru, but as evidenced by the references of the article, there has been a relative paucity of zonal data for the city of Lima. When present, this data seems to vary significantly, as in this article, the cited 2006 article (Iannaconne, et al, 2006), and an article by the same author in 2007 (Iannaconne, et al, 2007), a situation that calls for further investigation and definition of the problem. The data from the March study almost exactly matches our internal data gathered from regions as geographically disparate as San Juan de Miraflores in the southern cone of the city and Ventanilla in the northern cone of the city. The important point regarding this variation is that the different data indicate different answers to an important question: Should we initiate and/or support standardized programs to combat intestinal helminthes in the Lima metropolitan area? The World Health Organization recommendations on this point are clear, with 20% incidence as the accepted threshold for single dose treatment with albendazole for T. Trichura, A. duodenolae/N. Americanus, and A. lumbriciodes (Preventative Chemotherapy in Human Helminthiasis, WHO 2006). There are then different frequencies recommended based on the levels above this threshold. The numbers for the country of Peru as a whole meet the WHO threshold, but most of the data from Lima does not. Among numerous NGOs and even many government clinics, ‘deworming’ programs are the accepted policy, normally using a single treatment albendazole, 400 mg. A question that is alarmingly missing from such practice is - What are we treating when we do this? The answer seems to be: not much.
ß W. S. Maney & Son Ltd 2013 DOI 10.1179/2047772413Z.000000000156
As noted in the study, the most frequent pathogenic organism is G. Lamblia. While a longer course of albendazole has shown to be effective for G. Lamblia, a single dose treatment is ineffective, and it is unlikely that blanket treatment for this pathogenic protozoan would be effective anyway due to the high rate of re-infection in the absence of other extensive interventions. It was disappointing in the discussion section that the intestinal helminthes were not further subcategorized into intestinal nematodes and intestinal cestodes. The treatment for the two is fundamentally different. The nematodes respond to treatment with standard albendazole, but the cestodes (specifically H. nana in this case) are treated with praziquantel, a relatively expensive medicine that is used in mass deworming for schistosomiasis and in treatment of other parasitic disease. Thus, the total ‘intestinal helminth’ figure listed was deceptively high for assessing the need for implementing a deworming program. The susceptible helminthes for an albendazole program (nematodes) were only at about 8%. As stated, the threshold for standard deworming for these pathogens sits at 20% according to the World Health Organization. Anywhere below this number, individual treatment is the standard. While Peru’s numbers in general may be above the WHO standard, these are numbers that also include the mountains, and more importantly, the jungle, where the soil transmitted nematode rate would be much higher. The city of Lima represents a much different incidence and deserves very different consideration when instituting treatment protocols. What are the downsides of indiscriminate use of albendazole, a relatively safe medicine? The obvious possible drawbacks include adverse reactions (admittedly low with this medicine) and resource wastage. However, there is a more subtle problem as well. If we are focused on the wrong pathogen (i.e. the wrong problem), then both the medical community and the individual patients and families risk not focusing on the correct problems, which are many.
Pathogens and Global Health
2013
VOL .
107
NO .
6
281
In the interest of reasonable resource utilization for marginalized populations, it is imperative to further define the pathogenic problems for the microcommunities of Lima. I applaud the authors for their contribution to the discussion, and I look forward to further scientific inquiry into optimal approaches for treatment and resource allocation.
References: 1 Bailey, C., Lopez, S., Camero, A., Taiquiri, C., Arhuay, Y., & Moore, D. (2013). Factors associated with parasitic infection
282
Pathogens and Global Health
2013
VOL .
107
NO .
6
amongst street children in orphanages across Lima, Peru. Pathogens in Global Health, 107 (2), 52–57 2 Iannaconne, J., & Alvarin˜o, L. (2007). Helmintos intestinales en escolares de Chorrillos y Pachacamac, Lima, Peru´. Biologist (Lima), 5 (1), 27–34 3 Iannaconne, J., Benites, M. J., & Chirinos, L. (2006). Prevalencia de infeccio´n por para´sitos intestinales en escolares de primaria de Santiago de Surco, Lima, Peru´. Parasitologı´a´ Latinoamericana. 2006; 1–2 (61), 54– 62. 4 World Health Organization. (2006). Preventive Chemotherapy in human helminthiasis : coordinated use of antihelminthic drugs in control interventions : a manual for health professionals and programme managers. Geneva, Switzerland.
