Earthquake in Haiti: is the Latin American and Caribbean region’s highest tuberculosis rate destined to become higher?

Keywords::

• disasters
• earthquakes
• Haiti
• national health programs
• public health
• tuberculosis

Haiti carries many titles: the Western hemisphere’s second oldest republic, the first country in the hemisphere to abolish slavery and the world’s first post-colonial state. Unfortunately, in recent years it has also been the Western hemisphere’s poorest country. It has the highest HIV burden in the hemisphere (2.2% of adults 18–49 years of age in 2007), and the highest TB notification rate in the Latin American and Caribbean region: 161 new sputum smear-positive cases per 100,000 population in 2007 [101,102]. On January 12 2010, an earthquake destroyed most of the existing infrastructure of the capital city, Port-au-Prince. It would seem obvious that a horrific natural disaster of this magnitude must result in an increased toll of infectious diseases, including TB. But is this necessarily true? Must all nations confronted by natural disasters or other catastrophes experience worsening TB epidemics?

Historical perspective: TB, military conflict & complex emergencies

As early as 1918, it was recognized that disruption of social infrastructure hampered TB control [1]. Even in the pre-antimicrobial era, the effects of war on malnutrition, overcrowding and resources for TB management were appreciated. Subsequently, several reports have examined the impact of humanitarian crises on population susceptibility and TB control programs [2–7]. Complex emergencies (or humanitarian emergencies) are distinguished from natural disasters in that the former are characterized by a ‘total or considerable breakdown of authority resulting from internal or external conflict that requires an international response’ [8]. Common elements of such complex emergencies include population displacement and breakdown of social and economic infrastructure – all of which are important determinants of health, including TB control.

There is evidence that TB rates increase during military conflicts. Several reports following World Wars I and II demonstrated an increase in the incidence and mortality from TB [3–5]. For example, comparison of data from the Netherlands pre- and post-World War II occupation reveals a 77% increase in TB cases and a 66% increase in TB deaths. Barr and Menzies reviewed the literature on TB during wartime (including the World Wars) and observed a consistent increase in morbidity and mortality from TB [2]. However, more recent conflicts have had a variable impact on TB burden. Drobniewski and Verlander reviewed data on TB notification rates during 36 conflicts between 1975 and 1995 [6]. While overall crude rates increased from 81.9 to 105.1 per 100,000 population pre- and post-conflict, respectively, there was heterogeneity among countries, with India and Afghanistan accounting for the bulk of excess cases. More recently, the 1999 conflict in the Democratic Republic of Timor-Leste coincided with a threefold increase in smear-positive TB cases [9].

TB & natural disasters

In contrast to the literature on TB and conflicts, data associating natural disasters with TB incidence are nearly non-existent. More broadly, some authors have questioned the assertion that natural disasters are associated with epidemics of infectious diseases. Spiegel and colleagues found that complex emergencies were more likely than natural disasters to be associated with epidemics [8]. A review by Floret and colleagues found only three reports of epidemics emerging in the short-term wake of the 600 geophysical disasters they examined between 1985 and 2004, none of them TB [10]. Chapin and colleagues systematically sampled Peruvian health facilities following the 2007 Ica earthquake [11]. During the brief follow-up period of 6 months, TB rates were similar to those seen before the earthquake. Our own literature search did not yield any examples of worsening of TB incidence following natural disasters.

However, there are significant challenges inherent to quantifying the health effects of complex emergencies. These crises vary in severity and duration, as well as in their impact on public health infrastructure. In some cases, they attract humanitarian aid that was previously absent, resulting in rapid rises in TB notifications owing to improved diagnostic capacity. The true impact of catastrophes on underlying TB incidence may in fact take years to manifest [2].

In broad terms, potential mechanisms include population susceptibility and public health infrastructure. Humanitarian crises often result in displacement of large populations into temporary housing. Crowded living conditions promote TB transmission. Hence, the design of temporary housing facilities, and the duration of time for which they are used both influence TB spread [12]. Malnutrition is another potential consequence of natural disasters that can promote TB reactivation. After the 2004 Indonesian earthquake and tsunami, there were reports of acute and chronic malnutrition among children in relief camps [13]. On the other hand, there were low rates of malnutrition after the 1999 Athens earthquake, suggesting the risk is lower if the population was previously well nourished [14].

The WHO field manual for TB care and control in refugee and displaced populations outlines several mechanisms by which natural disasters can adversely affect the TB control infrastructure [12]. These include access to drugs for both newly diagnosed patients and those already on therapy; sufficient numbers of properly trained TB providers to ensure appropriate care; tracking of displaced patients to prevent loss to follow-up and increased drug resistance. All are likely to be severely compromised in the weeks and months after a disaster of the magnitude of the Haitian earthquake. Beyond provision of basic diagnostic and treatment services at sufficient points of care for a large displaced population, the coordination of TB care between various state and non-governmental organization (NGO) providers poses substantial organizational challenges.

The impact of health infrastructure on TB control

While documentation surrounding TB after natural disasters is necessarily limited, numerous historical examples demonstrate the fundamental importance of healthcare infrastructure to TB control. Reduced funding for TB control programs in the USA in the 1970s probably paved the way for the resurgence of TB in the 1980s [15,16]. Similarly, government cutbacks in TB funding with cessation of the National Tuberculosis Program, and an under-funded decentralization strategy, were associated with worsening TB control in Brazil [17].

A study of post-communist countries in Eastern Europe and the former Soviet Union countries suggested that participation in International Monetary Fund (IMF) lending programs was associated with increased TB mortality rates, while non-IMF lending programs were associated with decreased mortality rates [18]. Unlike the non-IMF lending programs, IMF programs were associated with reduced TB funding and fewer physicians per capita (as well as reduced general government expenditures), suggesting that these factors may explain differences in TB mortality [19].

Just as deterioration of TB control programs results in worsening incidence and outcomes, implementation or maintenance of such programs improves TB control and outcomes, even during catastrophic events or in settings of extreme poverty [20–22]. An investment of US$50 million in India’s national TB control program between 1993 and 2001 led to coverage of over 40% of that country’s population, with an estimated 200,000 deaths averted and $400 million in indirect cost savings [23]. A previous analysis suggested that expansion of the Haitian TB control program would cost less than US$5 million and result in over 50,000 deaths averted, with net savings exceeding $130 million [24].

What comes next?

Hence, despite the devastation wrought on Haiti by the January 2010 earthquake, worsened TB control need not be the inevitable and lasting result. In the coming months and years, TB incidence will be shaped by the level of international investment in Haiti’s public health infrastructure, and the urgency and coordination with which TB control is pursued. The earthquake also provides a key opportunity to re-evaluate how international funding agencies, donor governments and NGOs operate in Haiti. In the past, their efforts have been poorly coordinated and have often excluded the Haitian government, potentially limiting the government’s ability to effect improvements in health [25]. In recent years, much of the funding for development operations was distributed through NGOs rather than the elected government, owing to an embargo by donor agencies [26,103].

An adequate response to Haiti’s TB epidemic must involve strengthening of the national healthcare infrastructure and the aftermath of January’s earthquake provides a prime opportunity for this. This will require coordinated funding decisions by foreign governments and donor agencies, in concert with Haitian authorities, followed by effective program implementation. Of course, these are hugely complex and challenging steps. It remains to be seen whether any good can ultimately result from Haiti’s devastation.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.