TB and malnutrition increase

This study is the first to demonstrate an association between rising TB incidence and national economic decline in the absence of armed conflict. Since 1995 to 31 March 2009 information has been prospectively collected on diagnoses made at a rural mission hospital, Howard Hospital, in Zimbabwe. National surveillance data showing a decline in TB incidence since 2004 is likely to be skewed, given that most health care facilities shut down during the peak of the economic crisis.

Howard Hospital is one of the few mission hospitals that remained functioning and hence its data are likely to be more reliable for determining burden of disease. During the period of the study from 1995 to 2009, 8,770 cases of TB, 6, 695 cases of nutritional diseases and 27 399 cases of diarrhoea were diagnosed. 81.8 per cent of the TB cases were co-infected with HIV.

Between 1995 and 2001, the study found that TB incidence had risen gradually from 176 per 100,000 to 281 per 100,000, however this finding correlated with the rising HIV epidemic in Zimbabwe.

However, a further rapid rise in TB incidence to 426 per 100 000 corresponded with the onset of hyperinflation between 2003 and 2007. During this period there was also an increase in the incidence of pellagra, kwashiorkor and diarrhoeal illnesses.

TB incidence remained stable between 2003 and 2007, but rose a further 35% in 2008 to 556 per 100 000, with a further 15 per cent increase occurring in the first five months of 2009.

Monthly time-series analyses showed that increasing economic inflation was associated with subsequent increases in TB incidence. A seasonal pattern in TB incidence was observed by the investigators.